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Council of Trent
|
The Council of Trent (), held between 1545 and 1563 in Trent (or Trento), now in northern Italy, was the 19th ecumenical council of the Catholic Church. Prompted by the Protestant Reformation at the time, it has been described as the "most impressive embodiment of the ideals of the Counter-Reformation." It was the last time an ecumenical council was organised outside the city of Rome.
The Council issued key statements and clarifications of the Church's doctrine and teachings, including scripture, the biblical canon, sacred tradition, original sin, justification, salvation, the sacraments, the Mass, and the veneration of saints and also issued condemnations of what it defined to be heresies committed by proponents of Protestantism. The consequences of the council were also significant with regard to the Church's liturgy and censorship.
The Council met for twenty-five sessions between 13 December 1545 and 4 December 1563. Pope Paul III, who convoked the council, oversaw the first eight sessions (1545–1547), while the twelfth to sixteenth sessions (1551–52) were overseen by Pope Julius III and the seventeenth to twenty-fifth sessions (1562–63) by Pope Pius IV. More than three hundred years passed until the next ecumenical council, the First Vatican Council, was convened in 1869.
== Background information ==
=== Obstacles and events before the Council's problem area ===
On 15 March 1517, the Fifth Council of the Lateran closed its activities with a number of reform proposals (on the selection of bishops, taxation, censorship and preaching) but not on the new major problems that confronted the Church in Germany and other parts of Europe. A few months later, on 31 October 1517, Martin Luther issued his 95 Theses in Wittenberg.
=== A general, free council in Germany ===
Luther's position on ecumenical councils shifted over time, but in 1520 he appealed to the German princes to oppose the papal Church at the time, if necessary with a council in Germany, open and free of the Papacy. After the Pope condemned in Exsurge Domine fifty-two of Luther's theses as heresy, German opinion considered a council the best method to reconcile existing differences. German Catholics, diminished in number, hoped for a council to clarify matters.
It took a generation for the council to materialise, partly due to papal fears over potentially renewing a schism over conciliarism; partly because Lutherans demanded the exclusion of the papacy from the council; partly because of ongoing political rivalries between France and the Holy Roman Empire; and partly due to the Turkish dangers in the Mediterranean. Under Pope Clement VII (1523–34), mutinous troops many of whom were Lutheran belonging to the Catholic Holy Roman Emperor Charles V sacked Papal Rome in 1527, "raping, killing, burning, stealing, the like had not been seen since the Vandals". Saint Peter's Basilica and the Sistine Chapel were used for horses. Pope Clement, fearful of the potential for more violence, delayed calling the council.
== Occasion, sessions, and attendance ==
In the to-and-fro of medieval politics, Pope Pius II, in his bull Execrabilis (1460) and his reply to the University of Cologne (1463), had set aside the theory of the supremacy of general councils laid down by the Council of Constance,
Martin Luther had appealed for a general council, in response to the Papal bull Exsurge Domine of Pope Leo X (1520). In 1522 German diets joined in the appeal, with Charles V seconding and pressing for a council as a means of reunifying the Church and settling the Reformation controversies. Pope Clement VII (1523–34) was vehemently against the idea of a council, agreeing with Francis I of France.
=== Sessions ===
The history of the council is divided into three distinct periods: 1545–1549, 1551–1552 and 1562–1563.
The number of attending members in the three periods varied considerably. It increased toward the close, but never reached the number of the First Council of Nicaea (which had 318 members)
==== Pre-council ====
Pope Paul III (1534–1549), seeing that the Protestant Reformation was no longer confined to a few preachers, but had won over various princes, especially in Germany, to its ideas, desired a council. Yet when he proposed the idea to his cardinals, it was almost unanimously opposed. Nonetheless, he sent nuncios throughout Europe to propose the idea. Paul III issued a decree for a general council to be held in Mantua, Italy, to begin on 23 May 1537. Martin Luther wrote the Smalcald Articles in preparation for the general council. The Smalcald Articles were designed to sharply define where the Lutherans could and could not compromise. The council was ordered by the Emperor and Pope Paul III to convene in Mantua on 23 May 1537.
It failed to convene after another war broke out between France and Charles V, resulting in a non-attendance of French prelates. Protestants refused to attend as well. Financial difficulties in Mantua led the Pope in the autumn of 1537 to move the council to Vicenza, where participation was poor. The council was postponed indefinitely on 21 May 1539.
Pope Paul III then initiated several internal Church reforms while Emperor Charles V convened with Protestants and Cardinal Gasparo Contarini at the Diet of Regensburg, to reconcile differences. Mediating and conciliatory formulations were developed on certain topics. In particular, a two-part doctrine of justification was formulated that would later be rejected at Trent. Unity failed between Catholic and Protestant representatives "because of different concepts of Church and Justification".
==== First period ====
However, the council was delayed until 1545 and, as it happened, convened right before Luther's death. Unable, however, to resist the urging of Charles V, the pope, after proposing Mantua as the place of meeting, convened the council at Trent (at that time ruled by a prince-bishop under the Holy Roman Empire),
==== Second period ====
Reopened at Trent on 1 May 1551 by the convocation of Pope Julius III (1550–1555), it was broken up by the sudden victory of Maurice, Elector of Saxony over Emperor Charles V and his march into surrounding state of Tirol on 28 April 1552. There was no hope of reassembling the council while the very anti-Protestant Paul IV was Pope.
The French monarchy boycotted the entire council until the last minute when a delegation led by Charles de Guise, Cardinal of Lorraine finally arrived in November 1562. The first outbreak of the French Wars of Religion had occurred earlier in the year and the French Church, facing a significant and powerful Protestant minority in France, experienced iconoclasm violence regarding the use of sacred images. Such concerns were not primary in the Italian and Spanish Churches. The last-minute inclusion of a decree on sacred images was a French initiative, and the text, never discussed on the floor of the council or referred to council theologians, was based on a French draft.
== Objectives and overall results ==
The main objectives of the council were twofold:
To condemn the principles and doctrines of Protestantism and to clarify the doctrines of the Catholic Church on all disputed points. This had not been done formally since the 1530 Confutatio Augustana. It is true that the emperor intended it to be a strictly general or truly ecumenical council, at which the Protestants should have a fair hearing. He secured, during the council's second period, 1551–1553, an invitation, twice given, to the Protestants to be present and the council issued a letter of safe conduct (thirteenth session) and offered them the right of discussion, but denied them a vote. Melanchthon and Johannes Brenz, with some other German Lutherans, actually started in 1552 on the journey to Trent. Brenz offered a confession and Melanchthon, who got no farther than Nuremberg, took with him the Confessio Saxonica. But the refusal to give the Protestants the vote and the consternation produced by the success of Maurice in his campaign against Charles V in 1552 effectually put an end to Protestant cooperation. Also, the Bible and church tradition (the tradition that composed part of the Catholic faith) were equally and independently authoritative.
The relationship of faith and works in salvation was defined, following controversy over Martin Luther's doctrine of "justification by faith alone".
Other Catholic practices that had drawn the ire of reformers within the Church, such as indulgences, pilgrimages, the veneration of saints and relics, and the veneration of the Virgin Mary were strongly reaffirmed, though abuses of them were forbidden. Decrees concerning sacred music and religious art, though inexplicit, were subsequently amplified by theologians and writers to condemn many types of Renaissance and medieval styles and iconographies, impacting heavily on the development of these art forms.
The doctrinal decisions of the council were set forth in decrees (decreta), which are divided into chapters (capita), which contain the positive statement of the conciliar dogmas, and into short canons (canones), which condemn incorrect views (often a Protestant-associated notion stated in an extreme form) with the concluding anathema sit ("let him be anathema" i.e., excluded from the society of the faithful). In doing so, they commissioned the creation of a revised and standardized Vulgate in light of textual criticism, although this was not achieved until the 1590s. The council also officially affirmed the traditional Catholic Canon of biblical books, which was identical to the canon of Scripture issued by the Council of Rome under Pope Damasus in 382. This was in response to the increasing Protestant exclusion of the deuterocanonical books. the doctrines of purgatory, the invocation of saints and the veneration of relics were reaffirmed, as was also the efficacy of indulgences as dispensed by the Church according to the power given her, but with some cautionary recommendations,
Baroque Art is in part a consequence of the Council of Trent more specifically its twenty-fifth session where it emphasized that sacred art should educate the faithful, inspire devotion, and accurately represent biblical narratives. All this led to a renewed focus on emotional engagement and clarity in religious paintings. Due to these new directives, the Catholic Church began to promote baroque art characterized by dramatic compositions, chiaroscuro, and theatrical gestures. The churches adoption of the art style would help to increase its spread of influence.
=== Practical ===
On the language of the Mass, "contrary to what is often said", the council condemned the insistence that only vernacular languages must be used, while affirming on the use of Latin for the Roman rite. However, elements of the Prône, the vernacular catechetical preaching service common in the medieval High Mass (and some extra-liturgical situations) became mandatory for Sundays and feast days (fifth session, chapter 2).
The council appointed, in 1562 (eighteenth session), a commission to prepare a list of forbidden books (Index Librorum Prohibitorum), but it later left the matter to the Pope. The preparation of a catechism and the revision of the Breviary and Missal were also left to the pope. No attempt was made to introduce it into England. Pius IV sent the decrees to Mary, Queen of Scots, with a letter dated 13 June 1564, requesting that she publish them in Scotland, but she dared not do it in the face of John Knox and the Reformation.
== List of doctrinal decrees ==
==Protestant response==
Out of 87 books written between 1546 and 1564 attacking the Council of Trent, 41 were written by Pier Paolo Vergerio, a former papal nuncio turned Protestant Reformer. The 1565–73 Examen decretorum Concilii Tridentini (Examination of the Council of Trent) by Martin Chemnitz was the main Lutheran response to the Council of Trent. Making extensive use of scripture and patristic sources, it was presented in response to a polemical writing which Diogo de Payva de Andrada had directed against Chemnitz. The Examen had four parts: Volume I examined sacred scripture, free will, original sin, justification, and good works. Volume II examined the sacraments, including baptism, confirmation, the sacrament of the Eucharist, communion under both kinds, the Mass, penance, extreme unction, holy orders, and matrimony. Volume III examined virginity, celibacy, purgatory, and the invocation of saints. Volume IV examined the relics of the saints, images, indulgences, fasting, the distinction of foods, and festivals.
In response, Andrada wrote the five-part Defensio Tridentinæ fidei, which was published posthumously in 1578. However, the Defensio did not circulate as extensively as the Examen, nor were full translations initially published. A French translation of the Examen by Eduard Preuss was published in 1861. German translations were published in 1861, 1884, and 1972. In English, a complete translation by Fred Kramer drawing from the original Latin and the 1861 German was published beginning in 1971.
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6,355 |
Chloroplast
|
A chloroplast () is a type of organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like Arabidopsis and wheat.
Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must be inherited by each daughter cell during cell division, which is thought to be inherited from their ancestor—a photosynthetic cyanobacterium that was engulfed by an early eukaryotic cell.
Chloroplasts evolved from an ancient cyanobacterium that was engulfed by an early eukaryotic cell. Because of their endosymbiotic origins, chloroplasts, like mitochondria, contain their own DNA separate from the cell nucleus. With one exception (the amoeboid Paulinella chromatophora), all chloroplasts can be traced back to a single endosymbiotic event. Despite this, chloroplasts can be found in extremely diverse organisms that are not directly related to each other—a consequence of many secondary and even tertiary endosymbiotic events.
== Discovery and etymology ==
The first definitive description of a chloroplast (Chlorophyllkörnen, "grain of chlorophyll") was given by Hugo von Mohl in 1837 as discrete bodies within the green plant cell. In 1883, Andreas Franz Wilhelm Schimper named these bodies as "chloroplastids" (Chloroplastiden). In 1884, Eduard Strasburger adopted the term "chloroplasts" (Chloroplasten).
The word chloroplast is derived from the Greek words chloros (χλωρός), which means green, and plastes (πλάστης), which means "the one who forms".
== Endosymbiotic origin of chloroplasts ==
Chloroplasts are one of many types of organelles in photosynthetic eukaryotic cells. They evolved from cyanobacteria through a process called organellogenesis. Cyanobacteria are a diverse phylum of gram-negative bacteria capable of carrying out oxygenic photosynthesis. Like chloroplasts, they have thylakoids. The thylakoid membranes contain photosynthetic pigments, including chlorophyll a. This origin of chloroplasts was first suggested by the Russian biologist Konstantin Mereschkowski in 1905 after Andreas Franz Wilhelm Schimper observed in 1883 that chloroplasts closely resemble cyanobacteria. and some species of the amoeboid Paulinella.
Mitochondria are thought to have come from a similar endosymbiosis event, where an aerobic prokaryote was engulfed.
=== Primary endosymbiosis ===
In most, but not all cases, nuclear-encoded chloroplast proteins are translated with a cleavable transit peptide that's added to the N-terminus of the protein precursor. Sometimes the transit sequence is found on the C-terminus of the protein, or within the functional part of the protein. phosphorylates, or adds a phosphate group to many (but not all) of them in their transit sequences. At the same time, they have to keep just enough shape so that they can be recognized by the chloroplast. These proteins also help the polypeptide get imported into the chloroplast. a cup (e.g., Chlamydomonas), a ribbon-like spiral around the edges of the cell (e.g., Spirogyra), or slightly twisted bands at the cell edges (e.g., Sirogonium). Some algae have two chloroplasts in each cell; they are star-shaped in Zygnema, or may follow the shape of half the cell in order Desmidiales. In some algae, the chloroplast takes up most of the cell, with pockets for the nucleus and other organelles, for example, some species of Chlorella have a cup-shaped chloroplast that occupies much of the cell.
All chloroplasts have at least three membrane systems—the outer chloroplast membrane, the inner chloroplast membrane, and the thylakoid system. The two innermost lipid-bilayer membranes that surround all chloroplasts correspond to the outer and inner membranes of the ancestral cyanobacterium's gram negative cell wall, and not the phagosomal membrane from the host, which was probably lost. that makes up much of a chloroplast's volume, and in which the thylakoid system floats.
There are some common misconceptions about the outer and inner chloroplast membranes. The fact that chloroplasts are surrounded by a double membrane is often cited as evidence that they are the descendants of endosymbiotic cyanobacteria. This is often interpreted as meaning the outer chloroplast membrane is the product of the host's cell membrane infolding to form a vesicle to surround the ancestral cyanobacterium—which is not true—both chloroplast membranes are homologous to the cyanobacterium's original double membranes. In addition, in terms of function, the inner chloroplast membrane, which regulates metabolite passage and synthesizes some materials, has no counterpart in the mitochondrion. However, it is not permeable to larger proteins, so chloroplast polypeptides being synthesized in the cell cytoplasm must be transported across the outer chloroplast membrane by the TOC complex, or translocon on the outer chloroplast membrane. They may exist to increase the chloroplast's surface area for cross-membrane transport, because they are often branched and tangled with the endoplasmic reticulum. When they were first observed in 1962, some plant biologists dismissed the structures as artifactual, claiming that stromules were just oddly shaped chloroplasts with constricted regions or dividing chloroplasts. However, there is a growing body of evidence that stromules are functional, integral features of plant cell plastids, not merely artifacts.
=== Intermembrane space and peptidoglycan wall ===
Usually, a thin intermembrane space about 10–20 nanometers thick exists between the outer and inner chloroplast membranes.
Glaucophyte algal chloroplasts have a peptidoglycan layer between the chloroplast membranes. It corresponds to the peptidoglycan cell wall of their cyanobacterial ancestors, which is located between their two cell membranes. These chloroplasts are called muroplasts (from Latin "mura", meaning "wall"). Other chloroplasts were assumed to have lost the cyanobacterial wall, leaving an intermembrane space between the two chloroplast envelope membranes,
=== Inner chloroplast membrane ===
The inner chloroplast membrane borders the stroma and regulates passage of materials in and out of the chloroplast. After passing through the TOC complex in the outer chloroplast membrane, polypeptides must pass through the TIC complex (translocon on the inner chloroplast membrane) which is located in the inner chloroplast membrane. The chloroplast peripheral reticulum consists of a maze of membranous tubes and vesicles continuous with the inner chloroplast membrane that extends into the internal stromal fluid of the chloroplast. Its purpose is thought to be to increase the chloroplast's surface area for cross-membrane transport between its stroma and the cell cytoplasm. The small vesicles sometimes observed may serve as transport vesicles to shuttle stuff between the thylakoids and intermembrane space.
Small subunit ribosomal RNAs in several Chlorophyta and euglenid chloroplasts lack motifs for Shine-Dalgarno sequence recognition, which is considered essential for translation initiation in most chloroplasts and prokaryotes. Such loss is also rarely observed in other plastids and prokaryotes. An additional 4.5S rRNA with homology to the 3' tail of 23S is found in "higher" plants. or when it ages and transitions into a gerontoplast. though in mature chloroplasts, it is rare for a starch granule to be completely consumed or for a new granule to accumulate.
Starch granules vary in composition and location across different chloroplast lineages. In red algae, starch granules are found in the cytoplasm rather than in the chloroplast. In plants, mesophyll chloroplasts, which do not synthesize sugars, lack starch granules. and algae contain structures called pyrenoids. They are not found in higher plants. Pyrenoids are roughly spherical and highly refractive bodies which are a site of starch accumulation in plants that contain them. They consist of a matrix opaque to electrons, surrounded by two hemispherical starch plates. The starch is accumulated as the pyrenoids mature.
=== Thylakoid system ===
thumb|660px|Scanning transmission electron microscope imaging of a chloroplast(Top) 10-nm-thick STEM tomographic slice of a lettuce chloroplast. Grana stacks are interconnected by unstacked stromal thylakoids, called "stroma lamellae". Round inclusions associated with the thylakoids are plastoglobules. Scalebar=200 nm. See. are small interconnected sacks which contain the membranes that the [[light reactions of photosynthesis take place on. The word thylakoid comes from the Greek word thylakos which means "sack".
Suspended within the chloroplast stroma is the thylakoid system, a highly dynamic collection of membranous sacks called thylakoids where chlorophyll is found and the light reactions of photosynthesis happen. Another model known as the 'bifurcation model', which was based on the first electron tomography study of plant thylakoid membranes, depicts the stromal membranes as wide lamellar sheets perpendicular to the grana columns which bifurcates into multiple parallel discs forming the granum-stroma assembly. The helical model was supported by several additional works, but ultimately it was determined in 2019 that features from both the helical and bifurcation models are consolidated by newly discovered left-handed helical membrane junctions. Likely for ease, the thylakoid system is still commonly depicted by older "hub and spoke" models where the grana are connected to each other by tubes of stromal thylakoids.
Grana consist of a stacks of flattened circular granal thylakoids that resemble pancakes. Each granum can contain anywhere from two to a hundred thylakoids, partially responsible for giving most cyanobacteria and chloroplasts their color. Other forms of chlorophyll exist, such as the accessory pigments chlorophyll b, chlorophyll c, chlorophyll d,
==== Carotenoids ====
{{plain image with caption|File:Delesseria sanguinea Helgoland.JPG|Delesseria sanguinea, a red alga, has chloroplasts that contain red pigments like phycoerytherin that mask their blue-green chlorophyll a. They help transfer and dissipate excess energy, β-carotene is a bright red-orange carotenoid found in nearly all chloroplasts, like chlorophyll a. Phycobilins come in all colors, though phycoerytherin is one of the pigments that makes many red algae red. Phycobilins often organize into relatively large protein complexes about 40 nanometers across called phycobilisomes.
plants evolved a way to solve this—by spatially separating the light reactions and the Calvin cycle. The light reactions, which store light energy in ATP and NADPH, are done in the mesophyll cells of a leaf. The Calvin cycle, which uses the stored energy to make sugar using RuBisCO, is done in the bundle sheath cells, a layer of cells surrounding a vein in a leaf. which they use to make ATP and NADPH, as well as oxygen. They store in a four-carbon compound, which is why the process is called photosynthesis. The four-carbon compound is then transported to the bundle sheath chloroplasts, where it drops off and returns to the mesophyll. Bundle sheath chloroplasts do not carry out the light reactions, preventing oxygen from building up in them and disrupting RuBisCO activity. Mesophyll chloroplasts have a little more peripheral reticulum than bundle sheath chloroplasts.
== Function and chemistry ==
=== Guard cell chloroplasts ===
Unlike most epidermal cells, the guard cells of plant stomata contain relatively well-developed chloroplasts. However, exactly what they do is controversial.
=== Plant innate immunity ===
Plants lack specialized immune cells—all plant cells participate in the plant immune response. Chloroplasts, along with the nucleus, cell membrane, and endoplasmic reticulum, are key players in pathogen defense. Due to its role in a plant cell's immune response, pathogens frequently target the chloroplast. help synthesize an important defense molecule, jasmonate. Chloroplasts synthesize all the fatty acids in a plant cell—linoleic acid, a fatty acid, is a precursor to jasmonate.
==== Light reactions ====
The light reactions take place on the thylakoid membranes. They take light energy and store it in NADPH, a form of NADP+, and ATP to fuel the dark reactions.
===== Energy carriers =====
ATP is the phosphorylated version of adenosine diphosphate (ADP), which stores energy in a cell and powers most cellular activities. ATP is the energized form, while ADP is the (partially) depleted form. NADP+ is an electron carrier which ferries high energy electrons. In the light reactions, it gets reduced, meaning it picks up electrons, becoming NADPH.
===== Photophosphorylation =====
Like mitochondria, chloroplasts use the potential energy stored in an H+, or hydrogen ion, gradient to generate ATP energy. The two photosystems capture light energy to energize electrons taken from water, and release them down an electron transport chain. The molecules between the photosystems harness the electrons' energy to pump hydrogen ions into the thylakoid space, creating a concentration gradient, with more hydrogen ions (up to a thousand times as many) Because chloroplast ATP synthase projects out into the stroma, the ATP is synthesized there, in position to be used in the dark reactions.
===== NADP+ reduction =====
Electrons are often removed from the electron transport chains to charge NADP+ with electrons, reducing it to NADPH. Like ATP synthase, ferredoxin-NADP+ reductase, the enzyme that reduces NADP+, releases the NADPH it makes into the stroma, right where it is needed for the dark reactions.
===== Cyclic photophosphorylation =====
While photosystem II photolyzes water to obtain and energize new electrons, photosystem I simply reenergizes depleted electrons at the end of an electron transport chain. Normally, the reenergized electrons are taken by NADP+, though sometimes they can flow back down more H+-pumping electron transport chains to transport more hydrogen ions into the thylakoid space to generate more ATP. This is termed cyclic photophosphorylation because the electrons are recycled. Cyclic photophosphorylation is common in plants, which need more ATP than NADPH.
Alternatively, glucose monomers in the chloroplast can be linked together to make starch, which accumulates into the starch grains found in the chloroplast.
While linked to low photosynthesis rates, the starch grains themselves may not necessarily interfere significantly with the efficiency of photosynthesis, and might simply be a side effect of another photosynthesis-depressing factor. while the stroma is slightly basic, with a pH of around 8.
The optimal stroma pH for the Calvin cycle is 8.1, with the reaction nearly stopping when the pH falls below 7.3.
=== Amino acid synthesis ===
Chloroplasts alone make almost all of a plant cell's amino acids in their stroma The chloroplast is known to make the precursors to methionine but it is unclear whether the organelle carries out the last leg of the pathway or if it happens in the cytosol.
=== Other nitrogen compounds ===
Chloroplasts make all of a cell's purines and pyrimidines—the nitrogenous bases found in DNA and RNA. The carbon used to form the majority of the lipid is from acetyl-CoA, which is the decarboxylation product of pyruvate. Pyruvate is also made in the plastid from phosphoenolpyruvate, a metabolite made in the cytosol from pyruvate or PGA. The typical length of fatty acids produced in the plastid are 16 or 18 carbons, with 0-3 cis double bonds.
The biosynthesis of fatty acids from acetyl-CoA primarily requires two enzymes. Acetyl-CoA carboxylase creates malonyl-CoA, used in both the first step and the extension steps of synthesis. Fatty acid synthase (FAS) is a large complex of enzymes and cofactors including acyl carrier protein (ACP) which holds the acyl chain as it is synthesized. The initiation of synthesis begins with the condensation of malonyl-ACP with acetyl-CoA to produce ketobutyryl-ACP. 2 reductions involving the use of NADPH and one dehydration creates butyryl-ACP. Extension of the fatty acid comes from repeated cycles of malonyl-ACP condensation, reduction, and dehydration. A plant cell which contains chloroplasts is known as a chlorenchyma cell. A typical chlorenchyma cell of a land plant contains about 10 to 100 chloroplasts.
In some plants such as cacti, chloroplasts are found in the stems, though in most plants, chloroplasts are concentrated in the leaves. One square millimeter of leaf tissue can contain half a million chloroplasts. This ability to distribute chloroplasts so that they can take shelter behind each other or spread out may be the reason why land plants evolved to have many small chloroplasts instead of a few big ones. Mitochondria have also been observed to follow chloroplasts as they move.
In higher plants, chloroplast movement is run by phototropins, blue light photoreceptors also responsible for plant phototropism. In some algae, mosses, ferns, and flowering plants, chloroplast movement is influenced by red light in addition to blue light, or fertilized egg. Proplastids are commonly found in an adult plant's apical meristems. Chloroplasts do not normally develop from proplastids in root tip meristems—instead, the formation of starch-storing amyloplasts is more common.
If angiosperm shoots are not exposed to the required light for chloroplast formation, proplastids may develop into an etioplast stage before becoming chloroplasts. An etioplast is a plastid that lacks chlorophyll, and has inner membrane invaginations that form a lattice of tubes in their stroma, called a prolamellar body. While etioplasts lack chlorophyll, they have a yellow chlorophyll precursor stocked.
In single-celled algae, chloroplast division is the only way new chloroplasts are formed. There is no proplastid differentiation—when an algal cell divides, its chloroplast divides along with it, and each daughter cell receives a mature chloroplast. Chloroplasts have no definite S-phase—their DNA replication is not synchronized or limited to that of their host cells.
Much of what we know about chloroplast division comes from studying organisms like Arabidopsis and the red alga Cyanidioschyzon merolæ. The Min system manages the placement of the Z-ring, ensuring that the chloroplast is cleaved more or less evenly. The protein MinD prevents FtsZ from linking up and forming filaments. Another protein ARC3 may also be involved, but it is not very well understood. These proteins are active at the poles of the chloroplast, preventing Z-ring formation there, but near the center of the chloroplast, MinE inhibits them, allowing the Z-ring to form.
Later, the dynamins migrate under the outer plastid dividing ring, into direct contact with the chloroplast's outer membrane,
Gymnosperms, such as pine trees, mostly pass on chloroplasts paternally, while flowering plants often inherit chloroplasts maternally.
Angiosperms, which pass on chloroplasts maternally, have many ways to prevent paternal inheritance. Most of them produce sperm cells that do not contain any plastids. There are many other documented mechanisms that prevent paternal inheritance in these flowering plants, such as different rates of chloroplast replication within the embryo.
== Footnotes ==
|
[
"symbiogenesis",
"tRNA",
"disease resistance",
"prokaryote",
"secretory pathway",
"carbonic acid",
"fruit",
"wikt:anticlinal",
"Haptophyte",
"lipid",
"Apicomplexa",
"Radiant energy",
"protists",
"RNA",
"Beta carotene",
"protist",
"Mesophyll tissue",
"cytoplasm",
"pH",
"Cyanidium",
"photosystem I",
"mitochondrial genome",
"angiosperms",
"kleptoplast",
"accessory pigments",
"cyanobacterial",
"Archaeplastida",
"hypersensitive response",
"phycoerytherin",
"polypeptides",
"phycobilin",
"guard cells",
"Cis–trans isomerism",
"kleptoplasty",
"orange (colour)",
"Cyanobacteria",
"yellow",
"Plant stem",
"Streptophyta",
"RuBisCO",
"disaccharide",
"carbon dioxide",
"Apicomplexans",
"diffuse",
"Phylogenetics",
"parasite",
"Synechococcus",
"protein targeting system",
"isopentenyl pyrophosphate",
"Elaioplast",
"hornworts",
"Vallisneria gigantea",
"Flowering plant",
"phylum",
"Haematococcus pluvialis",
"iron-sulfur clusters",
"genome reduction",
"phytol",
"wikt:periclinal",
"protein",
"3-Phosphoglyceric acid",
"mixotrophic",
"Eyespot apparatus",
"Laurencia",
"Chromoplast",
"chlorophyll d",
"Chlorella",
"Autotroph",
"operons",
"phosphorylate",
"secondary endosymbiotic events",
"monophyly",
"mesophyll tissue",
"proton pumps",
"Chlamydomonas reinhardtii",
"Desmidiales",
"adenosine triphosphate",
"jasmonate",
"Prototheca",
"oxygen",
"light reactions",
"space-filling model",
"DNA repair",
"nicotinamide adenine dinucleotide phosphate",
"Alveolata",
"plastid",
"ciliate",
"N-terminus",
"chlorophyll f",
"glyceraldehyde-3-phosphate",
"Chlorarachniophytes",
"biological containment",
"Chlamydomonas",
"Green algae",
"Proplastid",
"chlorophyll",
"Xanthophylls",
"protein routing",
"cytosol",
"peptidoglycan cell wall",
"File:Plastids types flat.svg",
"heme",
"paraphyletic",
"phylogenetics",
"Deciduous tree",
"Cryptosporidium",
"monomers",
"Mitochondrion",
"Epidermis (botany)",
"ribosomal RNA",
"plastid-dividing rings",
"plastids",
"amylopectin",
"amino group",
"Chlorophyll f",
"red tide",
"heterokontophyte",
"purple sulfur bacteria",
"endoplasmic reticulum lumen",
"electron microscopy",
"Chlorophyta",
"Chromera velia",
"dinoflagellate",
"Oedogonium",
"fucoxanthin",
"light-harvesting complexes",
"Yellow-green algae",
"cell membrane",
"alkaline",
"Serial endosymbiosis",
"chlorarachniophyte",
"zygote",
"plastoglobuli",
"order (biology)",
"Shine-Dalgarno sequence",
"Chlorarachniophyta",
"root tip meristems",
"Enzyme substrate (biology)",
"DNA damage (naturally occurring)",
"endoplasmic reticulum",
"floridean starch",
"19′-butanoyloxy-fucoxanthin",
"serial endosymbiosis",
"Adenosine triphosphate",
"transport vesicles",
"photosystem II",
"adenosine diphosphate",
"zeaxanthin",
"bacteria",
"peptidoglycan wall",
"ARC3",
"reduction reaction",
"Konstantin Mereschkowski",
"chlorarachniophytes",
"Karlodinium",
"Transmission electron micrograph",
"chromoplast",
"microfilament",
"Chlorophyll d",
"plant",
"prolamellar body",
"Glaucophytes",
"prasinophyte",
"parenchyma",
"Leucoplast",
"Ochrophyta",
"gene",
"metabolism",
"Photorespiration",
"algae",
"rhodoplast",
"red",
"Chromatophore (bacteria)",
"Plant",
"Dinophysis",
"prokaryotic",
"photolyzes",
"flagellated",
"Nucleoid",
"Cyanidioschyzon merolæ",
"Gymnosperms",
"nucleomorph",
"Karenia (dinoflagellate)",
"endosymbiotic gene transfer",
"meristematic",
"Glaucophyte algal",
"Photoreceptor protein",
"chloroplast intermembrane space",
"mitochondrion",
"phagosomal vacuole",
"genera",
"rough endoplasmic reticulum",
"Min system",
"vein (botany)",
"lipid bilayer",
"Eduard Strasburger",
"vascular plant",
"DNA",
"chloroplastida",
"Paper chromatography",
"amyloplast",
"translocon",
"ARC6",
"red alga",
"Delesseria sanguinea",
"Land plants",
"Zygnema",
"glaucophytes",
"gymnosperm",
"mitochondria",
"cacti",
"dinophyte",
"golden algae",
"etioplast",
"β-carotene",
"phagosomal",
"genome",
"Water",
"Chlorophyll",
"gamete",
"apicoplast",
"Prochlorococcus",
"free phosphate",
"stroma (fluid)",
"chemical energy",
"flowering plant",
"reactive oxygen species",
"C4 plants",
"polypeptide",
"photooxidative damage",
"3-phosphoglyceric acid",
"cyanobacteria",
"lipid monolayer",
"pollen",
"xanthophyll",
"millimeter",
"analogy (biology)",
"sulfur-containing amino acids",
"chlorophylls",
"helicoid",
"chromist",
"vitamin E",
"red algae",
"Chlorophyll c",
"Pseudoblepharisma tenue",
"sperm cells",
"Euglenophyta",
"Starch granules",
"cell wall",
"blue-green",
"diatoms",
"purine",
"topologically",
"MinD",
"phloem",
"Glyceraldehyde 3-phosphate",
"cyclic photophosphorylation",
"retrograde signaling",
"ferredoxin—NADP+ reductase",
"C4 carbon fixation",
"ammonia",
"fatty acid synthesis",
"paramylon",
"Shoot (botany)",
"cysteine",
"Chlorophyll a",
"eukaryotic",
"proplastid",
"carboxysome",
"periplastid space",
"thylakoid",
"TIC translocon",
"CO2",
"pyrimidine",
"Myzozoa",
"endosymbiotic event",
"hydronium",
"glaucophyte",
"sugars",
"starch",
"precursor (chemistry)",
"red algal",
"chromatophore",
"fern",
"light energy",
"phycobilisome",
"dalton (unit)",
"carbon dioxide concentrating mechanism",
"Conserved sequence",
"programmed cell death",
"Peyssonnelia squamaria",
"helicosproidia",
"amyloplasts",
"NADPH",
"inverted repeat",
"Alpha carotene",
"plant innate immunity",
"Gram-negative bacteria",
"Gloeomargarita lithophora",
"diatom",
"Kryptoperidinium",
"dynamin",
"dinoflagellates",
"surface area",
"mitochondrial DNA",
"oxidative phosphorylation",
"Cryptomonad",
"Phycobilins",
"leaf",
"green algal derived chloroplast",
"Cryptophyte",
"nanometers",
"flowers",
"chloroplast DNA",
"retrograde signaling (cell biology)",
"peridinin",
"ribosome",
"light microscope",
"nitrogen",
"Ribulose bisphosphate",
"nuclear genome",
"Chlorophyll b",
"photosystem I",
"base pair",
"cell division",
"Stroma (fluid)",
"Selection bias",
"electrons",
"Greek language",
"Symbiogenesis",
"Nicotiana tabacum",
"carboxyl group",
"Arabidopsis thaliana",
"protein synthesis",
"Mixotroph",
"organelle",
"Andreas Franz Wilhelm Schimper",
"olive green",
"chlorophyll b",
"oxidative stress",
"FtsZ2",
"Non-mevalonate pathway",
"amino acids",
"proplastids",
"green algal",
"Plastoquinone",
"photosystems",
"spinach",
"plant cell",
"surface area to volume ratio",
"Helix",
"Arabidopsis",
"Translation (biology)",
"Proteinoplast",
"Homology (biology)",
"leaves",
"MinE",
"mRNAs",
"gene expression",
"Crassulacean acid metabolism",
"Etioplast",
"photosynthetic",
"NADP+",
"wheat",
"Hugo von Mohl",
"transgene",
"beta-carotene",
"angiosperm",
"Photosystem II",
"Hybrid (biology)",
"histone",
"RecA",
"pyrenoid",
"Ochrophyte",
"red algal derived chloroplast",
"sucrose",
"peroxisome",
"potato",
"Calvin cycle",
"cell (biology)",
"deamination",
"Amyloplast",
"Aerobic organism",
"fructose",
"plastid transformation",
"malaria",
"dark reactions",
"secondary metabolite",
"leaf veins",
"cyanobacterium",
"fatty acid",
"Cyanophora paradoxa",
"Thylakoid",
"apical meristem",
"Chromalveolata",
"nitrite",
"icosahedral",
"RNA polymerase",
"amino acid",
"Cellular respiration",
"TOC complex",
"redox reaction",
"bacterial ribosomes",
"Spirogyra",
"pyruvate",
"chlorenchyma",
"green algae",
"phycoerythrin",
"transmission electron microscope",
"chlorophyll c2",
"electron transport chains",
"Palisade mesophyll",
"rhodophyceae",
"Electrons",
"protein folding",
"Photosystem II",
"Thiodictyon",
"endosymbiosis",
"peroxisomes",
"chloroplast peripheral reticulum",
"salicylic acid",
"Gymnosperm",
"gram negative",
"lipid synthesis",
"genetically modified crops",
"acetyl-CoA",
"hydrogen atoms",
"Mesophyll cell",
"C4 plant",
"green alga",
"protein complexes",
"Cell nucleus",
"carbon fixation",
"Sirogonium",
"exaptations",
"cryptomonad",
"Dinoflagellate",
"Dinophyta",
"Red algae",
"algal",
"Archæplastida",
"shoot apical meristems",
"phagocytic vacuole",
"moss",
"Stramenopile",
"Phycobilin",
"land plants",
"concerted evolution",
"Haptophyta",
"amoeba",
"secondary endosymbiosis",
"RuBP",
"Gibberellin",
"peptidoglycan",
"photosynthesis",
"pigment",
"pathogen",
"jasmonic acid",
"methionine",
"Online Etymology Dictionary",
"plant cells",
"Physcomitrella patens",
"prokaryotes",
"concentration gradient",
"bundle sheath",
"immune cells",
"brown algae",
"amoeboid",
"bundle sheath cells",
"Chromatiaceae",
"Stigeoclonium",
"linoleic acid",
"electron transport chain",
"Durinskia",
"sterols",
"euglenid",
"cyclic electron flow",
"Micrasterias",
"carrot",
"diadinoxanthin",
"hydrogen ions",
"photosynthetic pigments",
"Eukaryotic Ribosome (80S)",
"dividing chloroplasts",
"dinoxanthin",
"acidic",
"stomata",
"potential energy",
"chloroplastidan",
"DNA sequencing",
"inner chloroplast membrane",
"aqueous",
"Volvox",
"homologous recombination",
"Bornetia secundiflora",
"nucleotide",
"glycolysis",
"pseudogenes",
"Mitosis",
"granum",
"Callophyllis laciniata",
"daughter cell",
"Embryophyte",
"chlorophyll a",
"carotenoid",
"concentric",
"phosphorylates",
"abscisic acid",
"root",
"phosphate group",
"Lepidodinium",
"chromerid",
"algal bloom",
"cell culture",
"19′-hexanoyloxy-fucoxanthin",
"enzyme specificity",
"gerontoplast",
"extracellular space",
"phototropism",
"chromoplasts",
"stramenopile",
"glaucophyta",
"Paulinella",
"Scenedesmus",
"Haptophytes",
"Rhizaria",
"Hydron (chemistry)",
"plastoquinone",
"Nanometre",
"TIC complex",
"systemic acquired resistance",
"De novo synthesis",
"vestigial",
"Algae",
"Viridiplantae",
"green",
"collenchyma",
"Plasmodium",
"hypoxanthine",
"Gephyrocapsa oceanica",
"direct repeat",
"S-phase",
"Potassium",
"introns",
"cleavable transit peptide",
"pine tree",
"haptophyte",
"nucleoid",
"autumn",
"Diaphoretickes",
"chrysolaminarin",
"leucoplast",
"Co-existence of genetically modified and conventional crops and derived food and feed",
"Helicosporidium",
"bacteriophage T4",
"Heterotroph",
"translation (biology)",
"Hydrodictyon",
"shoot meristematic",
"water",
"promoter (genetics)",
"phototropins",
"etioplasts",
"membrane-bound organelle",
"DNA mismatch repair",
"FtsZ1",
"glucose",
"nitric oxide",
"stromule",
"tertiary endosymbiotic events",
"Photosynthesis",
"euglenophyte",
"nitrogenous base",
"eukaryote",
"light micrograph",
"immune response",
"cell nucleus",
"ATP synthase",
"C3 plant",
"chloroplast starch granule",
"photosynthetic pigment",
"C-terminus",
"rhodophyte",
"ions"
] |
6,357 |
Camp David
|
Camp David is a country retreat for the president of the United States. It lies in the wooded hills of Catoctin Mountain Park, in Frederick County, Maryland, near the towns of Thurmont and Emmitsburg, about north-northwest of the national capital city, Washington, D.C. It is code-named Naval Support Facility Thurmont. Technically a military installation, it is staffed primarily by the Seabees, the Civil Engineer Corps (CEC), the United States Navy, and the United States Marine Corps. Naval construction battalions are tasked with Camp David construction and send detachments as needed.
Originally known as Hi-Catoctin, Camp David was built as a retreat for federal government agents and their families by the Works Progress Administration. Construction started in 1935 and was completed in 1938. In 1942, President Franklin D. Roosevelt converted it to a presidential retreat and renamed it "Shangri-La", after the fictional Himalayan paradise.
The Catoctin Mountain Park does not indicate the location of Camp David on park maps due to privacy and security concerns, Dwight Eisenhower held his first cabinet meeting there on November 22, 1955, following hospitalization and convalescence he required after a heart attack suffered in Denver, Colorado, on September 24. Eisenhower met Nikita Khrushchev there for two days of discussions in September 1959.
John F. Kennedy and his family often enjoyed riding and other recreational activities there, and Kennedy often allowed White House staff and Cabinet members to use the retreat when he or his family were not there. Lyndon B. Johnson met with advisors in this setting and hosted both Australian prime minister Harold Holt and Canadian prime minister Lester B. Pearson there. Richard Nixon was a frequent visitor. He personally directed the construction of a swimming pool and other improvements to Aspen Lodge. Gerald Ford hosted Indonesian president Suharto at Camp David.
Jimmy Carter initially favored closing Camp David in order to save money, but once he visited the retreat, he decided to keep it. Carter brokered the Camp David Accords there in September 1978 between Egyptian president Anwar al-Sadat and Israeli prime minister Menachem Begin. Reagan restored the nature trails that Nixon paved over so he could horseback ride at Camp David. George H. W. Bush's daughter, Dorothy Bush Koch, was married there in 1992, in the first wedding held at Camp David. During his tenure as president, Bill Clinton spent every Thanksgiving at Camp David with his family. In July 2000, he hosted the 2000 Camp David Summit negotiations between Israeli prime minister Ehud Barak and Palestinian Authority chairman Yasser Arafat there.
In February 2001, George W. Bush held his first meeting with a European leader, UK prime minister Tony Blair, at Camp David, to discuss missile defense, Iraq, and NATO. After the September 11 attacks, Bush held a Cabinet meeting at Camp David to prepare the United States invasion of Afghanistan. During his two terms in office, Bush visited Camp David 149 times, for a total of 487 days, for hosting foreign visitors as well as a personal retreat. He met Blair there four times. Among the numerous other foreign leaders he hosted at Camp David were Russian president Vladimir Putin and President Musharraf of Pakistan in 2003, Danish prime minister Anders Fogh Rasmussen in June 2006,
Barack Obama chose Camp David to host the 38th G8 summit in 2012. President Obama also hosted Russian prime minister Dmitry Medvedev at Camp David, as well as the GCC Summit there in 2015.
Donald Trump hosted Senate majority leader Mitch McConnell and Speaker of the House Paul Ryan at Camp David while the Republican Party prepared to defend both houses of Congress in the 2018 midterm elections. Trump also planned to meet with the Taliban at Camp David to negotiate a peace agreement in 2019, but refrained after a suicide bombing in Kabul killed US troops. The 46th G7 summit was to be held at Camp David on June 10–12, 2020, but was cancelled due to health concerns during what was at the time considered the height of the COVID-19 pandemic.
Joe Biden hosted the U.S.–Japan–Korea Summit with Japanese prime minister Fumio Kishida and South Korean president Yoon Suk Yeol at Camp David in August 2023, resulting in the declaration of the Camp David Principles on trilateral relations between the U.S., Japan, and South Korea.
=== Count of visits by each president ===
==Practice golf facility==
To be able to play his favorite sport, President Eisenhower had golf course architect Robert Trent Jones design a practice golf facility at Camp David. Around 1954, Jones built one golf hole—a par 3—with four different tees; Eisenhower added a driving range near the helicopter landing zone.
==Security incidents==
On July 2, 2011, an F-15 intercepted a civilian aircraft approximately from Camp David, when President Obama was in the residence. The two-seater, which was out of radio communication, was escorted to nearby Hagerstown, Maryland, without incident.
On July 10, 2011, an F-15 intercepted another small plane near Camp David when Obama was again in the residence; a total of three were intercepted that weekend.
|
[
"BBC News Online",
"José López Portillo",
"Harold Holt",
"Richard Nixon",
"Washington, D.C.",
"COVID-19 pandemic",
"Civil Engineer Corps",
"Anders Fogh Rasmussen",
"46th G7 summit",
"Barack Obama",
"Diplomacy",
"Prime Minister of Canada",
"Dorothy Bush Koch",
"Raven Rock Mountain Complex",
"United States Navy",
"Thurmont, Maryland",
"Google Maps",
"Joe Biden",
"Dwight D. Eisenhower Presidential Library",
"George W. Bush",
"Tony Blair",
"ABC News (United States)",
"Republican Party (United States)",
"Head of state",
"President of Egypt",
"Franklin D. Roosevelt",
"Donald Trump",
"President of Indonesia",
"Seabees",
"Works Progress Administration",
"Night of Camp David",
"Shangri-La",
"Musharraf",
"List of residences of presidents of the United States",
"Hagerstown, Maryland",
"United States invasion of Afghanistan",
"McDonnell Douglas F-15 Eagle",
"Camp Greentop",
"September 11 attacks",
"Prime Minister of the United Kingdom",
"Harrington Lake",
"United States",
"president of the United States",
"Prime Minister of Russia",
"Dwight D. Eisenhower",
"CNN",
"Simon & Schuster",
"Blair House",
"Taliban",
"Rapidan Camp",
"Commander (United States)",
"Prime Minister of Denmark",
"White House",
"Official residence",
"First Family of the United States",
"United States Marine Corps",
"Gordon Brown",
"Catoctin Mountain Park",
"Yoon Suk Yeol",
"Winston Churchill",
"Nikita Khrushchev",
"Jimmy Carter",
"5 September 2019 Kabul bombing",
"President of the United States",
"NARA",
"Orange One",
"President of Russia",
"Dwight Eisenhower",
"Naval District Washington",
"Thriller (genre)",
"2018 midterm elections",
"The Hill (newspaper)",
"Gulf Cooperation Council",
"Lester B. Pearson",
"Presidential Townhouse",
"Frederick County, Maryland",
"Maryland",
"Camp David Principles",
"Fumio Kishida",
"David Eisenhower",
"Camp Misty Mount Historic District",
"Trowbridge House",
"World War II",
"Paul Ryan",
"Camp David Accords",
"38th G8 summit",
"United States–Taliban deal",
"2000 Camp David Summit",
"Anwar Sadat",
"Ehud Barak",
"United States Department of Defense",
"whitehouse.gov",
"Suharto",
"Chequers",
"How Stuff Works",
"Lyndon B. Johnson",
"Dmitry Medvedev",
"The Washington Post",
"Bill Clinton",
"Margaret Thatcher",
"Yasser Arafat",
"Menachem Begin",
"Prime Minister of Australia",
"John F. Kennedy",
"Prime Minister of Israel",
"Ronald Reagan",
"George H. W. Bush",
"Denver",
"The New York Times",
"Gerald Ford",
"United States Census Bureau",
"Emmitsburg, Maryland",
"Mitch McConnell",
"Vladimir Putin",
"Pakistan",
"Robert Trent Jones"
] |
6,359 |
Crux
|
Crux () is a constellation of the southern sky that is centred on four bright stars in a cross-shaped asterism commonly known as the Southern Cross. It lies on the southern end of the Milky Way's visible band. The name Crux is Latin for cross. Even though it is the smallest of all 88 modern constellations, Crux is among the most easily distinguished as its four main stars each have an apparent visual magnitude brighter than +2.8. It has attained a high level of cultural significance in many Southern Hemisphere states and nations.
Blue-white α Crucis (Acrux) is the most southerly member of the constellation and, at magnitude 0.8, the brightest. The three other stars of the cross appear clockwise and in order of lessening magnitude: β Crucis (Mimosa), γ Crucis (Gacrux), and δ Crucis (Imai). ε Crucis (Ginan) also lies within the cross asterism. Many of these brighter stars are members of the Scorpius–Centaurus association, a large but loose group of hot blue-white stars that appear to share common origins and motion across the southern Milky Way.
Crux contains four Cepheid variables, each visible to the naked eye under optimum conditions. Crux also contains the bright and colourful open cluster known as the Jewel Box (NGC 4755) on its eastern border. Nearby to the southeast is a large dark nebula spanning 7° by 5° known as the Coalsack Nebula, portions of which are mapped in the neighbouring constellations of Centaurus and Musca.
==History==
The bright stars in Crux were known to the Ancient Greeks, where Ptolemy regarded them as part of the constellation Centaurus. They were entirely visible as far north as Britain in the fourth millennium BC. However, the precession of the equinoxes gradually lowered the stars below the European horizon, and they were eventually forgotten by the inhabitants of northern latitudes. By 400 AD, the stars in the constellation now called Crux never rose above the horizon throughout most of Europe. Dante may have known about the constellation in the 14th century, as he describes an asterism of four bright stars in the southern sky in his Divine Comedy. His description, however, may be allegorical, and the similarity to the constellation a coincidence.
The 15th century Venetian navigator Alvise Cadamosto made note of what was probably the Southern Cross on exiting the Gambia River in 1455, calling it the carro dell'ostro ("southern chariot"). However, Cadamosto's accompanying diagram was inaccurate. Historians generally credit João Faras for being the first European to depict it correctly. Faras sketched and described the constellation (calling it "las guardas") in a letter written on the beaches of Brazil on 1 May 1500 to the Portuguese monarch.
Explorer Amerigo Vespucci seems to have observed not only the Southern Cross but also the neighboring Coalsack Nebula on his second voyage in 1501–1502.
Another early modern description clearly describing Crux as a separate constellation is attributed to Andrea Corsali, an Italian navigator who from 1515 to 1517 sailed to China and the East Indies in an expedition sponsored by King Manuel I. In 1516, Corsali wrote a letter to the monarch describing his observations of the southern sky, which included a rather crude map of the stars around the south celestial pole including the Southern Cross and the two Magellanic Clouds seen in an external orientation, as on a globe.
Emery Molyneux and Petrus Plancius have also been cited as the first uranographers (sky mappers) to distinguish Crux as a separate constellation; their representations date from 1592, the former depicting it on his celestial globe and the latter in one of the small celestial maps on his large wall map. Both authors, however, depended on unreliable sources and placed Crux in the wrong position. Crux was first shown in its correct position on the celestial globes of Petrus Plancius and Jodocus Hondius in 1598 and 1600. Its stars were first catalogued separately from Centaurus by Frederick de Houtman in 1603. The constellation was later adopted by Jakob Bartsch in 1624 and Augustin Royer in 1679. Royer is sometimes wrongly cited as initially distinguishing Crux.
==Characteristics==
Crux is bordered by the constellations Centaurus (which surrounds it on three sides) on the east, north and west, and Musca to the south. Covering 68 square degrees and 0.165% of the night sky, it is the smallest of the 88 constellations. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Cru". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of four segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −55.68° and −64.70°. Its totality figures at least part of the year south of the 25th parallel north. They are among the highest-mass stellar members of the Lower Centaurus–Crux subgroup of the association, with ages of roughly 10 to 20 million years. Other members include the blue-white stars Zeta, Lambda and both the components of the visual double star, Mu.
===Variable stars===
Crux contains many variable stars. It boasts four Cepheid variables that may all reach naked eye visibility.
BG Crucis ranges from magnitude 5.34 to 5.58 over 3.3428 days,
T Crucis ranges from 6.32 to 6.83 over 6.73331 days,
S Crucis ranges from 6.22 to 6.92 over 4.68997 days,
R Crucis ranges from 6.4 to 7.23 over 5.82575 days.
Other well studied variable stars includes:
Lambda Crucis and Theta2 Crucis, that are both Beta Cepheid type variable stars. Discovered in October 1969, it has become redder and brighter (mean magnitude changing from 8.047 to 7.762) and its period lengthened by 25% in the first thirty years since its discovery.
===Host star exoplanets in Crux===
The star HD 106906 has been found to have a planet—HD 106906 b—that has one of the widest orbits of any currently known planetary-mass companions.
===Objects beyond the Local Arm===
Crux is backlit by the multitude of stars of the Scutum-Crux Arm (more commonly called the Scutum-Centaurus Arm) of the Milky Way. This is the main inner arm in the local radial quarter of the galaxy. Part-obscuring this is:
The Coalsack Nebula lies partially within Crux and partly in the neighboring constellations of Musca and Centaurus. It is the most prominent dark nebula in the skies, and is easily visible to the naked eye as a prominent dark patch in the southern Milky Way. It can be found 6.5° southeast from the centre of Crux or 3° east from α Crucis. Its large area covers about 7° by 5°, and is away from Earth.
A key feature of the Scutum-Crux Arm is:
The Jewel Box, κ Crucis Cluster or NGC 4755, is a small but bright open cluster that appears as a fuzzy star to the naked eye and is very close to the easternmost boundary of Crux: about 1° southeast of Beta Crucis. The combined or total magnitude is 4.2 and it lies at a distance of from Earth. The cluster was given its name by John Herschel, based on the range of colours visible throughout the star cluster in his telescope. About seven million years old, it is one of the youngest open clusters in the Milky Way, and it appears to have the shape of a letter 'A'. The Jewel Box Cluster is classified as Shapley class 'g' and Trumpler class 'I 3 r -' cluster; it is a very rich, centrally-concentrated cluster detached from the surrounding star field. It has more than 100 stars that range significantly in brightness. The brightest cluster stars are mostly blue supergiants, though the cluster contains at least one red supergiant. Kappa Crucis is a true member of the cluster that bears its name, and is one of the brighter stars at magnitude 5.9.
==Cultural significance==
The most prominent feature of Crux is the distinctive asterism known as the Southern Cross. It has great significance in the cultures of the southern hemisphere, particularly of Australia, Brazil, Chile and New Zealand.
===Flags and symbols===
Several southern countries and organisations have traditionally used Crux as a national or distinctive symbol. The four or five brightest stars of Crux appear, heraldically standardised in various ways, on the flags of Australia, Brazil, New Zealand, Papua New Guinea and Samoa. They also appear on the flags of the Australian state of Victoria, the Australian Capital Territory, the Northern Territory, as well as the flag of Magallanes Region of Chile, the flag of Londrina (Brazil) and several Argentine provincial flags and emblems (for example, Tierra del Fuego and Santa Cruz). The flag of the Mercosur trading zone displays the four brightest stars. Crux also appears on the Brazilian coat of arms and, , on the cover of Brazilian passports.
Five stars appear in the logo of the Brazilian football team Cruzeiro Esporte Clube and in the insignia of the Order of the Southern Cross, and the cross has featured as name of the Brazilian currency (the cruzeiro from 1942 to 1986 and again from 1990 to 1994). All coins of the (1998) series of the Brazilian real display the constellation.
Songs and literature reference the Southern Cross, including the Argentine epic poem Martín Fierro. The Argentinian singer Charly García says that he is "from the Southern Cross" in the song "No voy en tren".
The Cross gets a mention in the lyrics of the Brazilian National Anthem (1909): "A imagem do Cruzeiro resplandece" ("the image of the Cross shines").
The Southern Cross is mentioned in the Australian National Anthem, "Beneath our radiant Southern Cross we'll toil with hearts and hands"
The Southern Cross features in the coat of arms of William Birdwood, 1st Baron Birdwood, the British officer who commanded the Australian and New Zealand Army Corps during the Gallipoli Campaign of the First World War.
The Southern Cross is also mentioned in the Samoan
National Anthem.
"Vaai 'i na fetu o lo'u a agiagia ai: Le faailoga lea o Iesu, na maliu ai mo Samoa." ("Look at those stars that are waving on it: This is the symbol of Jesus, who died on it for Samoa.")
The 1952-53 NBC Television Series Victory At Sea contained a musical number entitled "Beneath the Southern Cross".
"Southern Cross" is a single released by Crosby, Stills and Nash in 1981. It reached #18 on Billboard Hot 100 in late 1982.
"The Sign of the Southern Cross" is a song released by Black Sabbath in 1981. The song was released on the album "Mob Rules".
The Order of the Southern Cross is a Brazilian order of chivalry awarded to "those who have rendered significant service to the Brazilian nation".
In "O Sweet Saint Martin's Land", the lyrics mention the Southern Cross: Thy Southern Cross the night.
A stylized version of Crux appears on the Australian Eureka Flag. The constellation was also used on the dark blue, shield-like patch worn by personnel of the U.S. Army's Americal Division, which was organized in the Southern Hemisphere, on the island of New Caledonia, and also on the blue diamond of the U.S. 1st Marine Division, which fought on the Southern Hemisphere islands of Guadalcanal and New Britain.
The Petersflagge flag of the German East Africa Company of 1885–1920, which included a constellation of five white five-pointed Crux "stars" on a red ground, later served as the model for symbolism associated with generic German colonial-oriented organisations: the Reichskolonialbund of 1936–1943 and the (1956/1983 to the present).
Southern Cross station is a major rail terminal in Melbourne, Australia.
The Personal Ordinariate of Our Lady of the Southern Cross is a personal ordinariate of the Roman Catholic Church primarily within the territory of the Australian Catholic Bishops Conference for groups of Anglicans who desire full communion with the Catholic Church in Australia and Asia.
The Knights of the Southern Cross (KSC) is a Catholic fraternal order throughout Australia.
===Various cultures===
In India, there is a story related to the creation of Trishanku Swarga (त्रिशंकु), meaning Cross (Crux), created by Sage Vishwamitra.
In Chinese, (), meaning Cross, refers to an asterism consisting of γ Crucis, α Crucis, β Crucis and δ Crucis.
In Australian Aboriginal astronomy, Crux and the Coalsack mark the head of the 'Emu in the Sky' (which is seen in the dark spaces rather than in the patterns of stars) in several Aboriginal cultures, while Crux itself is said to be a possum sitting in a tree (Boorong people of the Wimmera region of northwestern Victoria), a representation of the sky deity Mirrabooka (Quandamooka people of Stradbroke Island), a stingray (Yolngu people of Arnhem Land), or an eagle (Kaurna people of the Adelaide Plains). Two Pacific constellations also included Gamma Centauri. Torres Strait Islanders in modern-day Australia saw Gamma Centauri as the handle and the four stars as the left hand of Tagai, and the stars of Musca as the trident of the fishing spear he is holding. In Aranda traditions of central Australia, the four Cross stars are the talon of an eagle and Gamma Centauri as its leg.
Various peoples in the East Indies and Brazil viewed the four main stars as the body of a ray. In both Indonesia and Malaysia, it is known as Bintang Pari and Buruj Pari, respectively ("ray stars"). This aquatic theme is also shared by an archaic name of the constellation in Vietnam, where it was once known as sao Cá Liệt (the ponyfish star).
Among Filipino people, the southern cross have various names pertaining to tops, including kasing (Visayan languages), paglong (Bikol), and pasil (Tagalog). It is also called butiti (puffer fish) in Waray.
The Javanese people of Indonesia called this constellation Gubug pèncèng ("raking hut") or lumbung ("the granary"), because the shape of the constellation was like that of a raking hut.
The Southern Cross (α, β, γ and δ Crucis) together with μ Crucis is one of the asterisms used by Bugis sailors for navigation, called bintoéng bola képpang, meaning "incomplete house star"
The Māori name for the Southern Cross is Māhutonga and it is thought of as the anchor (Te Punga) of Tama-rereti's waka (the Milky Way), while the Pointers are its rope. In Tonga it is known as Toloa ("duck"); it is depicted as a duck flying south, with one of his wings (δ Crucis) wounded because Ongo tangata ("two men", α and β Centauri) threw a stone at it. The Coalsack is known as Humu (the "triggerfish"), because of its shape. In Samoa the constellation is called Sumu ("triggerfish") because of its rhomboid shape, while α and β Centauri are called Luatagata (Two Men), just as they are in Tonga. The peoples of the Solomon Islands saw several figures in the Southern Cross. These included a knee protector and a net used to catch Palolo worms. Neighboring peoples in the Marshall Islands saw these stars as a fish. Peninsular Malays also see the likeness of a fish in the Crux, particularly the Scomberomorus or its local name Tohok. Alpha and Beta Crucis make up one foot of the Great Rhea, a constellation encompassing Centaurus and Circinus along with the two bright stars. The Great Rhea was a constellation of the Bororo of Brazil. The Mocoví people of Argentina also saw a rhea including the stars of Crux. Their rhea is attacked by two dogs, represented by bright stars in Centaurus and Circinus. The dogs' heads are marked by Alpha and Beta Centauri. The rhea's body is marked by the four main stars of Crux, while its head is Gamma Centauri and its feet are the bright stars of Musca. The Bakairi people of Brazil had a sprawling constellation representing a bird snare. It included the bright stars of Crux, the southern part of Centaurus, Circinus, at least one star in Lupus, the bright stars of Musca, Beta and the optical double star Delta1,2 Chamaeleontis: and some of the stars of Volans, and Mensa. The Kalapalo people of Mato Grosso state in Brazil saw the stars of Crux as Aganagi angry bees having emerged from the Coalsack, which they saw as the beehive.
Among Tuaregs, the four most visible stars of Crux are considered iggaren, i.e. four Maerua crassifolia trees. The Tswana people of Botswana saw the constellation as Dithutlwa, two giraffes – Alpha and Beta Crucis forming a male, and Gamma and Delta forming the female.
|
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"Mensa (constellation)",
"New Caledonia"
] |
6,360 |
Cepheus
|
Cepheus (Ancient Greek: Κηφεύς Kepheús) may refer to:
==In Greek mythology==
Cepheus (father of Andromeda), and King of Aethiopia
Cepheus (son of Aleus), a king of Tegea, Arcadia
==In astronomy==
Cepheus (constellation), one of the 88 modern constellations
Cepheus (crater), a lunar impact crater
==In Computing==
Cepheus (poker bot)
==In modern fiction==
Cepheus Daidalos, a fictional character in the manga and anime, Saint Seiya
Cepheus, the FM king in Mega Man Star Force
In the Galaxy Railways, one of the squads is named the Cepheus Platoon.
==Other uses==
USS Cepheus (AKA-18), an Andromeda class attack cargo ship
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"Cepheus (father of Andromeda)",
"Cepheus Daidalos",
"Cepheus (poker bot)",
"Cepheus (constellation)"
] |
6,361 |
Cassiopeia
|
Cassiopeia or Cassiopea may refer to:
==Greek mythology==
Cassiopeia (mother of Andromeda), queen of Aethiopia and mother of Andromeda
Cassiopeia (wife of Phoenix), wife of Phoenix, king of Phoenicia
Cassiopeia, wife of Epaphus, king of Egypt, the son of Zeus and Io; mother of Libya
==Science==
Cassiopeia (constellation), a northern constellation representing the queen of Ethiopia
Cassiopeia A, a supernova remnant in that constellation
Cassiopea, the genus of the "upside-down" jellyfish
==Arts and entertainment==
===Film===
Cassiopeia (1996 film), a Brazilian CGI film
Cassiopeia (2022 film), a South Korean film
===Music===
Cassiopeia (TVXQ), the fan club of South Korean boy band TVXQ
"Cassiopeia", a song by Shabütie (now known as Coheed and Cambria) from their 1999 EP The Penelope EP
"Cassiopeia", a song by Joanna Newsom from her 2004 album The Milk-Eyed Mender
"Cassiopeia", a song by Dragonland from their 2006 album Astronomy
"Cassiopeia", a song by Sunny Lax from his 2006 EP P.U.M.A./Cassiopeia
"Cassiopeia", a song by Rain from his 2006 album Rain's World
"Cassiopeia", a song by Sara Bareilles from her 2013 album The Blessed Unrest
"Cassiopeia", a 2023 single by Bears in Trees
===Fictional characters===
Cassiopeia "Cassie" Sullivan, in The 5th Wave series written by Rick Yancey
Cassiopeia, a magical tortoise in Michael Ende's fantasy novel Momo
Cassiopeia (Battlestar Galactica), from the television series Battlestar Galactica
Cassiopea (Encantadia), the first Queen of Lireo in the Encantadia fantasy series of GMA Network
Cassiopeia, the mother of Octavian in The Astonishing Life of Octavian Nothing
Cassiopeia, the organizer and leader of "Operation Starfall" in the Starfall Street storyline in Pokémon Scarlet and Violet
==Other==
Casio Cassiopeia, a series of pocket PCs
Cassiopeia (train), an overnight rail service in Japan
USS Cassiopeia (AK-75), a cargo ship used by the United States Navy in World War II
|
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"The Milk-Eyed Mender",
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"Cassiopeia (2022 film)",
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"The 5th Wave (series)",
"Cassiopeia (1996 film)",
"Bears in Trees",
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"Coheed and Cambria",
"Cassiopeia (Battlestar Galactica)",
"USS Cassiopeia (AK-75)",
"Cassiopea (Encantadia)",
"The Astonishing Life of Octavian Nothing",
"Cassiopeia (constellation)",
"Boast of Cassiopeia"
] |
6,362 |
Cetus
|
{{Infobox constellation
| name = Cetus
| abbreviation = Cet
| genitive = Ceti
| pronounce = , genitive
| symbolism = the Whale, Shark, or Sea Monster
| RA = –
| dec= –]]
Cetus lies far from the galactic plane, so that many distant galaxies are visible, unobscured by dust from the Milky Way. Of these, the brightest is Messier 77 (NGC 1068), a 9th magnitude spiral galaxy near Delta Ceti. It appears face-on and has a clearly visible nucleus of magnitude 10. About 50 million light-years from Earth, M77 is also a Seyfert galaxy and thus a bright object in the radio spectrum. Recently, the galactic cluster JKCS 041 was confirmed to be the most distant cluster of galaxies yet discovered. The Pisces–Cetus Supercluster Complex is a galaxy filament that is one of the largest known structures in the observable Universe; it contains the Virgo supercluster which contains the Local Group of Milky Way and other galaxies.
The massive cD galaxy Holmberg 15A is also found in Cetus; as are the spiral galaxy NGC 1042, the elliptical galaxy NGC 1052 and the ultra-diffuse galaxy NGC 1052-DF2.
IC 1613 (Caldwell 51) is an irregular dwarf galaxy near the star 26 Ceti and is a member of the Local Group.
NGC 246 (Caldwell 56), also called the "Cetus Ring", is a planetary nebula with a magnitude of 8.0 at 1600 light-years from Earth. Among some amateur astronomers, NGC 246 has garnered the nickname "Pac-Man Nebula" because of the arrangement of its central stars and the surrounding star field.
The Wolf–Lundmark–Melotte (WLM) is a barred irregular galaxy discovered in 1909 by Max Wolf, located on the outer edges of the Local Group. The discovery of the nature of the galaxy was accredited to Knut Lundmark and Philibert Jacques Melotte in 1926.
UGC 1646, which is a spiral galaxy, also lies between the borders of the constellation. It is about 150 million light-years away from us. It can be seen near TYC 43-234-1 star.
==History and mythology==
Cetus may have originally been associated with a whale, which would have had mythic status amongst Mesopotamian cultures. It is often now called the Whale, though it is most strongly associated with Cetus the sea-monster, who was slain by Perseus as he saved the princess Andromeda from Poseidon's wrath. It is in the middle of "The Sea" recognised by mythologists, a set of water-associated constellations, its other members being Eridanus, Pisces, Piscis Austrinus and Aquarius.
Cetus has been depicted in many ways throughout its history. In the 17th century, Cetus was depicted as a "dragon fish" by Johann Bayer, while both Willem Blaeu and Andreas Cellarius depicted Cetus as a whale-like creature in the same century. However, Cetus has also been variously depicted with animal heads attached to a piscine body.
===In global astronomy===
In Chinese astronomy, the stars of Cetus are found among two areas: the Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ) and the White Tiger of the West (西方白虎, Xī Fāng Bái Hǔ).
The Tukano and Kobeua people of the Amazon used the stars of Cetus to create a jaguar, representing the god of hurricanes and other violent storms. Lambda, Mu, Xi, Nu, Gamma, and Alpha Ceti represented its head; Omicron, Zeta, and Chi Ceti represented its body; Eta Eri, Tau Cet, and Upsilon Cet marked its legs and feet; and Theta, Eta, and Beta Ceti delineated its tail.
In Hawaii, the constellation was called Na Kuhi, and Mira (Omicron Ceti) may have been called Kane.
==Namesakes==
USS Cetus (AK-77) was a United States Navy Crater class cargo ship named after the constellation.
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"main-sequence star",
"flare star",
"star system",
"Tau Ceti",
"October Cetids",
"Piscis Austrinus",
"Heracles",
"Alpha Ceti",
"red dwarfs",
"Prometheus Books",
"Kobeua people",
"Pisces (constellation)",
"spiral galaxy",
"Messier 77",
"Taurus (constellation)",
"sea monster",
"Black Tortoise",
"Crater class cargo ship",
"Aquarius (constellation)",
"List of largest cosmic structures",
"zodiac",
"NGC 1042",
"NGC 1052-DF2",
"Milky Way",
"Greek mythology",
"Gamma Ceti",
"International Astronomical Union",
"planetary nebula"
] |
6,363 |
Carina (constellation)
|
{{Infobox constellation
| name = Carina
| abbreviation = Car
| genitive = Carinae
| pronounce = , genitive
| dec= to Lacaille kept a single set of Greek letters for the whole of Argo, and separate sets of Latin letter designations for each of the three sections. Therefore, Carina has the α, β and ε, Vela has γ and δ, Puppis has ζ, and so on.
== Notable features ==
=== Stars ===
Carina contains Canopus, a white-hued supergiant that is the second-brightest star in the night sky at magnitude −0.72. Alpha Carinae, as Canopus is formally designated, is 313 light-years from Earth. Its traditional name comes from the mythological Canopus, who was a navigator for Menelaus, king of Sparta.
There are several other stars above magnitude 3 in Carina. Beta Carinae, traditionally called Miaplacidus, is a blue-white-hued star of magnitude 1.7, 111 light-years from Earth. Epsilon Carinae is an orange-hued giant star similarly bright to Miaplacidus at magnitude 1.9; it is 630 light-years from Earth. Another fairly bright star is the blue-white-hued Theta Carinae; it is a magnitude 2.7 star 440 light-years from Earth. Theta Carinae is also the most prominent member of the cluster IC 2602. Iota Carinae is a white-hued supergiant star of magnitude 2.2, 690 light-years from Earth.
Eta Carinae is the most prominent variable star in Carina, with a mass of approximately 100 solar masses and 4 million times as bright as the Sun. It was first discovered to be unusual in 1677, when its magnitude suddenly rose to 4, attracting the attention of Edmond Halley. Eta Carinae is inside NGC 3372, commonly called the Carina Nebula. It had a long outburst in 1827, when it brightened to magnitude 1, only fading to magnitude 1.5 in 1828. Its most prominent outburst made Eta Carinae the equal of Sirius; it brightened to magnitude −1.5 in 1843. In the decades following 1843 it appeared relatively placid, having a magnitude between 6.5 and 7.9. However, in 1998, it brightened again, though only to magnitude 5.0, a far less drastic outburst. Eta Carinae is a binary star, with a companion that has a period of 5.5 years; the two stars are surrounded by the Homunculus Nebula, which is composed of gas that was ejected in 1843.
There are several less prominent variable stars in Carina. l Carinae is a Cepheid variable noted for its brightness; it is the brightest Cepheid that is variable to the unaided eye. It is a yellow-hued supergiant star with a minimum magnitude of 4.2 and a maximum magnitude of 3.3; it has a period of 35.5 days.
V382 Carinae is a yellow hypergiant, one of the rarest types of stars. It is a slow irregular variable, with a minimum magnitude of 4.05 and a maximum magnitude of 3.77. As a hypergiant, V382 Carinae is a luminous star, with 212,000 times more luminosity than the Sun and over 480 times the Sun's size.
Two bright Mira variable stars are in Carina: R Carinae and S Carinae; both stars are red giants. R Carinae has a minimum magnitude of 10.0 and a maximum magnitude of 4.0. Its period is 309 days and it is 416 light-years from Earth. S Carinae is similar, with a minimum magnitude of 10.0 and a maximum magnitude of 5.0. However, S Carinae has a shorter period—150 days, though it is much more distant at 1,300 light-years from Earth.
Carina is home to several double stars and binary stars. Upsilon Carinae is a binary star with two blue-white-hued giant components, 1,600 light-years from Earth. The primary is of magnitude 3.0 and the secondary is of magnitude 6.0; the two components are distinguishable in a small amateur telescope.
Two asterisms are prominent in Carina. The 'Diamond Cross' is composed of the stars Beta, Theta, Upsilon and Omega Carinae. The Diamond Cross is visible south of 20ºN latitude, and is larger but fainter than the Southern Cross in Crux. Flanking the Diamond Cross is the False cross, composed of four stars - two stars in Carina, Iota Carinae and Epsilon Carinae, and two stars in Vela, Kappa Velorum and Delta Velorum - and is often mistaken for the Southern Cross, causing errors in astronavigation.
=== Deep-sky objects ===
Carina is known for its namesake nebula, NGC 3372, discovered by French astronomer Nicolas-Louis de Lacaille in 1751, which contains several nebulae. The Carina Nebula overall is an extended emission nebula approximately 8,000 light-years away and 300 light-years wide that includes vast star-forming regions. It has an overall magnitude of 8.0 and an apparent diameter of over 2 degrees. Its central region is called the Keyhole, or the Keyhole Nebula. This was described in 1847 by John Herschel, and likened to a keyhole by Emma Converse in 1873. The Keyhole is about seven light-years wide and is composed mostly of ionized hydrogen, with two major star-forming regions. The Homunculus Nebula is a planetary nebula visible to the naked eye that is being ejected by the erratic luminous blue variable star Eta Carinae, the most massive visible star known. Eta Carinae is so massive that it has reached the theoretical upper limit for the mass of a star and is therefore unstable. It is known for its outbursts; in 1840 it briefly became one of the brightest stars in the sky due to a particularly massive outburst, which largely created the Homunculus Nebula. Because of this instability and history of outbursts, Eta Carinae is considered a prime supernova candidate for the next several hundred thousand years because it has reached the end of its estimated million-year life span.
NGC 2516 is an open cluster that is both quite large (approximately half a degree square) and bright, visible to the unaided eye.
== Namesakes ==
was a United States Navy Crater-class cargo ship named after the constellation.
the Toyota Carina was named after it.
|
[
"red giant",
"Native Hawaiians",
"NGC 3114",
"Canopus",
"Volans",
"poop deck",
"intracluster medium",
"Bullet Cluster",
"Eta Carinids",
"latitude",
"galaxy cluster",
"United States Navy",
"Eta Carinae",
"Heavenly Waters (astronomy)",
"ancient Greece",
"slow irregular variable",
"ionized hydrogen",
"Ming dynasty",
"Chamaeleon",
"yellow hypergiant",
"IC 2602",
"Yale University Press",
"star",
"ellipse",
"constellation",
"Astronomy and Astrophysics",
"NGC 2516",
"HD 84810",
"Vermilion Bird",
"Musca",
"Jason",
"solar mass",
"South Pole",
"Homunculus Nebula",
"Chi Carinae",
"Nicolas-Louis de Lacaille",
"Māori people",
"supernova",
"southern sky",
"S Carinae",
"luminous blue variable",
"Edmond Halley",
"Chinese constellations",
"nebula",
"Celestial navigation",
"LHS 288",
"20th parallel north",
"keel",
"globular cluster",
"Golden Fleece",
"Ariki",
"variable star",
"Atutahi",
"D. Appleton and Company",
"Crux",
"NGC 3532",
"Crater-class cargo ship",
"Argonauts",
"Puppis",
"Mira variable",
"star formation",
"double star",
"redshift",
"List of brightest stars",
"Tuamotu",
"Canopus (mythology)",
"NGC 2808",
"Omega Carinae",
"Kappa Velorum",
"False cross",
"Theta Carinae",
"John Herschel",
"Cambridge University Press",
"Iota Carinae",
"Carina Nebula",
"binary star",
"Upsilon Carinae",
"Pleiades",
"R Carinae",
"Latin",
"light-year",
"gravitational interaction",
"emission nebula",
"Prometheus Books",
"Carina in Chinese astronomy",
"Cepheid variable",
"Toyota Carina",
"Pictor",
"V382 Carinae",
"Sirius",
"Delta Velorum",
"Epsilon Carinae",
"Centaurus",
"bow shock",
"Argo Navis",
"Vela (constellation)",
"Alpha Carinids",
"supergiant",
"Stellarium (software)",
"Keyhole Nebula",
"Polynesian people",
"Beta Carinae",
"Menelaus",
"International Astronomical Union",
"planetary nebula",
"Princeton University Press"
] |
6,364 |
Camelopardalis
|
{{Infobox constellation
| name = Camelopardalis
| abbreviation = Cam
| genitive = Camelopardalis
| pronounce = , genitive the same
| symbolism = Giraffe
| RA = –
| dec= – Some older astronomy books give Camelopardalus or Camelopardus as alternative forms of the name, but the version recognized by the International Astronomical Union matches the genitive form, seen suffixed to most of its key stars.
==Etymology==
First attested in English in 1785, the word camelopardalis comes from Latin, and it is the romanization of the Greek "καμηλοπάρδαλις" meaning "giraffe", from "κάμηλος" (kamēlos), "camel" + "πάρδαλις" (pardalis), "spotted", because it has a long neck like a camel and spots like a leopard.
==Features==
===Stars===
Although Camelopardalis is the 18th largest constellation, it is not a particularly bright constellation, as the brightest stars are only of fourth magnitude. In fact, it only contains four stars brighter than magnitude 5.0.
α Cam is a blue-hued supergiant star of magnitude 4.3, over 6,000 light-years from Earth. It is one of the most distant stars easily visible with the naked eye.
β Cam is the brightest star in Camelopardalis with an apparent magnitude of 4.03. This star is a double star, with components of magnitudes 4.0 and 8.6. The primary is a yellow-hued supergiant 1000 light-years from Earth.
11 Cam is a star of magnitude 5.2, 650 light-years from Earth. It appears without intense magnification very close to magnitude 6.1 12 Cam, at about the same distance from us, but the two are not a true double star; they have considerable separation.
Σ 1694 (Struve 1694, 32H Cam) is a binary star 300 light-years from Earth. Both components have a blue-white hue; the primary is of magnitude 5.4 and the secondary is of magnitude 5.9.
CS Cam is the second brightest star, though it has neither a Bayer nor a Flamsteed designation. It is of magnitude 4.21 and is slightly variable.
Z Cam (varying from amateur telescope visibility to extremely faint) is frequently observed as part of a program of AAVSO. It is the prototype of Z Camelopardalis variable stars.
Other variable stars are U Camelopardalis, VZ Camelopardalis, and Mira variables T Camelopardalis, X Camelopardalis, and R Camelopardalis. RU Camelopardalis is one of the brighter Type II Cepheids visible in the night sky.
In 2011 a supernova was discovered in the constellation.
===Deep-sky objects===
Camelopardalis is in the part of the celestial sphere facing away from the galactic plane. Accordingly, many distant galaxies are visible within its borders.
NGC 2403 is a galaxy in the M81 group of galaxies, located approximately 12 million light-years from Earth with a redshift of 0.00043. It is classified as being between an elliptical and a spiral galaxy because it has faint arms and a large central bulge. NGC 2403 was first discovered by the 18th century astronomer William Herschel, who was working in England at the time. It has an integrated magnitude of 8.0 and is approximately 0.25° long.
NGC 1502 is a magnitude 6.9 open cluster about 3,000 light years from Earth. It has about 45 bright members, and features also a double star of magnitude 7.0 at its center. NGC 1502 is also associated with Kemble's Cascade, a simple but beautiful asterism appearing in the sky as a chain of stars 2.5° long that is parallel to the Milky Way and is pointed towards Cassiopeia. * NGC 1501 is a planetary nebula located roughly 1.4° south of NGC 1502.
Stock 23 is an open star cluster at the southern part of the border between Camelopardalis and Cassiopeia. It is also known as Pazmino's Cluster. It could be categorized as an asterism because of the small number of stars in it (a small telescopic constellation).
IC 342 is one of the brightest two galaxies in the IC 342/Maffei Group of galaxies.
The dwarf irregular galaxy NGC 1569 is a magnitude 11.9 starburst galaxy, about 11 million light years away.
NGC 2655 is a large lenticular galaxy with visual magnitude 10.1.
UGC 3697 is known as the Integral Sign Galaxy (its location is 7:11:4 / +71°50').
MS0735.6+7421 is a galaxy cluster with a redshift of 0.216, located 2.6 billion light-years from Earth. It is unique for its intracluster medium, which emits X-rays at a very high rate. This galaxy cluster features two cavities 600,000 light-years in diameter, caused by its central supermassive black hole, which emits jets of matter. MS0735.6+7421 is one of the largest and most distant examples of this phenomenon.
Tombaugh 5 is a fairly dim open cluster in Camelopardalis. It has an overall magnitude of 8.4 and is located 5,800 light-years from Earth. It is a Shapley class c and Trumpler class III 1 r cluster, meaning that it is irregularly shaped and appears loose. Though it is detached from the star field, it is not concentrated at its center at all. It has more than 100 stars which do not vary widely in brightness, mostly being of the 15th and 16th magnitude.
NGC 2146 is an 11th magnitude barred spiral starburst galaxy conspicuously warped by interaction with a neighbour.
MACS0647-JD, one of the possible candidates for the farthest known galaxies in the universe (z= 10.7), is also in Camelopardalis.
=== Meteor showers ===
The annual May meteor shower Camelopardalids from comet 209P/LINEAR have a radiant in Camelopardalis.
==History==
Camelopardalis is not one of Ptolemy's 48 constellations in the Almagest. It was created by Petrus Plancius in 1613. It first appeared in a globe designed by him and produced by Pieter van den Keere. One year later, Jakob Bartsch featured it in his atlas. Johannes Hevelius depicted this constellation in his works which were so influential that it was referred to as Camelopardali Hevelii or abbreviated as Camelopard. Hevel.
Part of the constellation was hived off to form the constellation Sciurus Volans, the Flying Squirrel, by William Croswell in 1810. However this was not taken up by later cartographers.
==Equivalents==
In Chinese astronomy, the stars of Camelopardalis are located within a group of circumpolar stars called the Purple Forbidden Enclosure (紫微垣 Zǐ Wēi Yuán).
|
[
"M81 group",
"Redshift",
"Giraffe",
"intracluster medium",
"giraffe",
"Ptolemy",
"camel",
"10th parallel south",
"AAVSO",
"Auriga (constellation)",
"Ursa Minor",
"light year",
"Johannes Hevelius",
"romanization",
"William Herschel",
"11 Camelopardalis",
"Greek language",
"apparent magnitude",
"Cassiopeia (constellation)",
"Z Camelopardalis",
"constellation",
"12 Camelopardalis",
"T Camelopardalis",
"MACS0647-JD",
"Chinese astronomy",
"Purple Forbidden Enclosure",
"IC 342",
"Draco (constellation)",
"integrated magnitude",
"NGC 1569",
"NGC 1502",
"CS Camelopardalis",
"Petrus Plancius",
"elliptical galaxy",
"galactic plane",
"U Camelopardalis",
"Flamsteed designation",
"RU Camelopardalis",
"Pieter van den Keere",
"209P/LINEAR",
"October Camelopardalids",
"Gliese 445",
"variable star",
"Mira variable",
"Perseus Digital Library",
"double star",
"Almagest",
"redshift",
"Jakob Bartsch",
"Beta Camelopardalis",
"celestial sphere",
"open cluster",
"Alpha Camelopardalis",
"Bayer designation",
"Radiant (meteor shower)",
"NGC 2403",
"Camelopardalis (Chinese astronomy)",
"NGC 1501",
"Z Camelopardalis variable stars",
"X-ray",
"binary star",
"Struve 1694",
"Lynx (constellation)",
"Latin",
"NGC 2146",
"Ursa Major",
"Cepheus (constellation)",
"spiral galaxy",
"Perseus (constellation)",
"MS0735.6+7421",
"lenticular galaxy",
"Kemble's Cascade",
"Tarandus (constellation)",
"North Pole",
"starburst galaxy",
"Custos Messium",
"Ursa Major Family",
"NGC 2655",
"R Camelopardalis",
"IC 342/Maffei Group",
"X Camelopardalis",
"International Astronomical Union",
"VZ Camelopardalis",
"Type II Cepheid",
"supermassive black hole"
] |
6,365 |
Convention of Kanagawa
|
The Convention of Kanagawa, also known as the or the , was a treaty signed between the United States and the Tokugawa Shogunate on March 31, 1854. Signed under threat of force, it effectively meant the end of Japan's 220-year-old policy of national seclusion () by opening the ports of Shimoda and Hakodate to American vessels. It also ensured the safety of American castaways and established the position of an American consul in Japan. The treaty precipitated the signing of similar treaties establishing diplomatic relations with other Western powers.
==Isolation of Japan==
Since the beginning of the 17th century, the Tokugawa Shogunate pursued a policy of isolating the country from outside influences. Foreign trade was maintained only with the Dutch and the Chinese and was conducted exclusively at Nagasaki under a strict government monopoly. This "Pax Tokugawa" period is largely associated with domestic peace, social stability, commercial development, and expanded literacy. This policy had two main objectives:
To suppress the spread of Christianity. By the early 17th century, Catholicism had spread throughout the world. Tokugawa feared that trade with western powers would cause further instability in the nation. Thus, the isolation policy expelled foreigners and did not allow international travel.
The Japanese feared that foreign trade and the wealth developed would lead to the rise of a daimyo powerful enough to overthrow the ruling Tokugawa clan, especially after seeing what happened to China during the Opium Wars.
==Perry expedition==
In 1853, United States Navy Commodore Matthew C. Perry was sent with a fleet of warships by U.S. President Millard Fillmore to force the opening of Japanese ports to American trade, through the use of gunboat diplomacy if necessary. President Fillmore's letter shows the U.S. sought trade with Japan to open export markets for American goods like gold from California, enable U.S. ships to refuel in Japanese ports, and secure protections and humane treatment for any American sailors shipwrecked on Japan's shores. The growing commerce between America and China, the presence of American whalers in waters offshore Japan, and the increasing monopolization of potential coaling stations by the British and French in Asia were all contributing factors. The Americans were also driven by concepts of manifest destiny and the desire to impose the perceived benefits of western civilization and Christianity on what they perceived as backward Asian nations. From the Japanese perspective, increasing contacts with foreign warships and the increasing disparity between western military technology and the Japanese feudal armies fostered growing concern. The Japanese had been keeping abreast of world events via information gathered from Dutch traders in Dejima and had been forewarned by the Dutch of Perry's voyage. Such refusal was intentional, as Perry wrote in his journal: "To show these princes how little I regarded their order for me to depart, on getting on board I immediately ordered the whole squadron underway, not to leave the bay... but to go higher up... would produce a decided influence upon the pride and conceit of the government, and cause a more favorable consideration of the President's letter."
Despite years of debate on the isolation policy, Perry's letter created great controversy within the highest levels of the Tokugawa shogunate. The shogun himself, Tokugawa Ieyoshi, died days after Perry's departure and was succeeded by his sickly young son, Tokugawa Iesada, leaving effective administration in the hands of the Council of Elders () led by Abe Masahiro. Abe felt that it was impossible for Japan to resist the American demands by military force and yet was reluctant to take any action on his own authority for such an unprecedented situation. Attempting to legitimize any decision taken, Abe polled all of the daimyo for their opinions. This was the first time that the Tokugawa shogunate had allowed its decision-making to be a matter of public debate and had the unforeseen consequence of portraying the shogunate as weak and indecisive. The results of the poll also failed to provide Abe with an answer; of the 61 known responses, 19 were in favour of accepting the American demands and 19 were opposed. Of the remainder, 14 gave vague responses expressing concern of possible war, 7 suggested making temporary concessions and 2 advised that they would simply go along with whatever was decided.
Perry returned again on February 11, 1854, with an even larger force of eight warships and made it clear that he would not be leaving until a treaty was signed. Perry continued his manipulation of the setting, such as keeping himself aloof from lower-ranking officials, implying the use of force, surveying the harbor, and refusing to meet in the designated negotiation sites. Negotiations began on March 8 and proceeded for around one month. Each party shared a performance when Perry arrived. The Americans had a technology demonstration, and the Japanese had a sumo wrestling show. While the new technology awed the Japanese people, Perry was unimpressed by the sumo wrestlers and perceived such performance as foolish and degrading: "This disgusting exhibition did not terminate until the whole twenty-five had, successively, in pairs, displayed their immense powers and savage qualities."
==Treaty of Peace and Amity (1854)==
The "Japan-US Treaty of Peace and Amity" has twelve articles:
At the time, shogun Tokugawa Iesada was the de facto ruler of Japan; for the Emperor of Japan to interact in any way with foreigners was out of the question. Perry concluded the treaty with representatives of the shogun, led by plenipotentiary and the text was endorsed subsequently, albeit reluctantly, by Emperor Kōmei.
The treaty was ratified on February 21, 1855.
==Consequences of the treaty==
In the short term, the U.S. was content with the agreement since Perry had achieved his primary objective of breaking Japan's policy and setting the grounds for protection of American citizens and an eventual commercial agreement. On the other hand, the Japanese were forced into this trade, and many saw it as a sign of weakness. The Tokugawa shogunate could point out that the treaty was not actually signed by the shogun, or indeed any of his , and that it had at least averted the possibility of immediate military confrontation.
Externally, the treaty led to the United States-Japan Treaty of Amity and Commerce, the "Harris Treaty" of 1858, which allowed the establishment of foreign concessions, extraterritoriality for foreigners, and minimal import taxes for foreign goods. The Japanese chafed under the "unequal treaty system" which characterized Asian and western relations during this period. The Kanagawa treaty was also followed by similar agreements with the United Kingdom (Anglo-Japanese Friendship Treaty, October 1854), Russia (Treaty of Shimoda, February 7, 1855), and France (Treaty of Amity and Commerce between France and Japan, October 9, 1858).
Internally, the treaty had far-reaching consequences. Decisions to suspend previous restrictions on military activities led to re-armament by many domains and further weakened the position of the shogun. Debate over foreign policy and popular outrage over perceived appeasement to the foreign powers was a catalyst for the movement and a shift in political power from Edo back to the Imperial Court in Kyoto. The opposition of Emperor Kōmei to the treaties further lent support to the (overthrow the shogunate) movement, and eventually to the Meiji Restoration, which affected all realms of Japanese life. Following this period came an increase in foreign trade, the rise of Japanese military might, and the later rise of Japanese economic and technological advancement. Westernization at the time was a defense mechanism, but Japan has since found a balance between Western modernity and Japanese tradition.
|
[
"extraterritoriality",
"Treaty of Shimoda",
"Tokugawa clan",
"Qing Dynasty",
"sonnō jōi",
"Diplomatic Record Office of the Ministry of Foreign Affairs (Japan)",
"Tokugawa shogunate",
"blackface minstrelsy",
"Anglo-Japanese Friendship Treaty",
"Meiji Restoration",
"daimyo",
"Edo (Tokyo)",
"List of Westerners who visited Japan before 1868",
"Townsend Harris",
"Rōjū",
"Opium Wars",
"Michael Auslin",
"The Barbarian and the Geisha",
"Treaty of Amity and Commerce between France and Japan",
"University of Hong Kong",
"Tokugawa Shogunate",
"fuelling station",
"Kabuki",
"Edo Bay",
"Bayard Taylor",
"Uraga, Kanagawa",
"Harvard University Press",
"Emperor Kōmei",
"United States Navy",
"United States",
"consul (representative)",
"Matthew C. Perry",
"Japanese language",
"Franklin Pierce",
"Hayashi Akira",
"Ratification",
"Pax Tokugawa",
"Treaty of Amity and Commerce (United States–Japan)",
"Tokugawa Iesada",
"Bill of Rights Institute",
"shogun",
"Matthew Calbraith Perry",
"William II of the Netherlands",
"Tokugawa Ieyoshi",
"Emperor of Japan",
"Abe Masahiro",
"sumo",
"Kyoto",
"manifest destiny",
"James Biddle",
"Columbia University",
"Netherlands",
"Nagasaki",
"gunboat diplomacy",
"Yokohama Archives of History",
"Cambridge University Press",
"Dejima",
"Treaty of Kanghwa",
"Unequal treaty",
"Routledge",
"English language",
"sakoku",
"Yokohama",
"Kurihama, Yokosuka",
"unequal treaty",
"castaway",
"Shimoda, Shizuoka",
"Millard Fillmore",
"Hakodate",
"Duke University Press"
] |
6,366 |
Canis Major
|
{{Infobox constellation
| name = Canis Major
| abbreviation = CMa
| genitive = Canis Majoris
| pronounce = , genitive
| symbolism = the greater dog
| RA = to Ninurta was linked to the later deity Marduk, who was said to have slain the ocean goddess Tiamat with a great bow, and worshipped as the principal deity in Babylon. The Ancient Greeks replaced the bow and arrow depiction with that of a dog.
In Greek Mythology, Canis Major represented the dog Laelaps, a gift from Zeus to Europa; or sometimes the hound of Procris, Diana's nymph; or the one given by Aurora to Cephalus, so famed for its speed that Zeus elevated it to the sky. It was also considered to represent one of Orion's hunting dogs, pursuing Lepus the Hare or helping Orion fight Taurus the Bull; and is referred to in this way by Aratos, Homer and Hesiod. The ancient Greeks refer only to one dog, but by Roman times, Canis Minor appears as Orion's second dog. Alternative names include Canis Sequens and Canis Alter. Canis Syrius was the name used in the 1521 Alfonsine tables.
The Roman myth refers to Canis Major as Custos Europae, the dog guarding Europa but failing to prevent her abduction by Jupiter in the form of a bull, and as Janitor Lethaeus, "the watchdog". In medieval Arab astronomy, the constellation became al-Kalb al-Akbar, "the Greater Dog", transcribed as Alcheleb Alachbar by 17th century writer Edmund Chilmead. Islamic scholar Abū Rayḥān al-Bīrūnī referred to Orion as Kalb al-Jabbār, "the Dog of the Giant". Among the Merazig of Tunisia, shepherds note six constellations that mark the passage of the dry, hot season. One of them, called Merzem, includes the stars of Canis Major and Canis Minor and is the herald of two weeks of hot weather.
=== In non-western astronomy ===
In Chinese astronomy, the modern constellation of Canis Major is located in the Vermilion Bird (), where the stars were classified in several separate asterisms of stars. The Military Market () was a circular pattern of stars containing Nu3, Beta, Xi1 and Xi2, and some stars from Lepus. The Wild Cockerel () was at the centre of the Military Market, although it is uncertain which stars depicted what. Schlegel reported that the stars Omicron and Pi Canis Majoris might have been them, while Beta or Nu2 have also been proposed. Sirius was ' (), the Celestial Wolf, denoting invasion and plunder. To the Boorong people of Victoria, Sigma Canis Majoris was ' (which has become the official name of this star), and its flanking stars Delta and Epsilon were his two wives. The moon (, "native cat") sought to lure the further wife (Epsilon) away, but assaulted him and he has been wandering the sky ever since.
== Characteristics ==
Canis Major is a constellation in the Southern Hemisphere's summer (or northern hemisphere's winter) sky, bordered by Monoceros (which lies between it and Canis Minor) to the north, Puppis to the east and southeast, Columba to the southwest, and Lepus to the west. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "CMa". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a quadrilateral; in the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −11.03° and −33.25°. Covering 380 square degrees or 0.921% of the sky, it ranks 43rd of the 88 currently-recognized constellations in size.
== Features ==
=== Stars ===
Canis Major is a prominent constellation because of its many bright stars. These include Sirius (Alpha Canis Majoris), the brightest star in the night sky, as well as three other stars above magnitude 2.0. Furthermore, two other stars are thought to have previously outshone all others in the night sky—Adhara (Epsilon Canis Majoris) shone at −3.99 around 4.7 million years ago, and Mirzam (Beta Canis Majoris) peaked at −3.65 around 4.42 million years ago. Another, NR Canis Majoris, will be brightest at magnitude −0.88 in about 2.87 million years' time.
The German cartographer Johann Bayer used the Greek letters Alpha through Omicron to label the most prominent stars in the constellation, including three adjacent stars as Nu and two further pairs as Xi and Omicron, while subsequent observers designated further stars in the southern parts of the constellation that were hard to discern from Central Europe. Bayer's countryman Johann Elert Bode later added Sigma, Tau and Omega; the French astronomer Nicolas Louis de Lacaille added lettered stars a to k (though none are in use today). John Flamsteed numbered 31 stars, with 3 Canis Majoris being placed by Lacaille into Columba as Delta Columbae (Flamsteed had not recognised Columba as a distinct constellation). He also labelled two stars—his 10 and 13 Canis Majoris—as Kappa1 and Kappa2 respectively, but subsequent cartographers such as Francis Baily and John Bevis dropped the fainter former star, leaving Kappa2 as the sole Kappa. Flamsteed's listing of Nu1, Nu2, Nu3, Xi1, Xi2, Omicron1 and Omicron2 have all remained in use.
Sirius is the brightest star in the night sky at apparent magnitude −1.46 and one of the closest stars to Earth at a distance of 8.6 light-years. Its name comes from the Greek word for "scorching" or "searing". Sirius is also a binary star; its companion Sirius B is a white dwarf with a magnitude of 8.4–10,000 times fainter than Sirius A to observers on Earth. The two orbit each other every 50 years. Their closest approach last occurred in 1993 and they will be at their greatest separation between 2020 and 2025. Sirius was the basis for the ancient Egyptian calendar. The star marked the Great Dog's mouth on Bayer's star atlas.
Flanking Sirius are Beta and Gamma Canis Majoris. Also called Mirzam or Murzim, Beta is a blue-white Beta Cephei variable star of magnitude 2.0, which varies by a few hundredths of a magnitude over a period of six hours. Mirzam is 500 light-years from Earth, and its traditional name means "the announcer", referring to its position as the "announcer" of Sirius, as it rises a few minutes before Sirius does. Gamma, also known as Muliphein, is a fainter star of magnitude 4.12, in reality a blue-white bright giant of spectral type B8IIe located 441 light-years from earth. Iota Canis Majoris, lying between Sirius and Gamma, is another star that has been classified as a Beta Cephei variable, varying from magnitude 4.36 to 4.40 over a period of 1.92 hours. It is a remote blue-white supergiant star of spectral type B3Ib, around 46,000 times as luminous as the sun and, at 2500 light-years distant, 300 times further away than Sirius.
Epsilon, Omicron2, Delta, and Eta Canis Majoris were called Al Adzari "the virgins" in medieval Arabic tradition. Marking the dog's right thigh on Bayer's atlas is Epsilon Canis Majoris, also known as Adhara. At magnitude 1.5, it is the second-brightest star in Canis Major and the 23rd-brightest star in the sky. It is a blue-white supergiant of spectral type B2Iab, around 404 light-years from Earth. This star is one of the brightest known extreme ultraviolet sources in the sky. It is a binary star; the secondary is of magnitude 7.4. Its traditional name means "the virgins", having been transferred from the group of stars to Epsilon alone. Nearby is Delta Canis Majoris, also called Wezen. It is a yellow-white supergiant of spectral type F8Iab and magnitude 1.84, around 1605 light-years from Earth. With a traditional name meaning "the weight", Wezen is 17 times as massive and 50,000 times as luminous as the Sun. If located in the centre of the Solar System, it would extend out to Earth as its diameter is 200 times that of the Sun. Only around 10 million years old, Wezen has stopped fusing hydrogen in its core. Its outer envelope is beginning to expand and cool, and in the next 100,000 years it will become a red supergiant as its core fuses heavier and heavier elements. Once it has a core of iron, it will collapse and explode as a supernova. Nestled between Adhara and Wezen lies Sigma Canis Majoris, known as Unurgunite to the Boorong and Wotjobaluk people,
Also called Aludra, Eta Canis Majoris is a blue-white supergiant of spectral type B5Ia with a luminosity 176,000 times and diameter around 80 times that of the Sun. Classified as an Alpha Cygni type variable star, Aludra varies in brightness from magnitude 2.38 to 2.48 over a period of 4.7 days. It is located 1120 light-years away. To the west of Adhara lies 3.0-magnitude Zeta Canis Majoris or Furud, around 362 light-years distant from Earth. It is a spectroscopic binary, whose components orbit each other every 1.85 years, the combined spectrum indicating a main star of spectral type B2.5V.
Between these stars and Sirius lie Omicron1, Omicron2, and Pi Canis Majoris. Omicron2 is a massive supergiant star about 21 times as massive as the Sun. Only 7 million years old, It is an Alpha Cygni variable that undergoes periodic non-radial pulsations, which cause its brightness to cycle from magnitude 2.93 to 3.08 over a 24.44-day interval. Omicron1 is an orange K-type supergiant of spectral type K2.5Iab that is an irregular variable star, varying between apparent magnitudes 3.78 and 3.99. Around 18 times as massive as the Sun, it shines with 65,000 times its luminosity.
North of Sirius lie Theta and Mu Canis Majoris, Theta being the most northerly star with a Bayer designation in the constellation. Around 8 billion years old, it is an orange giant of spectral type K4III that is around as massive as the Sun but has expanded to 30 times the Sun's diameter. Mu is a multiple star system located around 1244 light-years distant, The brighter star is a giant of spectral type K2III, while the companion is a main sequence star of spectral type B9.5V. Nu1 Canis Majoris is a yellow-hued giant star of magnitude 5.7, 278 light-years away; it is at the threshold of naked-eye visibility. It has a companion of magnitude 8.1.
At the southern limits of the constellation lie Kappa and Lambda Canis Majoris. Although of similar spectra and nearby each other as viewed from Earth, they are unrelated. which brightened by 50% between 1963 and 1978, from magnitude 3.96 or so to 3.52. It is around 659 light-years distant. Lambda is a blue-white B-type main sequence dwarf with an apparent magnitude of 4.48 located around 423 light-years from Earth. It is 3.7 times as wide as and 5.5 times as massive as the Sun, and shines with 940 times its luminosity. VY Canis Majoris is a remote red hypergiant located approximately 3,800 light-years away from Earth. It is one of largest stars known (sometimes described as the largest known) and is also one of the most luminous with a radius varying from 1,420 to 2,200 times the Sun's radius, and a luminosity around 300,000 times greater than the Sun. Its current mass is about 17 ± 8 solar masses, having shed material from an initial mass of 25–32 solar masses. VY CMa is also surrounded by a red reflection nebula that has been made by the material expelled by the strong stellar winds of its central star. W Canis Majoris is a type of red giant known as a carbon star—a semiregular variable, it ranges between magnitudes 6.27 and 7.09 over a period of 160 days. A cool star, it has a surface temperature of around 2,900 K and a radius 234 times that of the Sun, its distance estimated at 1,444–1,450 light-years from Earth. At the other extreme in size is RX J0720.4-3125, a neutron star with a radius of around 5 km. Exceedingly faint, it has an apparent magnitude of 26.6. Its spectrum and temperature appear to be mysteriously changing over several years. The nature of the changes are unclear, but it is possible they were caused by an event such as the star's absorption of an accretion disc. Its four main component stars are hot O-type stars, with a combined mass 80 times that of the Sun and shining with 500,000 times its luminosity, but little is known of their individual properties. A fifth component, a magnitude 10 star, lies at a distance of . The system is only 5 million years old. UW Canis Majoris is another Beta Lyrae-type star 3000 light-years from Earth; it is an eclipsing binary that ranges in magnitude from a minimum of 5.3 to a maximum of 4.8. It has a period of 4.4 days; its components are two massive hot blue stars, one a blue supergiant of spectral type O7.5–8 Iab, while its companion is a slightly cooler, less evolved and less luminous supergiant of spectral type O9.7Ib. The stars are 200,000 and 63,000 times as luminous as the Sun. However the fainter star is the more massive at 19 solar masses to the primary's 16. R Canis Majoris is another eclipsing binary that varies from magnitude 5.7 to 6.34 over 1.13 days, with a third star orbiting these two every 93 years. The shortness of the orbital period and the low ratio between the two main components make this an unusual Algol-type system.
Seven star systems have been found to have planets. Nu2 Canis Majoris is an ageing orange giant of spectral type K1III of apparent magnitude 3.91 located around 64 light-years distant. Around 1.5 times as massive and 11 times as luminous as the Sun, it is orbited over a period of 763 days by a planet 2.6 times as massive as Jupiter. HD 47536 is likewise an ageing orange giant found to have a planetary system—echoing the fate of the Solar System in a few billion years as the Sun ages and becomes a giant. Conversely, HD 45364 is a star 107 light-years distant that is a little smaller and cooler than the Sun, of spectral type G8V, which has two planets discovered in 2008. With orbital periods of 228 and 342 days, the planets have a 3:2 orbital resonance, which helps stabilise the system. HD 47186 is another sunlike star with two planets; the inner—HD 47186 b—takes four days to complete an orbit and has been classified as a Hot Neptune, while the outer—HD 47186 c—has an eccentric 3.7-year period orbit and has a similar mass to Saturn. HD 43197 is a sunlike star around 183 light-years distant that has two planets: a hot Jupiter-size planet with an eccentric orbit. The other planet, HD 43197 c, is another massive Jovian planet with a slightly oblong orbit outside of its habitable zone.
Z Canis Majoris is a star system a mere 300,000 years old composed of two pre-main-sequence stars—a FU Orionis star and a Herbig Ae/Be star, which has brightened episodically by two magnitudes to magnitude 8 in 1987, 2000, 2004 and 2008. The more massive Herbig Ae/Be star is enveloped in an irregular roughly spherical cocoon of dust that has an inner diameter of and outer diameter of . The cocoon has a hole in it through which light shines that covers an angle of 5 to 10 degrees of its circumference. Both stars are surrounded by a large envelope of in-falling material left over from the original cloud that formed the system. Both stars are emitting jets of material, that of the Herbig Ae/Be star being much larger—11.7 light-years long. Meanwhile, FS Canis Majoris is another star with infra-red emissions indicating a compact shell of dust, but it appears to be a main-sequence star that has absorbed material from a companion. These stars are thought to be significant contributors to interstellar dust.
=== Deep-sky objects ===
The band of the Milky Way goes through Canis Major, with only patchy obscurement by interstellar dust clouds. It is bright in the northeastern corner of the constellation, as well as in a triangular area between Adhara, Wezen and Aludra, with many stars visible in binoculars. Canis Major boasts several open clusters. The only Messier object is M41 (NGC 2287), an open cluster with a combined visual magnitude of 4.5, around 2300 light-years from Earth. Located 4 degrees south of Sirius, it contains contrasting blue, yellow and orange stars and covers an area the apparent size of the full moon—in reality around 25 light-years in diameter. Its most luminous stars have already evolved into giants. The brightest is a 6.3-magnitude star of spectral type K3. Located in the field is 12 Canis Majoris, though this star is only 670 light-years distant. NGC 2360, known as Caroline's Cluster after its discoverer Caroline Herschel, is an open cluster located 3.5 degrees west of Muliphein and has a combined apparent magnitude of 7.2. Around 15 light-years in diameter, it is located 3700 light-years away from Earth, and has been dated to around 2.2 billion years old. NGC 2362 is a small, compact open cluster, 5200 light-years from Earth. It contains about 60 stars, of which Tau Canis Majoris is the brightest member. Located around 3 degrees northeast of Wezen, it covers an area around 12 light-years in diameter, though the stars appear huddled around Tau when seen through binoculars. It is a very young open cluster as its member stars are only a few million years old. Lying 2 degrees southwest of NGC 2362 is NGC 2354 a fainter open cluster of magnitude 6.5, with around 15 member stars visible with binoculars. NGC 2359 (Thor's Helmet or the Duck Nebula) is a relatively bright emission nebula in Canis Major, with an approximate magnitude of 10, which is 10,000 light-years from Earth. The nebula is shaped by HD 56925, an unstable Wolf–Rayet star embedded within it.
In 2003, an overdensity of stars in the region was announced to be the Canis Major Dwarf, the closest satellite galaxy to Earth. However, there remains debate over whether it represents a disrupted dwarf galaxy or in fact a variation in the thin and thick disk and spiral arm populations of the Milky Way. Investigation of the area yielded only ten RR Lyrae variables—consistent with the Milky Way's halo and thick disk populations rather than a separate dwarf spheroidal galaxy. On the other hand, a globular cluster in Puppis, NGC 2298—which appears to be part of the Canis Major dwarf system—is extremely metal-poor, suggesting it did not arise from the Milky Way's thick disk, and instead is of extragalactic origin.
NGC 2207 and IC 2163 are a pair of face-on interacting spiral galaxies located 125 million light-years from Earth. About 40 million years ago, the two galaxies had a close encounter and are now moving farther apart; nevertheless, the smaller IC 2163 will eventually be incorporated into NGC 2207. As the interaction continues, gas and dust will be perturbed, sparking extensive star formation in both galaxies. Supernovae have been observed in NGC 2207 in 1975 (type Ia SN 1975a), 1999 (the type Ib SN 1999ec), 2003 (type 1b supernova SN 2003H), and 2013 (type II supernova SN 2013ai). Located 16 million light-years distant,
|
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6,367 |
Canis Minor
|
{{Infobox constellation
| name = Canis Minor
| abbreviation = CMi
| genitive = Canis Minoris
| pronounce = , genitive
| symbolism = The Lesser Dog
| RA = to and Procyon would be the brightest star in Luyten's Star's sky. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep-sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower that can be seen in early December.
== History and mythology ==
Though strongly associated with the Classical Greek uranographic tradition, Canis Minor originates from ancient Mesopotamia. Procyon and Gomeisa were called MASH.TAB.BA or "twins" in the Three Stars Each tablets, dating to around 1100 BC. In the later MUL.APIN, this name was also applied to the pairs of Pi3 and Pi4 Orionis and Zeta and Xi Orionis. The meaning of MASH.TAB.BA evolved as well, becoming the twin deities Lulal and Latarak, who are on the opposite side of the sky from Papsukkal, the True Shepherd of Heaven in Babylonian mythology. Canis Minor was also given the name DAR.LUGAL, its position defined as "the star which stands behind it [Orion]", in the MUL.APIN; the constellation represents a rooster. This name may have also referred to the constellation Lepus. DAR.LUGAL was also denoted DAR.MUŠEN and DAR.LUGAL.MUŠEN in Babylonia. Canis Minor was then called tarlugallu in Akkadian astronomy.
Canis Minor was one of the original 48 constellations formulated by Ptolemy in his second-century Almagest, in which it was defined as a specific pattern (asterism) of stars; Ptolemy identified only two stars and hence no depiction was possible.
In Greek mythology, Canis Minor was sometimes connected with the Teumessian Fox, a beast turned into stone with its hunter, Laelaps, by Zeus, who placed them in heaven as Canis Major (Laelaps) and Canis Minor (Teumessian Fox). Eratosthenes accompanied the Little Dog with Orion, while Hyginus linked the constellation with Maera, a dog owned by Icarius of Athens. As a reward for his faithfulness, the dog was placed along the "banks" of the Milky Way, which the ancients believed to be a heavenly river, where he would never suffer from thirst.
The medieval Arabic astronomers maintained the depiction of Canis Minor (al-Kalb al-Asghar in Arabic) as a dog; in his Book of the Fixed Stars, Abd al-Rahman al-Sufi included a diagram of the constellation with a canine figure superimposed. There was one slight difference between the Ptolemaic vision of Canis Minor and the Arabic; al-Sufi claims Mirzam, now assigned to Orion, as part of both Canis Minor—the collar of the dog—and its modern home. The Arabic names for both Procyon and Gomeisa alluded to their proximity and resemblance to Sirius, though they were not direct translations of the Greek; Procyon was called ash-Shi'ra ash-Shamiya, the "Syrian Sirius" and Gomeisa was called ash-Shira al-Ghamisa, the Sirius with bleary eyes.
The ancient Egyptians thought of this constellation as Anubis, the jackal god.
Alternative names have been proposed: Johann Bayer in the early 17th century termed the constellation Fovea "The Pit", and Morus "Sycamine Tree". Seventeenth-century German poet and author Philippus Caesius linked it to the dog of Tobias from the Apocrypha. Occasionally, Canis Minor is confused with Canis Major and given the name Canis Orionis ("Orion's Dog").
=== In non-Western astronomy ===
In Chinese astronomy, the stars corresponding to Canis Minor lie in the Vermilion Bird of the South (南方朱雀, Nán Fāng Zhū Què). Procyon, Gomeisa and Eta Canis Minoris form an asterism known as Nánhé, the Southern River. With its counterpart, the Northern River Beihe (Castor and Pollux), Nánhé was also associated with a gate or sentry. Along with Zeta and 8 Cancri, 6 Canis Minoris and 11 Canis Minoris formed the asterism Shuiwei, which literally means "water level". Combined with additional stars in Gemini, Shuiwei represented an official who managed floodwaters or a marker of the water level.
Polynesian peoples often did not recognize Canis Minor as a constellation, but they saw Procyon as significant and often named it; in the Tuamotu Archipelago it was known as Hiro, meaning "twist as a thread of coconut fiber", and Kopu-nui-o-Hiro ("great paunch of Hiro"), which was either a name for the modern figure of Canis Minor or an alternative name for Procyon. Other names included Vena (after a goddess), on Mangaia and Puanga-hori (false Puanga, the name for Rigel), in New Zealand. In the Society Islands, Procyon was called Ana-tahua-vahine-o-toa-te-manava, literally "Aster the priestess of brave heart", figuratively the "pillar for elocution". The Wardaman people of the Northern Territory in Australia gave Procyon and Gomeisa the names Magum and Gurumana, describing them as humans who were transformed into gum trees in the Dreaming. Although their skin had turned to bark, they were able to speak with a human voice by rustling their leaves.
The Aztec calendar was related to their cosmology. The stars of Canis Minor were incorporated along with some stars of Orion and Gemini into an asterism associated with the day called "Water".
== Characteristics ==
Lying directly south of Gemini's bright stars Castor and Pollux, Canis Minor is a small constellation bordered by Monoceros to the south, Gemini to the north, Cancer to the northeast, and Hydra to the east. It does not border Canis Major; Monoceros is in between the two. Covering 183 square degrees, Canis Minor ranks seventy-first of the 88 constellations in size. It appears prominently in the southern sky during the Northern Hemisphere's winter. The constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 14 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between and . Most visible in the evening sky from January to March, Canis Minor is most prominent at 10 p.m. during mid-February. It is then seen earlier in the evening until July, when it is only visible after sunset before setting itself, and rising in the morning sky before dawn. The constellation's three-letter abbreviation, as adopted by the International Astronomical Union in 1922, is "CMi".
== Features ==
=== Stars ===
Canis Minor contains only two stars brighter than fourth magnitude. At magnitude 0.34, Procyon, or Alpha Canis Minoris, is the eighth-brightest star in the night sky, as well as one of the closest. Its name means "before the dog" or "preceding the dog" in Greek, as it rises an hour before the "Dog Star", Sirius, of Canis Major. It is a binary star system, consisting of a yellow-white main-sequence star of spectral type F5 IV-V, named Procyon A, and a faint white dwarf companion of spectral type DA, named Procyon B. Procyon B, which orbits the more massive star every 41 years, is of magnitude 10.7. The system is from Earth, the shortest distance to a northern-hemisphere star of the first magnitude. Gomeisa, or Beta Canis Minoris, with a magnitude of 2.89, is the second-brightest star in Canis Minor. Lying from the Solar System, it is a blue-white main-sequence star of spectral class B8 Ve. Although fainter to Earth observers, it is much brighter than Procyon, and is 250 times as luminous and three times as massive as the Sun. Although its variations are slight, Gomeisa is classified as a shell star (Gamma Cassiopeiae variable), with a maximum magnitude of 2.84 and a minimum magnitude of 2.92. Its colour is obvious when seen through binoculars. It is a multiple system, consisting of the spectroscopic binary Gamma A and three optical companions, Gamma B, magnitude 13; Gamma C, magnitude 12; and Gamma D, magnitude 10. The two components of Gamma A orbit each other every 389.2 days, with an eccentric orbit that takes their separation between 2.3 and 1.4 astronomical units (AU). Epsilon Canis Minoris is a yellow bright giant of spectral class G6.5IIb of magnitude of 4.99. It lies from Earth, with 13 times the diameter and 750 times the luminosity of the Sun. Eta Canis Minoris is a giant of spectral class F0III of magnitude 5.24, which has a yellowish hue when viewed through binoculars as well as a faint companion of magnitude 11.1. Located 4 arcseconds from the primary, the companion star is actually around 440 AU from the main star and takes around 5,000 years to orbit it.
Near Procyon, three stars share the name Delta Canis Minoris. Delta1 is a yellow-white F-type giant of magnitude 5.25 located around from Earth. About 360 times as luminous and 3.75 times as massive as the Sun, it is expanding and cooling as it ages, having spent much of its life as a main sequence star of spectrum B6V. The last of the trio, Delta3 (also known as 9 Canis Minoris), is a white main sequence star of spectral type A0Vnn and magnitude 5.83 which is distant. These stars mark the paws of the Lesser Dog's left hind leg, while magnitude 5.13 Zeta marks the right.
Lying 222 ± 7 light-years away with an apparent magnitude of 4.39, HD 66141 is 6.8 billion years old and has evolved into an orange giant of spectral type K2III with a diameter around 22 times that of the Sun, and weighing 1.1 solar masses. It is 174 times as luminous as the Sun, with an absolute magnitude of −0.15. HD 66141 was mistakenly named 13 Puppis, as its celestial coordinates were recorded incorrectly when catalogued and hence mistakenly thought to be in the constellation of Puppis; Bode gave it the name Lambda Canis Minoris, which is now obsolete. The orange giant is orbited by a planet, HD 66141b, which was detected in 2012 by measuring the star's radial velocity. The planet has a mass around 6 times that of Jupiter and a period of 480 days. It is a semiregular variable star that varies between a maximum magnitude of 6.14 and minimum magnitude of 6.42. Periods of 27.7, 143.3 and 208.3 days have been recorded in its pulsations. AZ is of spectral type A5IV, and ranges between magnitudes 6.44 and 6.51 over a period of 2.3 hours. AD has a spectral type of F2III, and has a maximum magnitude of 9.21 and minimum of 9.51, with a period of approximately 2.95 hours. BI is of spectral type F2 with an apparent magnitude varying around 9.19 and a period of approximately 2.91 hours.
At least three red giants are Mira variables in Canis Minor. S Canis Minoris, of spectral type M7e, is the brightest, ranging from magnitude 6.6 to 13.2 over a period of 332.94 days. V Canis Minoris ranges from magnitude 7.4 to 15.1 over a period of 366.1 days. Similar in magnitude is R Canis Minoris, which has a maximum of 7.3, but a significantly brighter minimum of 11.6. An S-type star, it has a period of 337.8 days.
YZ Canis Minoris is a red dwarf of spectral type M4.5V and magnitude 11.2, roughly three times the size of Jupiter and from Earth. It is a flare star, emitting unpredictable outbursts of energy for mere minutes, which might be much more powerful analogues of solar flares. Luyten's Star (GJ 273) is a red dwarf star of spectral type M3.5V and close neighbour of the Solar System. Its visual magnitude of 9.9 renders it too faint to be seen with the naked eye, even though it is only away. Fainter still is PSS 544-7, an eighteenth-magnitude red dwarf around 20 per cent the mass of the Sun, located from Earth. First noticed in 1991, it is thought to be a cannonball star, shot out of a star cluster and now moving rapidly through space directly away from the galactic disc.
The WZ Sagittae-type dwarf nova DY Canis Minoris (also known as VSX J074727.6+065050) flared up to magnitude 11.4 over January and February 2008 before dropping eight magnitudes to around 19.5 over approximately 80 days. It is a remote binary star system where a white dwarf and low-mass star orbit each other close enough for the former star to draw material off the latter and form an accretion disc. This material builds up until it erupts dramatically.
=== Deep-sky objects ===
The Milky Way passes through much of Canis Minor, yet it has few deep-sky objects. William Herschel recorded four objects in his 1786 work Catalogue of Nebulae and Clusters of Stars, including two he mistakenly believed were star clusters. NGC 2459 is a group of five thirteenth- and fourteenth-magnitude stars that appear to lie close together in the sky but are not related. A similar situation has occurred with NGC 2394, also in Canis Minor. This is a collection of fifteen unrelated stars of ninth magnitude and fainter. Named as a single object by Herschel, NGC 2402 is actually a pair of near-adjacent galaxies that appear to be interacting with each other. Only of fourteenth and fifteenth magnitudes, respectively, the elliptical and spiral galaxy are thought to be approximately 245 million light-years distant, and each measure 55,000 light-years in diameter.
===Meteor showers===
The 11 Canis-Minorids, also called the Beta Canis Minorids, are a meteor shower that arise near the fifth-magnitude star 11 Canis Minoris and were discovered in 1964 by Keith Hindley, who investigated their trajectory and proposed a common origin with the comet D/1917 F1 Mellish. However, this conclusion has been refuted subsequently as the number of orbits analysed was low and their trajectories too disparate to confirm a link. They last from 4 to 15 December, peaking over 10 and 11 December.
|
[
"De astronomia",
"Johann Bayer",
"Orion (constellation)",
"red giant",
"Gomeisa",
"Ptolemy",
"Anubis",
"Luminosity",
"Mangaia",
"Pi3 Orionis",
"absolute magnitude",
"VSX J074727.6+065050",
"NGC 2394",
"Cancer (constellation)",
"galactic disc",
"giant star",
"bright giant",
"Northern Hemisphere",
"BC Canis Minoris",
"Richard A. Proctor",
"Icarius of Athens",
"Wardaman people",
"Catalogue of Nebulae and Clusters of Stars",
"Lulal",
"Teumessian fox",
"Delta Canis Minoris",
"white dwarf",
"Pollux (star)",
"Lepus (constellation)",
"Eugène Delporte",
"William Herschel",
"Delta1 Canis Minoris",
"spectral class",
"Northern Territory",
"8 Cancri",
"north pole",
"apparent magnitude",
"Vermilion Bird of the South",
"Virgo (constellation)",
"Aztec calendar",
"Jupiter",
"Popular Astronomy (US magazine)",
"constellation",
"Maera (hound)",
"deep-sky object",
"Sycamine",
"Canis Major",
"Babylonian mythology",
"arcsecond",
"Tunisia",
"HD 66141b",
"YZ Canis Minoris",
"Sun's mass",
"solar flare",
"stellar classification",
"Chinese astronomy",
"Boötes",
"Classical Greece",
"Philipp von Zesen",
"spectral type",
"orbital period",
"Mesopotamia",
"Delta2 Canis Minoris",
"Monoceros",
"accretion disc",
"Binary star",
"spectroscopic binary",
"Merazig",
"Stellar evolution",
"John Flamsteed",
"New Zealand",
"gum trees",
"6 Canis Minoris",
"Abd al-Rahman al-Sufi",
"MUL.APIN",
"Celestial sphere",
"R Canis Minoris",
"Lists of constellations",
"Ancient Greek",
"celestial charts",
"Virginia",
"Akkadian astronomy",
"right ascension",
"astronomical unit",
"Delta Scuti variable",
"shell star",
"Gemini (constellation)",
"Castor (star)",
"equatorial coordinate system",
"S Canis Minoris",
"Latarak",
"Erigone (daughter of Icarius)",
"Solar System",
"Centre de Données astronomiques de Strasbourg",
"trajectory",
"semiregular variable star",
"Zeus",
"11 Canis Minoris",
"F-type main-sequence star",
"dwarf nova",
"S-type star",
"Monthly Notices of the Royal Astronomical Society",
"the Dreaming",
"AD Canis Minoris",
"Mirzam",
"Puppis",
"Mira variable",
"Tuamotu Archipelago",
"Almagest",
"List of brightest stars",
"Urania's Mirror",
"NGC 2508",
"Pi4 Orionis",
"Rigel",
"Zeta Cancri",
"radial velocity",
"Epsilon Canis Minoris",
"Book of the Fixed Stars",
"Hydra (constellation)",
"flare star",
"Laelaps (mythology)",
"Atelier Typographique",
"Three Stars Each",
"stellar evolution",
"Zeta Geminorum",
"red dwarf",
"Eta Canis Minoris",
"NGC 2459",
"binary star",
"AZ Canis Minoris",
"Aztec astronomy",
"List of nearest stars",
"DY Canis Minoris",
"Arabic",
"NGC 2402",
"Latin",
"standard candles",
"astronomy in medieval Islam",
"white main sequence star",
"rooster",
"BI Canis Minoris",
"WZ Sagittae",
"B-type main-sequence star",
"HD 66141",
"Uranometria",
"main-sequence",
"Sirius",
"V Canis Minoris",
"Society Islands",
"Extrasolar Planets Encyclopaedia",
"lenticular galaxy",
"Canis-Minorids",
"goddess",
"Biblical apocrypha",
"PSS 544-7",
"Eratosthenes",
"Procyon",
"Papsukkal",
"astroseismology",
"75th parallel south",
"Luyten's Star",
"SIMBAD",
"meteor shower",
"declination",
"D/1917 F1",
"Milky Way",
"Polynesian people",
"Greek mythology",
"Earth",
"Gamma Canis Minoris",
"Asterism (astronomy)",
"celestial cartography",
"Zeta Canis Minoris",
"Delta3 Canis Minoris",
"International Astronomical Union",
"Xi Orionis"
] |
6,371 |
Centaurus
|
{{Infobox constellation
| name = Centaurus
| abbreviation = Cen
| genitive = Centauri
| pronounce = , genitive
| symbolism = the Centaur
| RA = –
| dec= –
PDS 70, (V1032 Centauri) a low mass T Tauri star is found in the constellation Centaurus. In July 2018 astronomers captured the first conclusive image of a protoplanetary disk containing a nascent exoplanet, named PDS 70b.
===Deep-sky objects===
ω Centauri (NGC 5139), despite being listed as the constellation's "omega" star, is in fact a naked-eye globular cluster, 17,000 light-years away with a diameter of 150 light-years. It is the largest and brightest globular cluster in the Milky Way; at ten times the size of the next-largest cluster,
One of the closest galaxy clusters to Earth is the Centaurus Cluster at 160 million light-years away, having redshift 0.0114. It has a cooler, denser central region of gas and a hotter, more diffuse outer region. The intracluster medium in the Centaurus Cluster has a high concentration of metals (elements heavier than helium) due to a large number of supernovae. This cluster also possesses a plume of gas whose origin is unknown.
The Greeks depicted the constellation as a centaur and gave it its current name. It was mentioned by Eudoxus in the 4th century BC and Aratus in the 3rd century BC. In the 2nd century AD, Claudius Ptolemy catalogued 37 stars in Centaurus, including Alpha Centauri. Large as it is now, in earlier times it was even larger, as the constellation Lupus was treated as an asterism within Centaurus, portrayed in illustrations as an unspecified animal either in the centaur's grasp or impaled on its spear. The Southern Cross, which is now regarded as a separate constellation, was treated by the ancients as a mere asterism formed of the stars composing the centaur's legs. Additionally, what is now the minor constellation Circinus was treated as undefined stars under the centaur's front hooves.
According to the Roman poet Ovid (Fasti v.379), the constellation honors the centaur Chiron, who was tutor to many of the earlier Greek heroes including Heracles (Hercules), Theseus, and Jason, the leader of the Argonauts. It is not to be confused with the more warlike centaur represented by the zodiacal constellation Sagittarius. The legend associated with Chiron says that he was accidentally poisoned with an arrow shot by Hercules, and was subsequently placed in the heavens.
==Equivalents==
In Chinese astronomy, the stars of Centaurus are found in three areas: the Azure Dragon of the East (東方青龍, Dōng Fāng Qīng Lóng), the Vermillion Bird of the South (南方朱雀, Nán Fāng Zhū Què), and the Southern Asterisms (近南極星區, Jìnnánjíxīngōu). Not all of the stars of Centaurus can be seen from China, and the unseen stars were classified among the Southern Asterisms by Xu Guangqi, based on his study of western star charts. However, most of the brightest stars of Centaurus, including α Centauri, θ Centauri (or Menkent), ε Centauri and η Centauri, can be seen in the Chinese sky.
Some Polynesian peoples considered the stars of Centaurus to be a constellation as well. On Pukapuka, Centaurus had two names: Na Mata-o-te-tokolua and Na Lua-mata-o-Wua-ma-Velo. In Tonga, the constellation was called by four names: O-nga-tangata, Tautanga-ufi, Mamangi-Halahu, and Mau-kuo-mau. Alpha and Beta Centauri were not named specifically by the people of Pukapuka or Tonga, but they were named by the people of Hawaii and the Tuamotus. In Hawaii, the name for Alpha Centauri was either Melemele or Ka Maile-hope and the name for Beta Centauri was either Polapola or Ka Maile-mua. In the Tuamotu islands, Alpha was called Na Kuhi and Beta was called Tere.
The Pointer (α Centauri and β Centauri) is one of the asterisms used by Bugis sailors for navigation, called bintoéng balué, meaning "the widowed-before-marriage". It is also called bintoéng sallatang meaning "southern star".
== Namesakes ==
Two United States Navy ships, and , were named after Centaurus, the constellation.
|
[
"Circinus (constellation)",
"carbon",
"active galaxy",
"Flamsteed number",
"red giant",
"Ptolemy",
"intracluster medium",
"dust lane",
"25th parallel north",
"NGC 5102",
"galaxy cluster",
"Gamma Centauri",
"United States Navy",
"list of brightest stars",
"white dwarf",
"Alpha Centauri",
"solar luminosity",
"Uranus",
"Antlia",
"dark matter halo",
"Eta Centauri",
"NGC 5253",
"European Southern Observatory",
"V766 Centauri",
"galaxy merger",
"apparent magnitude",
"3 Centauri",
"Yale University Press",
"Aratus",
"constellation",
"Alpha Centaurids",
"Hawaii",
"Libra (constellation)",
"Theseus",
"Eudoxus of Cnidus",
"dwarf galaxy",
"Chinese astronomy",
"Musca",
"Jason",
"semiregular variable",
"triple star system",
"Beta Centauri",
"Yellow dwarf star",
"protoplanetary disk",
"supernova",
"47 Tucanae",
"Chiron",
"R Centauri",
"southern sky",
"elliptical galaxy",
"Tuamotus",
"galaxy collision",
"Celestial sphere",
"Azure Dragon",
"Edmond Halley",
"Chinese constellations",
"Galactic Center",
"B-type star",
"Centaurus Cluster",
"EurekAlert!",
"Omega Centauri",
"ESO 270-17",
"Solar System",
"Theta Centauri",
"Stellar designations and names",
"Lupus (constellation)",
"90th parallel south",
"IAU designated constellations",
"binoculars",
"NGC 3766",
"proper motion",
"polar-ring galaxy",
"Carina (constellation)",
"globular cluster",
"NGC 3918",
"Claudius Ptolemy",
"Crux",
"Tonga",
"galactic merger",
"Mira variable",
"Circinus",
"redshift",
"Epsilon Centauri",
"Centaurus (Chinese astronomy)",
"List of brightest stars",
"dark matter",
"Iota Centauri",
"Lucy in the Sky with Diamonds",
"luminosity",
"Messier 83",
"spiral arm",
"PDS 70b",
"diamond",
"exoplanet",
"NGC 4650A",
"Hydra (constellation)",
"John Herschel",
"flare star",
"Bugis",
"centaur",
"red dwarf",
"Proxima Centauri",
"binary star",
"variable stars",
"Heracles",
"optical spectrum",
"light-year",
"Prometheus Books",
"spiral galaxy",
"Sagittarius (constellation)",
"Ovid",
"NGC 4622",
"Omicron Centaurids",
"Centaurus A",
"Centaur",
"synchrotron radiation",
"Vela (constellation)",
"zodiac",
"88 modern constellations by area",
"Xu Guangqi",
"James Dunlop",
"Pukapuka",
"irregular galaxy",
"star hopping",
"Milky Way",
"NGC 5460",
"declination",
"Greek mythology",
"Vermilion Bird (Chinese constellation)",
"V810 Centauri",
"Polynesian people",
"Asterism (astronomy)",
"Mashhad",
"Hercules Family",
"radio wave",
"Bayer letter",
"Precession (astronomy)",
"PDS 70",
"supermassive black hole",
"Theta Centaurids",
"planetary nebula",
"BPM 37093"
] |
6,372 |
Wikipedia:Historical archive/Complete list of encyclopedia topics
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This page has been rendered obsolete (indeed, harmful) by updates to Wikipedia software and the growth of Wikipedia in general.
To get a list of all pages that are currently in Wikipedia, see special:Allpages.
To get a list of pages that don't exist but which are in demand, see special:Wantedpages.
See also the most basic encyclopedia article topics or Wikipedia:List_of_encyclopedia_topics for an alternative method of finding subject areas to work on.
----
Please do not delete this page, under any circumstances - it, along with associated talk and subpages (and, more critically, their histories), contain important documentation of the early days of Wikipedia - documentation which will (someday) be very important to historians. See the talk page for more.
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[
"the most basic encyclopedia article topics",
"Wikipedia talk:Complete list of encyclopedia topics (obsolete)"
] |
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Wikipedia:Historical archive/Complete list of encyclopedia topics/6
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Wikipedia:Historical archive/Complete list of encyclopedia topics/Z
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Wikipedia:Historical archive/Complete list of encyclopedia topics/Y
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6,407 |
Wikipedia:Historical archive/Complete list of encyclopedia topics/A
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6,410 |
Wikipedia:Historical archive/Complete list of encyclopedia topics/0
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6,411 |
Wikipedia:Historical archive/Complete list of encyclopedia topics/S2
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Wikipedia:Historical archive/Complete list of encyclopedia topics/A2
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Wikipedia:Historical archive/Complete list of encyclopedia topics/B2
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6,415 |
Wikipedia:Historical archive/Complete list of encyclopedia topics/basic vocabulary
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6,416 |
Impact crater
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An impact crater is a depression in the surface of a solid astronomical body formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.
Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede, and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io, Titan, and Triton, visible impact craters are less common because they become eroded, buried, or transformed by tectonic and volcanic processes over time. Where such processes have destroyed most of the original crater topography, the terms impact structure or astrobleme are more commonly used. In early literature, before the significance of impact cratering was widely recognised, the terms cryptoexplosion or cryptovolcanic structure were often used to describe what are now recognised as impact-related features on Earth.
The cratering records of very old surfaces, such as Mercury, the Moon, and the southern highlands of Mars, record a period of intense early bombardment in the inner Solar System around 3.9 billion years ago. The rate of crater production on Earth has since been considerably lower, but it is appreciable nonetheless. Earth experiences, on average, from one to three impacts large enough to produce a crater every million years. This indicates that there should be far more relatively young craters on the planet than have been discovered so far. The cratering rate in the inner solar system fluctuates as a consequence of collisions in the asteroid belt that create a family of fragments that are often sent cascading into the inner solar system. Formed in a collision 80 million years ago, the Baptistina family of asteroids is thought to have caused a large spike in the impact rate. The rate of impact cratering in the outer Solar System could be different from the inner Solar System.
Although Earth's active surface processes quickly destroy the impact record, about 190 terrestrial impact craters have been identified. These range in diameter from a few tens of meters up to about , and they range in age from recent times (e.g. the Sikhote-Alin craters in Russia whose creation was witnessed in 1947) to more than two billion years, though most are less than 500 million years old because geological processes tend to obliterate older craters. They are also selectively found in the stable interior regions of continents. Few undersea craters have been discovered because of the difficulty of surveying the sea floor, the rapid rate of change of the ocean bottom, and the subduction of the ocean floor into Earth's interior by processes of plate tectonics.
==History==
Daniel M. Barringer, a mining engineer, was convinced already in 1903 that the crater he owned, Meteor Crater, was of cosmic origin. Most geologists at the time assumed it formed as the result of a volcanic steam eruption.
Grove Karl Gilbert suggested in 1893 that the Moon's craters were formed by large asteroid impacts. Ralph Baldwin in 1949 wrote that the Moon's craters were mostly of impact origin. Around 1960, Gene Shoemaker revived the idea. According to David H. Levy, Shoemaker "saw the craters on the Moon as logical impact sites that were formed not gradually, in eons, but explosively, in seconds." For his PhD degree at Princeton University (1960), under the guidance of Harry Hammond Hess, Shoemaker studied the impact dynamics of Meteor Crater. Shoemaker noted that Meteor Crater had the same form and structure as two explosion craters created from atomic bomb tests at the Nevada Test Site, notably Jangle U in 1951 and Teapot Ess in 1955. In 1960, Edward C. T. Chao and Shoemaker identified coesite (a form of silicon dioxide) at Meteor Crater, proving the crater was formed from an impact generating extremely high temperatures and pressures. They followed this discovery with the identification of coesite within suevite at Nördlinger Ries, proving its impact origin.
Armed with the knowledge of shock-metamorphic features, Carlyle S. Beals and colleagues at the Dominion Astrophysical Observatory in Victoria, British Columbia, Canada and Wolf von Engelhardt of the University of Tübingen in Germany began a methodical search for impact craters. By 1970, they had tentatively identified more than 50. Although their work was controversial, the American Apollo Moon landings, which were in progress at the time, provided supportive evidence by recognizing the rate of impact cratering on the Moon. Because the processes of erosion on the Moon are minimal, craters persist. Since the Earth could be expected to have roughly the same cratering rate as the Moon, it became clear that the Earth had suffered far more impacts than could be seen by counting evident craters.
==Crater formation==
Impact cratering involves high velocity collisions between solid objects, typically much greater than the speed of sound in those objects. Such hyper-velocity impacts produce physical effects such as melting and vaporization that do not occur in familiar sub-sonic collisions. On Earth, ignoring the slowing effects of travel through the atmosphere, the lowest impact velocity with an object from space is equal to the gravitational escape velocity of about 11 km/s. The fastest impacts occur at about 72 km/s
However, the slowing effects of travel through the atmosphere rapidly decelerate any potential impactor, especially in the lowest 12 kilometres where 90% of the Earth's atmospheric mass lies. Meteors of up to 7,000 kg lose all their cosmic velocity due to atmospheric drag at a certain altitude (retardation point), and start to accelerate again due to Earth's gravity until the body reaches its terminal velocity of 0.09 to 0.16 km/s.
Impacts at these high speeds produce shock waves in solid materials, and both impactor and the material impacted are rapidly compressed to high density. Following initial compression, the high-density, over-compressed region rapidly depressurizes, exploding violently, to set in train the sequence of events that produces the impact crater. Impact-crater formation is therefore more closely analogous to cratering by high explosives than by mechanical displacement. Indeed, the energy density of some material involved in the formation of impact craters is many times higher than that generated by high explosives. Since craters are caused by explosions, they are nearly always circular – only very low-angle impacts cause significantly elliptical craters.
This describes impacts on solid surfaces. Impacts on porous surfaces, such as that of Hyperion, may produce internal compression without ejecta, punching a hole in the surface without filling in nearby craters. This may explain the 'sponge-like' appearance of that moon.
It is convenient to divide the impact process conceptually into three distinct stages: (1) initial contact and compression, (2) excavation, (3) modification and collapse. In practice, there is overlap between the three processes with, for example, the excavation of the crater continuing in some regions while modification and collapse is already underway in others.
===Contact and compression===
In the absence of atmosphere, the impact process begins when the impactor first touches the target surface. This contact accelerates the target and decelerates the impactor. Because the impactor is moving so rapidly, the rear of the object moves a significant distance during the short-but-finite time taken for the deceleration to propagate across the impactor. As a result, the impactor is compressed, its density rises, and the pressure within it increases dramatically. Peak pressures in large impacts exceed 1 T Pa to reach values more usually found deep in the interiors of planets, or generated artificially in nuclear explosions.
In physical terms, a shock wave originates from the point of contact. As this shock wave expands, it decelerates and compresses the impactor, and it accelerates and compresses the target. Stress levels within the shock wave far exceed the strength of solid materials; consequently, both the impactor and the target close to the impact site are irreversibly damaged. Many crystalline minerals can be transformed into higher-density phases by shock waves; for example, the common mineral quartz can be transformed into the higher-pressure forms coesite and stishovite. Many other shock-related changes take place within both impactor and target as the shock wave passes through, and some of these changes can be used as diagnostic tools to determine whether particular geological features were produced by impact cratering.
==Identifying impact craters==
Non-explosive volcanic craters can usually be distinguished from impact craters by their irregular shape and the association of volcanic flows and other volcanic materials. Impact craters produce melted rocks as well, but usually in smaller volumes with different characteristics.
Impacts produce distinctive shock-metamorphic effects that allow impact sites to be distinctively identified. Such shock-metamorphic effects can include:
A layer of shattered or "brecciated" rock under the floor of the crater. This layer is called a "breccia lens".
Shatter cones, which are chevron-shaped impressions in rocks. Such cones are formed most easily in fine-grained rocks.
High-temperature rock types, including laminated and welded blocks of sand, spherulites and tektites, or glassy spatters of molten rock. The impact origin of tektites has been questioned by some researchers; they have observed some volcanic features in tektites not found in impactites. Tektites are also drier (contain less water) than typical impactites. While rocks melted by the impact resemble volcanic rocks, they incorporate unmelted fragments of bedrock, form unusually large and unbroken fields, and have a much more mixed chemical composition than volcanic materials spewed up from within the Earth. They also may have relatively large amounts of trace elements that are associated with meteorites, such as nickel, platinum, iridium, and cobalt. Note: scientific literature has reported that some "shock" features, such as small shatter cones, which are often associated only with impact events, have been found also in terrestrial volcanic ejecta.
Microscopic pressure deformations of minerals. These include fracture patterns in crystals of quartz and feldspar, and formation of high-pressure materials such as diamond, derived from graphite and other carbon compounds, or stishovite and coesite, varieties of shocked quartz.
Buried craters, such as the Decorah crater, can be identified through drill coring, aerial electromagnetic resistivity imaging, and airborne gravity gradiometry.
== Economic importance ==
On Earth, impact craters have resulted in useful minerals. Some of the ores produced from impact related effects on Earth include ores of iron, uranium, gold, copper, and nickel. It is estimated that the value of materials mined from impact structures is five billion dollars/year just for North America. The eventual usefulness of impact craters depends on several factors, especially the nature of the materials that were impacted and when the materials were affected. In some cases, the deposits were already in place and the impact brought them to the surface. These are called "progenetic economic deposits." Others were created during the actual impact. The great energy involved caused melting. Useful minerals formed as a result of this energy are classified as "syngenetic deposits." The third type, called "epigenetic deposits," is caused by the creation of a basin from the impact. Many of the minerals that our modern lives depend on are associated with impacts in the past. The Vredeford Dome in the center of the Witwatersrand Basin is the largest goldfield in the world, which has supplied about 40% of all the gold ever mined in an impact structure (though the gold did not come from the bolide). The asteroid that struck the region was wide. The Sudbury Basin was caused by an impacting body over in diameter. This basin is famous for its deposits of nickel, copper, and platinum group elements. An impact was involved in making the Carswell structure in Saskatchewan, Canada; it contains uranium deposits.
Hydrocarbons are common around impact structures. Fifty percent of impact structures in North America in hydrocarbon-bearing sedimentary basins contain oil/gas fields. a website concerned with 190 () scientifically confirmed impact craters on Earth.
===Some extraterrestrial craters===
Caloris Basin (Mercury)
Hellas Basin (Mars)
Herschel crater (Mimas)
Mare Orientale (Moon)
Petrarch crater (Mercury)
South Pole – Aitken basin (Moon)
===Largest named craters in the Solar System===
North Polar Basin/Borealis Basin (disputed) – Mars – Diameter: 10,600 km
South Pole-Aitken basin – Moon – Diameter: 2,500 km
Hellas Basin – Mars – Diameter: 2,100 km
Caloris Basin – Mercury – Diameter: 1,550 km
Sputnik Planitia – Pluto – Diameter: 1,300 km
Imbrium Basin – Moon – Diameter: 1,100 km
Isidis Planitia – Mars – Diameter: 1,100 km
Mare Tranquilitatis – Moon – Diameter: 870 km
Argyre Planitia – Mars – Diameter: 800 km
Rembrandt – Mercury – Diameter: 715 km
Serenitatis Basin – Moon – Diameter: 700 km
Mare Nubium – Moon – Diameter: 700 km
Beethoven – Mercury – Diameter: 625 km
Valhalla – Callisto – Diameter: 600 km, with rings to 4,000 km diameter
Hertzsprung – Moon – Diameter: 590 km
Turgis – Iapetus – Diameter: 580 km
Apollo – Moon – Diameter: 540 km
Engelier – Iapetus – Diameter: 504 km
Mamaldi – Rhea – Diameter: 480 km
Huygens – Mars – Diameter: 470 km
Schiaparelli – Mars – Diameter: 470 km
Rheasilvia – 4 Vesta – Diameter: 460 km
Gerin – Iapetus – Diameter: 445 km
Odysseus – Tethys – Diameter: 445 km
Korolev – Moon – Diameter: 430 km
Falsaron – Iapetus – Diameter: 424 km
Dostoevskij – Mercury – Diameter: 400 km
Menrva – Titan – Diameter: 392 km
Tolstoj – Mercury – Diameter: 390 km
Goethe – Mercury – Diameter: 380 km
Malprimis – Iapetus – Diameter: 377 km
Tirawa – Rhea – Diameter: 360 km
Orientale Basin – Moon – Diameter: 350 km, with rings to 930 km diameter
Evander – Dione – Diameter: 350 km
Epigeus – Ganymede – Diameter: 343 km
Gertrude – Titania – Diameter: 326 km
Telemus – Tethys – Diameter: 320 km
Asgard – Callisto – Diameter: 300 km, with rings to 1,400 km diameter
Vredefort impact structure – Earth – Diameter: 300 km
Burney – Pluto – Diameter: 296 km
There are approximately twelve more impact craters/basins larger than 300 km on the Moon, five on Mercury, and four on Mars. Large basins, some unnamed but mostly smaller than 300 km, can also be found on Saturn's moons Dione, Rhea and Iapetus.
|
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6,417 |
Corvus (disambiguation)
|
Corvus is a genus of birds commonly known as crows and ravens.
Corvus may also refer to:
==Companies==
Corvus Energy, a Norwegian supplier originally founded in Canada
Corvus Hungary, an aircraft manufacturer
Corvus Systems, an American defunct computer hardware manufacturer
==Fictional characters==
Corvus, a main antagonist in movie Pompeii (film)
Corvus, a character in Satyajit Ray's Professor Shonku series
Corvus, a character in the video game Call of Duty: Black Ops III
Corvus, a character in the video game Dragon Quest IX: Sentinels of the Starry Skies
Corvus, a character in the video games Heretic and Heretic II
Corvus Glaive, a Marvel comics character
==Military==
ASM-N-8 Corvus, a United States Navy missile
Corvus (boarding device), used by ancient Roman warships
Corvus chaff launcher, a British shipborne chaff decoy system manufactured by Vickers
SS Corvus, the name of two steamships, both put out of service in 1945
USS Corvus, a U.S. Navy attack cargo ship of World War II
==People==
Joannes Corvus (fl. 1512 – 1544), Flemish portrait painter
Marcus Valerius Corvus (c. 370–270 BC), Roman military commander and politician
Corvulus of Friuli, an 8th century AD Lombardic duke (name is a Latin diminutive of Corvus)
==Publishing==
Corvus (imprint), an imprint of Atlantic Books
Corvus: A Life with Birds, a 2008 non-fiction book by Esther Woolfson
==Other uses==
Corvus (constellation), a small constellation in the Southern Celestial Hemisphere
Corvus in Chinese astronomy, the same constellation as considered in traditional Chinese uranography
Corvus (heraldry), crows and ravens in heraldry
Corvus, a ship in the 2017 video game Star Wars Battlefront II
Corvus Corax (band), a German band known for playing neo-Medieval music
Gibson Corvus, a guitar product line
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6,420 |
Corona Borealis
|
Corona Borealis is a small constellation in the Northern Celestial Hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Its brightest stars form a semicircular arc. Its Latin name, inspired by its shape, means "northern crown". In classical mythology Corona Borealis generally represented the crown given by the god Dionysus to the Cretan princess Ariadne and set by her in the heavens. Other cultures likened the pattern to a circle of elders, an eagle's nest, a bear's den or a smokehole. Ptolemy also listed a southern counterpart, Corona Australis, with a similar pattern.
The brightest star is the magnitude 2.2 Alpha Coronae Borealis. The yellow supergiant R Coronae Borealis is the prototype of a rare class of giant stars—the R Coronae Borealis variables—that are extremely hydrogen deficient, and thought to result from the merger of two white dwarfs. T Coronae Borealis, also known as the Blaze Star, is another unusual type of variable star known as a recurrent nova. Normally of magnitude 10, it last flared up to magnitude 2 in 1946, and is predicted to do the same in 2025. ADS 9731 and Sigma Coronae Borealis are multiple star systems with six and five components respectively. Five stars in the constellation host Jupiter-sized exoplanets. Abell 2065 is a highly concentrated galaxy cluster one billion light-years from the Solar System containing more than 400 members, and is itself part of the larger Corona Borealis Supercluster.
== Characteristics ==
Covering 179 square degrees and hence 0.433% of the sky, Corona Borealis ranks 73rd of the IAU designated constellations by area.{{efn|1=While parts of the constellation technically rise above the horizon to observers between the 50°S and 64°S, stars within a few degrees of the horizon are to all intents and purposes unobservable. The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of eight segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between 39.71° and 25.54°. It has a counterpart—Corona Australis—in the Southern Celestial Hemisphere.
== Features ==
=== Stars ===
The seven stars that make up the constellation's distinctive crown-shaped pattern are all 4th-magnitude stars except for the brightest of them, Alpha Coronae Borealis. The other six stars are Theta, Beta, Gamma, Delta, Epsilon and Iota Coronae Borealis. The German cartographer Johann Bayer gave twenty stars in Corona Borealis Bayer designations from Alpha to Upsilon in his 1603 star atlas Uranometria. Zeta Coronae Borealis was noted to be a double star by later astronomers and its components designated Zeta1 and Zeta2. John Flamsteed did likewise with Nu Coronae Borealis; classed by Bayer as a single star, it was noted to be two close stars by Flamsteed. He named them 20 and 21 Coronae Borealis in his catalogue, alongside the designations Nu1 and Nu2 respectively. Chinese astronomers deemed nine stars to make up the asterism, adding Pi and Rho Coronae Borealis. Within the constellation's borders, there are 37 stars brighter than or equal to apparent magnitude 6.5. In fact, it is an Algol-type eclipsing binary that varies by 0.1 magnitude with a period of 17.4 days. The primary is a white main-sequence star of spectral type A0V that is 2.91 times the mass of the Sun () and 57 times as luminous (), and is surrounded by a debris disk out to a radius of around 60 astronomical units (AU). The secondary companion is a yellow main-sequence star of spectral type G5V that is a little smaller (0.9 times) the diameter of the Sun. Lying 75±0.5 light-years from Earth, Alphecca is believed to be a member of the Ursa Major Moving Group of stars that have a common motion through space.
Located 112±3 light-years away, The brighter component is a rapidly oscillating Ap star, pulsating with a period of 16.2 minutes. Of spectral type A5V with a surface temperature of around 7980 K, it has around , 2.6 solar radii (), and . The smaller star is of spectral type F2V with a surface temperature of around 6750 K, and has around , , and between 4 and . Near Nusakan is Theta Coronae Borealis, a binary system that shines with a combined magnitude of 4.13 located 380±20 light-years distant.
Flanking Alpha to the east is Gamma Coronae Borealis, yet another binary star system, whose components orbit each other every 92.94 years and are roughly as far apart from each other as the Sun and Neptune. The brighter component has been classed as a Delta Scuti variable star, though this view is not universal. Located 170±2 light-years away, For most of its existence, Delta Coronae Borealis was a blue-white main-sequence star of spectral type B before it ran out of hydrogen fuel in its core. Its luminosity and spectrum suggest it has just crossed the Hertzsprung gap, having finished burning core hydrogen and just begun burning hydrogen in a shell that surrounds the core.
Zeta Coronae Borealis is a double star with two blue-white components 6.3 arcseconds apart that can be readily separated at 100x magnification. The primary is of magnitude 5.1 and the secondary is of magnitude 6.0. Nu Coronae Borealis is an optical double, whose components are a similar distance from Earth but have different radial velocities, hence are assumed to be unrelated. The primary, Nu1 Coronae Borealis, is a red giant of spectral type M2III and magnitude 5.2, lying 640±30 light-years distant, and the secondary, Nu2 Coronae Borealis, is an orange-hued giant star of spectral type K5III and magnitude 5.4, estimated to be 590±30 light-years away. Sigma Coronae Borealis, on the other hand, is a true multiple star system divisible by small amateur telescopes. It is actually a complex system composed of two stars around as massive as the Sun that orbit each other every 1.14 days, orbited by a third Sun-like star every 726 years. The fourth and fifth components are a binary red dwarf system that is 14,000 AU distant from the other three stars. ADS 9731 is an even rarer multiple system in the constellation, composed of six stars, two of which are spectroscopic binaries.{{efn|1=The components are organised thus: Aa and Ab are yellow-white main sequence stars of spectral types F4V and F5V and 1.35 and 1.32 solar masses respectively, which orbit each other every 3.27 days. This pair is in a 450-year orbit with star B, a star of spectral type G4V that has around the same mass as the Sun. Star C is a yellow white star of spectral type F3V around 1.41 times as massive as the Sun, which has just started brightening and moving off the main sequence. It is in a 1000-year orbit with a pair of stars, Da and Db, a yellow-white main sequence star of spectral type F7V and a red dwarf of spectral type M3V. Da and Db take 14.28 days to orbit each other. Finally the system of stars C and Dab, and the system of stars Aab and B, take more than 20,000 years to orbit each other. T Coronae Borealis is a cataclysmic variable star also known as the Blaze Star. Normally placid around magnitude 10—it has a minimum of 10.2 and maximum of 9.9—it brightens to magnitude 2 in a period of hours, caused by a nuclear chain reaction and the subsequent explosion. T Coronae Borealis is one of a handful of stars called recurrent novae, which include T Pyxidis and U Scorpii. An outburst of T Coronae Borealis was first recorded in 1866; its second recorded outburst was in February 1946. T Coronae Borealis started dimming in March 2023 and it is known that before it goes nova it dims for about a year; for this reason it was initially expected to go nova at any time between March and September, 2024. T Coronae Borealis is a binary star with a red-hued giant primary and a white dwarf secondary, the two stars orbiting each other over a period of approximately 8 months. R Coronae Borealis is a yellow-hued variable supergiant star, over 7000 light-years from Earth, and prototype of a class of stars known as R Coronae Borealis variables. Normally of magnitude 6, its brightness periodically drops as low as magnitude 15 and then slowly increases over the next several months. These declines in magnitude come about as dust that has been ejected from the star obscures it. Direct imaging with the Hubble Space Telescope shows extensive dust clouds out to a radius of around 2000 AU from the star, corresponding with a stream of fine dust (composed of grains 5 nm in diameter) associated with the star's stellar wind and coarser dust (composed of grains with a diameter of around 0.14 μm) ejected periodically.
There are several other variables of reasonable brightness for amateur astronomer to observe, including three Mira-type long period variables: Located around 1946 light-years distant, it shines with a luminosity 16,643 times that of the Sun and has a surface temperature of 3033 K. One of the reddest stars in the sky, it is located near the junction of the border of Corona Borealis with Hercules and Bootes. Another red giant, RR Coronae Borealis is a M3-type semiregular variable star that varies between magnitudes 7.3 and 8.2 over 60.8 days. RS Coronae Borealis is yet another semiregular variable red giant, which ranges between magnitudes 8.7 to 11.6 over 332 days. It is unusual in that it is a red star with a high proper motion (greater than 50 milliarcseconds a year). Meanwhile, U Coronae Borealis is an Algol-type eclipsing binary star system whose magnitude varies between 7.66 and 8.79 over a period of 3.45 days
TY Coronae Borealis is a pulsating white dwarf (of ZZ Ceti) type, which is around 70% as massive as the Sun, yet has only 1.1% of its diameter. Discovered in 1990, UW Coronae Borealis is a low-mass X-ray binary system composed of a star less massive than the Sun and a neutron star surrounded by an accretion disk that draws material from the companion star. It varies in brightness in an unusually complex manner: the two stars orbit each other every 111 minutes, yet there is another cycle of 112.6 minutes, which corresponds to the orbit of the disk around the degenerate star. The beat period of 5.5 days indicates the time the accretion disk—which is asymmetrical—takes to precess around the star.
=== Extrasolar planetary systems ===
Extrasolar planets have been confirmed in five star systems, four of which were found by the radial velocity method. The spectrum of Epsilon Coronae Borealis was analysed for seven years from 2005 to 2012, revealing a planet around 6.7 times as massive as Jupiter () orbiting every 418 days at an average distance of around 1.3 AU. Epsilon itself is a orange giant of spectral type K2III that has swollen to and . Kappa Coronae Borealis is a spectral type K1IV orange subgiant nearly twice as massive as the Sun; around it lies a dust debris disk, This planet's mass is estimated at . The dimensions of the debris disk indicate it is likely there is a second substellar companion. Omicron Coronae Borealis is a K-type clump giant with one confirmed planet with a mass of that orbits every 187 days—one of the two least massive planets known around clump giants. XO-1 is a magnitude 11 yellow main-sequence star located approximately light-years away, of spectral type G1V with a mass and radius similar to the Sun. In 2006 the hot Jupiter exoplanet XO-1b was discovered orbiting XO-1 by the transit method using the XO Telescope. Roughly the size of Jupiter, it completes an orbit around its star every three days.
The discovery of a Jupiter-sized planetary companion was announced in 1997 via analysis of the radial velocity of Rho Coronae Borealis, a yellow main sequence star and Solar analog of spectral type G0V, around 57 light-years distant from Earth. More accurate measurement of data from the Hipparcos satellite subsequently showed it instead to be a low-mass star somewhere between 100 and 200 times the mass of Jupiter. Possible stable planetary orbits in the habitable zone were calculated for the binary star Eta Coronae Borealis, which is composed of two stars—yellow main sequence stars of spectral type G1V and G3V respectively—similar in mass and spectrum to the Sun. No planet has been found, but a brown dwarf companion about 63 times as massive as Jupiter with a spectral type of L8 was discovered at a distance of 3640 AU from the pair in 2001.
=== Deep-sky objects ===
Corona Borealis contains few galaxies observable with amateur telescopes. NGC 6085 and 6086 are a faint spiral and elliptical galaxy respectively close enough to each other to be seen in the same visual field through a telescope. Abell 2142 is a huge (six million light-year diameter), X-ray luminous galaxy cluster that is the result of an ongoing merger between two galaxy clusters. It has a redshift of 0.0909 (meaning it is moving away from us at 27,250 km/s) and a visual magnitude of 16.0. It is about 1.2 billion light-years away. Another galaxy cluster in the constellation, RX J1532.9+3021, is approximately 3.9 billion light-years from Earth. At the cluster's center is a large elliptical galaxy containing one of the most massive and most powerful supermassive black holes yet discovered. Another galaxy cluster, Abell 2162, is a member of the Hercules Superclusters.
== Mythology ==
In Greek mythology, Corona Borealis was linked to the legend of Theseus and the minotaur. It was generally considered to represent a crown given by Dionysus to Ariadne, the daughter of Minos of Crete, after she had been abandoned by the Athenian prince Theseus. When she wore the crown at her marriage to Dionysus, he placed it in the heavens to commemorate their wedding. An alternative version has the besotted Dionysus give the crown to Ariadne, who in turn gives it to Theseus after he arrives in Crete to kill the minotaur that the Cretans have demanded tribute from Athens to feed. The hero uses the crown's light to escape the labyrinth after disposing of the creature, and Dionysus later sets it in the heavens. , attributed to Hyginus, linked it to a crown or wreath worn by Bacchus (Dionysus) to disguise his appearance when first approaching Mount Olympus and revealing himself to the gods, having been previously hidden as yet another child of Jupiter's trysts with a mortal, in this case Semele. Its proximity to the constellations Hercules (which reports was once attributed to Theseus, among others) and Lyra (Theseus' lyre in one account), could indicate that the three constellations were invented as a group. Corona Borealis was one of the 48 constellations mentioned in the Almagest of classical astronomer Ptolemy.
In Welsh mythology, it was called Caer Arianrhod, "the Castle of the Silver Circle", and was the heavenly abode of the Lady Arianrhod. To the ancient Balts, Corona Borealis was known as Darželis, the "flower garden".
The Arabs called the constellation Alphecca (a name later given to Alpha Coronae Borealis), which means "separated" or "broken up" ( '), a reference to the resemblance of the stars of Corona Borealis to a loose string of jewels. This was also interpreted as a broken dish. Among the Bedouins, the constellation was known as ' (), or "the dish/bowl of the poor people".
The Skidi people of Native Americans saw the stars of Corona Borealis representing a council of stars whose chief was Polaris. The constellation also symbolised the smokehole over a fireplace, which conveyed their messages to the gods, as well as how chiefs should come together to consider matters of importance. The Shawnee people saw the stars as the Heavenly Sisters, who descended from the sky every night to dance on earth. Alphecca signifies the youngest and most comely sister, who was seized by a hunter who transformed into a field mouse to get close to her. They married though she later returned to the sky, with her heartbroken husband and son following later.
Polynesian peoples often recognized Corona Borealis; the people of the Tuamotus named it Na Kaua-ki-tokerau and probably Te Hetu. The constellation was likely called Kaua-mea in Hawaii, Rangawhenua in New Zealand, and Te Wale-o-Awitu in the Cook Islands atoll of Pukapuka. Its name in Tonga was uncertain; it was either called Ao-o-Uvea or Kau-kupenga.
In Australian Aboriginal astronomy, the constellation is called womera ("the boomerang") due to the shape of the stars. The Wailwun people of northwestern New South Wales saw Corona Borealis as mullion wollai "eagle's nest", with Altair and Vega—each called mullion—the pair of eagles accompanying it. The Wardaman people of northern Australia held the constellation to be a gathering point for Men's Law, Women's Law and Law of both sexes come together and consider matters of existence.
=== Later references ===
Corona Borealis was renamed Corona Firmiana in honour of the Archbishop of Salzburg in the 1730 Atlas Mercurii Philosophicii Firmamentum Firminianum Descriptionem by Corbinianus Thomas, but this was not taken up by subsequent cartographers. The constellation was featured as a main plot ingredient in the short story "Hypnos" by H. P. Lovecraft, published in 1923; it is the object of fear of one of the protagonists in the short story. Finnish band Cadacross released an album titled Corona Borealis in 2002.
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6,421 |
Cygnus (constellation)
|
Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. It also has some notable X-ray sources and the giant stellar association of Cygnus OB2. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole.
Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, an area around Cygnus.
Most of the east has part of the Hercules–Corona Borealis Great Wall in the deep sky, a giant galaxy filament that is the largest known structure in the observable universe, covering most of the northern sky.
== History and mythology ==
=== In Eastern and World astronomy ===
In Polynesia, Cygnus was often recognized as a separate constellation. In Tonga it was called Tuula-lupe, and in the Tuamotus it was called Fanui-tai. In New Zealand it was called Mara-tea, in the Society Islands it was called Pirae-tea or Taurua-i-te-haapa-raa-manu, and in the Tuamotus it was called Fanui-raro. Beta Cygni was named in New Zealand; it was likely called Whetu-kaupo. Gamma Cygni was called Fanui-runga in the Tuamotus.
Deneb was also often a given name, in the Islamic world of astronomy. The name Deneb comes from the Arabic name dhaneb, meaning "tail", from the phrase Dhanab ad-Dajājah, which means "the tail of the hen".
=== In Western astronomy ===
In Greek mythology, Cygnus has been identified with several different legendary swans. Zeus disguised himself as a swan to seduce Leda, Spartan king Tyndareus's wife, who gave birth to the Gemini, Helen of Troy, and Clytemnestra; Orpheus was transformed into a swan after his murder, and was said to have been placed in the sky next to his lyre (Lyra); and a man named Cygnus (Greek for swan) was transformed into his namesake.
Later Romans also associated this constellation with the tragic story of Phaethon, the son of Helios the sun god, who demanded to ride his father's sun chariot for a day. Phaethon, however, was unable to control the reins, forcing Zeus to destroy the chariot (and Phaethon) with a thunderbolt, causing it to plummet to the earth into the river Eridanus. According to the myth, Phaethon's close friend or lover, Cygnus of Liguria, grieved bitterly and spent many days diving into the river to collect Phaethon's bones to give him a proper burial. The gods were so touched by Cygnus's devotion that they turned him into a swan and placed him among the stars.
In Ovid's Metamorphoses, there are three people named Cygnus, all of whom are transformed into swans. Alongside Cygnus, noted above, he mentions a boy from Aetolia who throws himself off a cliff when his companion Phyllius refuses to give him a tamed bull that he demands, but he is transformed into a swan and flies away. He also mentions a son of Poseidon, an invulnerable warrior in the Trojan War who is eventually killed by Achilles, but Poseidon saves him by transforming him into a swan.
Together with other avian constellations near the summer solstice, Vultur cadens and Aquila, Cygnus may be a significant part of the origin of the myth of the Stymphalian Birds, one of The Twelve Labours of Hercules.
== Characteristics ==
A very large constellation, Cygnus is bordered by Cepheus to the north and east, Draco to the north and west, Lyra to the west, Vulpecula to the south, Pegasus to the southeast and Lacerta to the east. The three-letter abbreviation for the constellation, as adopted by the IAU in 1922, is "Cyg". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined as a polygon of 28 segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between 27.73° and 61.36°. Covering 804 square degrees and around 1.9% of the night sky, Cygnus ranks 16th of the 88 constellations in size.
Cygnus culminates at midnight on 29 June, and is most visible in the evening from the early summer to mid-autumn in the Northern Hemisphere.
== Features ==
There is an abundance of deep-sky objects, with many open clusters, nebulae of various types and supernova remnants found in Cygnus due to its position on the Milky Way.
Its molecular clouds form the Cygnus Rift dark nebula constellation, comprising one end of the Great Rift along the Milky Way's galactic plane. The rift begins around the Northern Coalsack, and partially obscures the larger Cygnus molecular cloud complex behind it, which the North America Nebula is part of.
=== Stars ===
Bayer catalogued many stars in the constellation, giving them the Bayer designations from Alpha to Omega and then using lowercase Roman letters to g. John Flamsteed added the Roman letters h, i, k, l and m (these stars were considered informes by Bayer as they lay outside the asterism of Cygnus), but were dropped by Francis Baily.]]
There are several bright stars in Cygnus. α Cygni, called Deneb, is the brightest star in Cygnus. It is a white supergiant star of spectral type A2Iae that varies between magnitudes 1.21 and 1.29, one of the largest and most luminous A-class stars known. It is located about 2600 light-years away. Its traditional name means "tail" and refers to its position in the constellation. Albireo, designated β Cygni, is a celebrated binary star among amateur astronomers for its contrasting hues. The primary is an orange-hued giant star of magnitude 3.1 and the secondary is a blue-green hued star of magnitude 5.1. The system is 430 light-years away and is visible in large binoculars and all amateur telescopes. γ Cygni, traditionally named Sadr, is a yellow-tinged supergiant star of magnitude 2.2, 1800 light-years away. Its traditional name means "breast" and refers to its position in the constellation. δ Cygni (the proper name is Fawaris) is another bright binary star in Cygnus, 166 light-years with a period of 800 years. The primary is a blue-white hued giant star of magnitude 2.9, and the secondary is a star of magnitude 6.6. The two components are visible in a medium-sized amateur telescope. The fifth star in Cygnus above magnitude 3 is Aljanah,
There are several other dimmer double and binary stars in Cygnus. μ Cygni is a binary star with an optical tertiary component. The binary system has a period of 790 years and is 73 light-years from Earth. The primary and secondary, both white stars, are of magnitude 4.8 and 6.2, respectively. The unrelated tertiary component is of magnitude 6.9. Though the tertiary component is visible in binoculars, the primary and secondary currently require a medium-sized amateur telescope to split, as they will through the year 2020. The two stars will be closest between 2043 and 2050, when they will require a telescope with larger aperture to split. The stars 30 and 31 Cygni form a contrasting double star similar to the brighter Albireo. The two are visible in binoculars. The primary, 31 Cygni, is an orange-hued star of magnitude 3.8, 1400 light-years from Earth. The secondary, 30 Cygni, appears blue-green. It is of spectral type A5IIIn and magnitude 4.83, and is around 610 light-years from Earth. 31 Cygni itself is a binary star; the tertiary component is a blue star of magnitude 7.0. ψ Cygni is a binary star visible in small amateur telescopes, with two white components. The primary is of magnitude 5.0 and the secondary is of magnitude 7.5. 61 Cygni is a binary star visible in large binoculars or a small amateur telescope. It is 11.4 light-years from Earth and has a period of 750 years. Both components are orange-hued dwarf (main sequence) stars; the primary is of magnitude 5.2 and the secondary is of magnitude 6.1. 61 Cygni is significant because Friedrich Wilhelm Bessel determined its parallax in 1838, the first star to have a known parallax.
Located near η Cygni is the X-ray source Cygnus X-1, which is now thought to be caused by a black hole accreting matter in a binary star system. This was the first X-ray source widely believed to be a black hole. It is located approximately 2.2 kiloparsecs from the Sun. There is also supergiant variable star in the system which is known as HDE 226868.
Cygnus also contains several other noteworthy X-ray sources. Cygnus X-3 is a microquasar containing a Wolf–Rayet star in orbit around a very compact object, with a period of only 4.8 hours. The system is one of the most intrinsically luminous X-ray sources observed. The system undergoes periodic outbursts of unknown nature, and during one such outburst, the system was found to be emitting muons, likely caused by neutrinos. While the compact object is thought to be a neutron star or possibly a black hole, it is possible that the object is instead a more exotic stellar remnant, possibly the first discovered quark star, hypothesized due to its production of cosmic rays that cannot be explained if the object is a normal neutron star. The system also emits cosmic rays and gamma rays, and has helped shed insight on to the formation of such rays. Cygnus X-2 is another X-ray binary, containing an A-type giant in orbit around a neutron star with a 9.8-day period. The system is interesting due to the rather small mass of the companion star, as most millisecond pulsars have much more massive companions. Another black hole in Cygnus is V404 Cygni, which consists of a K-type star orbiting around a black hole of around 12 solar masses. The black hole, similar to that of Cygnus X-3, has been hypothesized to be a quark star. 4U 2129+ 47 is another X-ray binary containing a neutron star which undergoes outbursts, as is EXO 2030+ 375.
Cygnus is also home to several variable stars. SS Cygni is a dwarf nova which undergoes outbursts every 7–8 weeks. The system's total magnitude varies from 12th magnitude at its dimmest to 8th magnitude at its brightest. The two objects in the system are incredibly close together, with an orbital period of less than 0.28 days. χ Cygni is a red giant and the second-brightest Mira variable star at its maximum. It ranges between magnitudes 3.3 and 14.2, and spectral types S6,2e to S10,4e (MSe) over a period of 408 days; it has a diameter of 300 solar diameters and is 350 light-years from Earth. P Cygni is a luminous blue variable that brightened suddenly to 3rd magnitude in 1600 AD. Since 1715, the star has been of 5th magnitude, despite being more than 5000 light-years from Earth. The star's spectrum is unusual in that it contains very strong emission lines resulting from surrounding nebulosity. W Cygni is a semi-regular variable red giant star, 618 light-years from Earth.It has a maximum magnitude of 5.10 and a minimum magnitude 6.83; its period of 131 days. It is a red giant ranging between spectral types M4e-M6e(Tc:)III, NML Cygni is a red hypergiant semi-regular variable star located at 5,300 light-years away from Earth. It is one of largest stars currently known in the galaxy with a radius exceeding 1,000 solar radii. Its magnitude is around 16.6, its period is about 940 days.
The star KIC 8462852 (Tabby's Star) has received widespread press coverage because of unusual light fluctuations.
=== Exoplanets ===
Cygnus is one of the constellations that the Kepler satellite surveyed in its search for exoplanets, and as a result, there are about a hundred stars in Cygnus with known planets, the most of any constellation. One of the most notable systems is the Kepler-11 system, containing six transiting planets, all within a plane of approximately one degree. It was the system with six exoplanets to be discovered. With a spectral type of G6V, the star is somewhat cooler than the Sun. All the planets are more massive than Earth, and all have low densities; and all but one are closer to Kepler-11 than Mercury is to the Sun. contains a planet orbiting one of the sun-like stars, found due to variations in the star's radial velocity. Gliese 777, another naked-eye multiple star system containing a yellow star and a red dwarf, also contains a planet. The planet is somewhat similar to Jupiter, but with slightly more mass and a more eccentric orbit. The Kepler-22 system is also notable for having the most Earth-like exoplanet when it was discovered in 2011.
=== Star clusters ===
The rich background of stars of Cygnus can make it difficult to make out open cluster.
===Molecular clouds===
NGC 6826, the Blinking Planetary Nebula, is a planetary nebula with a magnitude of 8.5, 3200 light-years from Earth. It appears to "blink" in the eyepiece of a telescope because its central star is unusually bright (10th magnitude). When an observer focuses on the star, the nebula appears to fade away. Less than one degree from the Blinking Planetary is the double star 16 Cygni.
The North America Nebula (NGC 7000) is one of the most well-known nebulae in Cygnus, because it is visible to the unaided eye under dark skies, as a bright patch in the Milky Way. However, its characteristic shape is only visible in long-exposure photographs – it is difficult to observe in telescopes because of its low surface brightness. It has low surface brightness because it is so large; at its widest, the North America Nebula is 2 degrees across. Illuminated by a hot embedded star of magnitude 6, NGC 7000 is 1500 light-years from Earth.
To the south of Epsilon Cygni is the Veil Nebula (NGC 6960, 6979, 6992, and 6995), a 5,000-year-old supernova remnant covering approximately 3 degrees of the sky -
The Gamma Cygni Nebula (IC 1318) includes both bright and dark nebulae in an area of over 4 degrees. DWB 87 is another of the many bright emission nebulae in Cygnus, 7.8 by 4.3 arcminutes. It is in the Gamma Cygni area. Two other emission nebulae include Sharpless 2-112 and Sharpless 2-115. When viewed in an amateur telescope, Sharpless 2–112 appears to be in a teardrop shape. More of the nebula's eastern portion is visible with an O III (doubly ionized oxygen) filter. There is an orange star of magnitude 10 nearby and a star of magnitude 9 near the nebula's northwest edge. Further to the northwest, there is a dark rift and another bright patch. The whole nebula measures 15 arcminutes in diameter. Sharpless 2–115 is another emission nebula with a complex pattern of light and dark patches. Two pairs of stars appear in the nebula; it is larger near the southwestern pair. The open cluster Berkeley 90 is embedded in this large nebula, which measures 30 by 20 arcminutes.
===Other features===
Cygnus is also the apparent source of the WIMP-wind due to the orientation of the solar system's rotation through the galactic halo.
The local Orion-Cygnus Arm and the distant Cygnus Arm are two minor galactic arms named after Cygnus for lying in its background.
|
[
"Johann Bayer",
"active galaxy",
"microquasar",
"red giant",
"Pausanias (geographer)",
"Supergiant star",
"Ptolemy",
"Eridanus (constellation)",
"molecular cloud",
"Gliese 777",
"NGC 6910",
"neutron star",
"NGC 6826",
"North America Nebula",
"Great Rift (astronomy)",
"Collinder 421",
"Pegasus (constellation)",
"Cygnus X (star complex)",
"X-ray binary",
"Cygnus-X (star complex)",
"stellar spectrum",
"galaxy cluster",
"Achilles",
"Cycnus (son of Apollo)",
"Sadr region",
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"Helen of Troy",
"Cygnus OB2",
"Maurus Servius Honoratus",
"Sharpless 2-115",
"Greek language",
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"New York City",
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"gamma ray",
"Kepler space telescope",
"Massachusetts Institute of Technology",
"parallax",
"40th parallel south",
"constellation",
"stellar association",
"deep-sky object",
"BBC",
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"Weakly interacting massive particle",
"Sun",
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"Astronomy in the medieval Islamic world",
"dark nebula constellation",
"Helios",
"31 Cygni",
"Draco (constellation)",
"Lyra",
"DR 6 nebula",
"John Flamsteed",
"Cygnus X-2",
"New Zealand",
"main sequence",
"Cygnus in Chinese astronomy",
"Ian Ridpath",
"elliptical galaxy",
"Tuamotus",
"galactic plane",
"neutrino",
"4U 2129+ 47",
"Sparta",
"luminous blue variable",
"KIC 8462852",
"EXO 2030+ 375",
"Cygnus A",
"cosmic ray",
"Castor and Pollux",
"right ascension",
"HDE 226868",
"astrophysical jet",
"Orion-Cygnus Arm",
"nebula",
"galactic arm",
"Phyllius",
"Culmination",
"equatorial coordinate system",
"supernova remnant",
"Altitude (triangle)",
"first-magnitude star",
"Orpheus",
"Lacerta",
"Zeus",
"brightest stars",
"16 Cygni",
"visible spectrum",
"Chi Cygni",
"Northern Coalsack",
"Veil Nebula",
"Southern Cross",
"globular cluster",
"Polynesia",
"Poseidon",
"dwarf nova",
"Messier 39",
"Description of Greece",
"quark star",
"swan",
"Cycnus",
"Monthly Notices of the Royal Astronomical Society",
"Cygnus OB2-12",
"Northern Cross (asterism)",
"Kepler Mission",
"Eugène Joseph Delporte",
"variable star",
"Deneb",
"SS Cygni",
"Cycnus of Kolonai",
"Gamma Cygni",
"Tonga",
"Albireo",
"Mira variable",
"Cygnus Loop",
"summer solstice",
"List of largest known stars",
"Kepler-11",
"surface brightness",
"Trojan War",
"Kepler-22",
"61 Cygni",
"The Twelve Labours",
"Clytemnestra",
"Sharpless 2-112",
"Gamma Cygni Nebula",
"Cycnus of Liguria",
"Aquila (constellation)",
"Dolidze 11",
"open cluster",
"Solar radius",
"Cygnus (spacecraft)",
"Bayer designation",
"black hole",
"exoplanet",
"Epsilon Cygni",
"Tyndareus",
"Aeneid",
"muon",
"NML Cygni",
"Summer Triangle",
"DWB 87",
"millisecond pulsar",
"K-type star",
"red dwarf",
"X-ray",
"lyre",
"binary star",
"Phaethon",
"WR 136",
"Berkeley 90",
"Arabic",
"Leda (mythology)",
"semi-regular variable",
"Hercules–Corona Borealis Great Wall",
"Dolidze 9",
"W Cygni",
"Crescent Nebula",
"List of largest stars",
"hypergiant",
"Delta Cygni",
"Mu Cygni",
"Kronberger 61",
"Cepheus (constellation)",
"List of most massive stars",
"Cygnus Molecular Nebula Complex",
"Wil Tirion",
"solar diameter",
"Eta Cygni",
"Society Islands",
"Ovid",
"asterism (astronomy)",
"Stymphalian Birds",
"Metamorphoses",
"Soap bubble nebula",
"V404 Cygni",
"Kappa Cygnids",
"30 Cygni",
"Hercules",
"NASA",
"active galactic nucleus",
"Vulpecula",
"Mercury (planet)",
"supermassive black hole",
"October Cygnids",
"North Pole",
"Francis Baily",
"galaxy filament",
"Cygnus Arm",
"O III",
"Cygnus X-1",
"supergiant",
"Latinisation of names",
"declination",
"Milky Way",
"Friedrich Wilhelm Bessel",
"Greek mythology",
"P Cygni",
"interstellar medium",
"Asterism (astronomy)",
"radio galaxy",
"Wolf–Rayet star",
"Hercules Family",
"Psi Cygni",
"International Astronomical Union",
"bird",
"Swan",
"planetary nebula"
] |
6,422 |
Communion
|
Communion may refer to:
==Religion==
Eucharist (also called Holy Communion or the Lord's Supper), the Christian rite involving the eating of bread and drinking of wine, reenacting the Last Supper
Communion (chant), the Gregorian chant that accompanies this rite
First Communion, a ceremony in some Christian traditions during which a person receives the Eucharist for the first time
Koinonia (communion or fellowship), the relationship between Christians as individuals and as churches
Communion of Saints, a doctrine of Christianity mentioned in the Apostles' Creed
Full communion, recognition between churches
==Arts, entertainment, and media==
===Films and literature===
Communion (2016 film), a documentary
Communion (book), a book by Whitley Strieber about his purported abductions by aliens
Communion (1989 film), a film based on the book
Alice, Sweet Alice or Communion, a 1976 horror film starring Brooke Shields
===Music===
Communion (Roy Campbell album), 1995
Communion (John Patitucci album), 2001
Communion (Septicflesh album), 2008
Communion (The Soundtrack of Our Lives album), 2008
Communion (Years & Years album), 2015
Communion (Rabit album), 2015
Communion (Park Jiha album), 2016
"Communion", a 2009 album by Raffi
"Communion", a song by Debbie Harry from Debravation
"Communion", a song by Third Day from Wherever You Are
"Communion", a song by Mystery Maker from Mystery Maker (1977)
Communion Music, an artist-led music community
|
[
"Communion (Park Jiha album)",
"Raffi",
"Eucharist",
"Koinonia",
"Debravation",
"First Communion",
"Communion (Roy Campbell album)",
"Full communion",
"Communion (Years & Years album)",
"Communion (Septicflesh album)",
"Communion (Rabit album)",
"Communion Music",
"Communion (2016 film)",
"Unmitigated communion",
"Communion (chant)",
"Communion (book)",
"Communio",
"Communion (The Soundtrack of Our Lives album)",
"Communion (1989 film)",
"Wherever You Are (Third Day album)",
"Communion (John Patitucci album)",
"Communion of Saints",
"Alice, Sweet Alice"
] |
6,423 |
Calorie
|
The calorie is a unit of energy that originated from the caloric theory of heat. It was first introduced by Nicolas Clément, as a unit of heat energy, in lectures on experimental calorimetry during the years 1819–1824. This was the "large" calorie. It is generally written "calorie" with lowercase "c" and symbol "cal", even in government publications.
In China, only kilojoules are given.
===Food energy===
The unit is most commonly used to express food energy, namely the specific energy (energy per mass) of metabolizing different types of food. For example, fat (triglyceride lipids) contains 9 kilocalories per gram (kcal/g), while carbohydrates (sugar and starch) and protein contain approximately 4 kcal/g. The "large" unit is also used to express recommended nutritional intake or consumption, as in "calories per day".
Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on reducing caloric intake, different kinds of calorie-reduced diets have been shown to be generally effective.
===Chemistry and physics===
In other scientific contexts, the term "calorie" and the symbol "cal" almost always refers to the small unit; the "large" unit being generally called "kilocalorie" with symbol "kcal". It is mostly used to express the amount of energy released in a chemical reaction or phase change, typically per mole of substance, as in kilocalories per mole. It is also occasionally used to specify other energy quantities that relate to reaction energy, such as enthalpy of formation and the size of activation barriers. However, it is increasingly being superseded by the SI unit, the joule (J); and metric multiples thereof, such as the kilojoule (kJ).
The lingering use in chemistry is largely because the energy released by a reaction in aqueous solution, expressed in kilocalories per mole of reagent, is numerically close to the concentration of the reagent in moles per liter multiplied by the change in the temperature of the solution in kelvins or degrees Celsius. However, this estimate assumes that the volumetric heat capacity of the solution is 1 kcal/(L⋅K), which is not exact even for pure water.
|
[
"nutritional value",
"physics",
"activation energy",
"SI unit",
"Satiety value",
"Dietary Reference Intake",
"General Conference on Weights and Measures",
"bond energy",
"A calorie is a calorie",
"SI derived unit",
"Dieting",
"aqueous solution",
"chemistry",
"heat",
"List of diets",
"CIPM",
"caloric theory",
"kilojoule",
"body weight",
"joule",
"ISO 31-4",
"kilocalorie per mole",
"United States",
"food energy",
"Basal metabolic rate",
"kelvin",
"volumetric heat capacity",
"Marcellin Berthelot",
"Joule",
"International System of Units",
"eating",
"European Union",
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"energy",
"Calorie (disambiguation)",
"nutrition",
"mole (unit)",
"Caloric theory",
"chemical reaction",
"metabolic rate",
"specific energy",
"steam table",
"Wesleyan University",
"unit of energy",
"thermochemistry",
"Nutrition facts label",
"National Physical Laboratory (United Kingdom)",
"China",
"KCAL (disambiguation)",
"diabetes",
"nutrition facts label",
"British thermal unit",
"International Organization for Standardization",
"obesity",
"energy drink",
"Food energy",
"liter",
"erg",
"temperature",
"CGS system",
"Joseph Howard Raymond",
"Pierre Antoine Favre",
"Calorie restriction",
"Celsius",
"UK Metric Association",
"protein (nutrient)",
"Empty calorie",
"Conversion of units of energy",
"standard atmospheric pressure",
"Phase transition",
"water",
"Wilbur Olin Atwater",
"food science",
"calorimetry",
"Nicolas Clément",
"Calorie",
"milliliter",
"litre",
"Thermochemistry",
"carbohydrate"
] |
6,424 |
Corona Australis
|
Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.
Although fainter than its northern counterpart, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming regions to the Solar System—a dusty dark nebula known as the Corona Australis Molecular Cloud, lying about 430 light years away. Within it are stars at the earliest stages of their lifespan. The variable stars R and TY Coronae Australis light up parts of the nebula, which varies in brightness accordingly.
== Name ==
The name of the constellation was entered as "Corona Australis" when the International Astronomical Union (IAU) established the 88 modern constellations in 1922.
In 1932, the name was instead recorded as "Corona Austrina" when the IAU's commission on notation approved a list of four-letter abbreviations for the constellations.
The four-letter abbreviations were repealed in 1955. The IAU presently uses "Corona Australis" exclusively.
== Characteristics ==
Corona Australis is a small constellation bordered by Sagittarius to the north, Scorpius to the west, Telescopium to the south, and Ara to the southwest. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "CrA". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of four segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −36.77° and −45.52°. Covering 128 square degrees, Corona Australis culminates at midnight around the 30th of June and ranks 80th in area. Only visible at latitudes south of 53° north, Corona Australis cannot be seen from the British Isles as it lies too far south, but it can be seen from southern Europe and readily from the southern United States.
== Features ==
While not a bright constellation, Corona Australis is nonetheless distinctive due to its easily identifiable pattern of stars, which has been described as horseshoe- or oval-shaped. Though it has no stars brighter than 4th magnitude, it still has 21 stars visible to the unaided eye (brighter than magnitude 5.5). Nicolas Louis de Lacaille used the Greek letters Alpha through to Lambda to label the most prominent eleven stars in the constellation, designating two stars as Eta and omitting Iota altogether. Mu Coronae Australis, a yellow star of spectral type G5.5III and apparent magnitude 5.21, was labelled by Johann Elert Bode and retained by Benjamin Gould, who deemed it bright enough to warrant naming.
=== Stars ===
The only star in the constellation to have received a name is Alfecca Meridiana or Alpha CrA. The name combines the Arabic name of the constellation with the Latin for "southern". In Arabic, Alfecca means "break", and refers to the shape of both Corona Australis and Corona Borealis. Also called simply "Meridiana", it is a white main sequence star located 125 light years away from Earth, with an apparent magnitude of 4.10 and spectral type A2Va. A rapidly rotating star, it spins at almost 200 km per second at its equator, making a complete revolution in around 14 hours. Like the star Vega, it has excess infrared radiation, which indicates it may be ringed by a disk of dust. It is currently a main-sequence star, but will eventually evolve into a white dwarf; currently, it has a luminosity 31 times greater, and a radius and mass of 2.3 times that of the Sun. Beta Coronae Australis is an orange giant 474 light years from Earth. Its spectral type is K0II, and it is of apparent magnitude 4.11. Since its formation, it has evolved from a B-type star to a K-type star. Its luminosity class places it as a bright giant; its luminosity is 730 times that of the Sun, designating it one of the highest-luminosity K0-type stars visible to the naked eye. 100 million years old, it has a radius of 43 solar radii () and a mass of between 4.5 and 5 solar masses (). Alpha and Beta are so similar as to be indistinguishable in brightness to the naked eye.
Some of the more prominent double stars include Gamma Coronae Australis—a pair of yellowish white stars 58 light years away from Earth, which orbit each other every 122 years. Widening since 1990, the two stars can be seen as separate with a 100 mm aperture telescope; they are separated by 1.3 arcseconds at an angle of 61 degrees. They have a combined visual magnitude of 4.2; each component is an F8V dwarf star with a magnitude of 5.01. Epsilon Coronae Australis is an eclipsing binary belonging to a class of stars known as W Ursae Majoris variables. These star systems are known as contact binaries as the component stars are so close together they touch. Varying by a quarter of a magnitude around an average apparent magnitude of 4.83 every seven hours, the star system lies 98 light years away. Its spectral type is F4VFe-0.8+. At the southern end of the crown asterism are the stars Eta1 and Eta2 CrA, which form an optical double. Of magnitude 5.1 and 5.5, they are separable with the naked eye and are both white. Kappa Coronae Australis is an easily resolved optical double—the components are of apparent magnitudes 6.3 and 5.6 and are about 1000 and 150 light years away respectively. They appear at an angle of 359 degrees, separated by 21.6 arcseconds. Kappa2 is actually the brighter of the pair and is more bluish white, with a spectral type of B9V, while Kappa1 is of spectral type A0III. Lying 202 light years away, Lambda Coronae Australis is a double splittable in small telescopes. The primary is a white star of spectral type A2Vn and magnitude of 5.1, while the companion star has a magnitude of 9.7. The two components are separated by 29.2 arcseconds at an angle of 214 degrees.
Zeta Coronae Australis is a rapidly rotating main sequence star with an apparent magnitude of 4.8, 221.7 light years from Earth. The star has blurred lines in its hydrogen spectrum due to its rotation. Its spectral type is B9V. Theta Coronae Australis lies further to the west, a yellow giant of spectral type G8III and apparent magnitude 4.62. Corona Australis harbours RX J1856.5-3754, an isolated neutron star that is thought to lie 140 (±40) parsecs, or 460 (±130) light years, away, with a diameter of 14 km. It was once suspected to be a strange star, but this has been discounted.
===Corona Australis Molecular Cloud===
The Corona Australis Molecular Cloud is a dark molecular cloud just north of Beta Coronae Australis. Illuminated by a number of embedded reflection nebulae the cloud fans out from Epsilon Coronae Australis eastward along the constellation border with Sagittarius. It contains , Herbig–Haro objects (protostars) and some very young stars, being one of the closest star-forming regions, 430 light years (130 parsecs) to the Solar System, at the surface of the Local Bubble. The first nebulae of the cloud were recorded in 1865 by Johann Friedrich Julius Schmidt.
Between Epsilon and Gamma Coronae Australis the cloud consists of the particular dark nebula and star forming region Bernes 157. It is 55 by 18 arcminutes wide and possesses several stars around magnitude 13. These stars are dimmed by up to 8 magnitudes because of the obscuring dust clouds. At the center of the active star-forming region lies the Coronet cluster (also called R CrA Cluster), which is used in studying star and protoplanetary disk formation. R Coronae Australis (R CrA) is an irregular variable star ranging from magnitudes 9.7 to 13.9. Blue-white, it is of spectral type B5IIIpe. A very young star, it is still accumulating interstellar material. It is obscured by, and illuminates, the surrounding nebula, NGC 6729, which brightens and darkens with it. The nebula is often compared to a comet for its appearance in a telescope, as its length is five times its width. Other stars of the cluster include S Coronae Australis, a G-class dwarf and T Tauri star.
Nearby north, another young variable star, TY Coronae Australis, illuminates another nebula: reflection nebula NGC 6726/NGC 6727. TY Coronae Australis ranges irregularly between magnitudes 8.7 and 12.4, and the brightness of the nebula varies with it. Blue-white, it is of spectral type B8e. The largest young stars in the region, R, S, T, TY and VV Coronae Australis, are all ejecting jets of material which cause surrounding dust and gas to coalesce and form Herbig–Haro objects, many of which have been identified nearby.
Not part of it is the globular cluster known as NGC 6723, which can be seen adjacent to the nebulosity in the neighbouring constellation of Sagittarius, but is much much further away.
=== Deep sky objects ===
IC 1297 is a planetary nebula of apparent magnitude 10.7, which appears as a green-hued roundish object in higher-powered amateur instruments. The nebula surrounds the variable star RU Coronae Australis, which has an average apparent magnitude of 12.9 and is a WC class Wolf–Rayet star. IC 1297 is small, at only 7 arcseconds in diameter; it has been described as "a square with rounded edges" in the eyepiece, elongated in the north–south direction. Descriptions of its color encompass blue, blue-tinged green, and green-tinged blue.
Corona Australis' location near the Milky Way means that galaxies are uncommonly seen. NGC 6768 is a magnitude 11.2 object 35′ south of IC 1297. It is made up of two galaxies merging, one of which is an elongated elliptical galaxy of classification E4 and the other a lenticular galaxy of classification S0. IC 4808 is a galaxy of apparent magnitude 12.9 located on the border of Corona Australis with the neighbouring constellation of Telescopium and 3.9 degrees west-southwest of Beta Sagittarii. However, amateur telescopes will only show a suggestion of its spiral structure. It is 1.9 arcminutes by 0.8 arcminutes. The central area of the galaxy does appear brighter in an amateur instrument, which shows it to be tilted northeast–southwest.
Southeast of Theta and southwest of Eta lies the open cluster ESO 281-SC24, which is composed of the yellow 9th magnitude star GSC 7914 178 1 and five 10th to 11th magnitude stars. Halfway between Theta Coronae Australis and Theta Scorpii is the dense globular cluster NGC 6541. Described as between magnitude 6.3 and magnitude 6.6, it is visible in binoculars and small telescopes. Around 22000 light years away, it is around 100 light years in diameter. It is estimated to be around 14 billion years old. NGC 6541 appears 13.1 arcminutes in diameter and is somewhat resolvable in large amateur instruments; a 12-inch telescope reveals approximately 100 stars but the core remains unresolved.
=== Meteor showers ===
The Corona Australids are a meteor shower that takes place between 14 and 18 March each year, peaking around 16 March. This meteor shower does not have a high peak hourly rate. In 1953 and 1956, observers noted a maximum of 6 meteors per hour and 4 meteors per hour respectively; in 1955 the shower was "barely resolved". However, in 1992, astronomers detected a peak rate of 45 meteors per hour. The Corona Australids' rate varies from year to year. At only six days, the shower's duration is particularly short, and its meteoroids are small; the stream is devoid of large meteoroids. The Corona Australids were first seen with the unaided eye in 1935 and first observed with radar in 1955. Corona Australid meteors have an entry velocity of 45 kilometers per second. In 2006, a shower originating near Beta Coronae Australis was designated as the Beta Coronae Australids. They appear in May, the same month as a nearby shower known as the May Microscopids, but the two showers have different trajectories and are unlikely to be related.
== History ==
Corona Australis may have been recorded by ancient Mesopotamians in the MUL.APIN, as a constellation called MA.GUR ("The Bark"). However, this constellation, adjacent to SUHUR.MASH ("The Goat-Fish", modern Capricornus), may instead have been modern Epsilon Sagittarii. As a part of the southern sky, MA.GUR was one of the fifteen "stars of Ea".
In the 3rd century BC, the Greek didactic poet Aratus wrote of, but did not name the constellation, instead calling the two crowns Στεφάνοι (Stephanoi). The Greek astronomer Ptolemy described the constellation in the 2nd century AD, though with the inclusion of Alpha Telescopii, since transferred to Telescopium. Ascribing 13 stars to the constellation, he named it Στεφάνος νοτιος (), "Southern Wreath", while other authors associated it with either Sagittarius (having fallen off his head) or Centaurus; with the former, it was called Corona Sagittarii. Similarly, the Romans called Corona Australis the "Golden Crown of Sagittarius". It was known as Parvum Coelum ("Canopy", "Little Sky") in the 5th century. The 18th-century French astronomer Jérôme Lalande gave it the names Sertum Australe ("Southern Garland") and Orbiculus Capitis, while German poet and author Philippus Caesius called it Corolla ("Little Crown") or Spira Australis ("Southern Coil"), and linked it with the Crown of Eternal Life from the New Testament. Seventeenth-century celestial cartographer Julius Schiller linked it to the Diadem of Solomon. Sometimes, Corona Australis was not the wreath of Sagittarius but arrows held in his hand.
Corona Australis has been associated with the myth of Bacchus and Stimula. Jupiter had impregnated Stimula, causing Juno to become jealous. Juno convinced Stimula to ask Jupiter to appear in his full splendor, which the mortal woman could not handle, causing her to burn. After Bacchus, Stimula's unborn child, became an adult and the god of wine, he honored his deceased mother by placing a wreath in the sky.
In Chinese astronomy, the stars of Corona Australis are located within the Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ). The constellation itself was known as ti'en pieh ("Heavenly Turtle") and during the Western Zhou period, marked the beginning of winter. However, precession over time has meant that the "Heavenly River" (Milky Way) became the more accurate marker to the ancient Chinese and hence supplanted the turtle in this role. Arabic names for Corona Australis include Al Ķubbah "the Tortoise", Al Ĥibā "the Tent" or Al Udḥā al Na'ām "the Ostrich Nest". It was later given the name Al Iklīl al Janūbiyyah, which the European authors Chilmead, Riccioli and Caesius transliterated as Alachil Elgenubi, Elkleil Elgenubi and Aladil Algenubi respectively.
The ǀXam speaking San people of South Africa knew the constellation as ≠nabbe ta !nu "house of branches"—owned originally by the Dassie (rock hyrax), and the star pattern depicting people sitting in a semicircle around a fire.
The indigenous Boorong people of northwestern Victoria saw it as Won, a boomerang thrown by Totyarguil (Altair). The Aranda people of Central Australia saw Corona Australis as a coolamon carrying a baby, which was accidentally dropped to earth by a group of sky-women dancing in the Milky Way. The impact of the coolamon created Gosses Bluff crater, 175 km west of Alice Springs. The Torres Strait Islanders saw Corona Australis as part of a larger constellation encompassing part of Sagittarius and the tip of Scorpius's tail; the Pleiades and Orion were also associated. This constellation was Tagai's canoe, crewed by the Pleiades, called the Usiam, and Orion, called the Seg. The myth of Tagai says that he was in charge of this canoe, but his crewmen consumed all of the supplies onboard without asking permission. Enraged, Tagai bound the Usiam with a rope and tied them to the side of the boat, then threw them overboard. Scorpius's tail represents a suckerfish, while Eta Sagittarii and Theta Corona Australis mark the bottom of the canoe. On the island of Futuna, the figure of Corona Australis was called Tanuma and in the Tuamotus, it was called Na Kaua-ki-Tonga.
|
[
"Orion (constellation)",
"Nicolas Louis de Lacaille",
"meteoroid",
"Ptolemy",
"molecular cloud",
"neutron star",
"Chamaeleon complex",
"RX J1856.5-3754",
"giant star",
"bright giant",
"Crown (headgear)",
"Beta Coronae Australis",
"NGC 6723",
"Infrared excess",
"protostar",
"white dwarf",
"Southern Celestial Hemisphere",
"IC 1297",
"South",
"reflection nebula",
"solar radius",
"rock hyrax",
"New York City",
"apparent magnitude",
"T Coronae Australis",
"Aratus",
"Popular Astronomy (US magazine)",
"Star formation",
"Theta Scorpii",
"Juno (mythology)",
"constellation",
"Ara (constellation)",
"Herbig–Haro object",
"Alpha Coronae Australis",
"Astronomy and Astrophysics",
"Dover Publications",
"Chinese astronomy",
"solar mass",
"Philipp von Zesen",
"South Pole",
"Giovanni Battista Riccioli",
"Contact binary",
"Mesopotamia",
"W Ursae Majoris variable",
"ESO 281-SC24",
"Western Zhou",
"dwarf star",
"Semele",
"Scorpius (constellation)",
"Binary star",
"protoplanetary disk",
"NGC 6768",
"main sequence",
"Alice Springs",
"night sky",
"elliptical galaxy",
"Remora",
"Tuamotus",
"galactic plane",
"Eta2 Coronae Australis",
"Gamma Coronae Australis",
"MUL.APIN",
"Corona Australis (Chinese astronomy)",
"Virginia",
"Beta Sagittarii",
"Axial precession",
"Mu Coronae Australis",
"Galactic Center",
"right ascension",
"B-type star",
"Ea (god)",
"Kappa1 Coronae Australis",
"Jérôme Lalande",
"equatorial coordinate system",
"Scorpius",
"New York (state)",
"Local Bubble",
"Zeta Coronae Australis",
"Solar System",
"comet",
"globular cluster",
"Coronet cluster",
"luminosity class",
"Capricornus (constellation)",
"Corona Borealis",
"Eugène Joseph Delporte",
"40th parallel north",
"Johann Friedrich Julius Schmidt",
"NGC 6726",
"Futuna (Wallis and Futuna)",
"star formation",
"HD 166348",
"Jupiter (mythology)",
"Altair",
"Dionysis",
"T Tauri star",
"open cluster",
"NGC 6541",
"ǀXam language",
"Corona Australis Molecular Cloud",
"main-sequence star",
"53rd parallel north",
"Didacticism",
"Cambridge University Press",
"stellar evolution",
"K-type star",
"S Coronae Australis",
"IC 4808",
"Eta1 Coronae Australis",
"R Coronae Australis",
"Edmund Chilmead",
"Vega",
"Pleiades",
"Arabic",
"Quark star",
"Aranda people",
"Latin",
"Bernes 157",
"San people",
"Wergaia",
"radar",
"NGC 6727",
"Lambda Coronae Australis",
"TY Coronae Australis",
"Johann Elert Bode",
"Sagittarius (constellation)",
"Centaurus",
"Alpha Telescopii",
"lenticular galaxy",
"Epsilon Sagittarii",
"Julius Schiller",
"Stellar classification",
"VV Coronae Australis",
"optical double",
"Coolamon (vessel)",
"Epsilon Coronae Australis",
"SIMBAD",
"declination",
"Torres Strait Islanders",
"Milky Way",
"Benjamin Apthorp Gould",
"Telescopium",
"culmination",
"Theta Coronae Australis",
"Corona Australids",
"NGC 6729",
"Eta Sagittarii",
"dark nebula",
"Black Tortoise (Chinese constellation)",
"Wolf–Rayet star",
"Hercules Family",
"Kappa Coronae Australis",
"International Astronomical Union",
"Kappa2 Coronae Australis",
"planetary nebula",
"Gosses Bluff crater"
] |
6,426 |
Corcovado
|
Corcovado () which means "hunchback" in Portuguese, is a mountain in central Rio de Janeiro, Brazil. It is a granite peak located in the Tijuca Forest, a national park.
Corcovado hill lies just west of the city center but is wholly within the city limits and visible from great distances. It is known worldwide for the statue of Jesus atop its peak, entitled Christ the Redeemer.
==Access==
The peak and statue can be reached via a narrow road, by the Corcovado Rack Railway, which was opened in 1884 and refurbished in 1980, or by the walking trail on the south side of the mountain that starts from Parque Lage. The railway uses three electrically powered trains, with a capacity of 540 passengers per hour. The rail trip takes approximately 20 minutes and departs every 20 minutes. Due to its limited passenger capacity, the wait to board at the entry station can take several hours. The year-round schedule is 8:30 to 18:30.
From the train terminus and road, the observation deck at the foot of the statue is reached by 223 steps, or by elevators and escalators. Among the most popular year-round tourist attractions in Rio de Janeiro, the Corcovado railway, access roads, and statue platform are commonly crowded.
==Attractions==
Corcovado's most popular attraction is the statue depicting Jesus at its peak, entitled Christ the Redeemer (), and the viewing platform at its peak, drawing over 300,000 visitors per year. The statue was constructed from 1922 to 1931. From the peak's platform the panoramic view includes downtown Rio de Janeiro, Sugarloaf Mountain, the Rodrigo de Freitas lagoon, Copacabana and Ipanema beaches, Maracanã Stadium, and several of Rio de Janeiro's favelas. Cloud cover is common in Rio and the view from the platform is often obscured. Sunny days are recommended for optimal viewing.
Notable past visitors to the mountain peak include Charles Darwin, Pope Pius XII, Pope John Paul II, Alberto Santos-Dumont, Albert Einstein, Diana, Princess of Wales, General Sherman, and Karl Pilkington, among others. An additional attraction of the mountain is rock climbing. The south face had 54 climbing routes in 1992. The easiest way starts from Parque Lage.
==Geology==
The peak of Corcovado is a big granite dome, which describes a generally vertical rocky formation. It is claimed to be the highest such formation in Brazil, the second highest being Pedra Agulha, situated near the town of Pancas in Espírito Santo.
== References in Brazilian culture ==
Corcovado is considered an icon of Brazilian culture. "Corcovado" is a 1960 bossa nova song and jazz standard by Antônio Carlos Jobim whose lyrics draw on images of the hill. Corcovado has also been referenced in other artistic works (e.g. the lyrics of Ben Harper, literary works, films, etc.).
==Gallery==
Image:Marc Ferrez - IMS 007A6P4FP15-015.jpg|Corcovado before the construction of Christ the Redeemer, 19th century
File:Corcovado_visto_pela_Urca_-_panoramio.jpg|Corcovado seen from Urca
Image:A_lua_e_o_Cristo.jpg|The statue of Christ the Redeemer atop Corcovado
File:Corcovado_sunset_silhouette.jpg|Corcovado seen from Sugarloaf Mountain during sunset
File:Rio_de_Janeiro,_Pão_de_Açúcar_from_Cristo_Redentor_(15744316848).jpg|Botafogo bay seen from Corcovado
Image:Trem do Corcovado na Estação Paineiras 01.jpg|Corcovado Rack Railway
|
[
"Christ the Redeemer (statue)",
"Granite",
"Charles Darwin",
"hunchback",
"Albert Einstein",
"Pope John Paul II",
"Rodrigo de Freitas Lagoon",
"Rio de Janeiro",
"Maracanã Stadium",
"Sugarloaf Mountain",
"Corcovado (song)",
"Ipanema",
"Alberto Santos-Dumont",
"Ben Harper",
"favela",
"Google Maps",
"Pope Pius XII",
"bossa nova",
"General Sherman",
"Tijuca Forest",
"Diana, Princess of Wales",
"Pancas",
"escalator",
"Antônio Carlos Jobim",
"Urca",
"elevator",
"Jesus",
"Portuguese language",
"Espírito Santo",
"granite",
"Brazil",
"Copacabana, Rio de Janeiro",
"Botafogo",
"rock climbing",
"jazz standard",
"Parque Lage",
"Corcovado Rack Railway",
"granite dome"
] |
6,427 |
Cheddar, Somerset
|
Cheddar is a large village and civil parish in the English county of Somerset. It is situated on the southern edge of the Mendip Hills, north-west of Wells, south-east of Weston-super-Mare and south-west of Bristol. The civil parish includes the hamlets of Nyland and Bradley Cross. The parish had a population of 5,755 in 2011 and an acreage of as of 1961.
Cheddar Gorge, on the northern edge of the village, is the largest gorge in the United Kingdom and includes several show caves, including Gough's Cave. The gorge has been a centre of human settlement since Neolithic times, including a Saxon palace. It has a temperate climate and provides a unique geological and biological environment that has been recognised by the designation of several Sites of Special Scientific Interest. It is also the site of several limestone quarries. The village gave its name to Cheddar cheese and has been a centre for strawberry growing. The crop was formerly transported on the Cheddar Valley rail line, which closed in the late 1960s and is now a cycle path. The village is now a major tourist destination with several cultural and community facilities, including the Cheddar Show Caves Museum.
The village supports a variety of community groups including religious, sporting and cultural organisations. Several of these are based on the site of the Kings of Wessex Academy, which is the largest educational establishment.
== History ==
The name Cheddar comes from the Old English word ceodor, meaning deep dark cavity or pouch.
There is evidence of occupation from the Neolithic period in Cheddar. Britain's oldest complete human skeleton, Cheddar Man, estimated to be 9,000 years old, was found in Cheddar Gorge in 1903. Older remains from the Upper Late Palaeolithic era (12,000–13,000 years ago) have been found. There is some evidence of a Bronze Age field system at the Batts Combe quarry site. There is also evidence of Bronze Age barrows at the mound in the Longwood valley, which if man-made it is likely to be a field system. The remains of a Roman villa have been excavated in the grounds of the current vicarage. The ruins of the palace were excavated in the 1960s. They are located on the grounds of the Kings of Wessex Academy, together with a 14th-century chapel dedicated to St. Columbanus. Roman remains have also been uncovered at the site. Cheddar was listed in the Domesday Book of 1086 as Ceder, meaning "Shear Water", from the Old English scear and Old Welsh dŵr. An alternative spelling in earlier documents, common through the 1850s is Chedder.
As early as 1130 AD, the Cheddar Gorge was recognised as one of the "Four wonders of England". Historically, Cheddar's source of wealth was farming and cheese making for which it was famous as early as 1170 AD. The parish was part of the Winterstoke Hundred.
The manor of Cheddar was deforested in 1337 and Bishop Ralph was granted a licence by the King to create a hunting forest.
As early as 1527 there are records of watermills on the river. In the Victorian era it also became a centre for the production of clothing. The last mill, used as a shirt factory, closed in the early 1950s. In 1801, of common land were enclosed under the (35 Geo. 3. c. 39 ).
Cheddar remained a more dispersed dairy-farming village until the advent of tourism and the arrival of the railway in the Victorian era. Tourism of the Cheddar gorge and caves began with the opening of the Cheddar Valley Railway in 1869.
Cheddar, its surrounding villages and specifically the gorge has been subject to flooding. In the Chew Stoke flood of 1968 the flow of water washed large boulders down the gorge, washed away cars, and damaged the cafe and the entrance to Gough's Cave.
== Government ==
Cheddar is recognised as a village. The adjacent settlement of Axbridge, although only about a third the population of Cheddar, is a town. This apparently illogical situation is explained by the relative importance of the two places in historic times. While Axbridge grew in importance as a centre for cloth manufacturing in the Tudor period and gained a charter from King John, Cheddar remained a more dispersed mining and dairy-farming village. Its population grew with the arrival of the railways in the Victorian era and the advent of tourism.
The parish council, which has 15 members who are elected for four years, is responsible for local issues, including setting an annual precept (local rate) to cover the council's operating costs and producing annual accounts for public scrutiny. The parish council evaluates local planning applications and works with the police, district council officers, and neighbourhood watch groups on matters of crime, security, and traffic. The parish council's role also includes initiating projects for the maintenance and repair of parish facilities, as well as consulting with the district council on the maintenance, repair, and improvement of highways, drainage, footpaths, public transport, and street cleaning. Conservation matters (including trees and listed buildings) and environmental issues are also the responsibility of the council.
The village is in the 'Cheddar and Shipham' electoral ward. After including Shipham the total population of the ward taken at the 2011 census is 6,842.
For local government purposes, since 1 April 2023, the village comes under the unitary authority of Somerset Council. Prior to this, it was part of the non-metropolitan district of Sedgemoor, which was formed on 1 April 1974 under the Local Government Act 1972, having previously been part of Axbridge Rural District. Fire, police and ambulance services are provided jointly with other authorities through the Devon and Somerset Fire and Rescue Service, Avon and Somerset Constabulary and the South Western Ambulance Service.
It is also part of the Wells and Mendip Hills county constituency represented in the House of Commons of the Parliament of the United Kingdom. It elects one Member of Parliament (MP) by the first past the post system of election. Prior to Brexit in 2020, it was part of the South West England constituency of the European Parliament.
== International relations ==
Cheddar is twinned with Felsberg, Germany and Vernouillet, France, and it has an active programme of exchange visits. Initially, Cheddar twinned with Felsberg in 1984. In 2000, Cheddar twinned with Vernouillet, which had also been twinned with Felsberg. Cheddar also has a friendship link with Ocho Rios in Saint Ann Parish, Jamaica.
It is also twinned with the commune of Descartes in the Indre-et-Loire department.
== Geography ==
The area is underlain by Black Rock slate, Burrington Oolite and Clifton Down Limestone of the Carboniferous Limestone Series, which contain ooliths and fossil debris on top of Old Red Sandstone, and by Dolomitic Conglomerate of the Keuper. Evidence for Variscan orogeny is seen in the sheared rock and cleaved shales. In many places weathering of these strata has resulted in the formation of immature calcareous soils.
=== Gorge and caves ===
Cheddar Gorge, which is located on the edge of the village, is the largest gorge in the United Kingdom.
The gorge is the site of the Cheddar Caves, where Cheddar Man was found in 1903. leads around into the rock-face, and contains a variety of large rock chambers and formations. Cox's Cave, discovered in 1837, is smaller but contains many intricate formations. A further cave houses a children's entertainment walk known as the "Crystal Quest".
Cheddar Gorge, including Cox's Cave, Gough's Cave and other attractions, has become a tourist destination, attracting about 500,000 visitors per year.
In a 2005 poll of Radio Times readers, following its appearance on the 2005 television programme Seven Natural Wonders, Cheddar Gorge was named as the second greatest natural wonder in Britain, surpassed only by the Dan yr Ogof caves.
=== Sites of Special Scientific Interest ===
There are several large and unique Sites of Special Scientific Interest (SSSI) around the village.
Cheddar Reservoir is a near-circular artificial reservoir operated by Bristol Water. Dating from the 1930s, it has a capacity of 135 million gallons (614,000 cubic metres). The reservoir is supplied with water taken from the Cheddar Yeo, which rises in Gough's Cave in Cheddar Gorge and is a tributary of the River Axe. The inlet grate for the water pipe that is used to transport the water can be seen next to the sensory garden in Cheddar Gorge. It has been designated as a Site of Special Scientific Interest (SSSI) due to its wintering waterfowl populations.
Cheddar Wood and the smaller Macall's Wood form a biological Site of Special Scientific Interest from what remains of the wood of the Bishops of Bath and Wells in the 13th century and of King Edmund the Magnificent's wood in the 10th. During the 19th century, its lower fringes were grubbed out to make strawberry fields. Most of these have been allowed to revert to woodland. The wood was coppiced until 1917. This site compromises a wide range of habitats which include ancient and secondary semi-natural broadleaved woodland, unimproved neutral grassland, and a complex mosaic of calcareous grassland and acidic dry dwarf-shrub heath. Cheddar Wood is one of only a few English stations for starved wood-sedge (Carex depauperata).
By far the largest of the SSSIs is called Cheddar Complex and covers of the gorge, caves and the surrounding area. It is important because of both biological and geological features. It includes four SSSIs, formerly known as Cheddar Gorge SSSI, August Hole/Longwood Swallet SSSI, GB Cavern Charterhouse SSSI and Charterhouse on-Mendip SSSI. It is partly owned by the National Trust who acquired it in 1910 and partly managed by the Somerset Wildlife Trust.
=== Quarries ===
Close to the village and gorge are Batts Combe quarry and Callow Rock quarry, two of the active Quarries of the Mendip Hills where limestone is still extracted. Operating since the early 20th century, Batts Combe is owned and operated by Hanson Aggregates. The output in 2005 was around 4,000 tonnes of limestone per day, one third of which was supplied to an on-site lime kiln, which closed in 2009; the remainder was sold as coated or dusted aggregates. The limestone at this site is close to 99 percent carbonate of calcium and magnesium (dolomite).
The Chelmscombe Quarry finished its work as a limestone quarry in the 1950s and was then used by the Central Electricity Generating Board as a tower testing station. During the 1970s and 1980s it was also used to test the ability of containers of radioactive material to withstand impacts and other accidents.
=== Climate ===
Along with the rest of South West England, Cheddar has a temperate climate which is generally wetter and milder than the rest of the country. The annual mean temperature is approximately . Seasonal temperature variation is less extreme than most of the United Kingdom because of the adjacent sea, which moderates temperature. The summer months of July and August are the warmest with mean daily maxima of approximately . In winter mean minimum temperatures of are common. Residents lived in 2,209 households. The vast majority of households (2,183) gave their ethnic status at the 2001 census as white.
===2021 census===
According to the most recent 2021 census, the village had a total population of 6,263 with 51.1% female and 48.9% male.
Over 6,101 people or 97.3% identified as white, 1% (61) Asian, 0.3% (17) Black and 1.3% (79) as mixed.
The most common places of birth were: 94.1% or 5,900 born in the United Kingdom and 2.5% (156) born in the European Union, 81 Africa and 65 Middle East and Asia, 29 Americas and Caribbean. which is the most popular type of cheese in the United Kingdom. The cheese is now made and consumed worldwide, and only one producer remains in the village.
Since the 1880s, Cheddar's other main produce has been the strawberry, which is grown on the south-facing lower slopes of the Mendip hills.
The line ran from Yatton to Wells. When the rest of the line was closed and all passenger services ceased, the section of the line between Cheddar and Yatton remained open for goods traffic. It provided a fast link with the main markets for the strawberries in Birmingham and London, but finally closed in 1964, becoming part of the Cheddar Valley Railway Nature Reserve.
Cheddar Ales is a small brewery based in the village, producing beer for local public houses.
Tourism is a significant source of employment. Around 15 percent of employment in Sedgemoor is provided by tourism, but within Cheddar it is estimated to employ as many as 1,000 people.
The village also has a youth hostel, and a number of camping and caravan sites.
== Culture and community ==
Cheddar has a number of active service clubs including Cheddar Vale Lions Club, Mendip Rotary and Mendip Inner Wheel Club. The clubs raise money for projects in the local community and hold annual events such as a fireworks display, duck races in the Gorge, a dragon boat race on the reservoir and concerts on the grounds of the nearby St Michael's Cheshire Home.
Several notable people have been born or lived in Cheddar. Musician Jack Bessant, the bass guitarist with the band Reef grew up on his parents' strawberry farm, and Matt Goss and Luke Goss, former members of Bros, lived in Cheddar for nine months as children. Trina Gulliver, ten-time World Professional Darts Champion, previously lived in Cheddar until 2017. The comedian Richard Herring grew up in Cheddar. His 2008 Edinburgh Festival Fringe show, The Headmaster's Son is based on his time at The Kings of Wessex School, where his father Keith was the headmaster. The final performance of this show was held at the school in November 2009. He also visited the school in March 2010 to perform his show Hitler Moustache. In May 2013, a community radio station called Pulse was launched.
== Landmarks ==
The market cross in Bath Street dates from the 15th century, with the shelter having been rebuilt in 1834. It has a central octagonal pier, a socket raised on four steps, a hexagonal shelter with six arched four-centred openings, shallow two-stage buttresses at each angle, and an embattled parapet. The shaft is crowned by an abacus with figures in niches, probably from the late 19th century, although the cross is now missing. It was rebuilt by Thomas, Marquess of Bath. It is a scheduled monument (Somerset County No 21) and Grade II* listed building.
In January 2000, the cross was seriously damaged in a traffic accident. By 2002, the cross had been rebuilt and the area around it was redesigned to protect and enhance its appearance.
The cross was badly damaged again in March 2012, when a taxi crashed into it late at night demolishing two sides.
Repair work, which included the addition of wooden-clad steel posts to protect against future crashes, was completed in November 2012 at a cost of £60,000.
Hannah More, a philanthropist and educator, founded a school in the village in the late 18th century for the children of miners. Her first school was located in a 17th-century house. Now named "Hannah More's Cottage", the Grade II-listed building is used by the local community as a meeting place.
== Transport ==
The village is situated on the A371 road which runs from Wincanton, to Weston-super-Mare. It is approximately from the route of the M5 motorway with around a drive to junction 22.
It was on the Cheddar Valley line, a railway line that was opened in 1869 and closed in 1963. It became known as The Strawberry Line because of the large volume of locally-grown strawberries that it carried. It ran from Yatton railway station through to Wells (Tucker Street) railway station and joined the East Somerset Railway to make a through route via Shepton Mallet (High Street) railway station to Witham. Sections of the now-disused railway have been opened as the Strawberry Line Trail, which currently runs from Yatton to Cheddar. The Cheddar Valley line survived until the "Beeching Axe". Towards the end of its life there were so few passengers that diesel railcars were sometimes used. The Cheddar branch closed to passengers on 9 September 1963 and to goods in 1964.
The principal bus route is the hourly service 126 between Weston-super-Mare and Wells operated by First West of England. Other bus routes include the service 668 from Shipham to Street which runs every couple of hours operated by Libra Travel, as well as the college bus service 66 which runs from Axbridge to the Bridgwater Campus of Bridgwater and Taunton College in the mornings and evenings of college term times, and is operated by Bakers Dolphin.
== Education ==
The first school in Cheddar was set up by Hannah More during the 18th Century, however now Cheddar has three schools belonging to the Cheddar Valley Group of Schools, twelve schools that provide Cheddar Valley's three-tier education system. Cheddar First School has ten classes for children between 4 and 9 years. Fairlands Middle School, a middle school categorised as a middle-deemed-secondary school, has 510 pupils between 9 and 13. Fairlands takes children moving up from Cheddar First School as well as other first schools in the Cheddar Valley. The Kings of Wessex Academy, a coeducational comprehensive school, has been rated as "good" by Ofsted. It has 1,176 students aged 13 to 18, including 333 in the sixth form.
== Religious sites ==
The Church of St Andrew dates from the 14th century. It was restored in 1873 by William Butterfield. It is a Grade I listed building and contains some 15th-century stained glass and an altar table of 1631. The chest tomb in the chancel is believed to contain the remains of Sir Thomas Cheddar and is dated 1442. The tower, which rises to , contains a bell dating from 1759 made by Thomas Bilbie of the Bilbie family. The graveyard contains the grave of the hymn writer William Chatterton Dix.
There are also churches for Roman Catholic, Methodist and other denominations, including Cheddar Valley Community Church, who not only meet at the Kings of Wessex School on Sunday, but also have their own site on Tweentown for meeting during the week. The Baptist chapel was built in 1831.
== Sport ==
Kings Fitness & Leisure, situated on the grounds of the Kings of Wessex School, provides a venue for various sports and includes a 20-metre swimming pool, racket sport courts, a sports hall, dance studios and a gym. A youth sports festival was held on Sharpham Road Playing Fields in 2009. In 2010 a skatepark was built in the village, funded by the Cheddar Local Action Team.
Cheddar A.F.C., founded in 1892 and nicknamed "The Cheesemen", play in the Western Football League Division One. In 2009 plans were revealed to move the club from its present home at Bowdens Park on Draycott Road to a new larger site. They now play in the West of England Premier League Somerset Division. Cheddar Rugby Club, who own part of the Sharpham playing fields, was formed in 1836. The club organises an annual Cheddar Rugby Tournament. Cheddar Lawn Tennis Club, was formed in 1924, and play in the North Somerset League and also has social tennis and coaching. Cheddar Running Club organised an annual half marathon until 2009.
The village is both on the route of the West Mendip Way and Samaritans Way South West.
|
[
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"Edinburgh Festival Fringe",
"Old Red Sandstone",
"Central Electricity Generating Board",
"Catholic Church",
"stalactite",
"Thomas Thynne, 1st Marquess of Bath",
"Carboniferous",
"Cheddar Reservoir",
"local government in England",
"Dan yr Ogof",
"ITV News",
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"Technology College",
"Wards and electoral divisions of the United Kingdom",
"first past the post",
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"Yatton railway station",
"show cave",
"Cheddar A.F.C.",
"Ofsted",
"Cheddar Yeo",
"Convective",
"Crook Peak to Shute Shelve Hill",
"Edmund I of England",
"International Society for Horticultural Science",
"M5 motorway",
"Bakers Dolphin",
"Radio Times",
"public houses",
"scheduled monument",
"BBC News",
"Wedmore",
"Methodism",
"Priddy",
"The Independent",
"Cox's Cave",
"stained glass",
"Anglo-Saxons",
"Youth Hostels Association (England & Wales)",
"35 Geo. 3",
"dragon boat",
"church monument",
"brown argus",
"Batts Combe quarry",
"English Nature",
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"British House of Commons",
"BBC",
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"Yatton",
"Street, Somerset",
"Upper Paleolithic",
"sixth form",
"railcar",
"listed building",
"limestone",
"Cheddar Man",
"Saint Ann Parish",
"Devon and Somerset Fire and Rescue Service",
"strawberry",
"Birmingham",
"Cheddar cheese",
"Wincanton",
"Columbanus",
"Winterstoke",
"Bristol Water",
"Cheddar Wood",
"foundation school",
"quarry",
"non-metropolitan district",
"convection",
"Bronze Age",
"West Mendip Way",
"Somerset Levels",
"Richard Herring",
"Matt Goss",
"Weston-super-Mare",
"Ralph of Shrewsbury",
"Leonard Cheshire",
"William Butterfield",
"Campaign for Real Ale",
"The Kings of Wessex Academy",
"Bishops of Bath and Wells",
"BBC Radio 4",
"county constituency",
"Cheddar Palace",
"soldier beetle",
"Wells (Tucker Street) railway station",
"pearl-bordered fritillary",
"Shepton Mallet (High Street) railway station",
"Tudor dynasty",
"Jack Bessant",
"Mendip Way",
"wheat",
"Twin towns and sister cities",
"University of Bristol",
"Lithospermum purpurocaeruleum",
"Inner Wheel Club",
"Specialist school",
"Bridgwater and Taunton College",
"United Kingdom",
"Lawn Tennis",
"Samaritans Way South West",
"Cheddar Valley line",
"Hundred (county subdivision)",
"Hamlet (place)",
"three-tier education",
"Ocho Rios",
"Keuper",
"Descartes, Indre-et-Loire",
"South West England (European Parliament constituency)",
"Azores",
"middle school",
"dark green fritillary",
"Cheddar Gorge",
"2011 United Kingdom census",
"National Trust for Places of Historic Interest or Natural Beauty",
"British Geological Survey",
"Rotary International",
"faith school",
"Axbridge Rural District",
"Roman Britain",
"Seven Natural Wonders",
"Bros (British band)",
"silver-washed fritillary",
"Parliament of the United Kingdom",
"Beeching Axe",
"Witenagemot",
"Wells, Somerset",
"Sedgemoor",
"Victorian era",
"Neighbourhood Watch (UK)",
"Saxon",
"Butterflies",
"First West of England",
"Domesday Book",
"Somerset",
"youth hostel",
"biological Site of Special Scientific Interest",
"Luke Goss",
"Arion fasciatus",
"Gough's Cave",
"abacus",
"Fairlands Middle School",
"sensory garden",
"Western Football League",
"European Parliament",
"Bristol",
"Avon and Somerset Constabulary",
"Baptist",
"Axbridge",
"Low-pressure area",
"stalagmite",
"Old English",
"Brexit",
"Hannah More",
"Chew Stoke flood of 1968",
"Dolomite (rock)",
"calcareous grassland",
"Clergy house",
"Member of Parliament (United Kingdom)",
"coppice",
"Cheddar Ales",
"Cheddar Complex",
"John of England",
"Market Cross, Cheddar",
"Thomas Cheddar",
"East Somerset Railway",
"William Wilberforce",
"the Kings of Wessex Academy",
"half marathon",
"National Cycle Network",
"Neolithic",
"magnesium",
"starved wood-sedge",
"Trina Gulliver",
"West of England Premier League",
"Oolite",
"Bilbie family",
"comprehensive school",
"Local Government Act 1972",
"skatepark",
"South West England",
"Somerset Council",
"chancel",
"Rubber duck",
"Somerset County Council",
"Strawberry",
"River Axe (Bristol Channel)",
"canyon",
"Indre-et-Loire",
"Somerset Wildlife Trust",
"South Western Ambulance Service",
"Lions Clubs International",
"Callow Rock quarry",
"Felsberg, Hessen",
"Quarries of the Mendip Hills",
"tower testing station",
"Vernouillet, Eure-et-Loir",
"holly blue",
"the Kings of Wessex School",
"Wells and Mendip Hills (UK Parliament constituency)",
"Unitary authorities of England",
"William Chatterton Dix",
"Witham (Somerset) railway station",
"fossil",
"Temperateness",
"Shipham",
"Mendip Hills",
"slug",
"carbonate",
"Dolomite (mineral)",
"watermill",
"Hanson plc",
"A371 road",
"Victorian restoration",
"Church of England",
"civil parishes in England"
] |
6,429 |
Compact disc
|
The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. It uses the Compact Disc Digital Audio format which typically provides 74 minutes of audio on a disc. In later years, the compact disc was adapted for non-audio computer data storage purposes as CD-ROM and its derivatives. First released in Japan in October 1982, the CD was the second optical disc technology to be invented, after the much larger LaserDisc (LD). By 2007, 200 billion CDs (including audio CDs, CD-ROMs and CD-Rs) had been sold worldwide.
Standard CDs have a diameter of , and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about of data. Capacity is routinely extended to 80 minutes and , 90 minutes , or 99 minutes by arranging data more closely on the same-sized disc. The Mini CD has various diameters ranging from ; they have been used for CD singles or delivering device drivers.
The CD gained rapid popularity in the 1990s, quickly outselling all other audio formats in the United States by 1991, ending the market dominance of the phonograph record and the cassette tape. By 2000, the CD accounted for 92.3% of the entire market share in regard to US music sales. The CD is considered the last dominant audio format of the album era, as the rise of MP3, iTunes, cellular ringtones, and other downloadable music formats in the mid-2000s ended the decade-long dominance of the CD.
The format was later adapted (as CD-ROM) for general purpose data storage and initially could hold much more data than a personal computer hard disk drive. Several other formats were further derived, both pre-pressed and blank user writable, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i), Enhanced Music CD, and Super Audio CD (SACD) which may have a CD-DA layer.
== History ==
== Physical details ==
A CD is made from thick, polycarbonate plastic, and weighs 14–33 grams. From the center outward, components are: the center spindle hole (15 mm), the first-transition area (clamping ring), the clamping area (stacking ring), the second-transition area (mirror band), the program (data) area, and the rim. The inner program area occupies a radius from 25 to 58 mm.
A thin layer of aluminum or, more rarely, gold is applied to the surface, making it reflective. The metal is protected by a film of lacquer normally spin coated directly on the reflective layer. The label is printed on the lacquer layer, usually by screen printing or offset printing.
CD data is represented as tiny indentations known as pits, encoded in a spiral track molded into the top of the polycarbonate layer. The areas between pits are known as lands. Each pit is approximately 100 nm deep by 500 nm wide, and varies from 850 nm to 3.5 μm in length. The distance between the windings (the pitch) is 1.6 μm (measured center-to-center, not between the edges).
When playing an audio CD, a motor within the CD player spins the disc to a scanning velocity of 1.2–1.4 m/s (constant linear velocity, CLV)—equivalent to approximately 500 RPM at the inside of the disc, and approximately 200 RPM at the outside edge. The track on the CD begins at the inside and spirals outward so a disc played from beginning to end slows its rotation rate during playback.
The program area is 86.05 cm2 and the length of the recordable spiral is With a scanning speed of 1.2 m/s, the playing time is 74 minutes or 650 MiB of data on a CD-ROM. A disc with data packed slightly more densely is tolerated by most players (though some old ones fail). Using a linear velocity of 1.2 m/s and a narrower track pitch of 1.5 μm increases the playing time to 80 minutes, and data capacity to 700 MiB. Even denser tracks are possible, with semi-standard 90 minute/800 MiB discs having 1.33 μm, and 99 minute/870 MiB having 1.26 μm, but compatibility suffers as density increases.
A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. Because the pits are indented into the top layer of the disc and are read through the transparent polycarbonate base, the pits form bumps when read. The laser hits the disc, casting a circle of light wider than the modulated spiral track reflecting partially from the lands and partially from the top of any bumps where they are present. As the laser passes over a pit (bump), its height means that the round trip path of the light reflected from its peak is 1/2 wavelength out of phase with the light reflected from the land around it. This is because the height of a bump is around 1/4 of the wavelength of the light used, so the light falls 1/4 out of phase before reflection and another 1/4 wavelength out of phase after reflection. This causes partial cancellation of the laser's reflection from the surface. By measuring the reflected intensity change with a photodiode, a modulated signal is read back from the disc. The fungus Geotrichum candidum has been found—under conditions of high heat and humidity—to consume the polycarbonate plastic and aluminium found in CDs.
The data integrity of compact discs can be measured using surface error scanning, which can measure the rates of different types of data errors, known as C1, C2, CU and extended (finer-grain) error measurements known as E11, E12, E21, E22, E31 and E32, of which higher rates indicate a possibly damaged or unclean data surface, low media quality, deteriorating media and recordable media written to by a malfunctioning CD writer.
Error scanning can reliably predict data losses caused by media deterioration. Support of error scanning differs between vendors and models of optical disc drives, and extended error scanning (known as "advanced error scanning" in Nero DiscSpeed) has only been available on Plextor and some BenQ optical drives so far, as of 2020.
=== Disc shapes and diameters ===
The digital data on a CD begins at the center of the disc and proceeds toward the edge, which allows adaptation to the different sizes available. Standard CDs are available in two sizes. By far, the most common is in diameter, with a 74-, 80, 90, or 99-minute audio capacity and a 650, 700, 800, or 870 MiB (737,280,000-byte) data capacity. Discs are thick, with a center hole. The size of the hole was chosen by Joop Sinjou and based on a Dutch 10-cent coin: a dubbeltje. Philips/Sony patented the physical dimensions.
The official Philips history says the capacity was specified by Sony executive Norio Ohga to be able to contain the entirety of Beethoven's Ninth Symphony on one disc. according to Kees Immink, as the EFM code format had not yet been decided in December 1979, when the 120 mm size was adopted. The adoption of EFM in June 1980 allowed 30 percent more playing time that would have resulted in 97 minutes for 120 mm diameter or 74 minutes for a disc as small as . Instead, the information density was lowered by 30 percent to keep the playing time at 74 minutes. The 120 mm diameter has been adopted by subsequent formats, including Super Audio CD, DVD, HD DVD, and Blu-ray Disc. The diameter discs ("Mini CDs") can hold up to 24 minutes of music or 210 MiB.
===SHM-CD===
SHM-CD (short for Super High Material Compact Disc) is a variant of the Compact Disc, which replaces the polycarbonate base with a proprietary material. This material was created during joint research by Universal Music Japan and JVC into manufacturing high-clarity liquid-crystal displays.
SHM-CDs are fully compatible with all CD players since the difference in light refraction is not detected as an error. JVC claims that the greater fluidity and clarity of the material used for SHM-CDs results in a higher reading accuracy and improved sound quality. However, since the CD-Audio format contains inherent error correction, it is unclear whether a reduction in read errors would be great enough to produce an improved output.
== Logical format ==
=== Audio CD ===
The logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA) is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the color of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on a Red Book CD; thus, the mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono); an MP3 CD, can have audio file formats with mono sound.
CD-Text is an extension of the Red Book specification for an audio CD that allows for the storage of additional text information (e.g., album name, song name, artist) on a standards-compliant audio CD. The information is stored either in the lead-in area of the CD, where there are roughly five kilobytes of space available or in the subcode channels R to W on the disc, which can store about 31 megabytes.
Compact Disc + Graphics is a special audio compact disc that contains graphics data in addition to the audio data on the disc. The disc can be played on a regular audio CD player, but when played on a special CD+G player, it can output a graphics signal (typically, the CD+G player is hooked up to a television set or a computer monitor); these graphics are almost exclusively used to display lyrics on a television set for karaoke performers to sing along with. The CD+G format takes advantage of the channels R through W. These six bits store the graphics information.
CD + Extended Graphics (CD+EG, also known as CD+XG) is an improved variant of the Compact Disc + Graphics (CD+G) format. Like CD+G, CD+EG uses basic CD-ROM features to display text and video information in addition to the music being played. This extra data is stored in subcode channels R-W. Very few CD+EG discs have been published.
=== Super Audio CD ===
Super Audio CD (SACD) is a high-resolution, read-only optical audio disc format that was designed to provide higher-fidelity digital audio reproduction than the Red Book. Introduced in 1999, it was developed by Sony and Philips, the same companies that created the Red Book. SACD was in a format war with DVD-Audio, but neither has replaced audio CDs. The SACD standard is referred to as the Scarlet Book standard.
Titles in the SACD format can be issued as hybrid discs; these discs contain the SACD audio stream as well as a standard audio CD layer which is playable in standard CD players, thus making them backward compatible.
=== CD-MIDI ===
CD-MIDI is a format used to store music-performance data, which upon playback is performed by electronic instruments that synthesize the audio. Hence, unlike the original Red Book CD-DA, these recordings are not digitally sampled audio recordings. The CD-MIDI format is defined as an extension of the original Red Book.
=== CD-ROM ===
For the first few years of its existence, the CD was a medium used purely for audio. In 1988, the Yellow Book CD-ROM standard was established by Sony and Philips, which defined a non-volatile optical data computer data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive.
=== Video CD ===
Video CD (VCD, View CD, and Compact Disc digital video) is a standard digital format for storing video media on a CD. VCDs are playable in dedicated VCD players, most modern DVD-Video players, personal computers, and some video game consoles. The VCD standard was created in 1993 by Sony, Philips, Matsushita, and JVC and is referred to as the White Book standard.
Overall picture quality is intended to be comparable to VHS video. Poorly compressed VCD video can sometimes be of lower quality than VHS video, but VCD exhibits block artifacts rather than analog noise and does not deteriorate further with each use. 352×240 (or SIF) resolution was chosen because it is half the vertical and half the horizontal resolution of the NTSC video. 352×288 is a similarly one-quarter PAL/SECAM resolution. This approximates the (overall) resolution of an analog VHS tape, which, although it has double the number of (vertical) scan lines, has a much lower horizontal resolution.
=== Super Video CD ===
Super Video CD (Super Video Compact Disc or SVCD) is a format used for storing video media on standard compact discs. SVCD was intended as a successor to VCD and an alternative to DVD-Video and falls somewhere between both in terms of technical capability and picture quality.
SVCD has two-thirds the resolution of DVD, and over 2.7 times the resolution of VCD. One CD-R disc can hold up to 60 minutes of standard-quality SVCD-format video. While no specific limit on SVCD video length is mandated by the specification, one must lower the video bit rate, and therefore quality, to accommodate very long videos. It is usually difficult to fit much more than 100 minutes of video onto one SVCD without incurring a significant quality loss, and many hardware players are unable to play a video with an instantaneous bit rate lower than 300 to 600 kilobits per second.
=== Photo CD ===
Photo CD is a system designed by Kodak for digitizing and storing photos on a CD. Launched in 1992, the discs were designed to hold nearly 100 high-quality images, scanned prints, and slides using special proprietary encoding. Photo CDs are defined in the Beige Book and conform to the CD-ROM XA and CD-i Bridge specifications as well. They are intended to play on CD-i players, Photo CD players, and any computer with suitable software (irrespective of operating system). The images can also be printed out on photographic paper with a special Kodak machine. This format is not to be confused with Kodak Picture CD, which is a consumer product in CD-ROM format.
=== CD-i ===
The Philips Green Book specifies a standard for interactive multimedia compact discs designed for CD-i players (1993). CD-i discs can contain audio tracks that can be played on regular CD players, but CD-i discs are not compatible with most CD-ROM drives and software. The CD-i Ready specification was later created to improve compatibility with audio CD players, and the CD-i Bridge specification was added to create CD-i-compatible discs that can be accessed by regular CD-ROM drives.
=== CD-i Ready ===
Philips defined a format similar to CD-i called CD-i Ready, which puts CD-i software and data into the pregap of track 1. This format was supposed to be more compatible with older audio CD players.
=== Enhanced Music CD (CD+) ===
Enhanced Music CD, also known as CD Extra or CD Plus, is a format that combines audio tracks and data tracks on the same disc by putting audio tracks in a first session and data in a second session. It was developed by Philips and Sony, and it is defined in the Blue Book.
=== VinylDisc ===
VinylDisc is the hybrid of a standard audio CD and the vinyl record. The vinyl layer on the disc's label side can hold approximately three minutes of music.
== Manufacture, cost, and pricing ==
In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. The wholesale cost of CDs was $0.75 to $1.15, while the typical retail price of a prerecorded music CD was $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent.
== Writable compact discs ==
=== Recordable CD ===
Recordable Compact Discs, CD-Rs, are injection-molded with a blank data spiral. A photosensitive dye is then applied, after which the discs are metalized and lacquer-coated. The write laser of the CD recorder changes the color of the dye to allow the read laser of a standard CD player to see the data, just as it would with a standard stamped disc. The resulting discs can be read by most CD-ROM drives and played in most audio CD players. CD-Rs follow the Orange Book standard.
CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. Errors can be predicted using surface error scanning. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. Testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions.
The recordable audio CD is designed to be used in a consumer audio CD recorder. These consumer audio CD recorders use SCMS (Serial Copy Management System), an early form of digital rights management (DRM), to conform to the AHRA (Audio Home Recording Act). The Recordable Audio CD is typically somewhat more expensive than CD-R due to lower production volume and a 3 percent AHRA royalty used to compensate the music industry for the making of a copy. The higher capacity is incompatible with some recorders and recording software.
=== ReWritable CD ===
CD-RW is a re-recordable medium that uses a metallic alloy instead of a dye. The write laser, in this case, is used to heat and alter the properties (amorphous vs. crystalline) of the alloy, and hence change its reflectivity. A CD-RW does not have as great a difference in reflectivity as a pressed CD or a CD-R, and so many earlier CD audio players cannot read CD-RW discs, although most later CD audio players and stand-alone DVD players can. CD-RWs follow the Orange Book standard.
The ReWritable Audio CD is designed to be used in a consumer audio CD recorder, which will not (without modification) accept standard CD-RW discs. These consumer audio CD recorders use the Serial Copy Management System (SCMS), an early form of digital rights management (DRM), to conform to the United States' Audio Home Recording Act (AHRA). The ReWritable Audio CD is typically somewhat more expensive than CD-R due to (a) lower volume and (b) a 3 percent AHRA royalty used to compensate the music industry for the making of a copy.
== Copy protection ==
The Red Book audio specification, except for a simple anti-copy statement in the subcode, does not include any copy protection mechanism. Known at least as early as 2001, attempts were made by record companies to market copy-protected non-standard compact discs, which cannot be ripped, or copied, to hard drives or easily converted to other formats (like FLAC, MP3 or Vorbis). One major drawback to these copy-protected discs is that most will not play on either computer CD-ROM drives or some standalone CD players that use CD-ROM mechanisms. Philips has stated that such discs are not permitted to bear the trademarked Compact Disc Digital Audio logo because they violate the Red Book specifications. Numerous copy-protection systems have been countered by readily available, often free, software, or even by simply turning off automatic AutoPlay to prevent the running of the DRM executable program.
|
[
"Ripping",
"non-return-to-zero, inverted",
"Super Audio CD",
"CD Digital Audio",
"Business card",
"Geotrichum candidum",
"MiB",
"digital rights management",
"Compact Disc Digital Audio",
"CD-i Bridge",
"device driver",
"Optical disc",
"Blue Book (CD standard)",
"linear motor",
"DVD-Audio",
"computer data storage",
"Blu-ray",
"semiconductor laser",
"data integrity",
"VHS",
"Serial Copy Management System",
"CD player",
"MP3 CD",
"CD + Extended Graphics",
"dubbeltje",
"music sales",
"audio formats",
"cassette tape",
"karaoke",
"Extended Resolution Compact Disc",
"polycarbonate",
"CD recorder",
"stereo",
"Beethoven's Ninth Symphony",
"Monaural",
"kilobit",
"subcode",
"copy protection",
"worm gear",
"Comparison of popular optical data-storage systems",
"phonograph record",
"iTunes",
"photodiode",
"United States",
"C2 error",
"Megabyte",
"screen printing",
"near infrared",
"μm",
"mono sound",
"LaserDisc",
"MP3",
"JVC",
"Optical disc authoring",
"market share",
"Norio Ohga",
"CD writer",
"8-track cartridges",
"Session (CD)",
"Enhanced Music CD",
"CD",
"Eight-to-fourteen modulation",
"spin coated",
"Wave interference",
"MIDI",
"List of optical disc manufacturers",
"visible spectrum",
"AutoPlay",
"CD-DA",
"compact cassette",
"Ecma International",
"PCM",
"ringtones",
"Picture CD",
"Music download",
"Rainbow Books",
"Philips",
"hard disk drive",
"HD DVD",
"Compact Disc + Graphics",
"Four-channel Compact Disc Digital Audio",
"audio storage",
"Optical disc packaging",
"eight-to-fourteen modulation",
"Source Input Format",
"wavelength",
"Heitaro Nakajima",
"Kodak",
"Pregap",
"format war",
"Sony",
"Nanometre",
"CD-ROM",
"Audio Home Recording Act",
"Gramophone record",
"executable",
"FLAC",
"DVD-Video",
"Vorbis",
"binary data",
"Apple Inc.",
"Photo CD",
"Gold compact disc",
"Mini CD",
"consumer",
"market dominance",
"CD-i",
"Optical disc drive",
"Universal Music Japan",
"album era",
"Super Video CD",
"CD-RW",
"mechanical pencil",
"44.1 kHz",
"DVD",
"infrared",
"CD single",
"CD-R",
"BenQ",
"high fidelity",
"CD-i Ready",
"diffraction grating",
"data storage",
"operating system",
"Optical Disc",
"Liquid-crystal display",
"Digital media",
"Kees Immink",
"CD-Text",
"Plextor",
"The New York Times",
"helium–neon laser",
"digital audio",
"Video CD",
"Nero DiscSpeed",
"offset printing",
"aluminum",
"Panasonic",
"Japan",
"sampling rate",
"display resolution",
"CD-ROM XA",
"disc rot",
"Green Book (CD standard)",
"cross-interleaved Reed–Solomon coding",
"constant linear velocity",
"optical disc",
"personal computer"
] |
6,431 |
Charles Farrar Browne
|
Charles Farrar Browne (April 26, 1834 – March 6, 1867) was an American humor writer, better known under his nom de plume, Artemus Ward, which as a character, an illiterate rube with "Yankee common sense", Browne also played in public performances. He is considered to be America's first stand-up comedian. His birth name was Brown but he added the "e" after he became famous.
==Biography==
Browne was born in Waterford, Maine. He began his career as a compositor
Browne's companion at the Plain Dealer, George Hoyt, wrote: "his desk was a rickety table which had been whittled and gashed until it looked as if it had been the victim of lightning. His chair was a fit companion thereto, a wabbling, unsteady affair, sometimes with four and sometimes with three legs. But Browne saw neither the table, nor the chair, nor any person who might be near, nothing, in fact, but the funny pictures which were tumbling out of his brain. When writing, his gaunt form looked ridiculous enough. One leg hung over the arm of his chair like a great hook, while he would write away, sometimes laughing to himself, and then slapping the table in the excess of his mirth."
In 1860, he became editor of the first Vanity Fair, a humorous New York weekly that failed in 1863. At about the same time, he began to appear as a lecturer who, by his droll and eccentric humor, attracted large audiences. Browne was also known as a member of the New York bohemian set which included leader Henry Clapp Jr., Walt Whitman, Fitz Hugh Ludlow, and actress Adah Isaacs Menken. playing the part of Artemus Ward as an illiterate rube but with "Yankee common sense." In the American Garden of the Cleveland Cultural Gardens in Rockefeller Park, a monument of him was erected, next to Mark Twain.
==Stories==
A Visit to Brigham Young
Women's Rights
One of Mr Ward's Business Letters
On "Forts"
Fourth of July Oration
High-Handed Outrage at Utica
Artemus Ward and the Prince of Wales
Interview with Lincoln
Letters to his Wife
==Books==
Artemus Ward His Book (1862) (full text online)
Artemus Ward His Travels (1865) (full text online)
Artemus Ward Among the Mormons (1865) (full text online)
Artemus Ward in London (1867) (full text online)
Artemus Ward's Panorama (1869) (full text online)
Artemus Ward's Lecture (1869) (full text online)
|
[
"President of the United States",
"Abraham Lincoln",
"humor",
"Fitz Hugh Ludlow",
"Compositor (typesetting)",
"Kensal Green Cemetery",
"Punch (magazine)",
"Cleveland, Ohio",
"Brigham Young",
"Waterford, Maine",
"Walt Whitman",
"Adah Isaacs Menken",
"San Francisco",
"Platt's Music Hall",
"Southampton",
"Hampshire",
"The Plain Dealer",
"Railcar",
"Flatboat",
"Virginia City, Nevada",
"rock salt",
"California Legacy Project",
"Bohemianism",
"the Golden Era",
"Bret Harte",
"pen name",
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"Former magazines named Vanity Fair",
"Cleveland",
"elementary school",
"Nevada",
"Mark Twain",
"England",
"canal",
"Rockefeller Park",
"tuberculosis",
"Dan De Quille",
"Henry Clapp Jr.",
"Cleveland Cultural Gardens",
"shotgun"
] |
6,432 |
Caelum
|
{{Infobox constellation
| name = Caelum
| abbreviation = Cae
| genitive = Caeli It is the eighth-smallest constellation, and subtends a solid angle of around 0.038 steradians, just less than that of Corona Australis.
Due to its small size and location away from the plane of the Milky Way, Caelum is a rather barren constellation, with few objects of interest. The constellation's brightest star, Alpha Caeli, is only of magnitude 4.45, and only one other star, (Gamma) γ1 Caeli, is brighter than magnitude 5 . Other notable objects in Caelum are RR Caeli, a binary star with one known planet approximately away; X Caeli, a Delta Scuti variable that forms an optical double with γ1 Caeli; and HE0450-2958, a Seyfert galaxy that at first appeared as just a jet, with no host galaxy visible.
== History ==
Caelum was incepted as one of fourteen southern constellations in the 18th century by Nicolas Louis de Lacaille, a French astronomer and celebrated of the Age of Enlightenment.
It retains its name Burin among French speakers, latinized in his catalogue of 1763 as Caelum Sculptoris (“Engraver's Chisel”).
Francis Baily shortened this name to Caelum, as suggested by John Herschel. In Lacaille's original chart, it was shown as a pair of engraver's tools: a standard burin and more specific shape-forming échoppe tied by a ribbon, but came to be ascribed a simple chisel.
== Characteristics ==
Caelum is bordered by Dorado and Pictor to the south, Horologium and Eridanus to the east, Lepus to the north, and Columba to the west. Covering only 125 square degrees, it ranks 81st of the 88 modern constellations in size.
Its main asterism consists of four stars, and twenty stars in total are brighter than magnitude 6.5 . The International Astronomical Union (IAU) adopted the three-letter abbreviation “Cae” for the constellation in 1922.
Its main stars are visible in favourable conditions and with a clear southern horizon, for part of the year as far as about the 41st parallel north{{efn|1=While parts technically reach the horizon to observers between 41°N and 62°N, stars within a few degrees of the horizon are to all intents and purposes unobservable. Caelum is too far south for any of its stars to bear Flamsteed designations.
The brightest star, (Alpha) α Caeli, is a double star, containing an F-type main-sequence star of magnitude 4.45 and a red dwarf of magnitude 12.5 , from Earth. (Beta) β Caeli, another F-type star of magnitude 5.05 , is further away, being located from Earth. Unlike α, β Caeli is a subgiant star, slightly evolved from the main sequence. (Delta) δ Caeli, also of magnitude 5.05 , is a B-type subgiant and is much farther from Earth, at .
(Gamma) γ1Caeli is a double-star with a red giant primary of magnitude 4.58 and a secondary of magnitude 8.1 . The primary is from Earth. The two components are difficult to resolve with small amateur telescopes because of their difference in visual magnitude and their close separation. This star system forms an optical double with the unrelated X Caeli (previously named γ2Caeli), a Delta Scuti variable located from Earth. These are a class of short-period (six hours at most) pulsating stars that have been used as standard candles and as subjects to study astroseismology. The only other variable star in Caelum visible to the naked eye is RV Caeli, a pulsating red giant of spectral type M1III, which varies between magnitudes 6.44 and 6.56 .
Three other stars in Caelum are still occasionally referred to by their Bayer designations, although they are only on the edge of naked-eye visibility. (Nu) ν Caeli is another double star, containing a white giant of magnitude 6.07 and a star of magnitude 10.66, with unknown spectral type. The system is approximately away. at magnitude 6.24, is much redder and farther away, being a red giant around from Earth. (Zeta) ζ Caeli is even fainter, being only of magnitude 6.36 . This star, located away, is a K-type subgiant of spectral type K1. The other twelve naked-eye stars in Caelum are not referred to by Bode's Bayer designations anymore, including RV Caeli.
One of the nearest stars in Caelum is the eclipsing binary star RR Caeli, at a distance of . Despite its closeness to the Earth, the system's apparent magnitude is only 14.40 due to the faintness of its components, and thus it cannot be easily seen with amateur equipment. The system is a post-common-envelope binary and is losing angular momentum over time, which will eventually cause mass transfer from the red dwarf to the white dwarf. In approximately 9–20 billion years, this will cause the system to become a cataclysmic variable. In 2012, the system was found to contain a giant planet, and there is evidence for a second substellar body. , it is believed two planets orbit RR Caeli.
Another nearby star is LHS 1678, an astrometric binary located some 65 light-years away. The primary star is a red dwarf hosting three close-in exoplanets, all smaller than Earth, the secondary component is a likely brown dwarf. This system is notable as the closest star to Alpha Caeli, just 3.3 light-years distant. Due to its closeness, α Caeli would shine at magnitude from LHS 1678, brighter than Sirius in our sky.
=== Deep-sky objects ===
Due to its small size and location away from the plane of the Milky Way, Caelum is rather devoid of deep-sky objects, and contains no Messier objects. The only deep-sky object in Caelum to receive much attention is HE0450-2958, an unusual Seyfert galaxy. Originally, the jet's host galaxy proved elusive to find, and this jet appeared to be emanating from nothing. Although it has been suggested that the object is an ejected supermassive black hole, the host is now agreed to be a small galaxy that is difficult to see due to light from the jet and a nearby starburst galaxy.
The 13th magnitude planetary nebula PN G243-37.1 is also in the eastern regions of the constellation. It is one of only a few planetary nebulae found in the galactic halo, being light-years below the Milky Way's 1000 light-year-thick disk.
Galaxies NGC 1595, NGC 1598, and the Carafe galaxy are known as the Carafe group. The Carafe galaxy is a Seyfert galaxy with ring. Its location is 4:28 / -47°54' (2000.0).
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] |
6,433 |
Clarinet
|
The clarinet is a single-reed musical instrument in the woodwind family, with a nearly cylindrical bore and a flared bell.
Clarinets comprise a family of instruments of differing sizes and pitches. The clarinet family is the largest woodwind family, ranging from the BB♭ contrabass to the A♭ piccolo. The B soprano clarinet is the most common type, and is the instrument usually indicated by the word "clarinet".
German instrument maker Johann Christoph Denner is generally credited with inventing the clarinet sometime around 1700 by adding a register key to the chalumeau, an earlier single-reed instrument. Over time, additional keywork and airtight pads were added to improve the tone and playability. Today the clarinet is a standard fixture of the orchestra and concert band and is used in classical music, military bands, klezmer, jazz, and other styles.
==Etymology==
The word "clarinet" may have entered the English language via the French (the feminine diminutive of Old French ), or from Provençal , originating from the Latin root . The word is related to Middle English , a type of trumpet, the name of which derives from the same root.
The earliest mention of the word "clarinette" being used for the instrument dates to a 1710 order placed by the Duke of Gronsfeld for two instruments made by Jacob Denner. The English form "clarinet" is found as early as 1733, and the now-archaic "clarionet" appears from 1784 until the early 20th century.
A person who plays the clarinet is called a clarinetist (in North American English), a clarinettist (in British English), or simply a clarinet player.
==Development==
The clarinet has its roots in early single-reed instruments used in Ancient Greece and Ancient Egypt. The modern clarinet developed from a Baroque instrument called the chalumeau. This instrument was similar to a recorder, but with a single-reed mouthpiece and a cylindrical bore. Lacking a register key, it was played mainly in its fundamental register, with a limited range of about one and a half octaves. It had eight finger holes, like a recorder, and a written pitch range from F3 to G4. At this time, contrary to modern practice, the reed was placed in contact with the upper lip.
Around the beginning of the 18th century the German instrument maker Johann Christoph Denner (or possibly his son Jacob Denner) equipped a chalumeau in the alto register with two keys, one of which enabled access to a higher register. This second register did not begin an octave above the first, as with other woodwind instruments, but started an octave and a perfect fifth higher than the first. A second key, at the top, extended the range of the first register to A4 and, together with the register key, to B4. Later, Denner lengthened the bell and provided it with a third key to extend the pitch range down to E3. In 1791 Mozart composed the Concerto for Clarinet and Orchestra in A major for this instrument, with passages ranging down to C3. By the time of Beethoven (), the clarinet was a fixed member in the orchestra.
The number of keys was limited because their felt pads did not seal tightly. Iwan Müller invented the stuffed pad, originally made of kid leather. These in combination with countersunk tone holes sealed the keyholes sufficiently to permit the use of an increased number of keys. In 1812 Müller presented a clarinet with seven finger holes and thirteen keys, which he called "clarinet omnitonic" since it was capable of playing in all keys. It was no longer necessary to use differently tuned clarinets for a different keys. Müller is also considered the inventor of the metal ligature and the thumb rest. During this period the typical embouchure also changed, orienting the mouthpiece with the reed facing downward. This was first recommended in 1782 and became standard by the 1830s.
In the late 1830s, and the Reform Boehm system, which combined Boehm-system keywork with a German mouthpiece and bore.
The Albert clarinet was developed by Eugène Albert in 1848. This model was based on the Müller clarinet with some changes to keywork, and was also known as the "simple system". It included a "spectacle key" patented by Adolphe Sax and rollers to improve little-finger movement. After 1861, a "patent C sharp" key developed by Joseph Tyler was added to other clarinet models. Improved versions of Albert clarinets were built in Belgium and France for export to the UK and the US.
Around 1860, clarinettist Carl Baermann and instrument maker Georg Ottensteiner developed the patented Baermann/Ottensteiner clarinet. This instrument had new connecting levers, allowing multiple fingering options to operate some of the pads. In the early 20th century, the German clarinetist and clarinet maker Oskar Oehler presented a clarinet using similar fingerings to the Baermann instrument, with significantly more toneholes than the Böhm model. The new clarinet was called the Oehler system clarinet or German clarinet, while the Böhm clarinet has since been called the French clarinet. The French clarinet differs from the German not only in fingering but also in sound. Richard Strauss noted that "French clarinets have a flat, nasal tone, while German ones approximate the singing voice". Among modern instruments the difference is smaller, although intonation differences persist.
Today the Boehm system is standard everywhere except in Germany and Austria, where the Oehler clarinet is still used. Some contemporary Dixieland players continue to use Albert system clarinets. The Reform Boehm system is also popular in the Netherlands.
==Acoustics==
The clarinet's cylindrical bore is the main reason for its distinctive timbre, which varies between the three main registers (the chalumeau, clarion, and altissimo). The A and B clarinets have nearly the same bore and nearly identical tonal quality, although the A typically has a slightly warmer sound. The tone of the E clarinet is brighter and can be heard through loud orchestral textures. The bass clarinet has a characteristically deep, mellow sound, and the alto clarinet sounds similar to the bass, though not as dark.
The production of sound by a clarinet follows these steps:
The mouthpiece and reed are surrounded by the player's lips, which put light, even pressure on the reed and form an airtight seal. Air is blown past the reed and down the instrument. In the same way a flag flaps in the breeze, the air rushing past the reed causes it to vibrate. As air pressure from the mouth increases, the amount the reed vibrates increases until the reed hits the mouthpiece.The reed stays pressed against the mouthpiece until either the springiness of the reed forces it to open or a returning pressure wave 'bumps' into the reed and opens it. Each time the reed opens, a puff of air goes through the gap, after which the reed swings shut again. When played loudly, the reed can spend up to 50% of the time shut. The 'puff of air' or compression wave (at around 3% greater pressure than the surrounding air This in combination with the cut-off frequency (where a significant drop in resonance occurs) results in the characteristic tone of the clarinet.
The bore is cylindrical for most of the tube with an inner bore diameter between , but there is a subtle hourglass shape, with the thinnest part below the junction between the upper and lower joint. This hourglass shape, although invisible to the naked eye, helps to correct the pitch and responsiveness of the instrument. The diameter of the bore affects the instrument's sound characteristics. The bell at the bottom of the clarinet flares out to improve the tone and tuning of the lowest notes. Covering or uncovering the tone holes varies the length of the pipe, changing the resonant frequencies of the enclosed air column and hence the pitch. The player moves between the chalumeau and clarion registers through use of the register key. The open register key stops the fundamental frequency from being reinforced, making the reed vibrate at three times the frequency, which produces a note a twelfth above the original note. Their vocal tract will be shaped to resonate at frequencies associated with the tone being produced.
Vibrato, a pulsating change of pitch, is rare in classical literature; however, certain performers, such as Richard Stoltzman, use vibrato in classical music. Other effects are glissando, growling, trumpet sounds, double tongue, flutter tongue and circular breathing. Special lip-bending may be used to play microtonal intervals. There have also been efforts to create a quarter tone clarinet.
==Construction==
===Materials===
Clarinet bodies have been made from a variety of materials including wood, plastic, hard rubber or Ebonite, metal, and ivory. The vast majority of wooden clarinets are made from African blackwood (grenadilla), or, more uncommonly, Honduran rosewood or cocobolo. Historically other woods, particularly boxwood and ebony, were used. Since the mid-20th century, clarinets (particularly student or band models) are also made from plastics, such as acrylonitrile butadiene styrene (ABS). One of the first such blends of plastic was Resonite, a term originally trademarked by Selmer. The Greenline model by Buffet Crampon is made from a composite of resin and the African blackwood powder left over from the manufacture of wooden clarinets.
Metal soprano clarinets were popular in the late 19th century, particularly for military use. Metal is still used for the bodies of some contra-alto and contrabass clarinets and the necks and bells of nearly all alto and larger clarinets.
Mouthpieces are generally made of hard rubber, although some inexpensive mouthpieces may be made of plastic. Other materials such as glass, wood, ivory, and metal have also been used. Ligatures are often made of metal and tightened using one or more adjustment screws; other materials include plastic, string, or fabric.
===Reed===
The clarinet uses a single reed made from the cane of Arundo donax. Reeds may also be manufactured from synthetic materials. The ligature fastens the reed to the mouthpiece. When air is blown through the opening between the reed and the mouthpiece facing, the reed vibrates and produces the clarinet's sound.
Most players buy manufactured reeds, although many make adjustments to these reeds, and some make their own reeds from cane "blanks". Reeds come in varying degrees of hardness, generally indicated on a scale from one (soft) through five (hard). This numbering system is not standardized—reeds with the same number often vary in hardness across manufacturers and models. Reed and mouthpiece characteristics work together to determine ease of playability and tonal characteristics.
===Components===
The reed is attached to the mouthpiece by the ligature, and the top half-inch or so of this assembly is held in the player's mouth. In the past, string was used to bind the reed to the mouthpiece. The formation of the mouth around the mouthpiece and reed is called the embouchure. The reed is on the underside of the mouthpiece, pressing against the player's lower lip, while the top teeth normally contact the top of the mouthpiece (some players roll the upper lip under the top teeth to form what is called a 'double-lip' embouchure). Adjustments in the strength and shape of the embouchure change the tone and intonation. Players sometimes relieve the pressure on the upper teeth and inner lower lip by attaching a pad to the top of the mouthpiece or putting temporary cushioning on the lower teeth.
The mouthpiece attaches to the barrel. Tuning can be adjusted by using barrels of varying lengths or by pulling out the barrel to increase the instrument's length. On basset horns and lower clarinets, there is a curved metal neck instead of a barrel.
The main body of most clarinets has an upper joint, whose mechanism is mostly operated by the left hand, and a lower joint, mostly operated by the right hand. Some clarinets have a one-piece body. The modern soprano clarinet has numerous tone holes—seven are covered with the fingertips and the rest are operated using a set of 17 keys. The most common system of keys was named the Boehm system by its designer Hyacinthe Klosé after flute designer Theobald Boehm, but it is not the same as the Boehm system used on flutes. The other main key system is the Oehler system, which is used mostly in Germany and Austria. The related Albert system is used by some jazz, klezmer, and eastern European folk musicians. The Albert and Oehler systems are both based on the early Mueller system.
The cluster of keys at the bottom of the upper joint (protruding slightly beyond the cork of the joint) are known as the trill keys and are operated by the right hand. The entire weight of the smaller clarinets is supported by the right thumb behind the lower joint on what is called the thumb rest. Larger clarinets are supported with a neck strap or a floor peg.
Below the main body is a flared end known as the bell. The bell does not amplify the sound but improves the uniformity of the instrument's tone for the lowest notes in each register.
==Clarinet family and ranges==
Clarinets have the largest pitch range of common woodwinds. The range of a clarinet is usually divided into three registers. The low chalumeau register extends from the notated E3 (C3 if available) to the notated B4. The middle clarion register covers a little more than an octave (from the written B4 to C5). The high altissimo register consists of the notes above it. The three registers have characteristically different sounds: the chalumeau is full and dark, the clarion register is brighter and sweet, like a high trumpet from a distance, and the altissimo can be piercing and sometimes shrill.
Initially only C clarinets were available, but soon clarinets in B and A and the basset horn in F and G were developed. From the 19th century to the middle of the 20th century, an extensive family of clarinets developed, from high A to subcontrabass. Apart from the clarinets tuned in C (C soprano clarinet and basset clarinet in C), all clarinets are transposing instruments. The instruments above the C clarinet sound higher than notated, such as the aforementioned A clarinet a sixth higher, the longer instruments sound lower, such as the B clarinet by one tone and the B contrabass clarinet by two octaves and one tone.
==Performance practice==
The modern orchestra frequently includes two clarinetists, each usually equipped with a B and an A clarinet, and clarinet parts commonly alternate between the instruments. The standard of using are soprano clarinets in B and A has to do partly with the history of the instrument and partly with acoustics and aesthetics. Before about 1800, due to the lack of airtight pads, practical woodwinds could have only a few keys. The low (chalumeau) register of the clarinet spans a twelfth (an octave plus a perfect fifth) before overblowing, so the clarinet needs keys/holes to produce all nineteen notes in this range. This involves more keywork than on instruments that "overblow" at the octave—oboes, flutes, bassoons, and saxophones need only twelve notes before overblowing. Since clarinets with few keys cannot play chromatically, they are limited to playing in closely related keys. With the advent of airtight pads and improved key technology, more keys were added to woodwinds and the need for clarinets in multiple keys was reduced. The use of instruments in C, B, and A persisted, with each used as specified by the composer.
The lower-pitched clarinets sound "mellower" (less bright), and the C clarinet—the highest and brightest sounding of these three—fell out of favor as the other two could cover its range and their sound was considered better.
Clarinet trio: clarinet, piano, and another instrument (for example, a string instrument).
Clarinet quartet: three B clarinets and bass clarinet; two B clarinets, alto clarinet, and bass; two B, an E alto clarinet, and a B bass clarinet; sometimes four B sopranos; and other possibilities such as the use of a basset horn, especially in European classical works.
Clarinet quintet: a clarinet plus a string quartet or, in more contemporary music, a configuration of five clarinets.
Wind quintet: flute, oboe, clarinet, bassoon, and horn.
The A clarinet, B clarinet, alto clarinet, bass clarinet, and contra-alto/contrabass clarinet are commonly used in concert bands, which generally have multiple B clarinets; there are commonly three or even four B clarinet parts with two to three players per part. The clarinet is also used in military bands; author Eric Hoeprich suggests that "it was the role of the clarinet in the military band... that ultimately provided the key to its future popularity", since it was particularly suited to the ensemble.
Clarinet choir contains many clarinets playing together, usually including several members of the clarinet family. This ensemble first emerged in 1927. The homogeneity of tone across the different members of the clarinet family produces an effect with some similarities to a human choir. Parts for non-clarinets, such as voice or French horn, are sometimes included in the repertoire.
==Repertoire==
=== Classical ===
The clarinet evolved later than other orchestral woodwind instruments, leaving solo repertoire from the Classical period onward, but few works from the Baroque era. Examples of the first uses of clarinets include Vivaldi's 1716 oratorio Juditha triumphans with two C clarinets, and Handel's 1740 Ouverture for two clarinets and horn. In the 1750s, clarinets were introduced in the orchestra of La Pouplinière in Paris. Johann Stamitz composed the first known concerto for B clarinet for the principal clarinetist of this orchestra. Johann Melchior Molter wrote six clarinet concertos for clarinet in D, the first dated to around 1742.
Clarinets appeared in the Mannheim orchestra under Stamitz and in other orchestras from 1758, but were not commonly used before the 19th century. Harmonie wind ensembles including clarinets were common from the mid-18th century. Classical composers of solo or duo concertos for this instrument included Karl Stamitz and František Xaver Pokorný. The first clarinet sonata was written in 1770 by the Neapolitan composer Gregorio Sciroli.
Wolfgang Amadeus Mozart first used the clarinet in 1771 in his Divertimento K. 113 and later in the Paris Symphony of 1778. From Idomeneo onward, the clarinet appeared in all his operas, as well as in his symphonies and piano concertos. His chamber works for clarinet include the Gran Partita, the Clarinet Quintet, and the Kegelstatt Trio. The latter two works were written for his friend, virtuoso Anton Stadler, as was his Clarinet Concerto. Beethoven's chamber music highlights the instrument, particularly in the Quintet Op. 16, the Septet Op. 20 and Trio Op. 38.
While the Classical period often used the clarinet, the Romantic era incorporated it more as an integral part of the orchestra. The clarinet became a staple, with composers such as Schubert, Mendelssohn, Berlioz, Dvořák, Smetana, Brahms, Tchaikovsky, and Rimsky-Korsakov writing prominent clarinet passages in their orchestral works. In Romantic opera orchestration, the clarinet frequently takes on expressive, lyrical roles. The clarinet section expanded to three or more players, with some performing on auxiliary instruments such as the bass clarinet. Certain operas, such as Strauss's Elektra, require up to eight players.
Chamber music featuring the clarinet became increasingly diverse. The instrument appears in the works of Franz Schubert (Octet), Felix Mendelssohn (sonata with piano), Robert Schumann (Phantasiestücke for clarinet and piano, Märchenerzählungen with piano and viola), and Johannes Brahms (two sonatas, the Trio with cello and piano and the Clarinet Quintet for Clarinet in A and string quartet). Carl Maria von Weber wrote several major works for the clarinet, including the Clarinet Concerto No. 1 in F minor, the Clarinet Concerto No. 2 in E flat major, and the Grand Duo Concertant for clarinet and piano. However, from 1830 until 1900 "no major composer wrote a clarinet concerto, and the few concertos written for the instrument in this time period have not found a secure place in the repertoire".
The clarinet is used frequently in 20th- and 21st-century classical music. It embodies the cat in Peter and the Wolf by Sergei Prokofiev, and the symphonies of Shostakovich "provide a veritable compendium of writing for all members of the orchestral clarinet family; for him the instruments provided a toolkit for the expression of the deepest tragedy as well as the sharpest satire". Significant pieces for unaccompanied clarinet include Three Pieces (1919) by Igor Stravinsky and "L'abîme des oiseaux" from the Quatuor pour la fin du temps (1941) by Olivier Messiaen. Concertos with orchestral accompaniment from this period include those by Carl Nielsen and Aaron Copland. Sonatas were composed by Felix Draeseke, Max Reger, Arnold Bax, John Ireland, Francis Poulenc, Leonard Bernstein, and Paul Hindemith. Notable chamber works include Four Pieces by Alban Berg, Contrastes with violin and piano by Béla Bartók, The Soldier's Tale by Stravinsky, and the Suite for clarinet, violin and piano by Darius Milhaud.
===Jazz===
The clarinet was a central instrument in jazz, beginning with early jazz players in the 1910s. It remained a signature instrument of the genre through much of the big band era into the 1940s. One of the most recognizable clarinet excerpts is the virtuoso glissando that introduces the 1924 Rhapsody in Blue by George Gershwin. Swing performers such as Benny Goodman and Artie Shaw rose to prominence in the late 1930s.
Beginning in the 1940s, the clarinet faded from its prominent position in jazz. By that time, an interest in Dixieland, a revival of traditional New Orleans jazz, had begun. Pete Fountain was one of the best known performers in this genre. The clarinet's place in the jazz ensemble was usurped by the saxophone, which projects a more powerful sound and uses a less complicated fingering system. The clarinet did not entirely disappear from jazz—prominent players since the 1950s include Stan Hasselgård, Jimmy Giuffre, Eric Dolphy (on bass clarinet), Perry Robinson, and John Carter. In the US, the prominent players on the instrument since the 1980s have included Eddie Daniels, Don Byron, Marty Ehrlich, Ken Peplowski, and others playing in both traditional and contemporary styles.
===Other genres===
The clarinet is uncommon, but not unheard of, in rock music. Jerry Martini played clarinet on Sly and the Family Stone's 1968 hit, "Dance to the Music". The Beatles included a trio of clarinets in "When I'm Sixty-Four" from their Sgt. Pepper's Lonely Hearts Club Band album. A clarinet is prominently featured in what a Billboard reviewer termed a "Benny Goodman-flavored clarinet solo" in "Breakfast in America", the title song from the Supertramp album of the same name.
The clarinet has a significant role in vernacular music in many parts of the world. Clarinets feature prominently in klezmer music, which employs a distinctive style of playing. The popular Brazilian music style of choro uses the clarinet, as does Albanian saze and Greek kompania folk music, and Bulgarian wedding music. In Turkish folk music, the Albert system clarinet in G is often used, commonly called a "Turkish clarinet".
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"Robert Schumann",
"growling",
"Ken Peplowski",
"Jerry Martini",
"Pitch (music)",
"Arnold Bax",
"reed (instrument)",
"Alban Berg",
"harmonics",
"Sly and the Family Stone",
"Felix Draeseke",
"Dvořák",
"Wind quintet",
"aerophone",
"altissimo",
"Franz Schubert",
"Darius Milhaud",
"Albert system",
"Buffet Crampon",
"Clarinet Quintet (Mozart)",
"Clarinet Quintet (Brahms)",
"thumb rest",
"Mendelssohn",
"Symphony No. 9 (Mahler)",
"B♭ (musical note)",
"kid leather",
"František Xaver Pokorný",
"Ebonite",
"Brahms",
"Peter and the Wolf",
"Dance to the Music (song)",
"Clarinet trio",
"The Journal of the Acoustical Society of America",
"contra alto clarinet",
"acoustic resonance",
"Reform Boehm system (clarinet)",
"chalumeau",
"Requiem (Mozart)",
"John Carter (jazz musician)",
"rarefaction",
"The Galpin Society Journal",
"Dixieland",
"Max Reger",
"musical tuning",
"Smetana",
"Symphony No. 8 (Beethoven)",
"Twelfth (interval)",
"string instrument",
"Yearbook for Traditional Music",
"Iwan Müller",
"Ligature (instrument)",
"Stravinsky",
"Antonio Vivaldi",
"Harmonie",
"Francis Poulenc",
"Mazzeo system",
"Juditha triumphans",
"Clarinet choir",
"List of clarinetists",
"chamfer",
"Boehm system (clarinet)",
"Contra-alto clarinet",
"Jimmy Giuffre",
"concert band",
"Basset horn",
"vernacular music",
"string quartet",
"concert pitch",
"Hyacinthe Klosé",
"Richard Stoltzman",
"quarter tone clarinet",
"cocobolo",
"Soprano clarinet",
"Subcontrabass clarinet",
"Leonard Bernstein",
"Sgt. Pepper's Lonely Hearts Club Band",
"circular breathing",
"Le Sacre du Printemps",
"glissando",
"Eric Dolphy",
"Leblanc (musical instrument manufacturer)",
"Banda (opera)",
"Chalumeau",
"Karl Stamitz",
"21st-century classical music",
"Recorder (musical instrument)",
"Johannes Brahms",
"Theobald Böhm",
"The American Heritage Dictionary",
"Boehm system",
"oboe",
"United States Marine Band",
"Breakfast in America (song)",
"French horn",
"Adolphe Sax",
"British English",
"Jacob Denner",
"basset clarinet",
"Aaron Copland",
"Classical music era",
"Heckelphone-clarinet",
"Ligature (musical instrument)",
"register (music)",
"Idomeneo",
"Octet (Schubert)",
"Marty Ehrlich",
"ebony",
"Rimsky-Korsakov",
"Basset-horn",
"Bulgarian wedding music",
"Clarinet family",
"acrylonitrile butadiene styrene",
"Piano concertos by Wolfgang Amadeus Mozart",
"Old French",
"bore (wind instruments)",
"Basset clarinet",
"alto clarinet",
"embouchure",
"Berlioz",
"Quatuor pour la fin du temps",
"Till Eulenspiegel's Merry Pranks",
"bass clarinet",
"Ludwig van Beethoven",
"Vibrato",
"clarinet sonata",
"bassoon",
"Sergei Prokofiev",
"La Clemenza di Tito",
"Arnold Schoenberg",
"Five Pieces for Orchestra",
"Beethoven",
"hertz",
"ivory",
"Boléro",
"Felix Mendelssohn",
"Carl Baermann",
"Music Educators Journal",
"Clarinet Concerto No. 2 (Weber)",
"Béla Bartók",
"clarinet family",
"register key",
"Ancient Egypt",
"Musical tuning",
"cylinder (geometry)",
"flutter tongue",
"The Beatles",
"Elektra (opera)",
"woodwind",
"E-flat clarinet",
"Paul Hindemith",
"Fourth (interval)",
"Eugène Albert",
"military band",
"The New York Times",
"Tárogató",
"Don Byron",
"Eddie Daniels",
"Benny Goodman",
"A-flat clarinet",
"Carl Nielsen",
"Occitan language",
"Middle English",
"Clarinet concerto",
"Henri Selmer Paris",
"Buxus",
"compression wave",
"Clarinet Concerto (Mozart)",
"Louis Auguste Buffet",
"Clarinet quintet"
] |
6,434 |
Chojnów
|
Chojnów () is a small town in Legnica County, Lower Silesian Voivodeship, in south-western Poland. It is located on the Skora river, a tributary of the Kaczawa at an average altitude of above sea level. Chojnów is the administrative seat of the rural gmina called Gmina Chojnów, although the town is not part of its territory and forms a separate urban gmina. As of December 2021, the town has 13,002 inhabitants. Possible the name of nearby Hainau Island. The name is of Polish origin, and in more modern records from the 19th century, the Polish name appears as Hajnów, while Haynau is the Germanized version of the original Polish name.
The settlement of Haynow was mentioned in a 1272 deed. It was already called a civitas in a 1288 document issued by the Piast duke Henry V of Legnica, and officially received town privileges in 1333 from Duke Bolesław III the Generous. In 1292 the first castellan of Chojnów, Bronisław Budziwojowic, was mentioned. In the 14th and early 15th centuries Chojnów was granted various privileges, including staple right and gold mining right, thanks to which it flourished. In 1740 the town was captured by Prussia and subsequently annexed in 1742. In 1804 it suffered a flood.
==Population==
==Economy==
Chojnów is an industrial and agricultural town. Among local products are: paper, agricultural machinery, chains, metal furniture for hospitals, equipment for the meat industry, beer, wine, leather clothing, and clothing for infants, children and adults.
==Sights and nature==
Among the interesting monuments of Chojnów are the 13th-century castle of the Dukes of Legnica (currently used as a museum), two old churches, the Baszta Tkaczy (Weavers' Tower) and preserved fragments of city walls.
The biggest green area in Chojnów is small forest Park Piastowski (Piast's Park), named after Piast dynasty. Wild animals that can be found in the Chojnów area are roe deer, foxes, rabbits and wild domestic animals, especially cats.
==Culture and sport==
Every year in the first days of June, the Days of Chojnów (Dni Chojnowa) are celebrated. The Whole-Poland bike race Masters has been organized yearly in Chojnów for the past few years.
Chojnów has a Municipal sports and recreation center formed in 2008 holding various events, festivals, reviews, exhibitions, and competitions. The regional Museum is housed in the old Piast era castle. The collections include tiles, relics, and the castle garden. Next to the Museum there is a municipal library. In śródmiejskim Park, near the Town Hall is the amphitheatre.
The local government-run weekly newspaper is Gazeta Chojnowska, which has been published since 1992.
It is published biweekly. Editions have a run of 900 copies and it is one of the oldest newspapers in Poland issued without interruption. The Chojnów is the official newspaper of Chojnów with copy run of 750 copies.
==Education==
In Chojnów, there are two kindergartens, two elementary schools and two middle schools.
Mary Konopnickiej is the smallest elementary school in Chojnów, and is located in the northern part of the city, close to the train station and founded in 1962.
Janusz Korczak is the largest primary school in Chojnów in the southern part of the town.
Middle School No. (Pope John Paul II), it is situated in the north-western part of the city next to the "Small Church".
Gimnazjum nr 2 im. Nicolaus Copernicus is the largest high school in Chojnów.
Liceum Ogólnokształcące im. Nicolaus Copernicus
==Religion==
Chojnów is in the Catholic deanery of Chojnów and has two parishes, Immaculate Conception of the Blessed Virgin Mary and also the Holy Apostles Peter and Paul. Both parishes have active congregations.
There are also two Congregations of Jehovah's witnesses.
==Notable people==
Johann Wilhelm Ritter (1776–1810), chemist and physicist
Georg Michaelis (1857–1936), politician, Chancellor of Germany (1917).
Edith Jacobson (1897–1978), German psychoanalyst
Oswald Lange (1912–2000), German–American aerospace engineer
Horst Mahler (born 1936), German lawyer, former Red Army Faction militant, now Neo-Nazi activist
==Twin towns – sister cities==
Chojnów is twinned with:
Commentry, France
Egelsbach, Germany
Mnichovo Hradiště, Czech Republic
==Gallery==
Chojnow(js).jpg|Entrance to the Piast Castle
Chojnów, Ab-047.JPG|Flower beds in Chojnów
Chojnów, Wzgórze Chmielowe.jpg|Park Piastowski
Chojnów, Ratusz (2).jpg|Town hall
SM Chojnów kościół Niepokalanego Poczęcia NMP (5) ID 593383.jpg|Immaculate Conception Church
SM Chojnów Konarskiego4 (0).jpg|Nicolaus Copernicus Gymnasium No. 2
Chojnów, Ab-057.JPG|Monument to Polish soldiers killed in World War II and murdered in labour camps and exiled to Siberia
Łabędzi Staw.jpg|Swan's Pond (Łabędzi Staw) in winter
Chojnów, Dworzec kolejowy (2).jpg|Chojnów Railway Station
Chojnow 055 most kolejowy.jpg|Railway bridge
|
[
"Duchy of Legnica",
"Powiat",
"Dresden",
"Silesian Piasts",
"Lower Silesia",
"gmina",
"Johann Wilhelm Ritter",
"Warsaw",
"Gmina Chojnów",
"Poland",
"Habsburg monarchy",
"amphitheatre",
"Gazeta Chojnowska",
"Chancellor of Germany",
"Egelsbach",
"Red Army",
"Georg Michaelis",
"Sister city",
"A4 autostrada (Poland)",
"Silesian Eagle",
"Henry V, Duke of Legnica",
"Voivodeships of Poland",
"Lower Silesian Voivodeship",
"Polish car number plates",
"Escutcheon (heraldry)",
"Swedish Empire",
"Skora",
"Polish people",
"Kingdom of Bohemia",
"Gas light",
"Sewerage",
"refugees of the Greek Civil War",
"Bolesław III the Generous",
"Augustus III of Poland",
"Territories of Poland annexed by the Soviet Union",
"physicist",
"Polish Academy of Sciences",
"People's Republic of Poland",
"Oder-Neisse line",
"Sybirak",
"House of Habsburg",
"Commentry",
"staple right",
"Edith Jacobson",
"List of sovereign states",
"town privileges",
"Legnica County",
"Neo-Nazism",
"Złotoryja",
"castellan",
"Kingdom of Prussia",
"Zakład Narodowy im. Ossolińskich",
"Duchy of Silesia",
"Red Army Faction",
"Napoleonic wars",
"privilege (law)",
"Kingdom of Poland (1025–1385)",
"roe deer",
"Kaczawa",
"Henry III the White",
"Wrocław",
"Central European Time",
"World War II",
"Augustus II the Strong",
"Horst Mahler",
"meat industry",
"Józef Poniatowski",
"Mnichovo Hradiště",
"Duchy of Głogów",
"Legnica",
"Piast dynasty",
"Thirty Years' War",
"Napoleon Bonaparte",
"Skora River",
"Central European Summer Time",
"Gmina",
"Hussite",
"Bolesławiec",
"Roman Catholic Church",
"Oswald Lange"
] |
6,435 |
Canes Venatici
|
The English astronomer William Henry Smyth wrote in 1844 that α CVn was brighter than usual during the Restoration, as Charles II returned to England to take the throne, but gave no source for this statement, which seems to be apocryphal. Cor Caroli is a wide double star, with a primary of magnitude 2.9 and a secondary of magnitude 5.6; the primary is 110 light-years from Earth. The primary also has an unusually strong variable magnetic field.
Beta Canum Venaticorum, or Chara, is a yellow-hued main sequence star of magnitude 4.25, However, no exoplanets have been discovered around it so far.
Y Canum Venaticorum (La Superba) is a semiregular variable star that varies between magnitudes 5.0 and 6.5 over a period of around 158 days. It is a carbon star and is deep red in color,
AM Canum Venaticorum, a very blue star of magnitude 14, is the prototype of a special class of cataclysmic variable stars, in which the companion star is a white dwarf, rather than a main sequence star. It is 143 parsecs distant from the Sun.
RS Canum Venaticorum is the prototype of a special class of binary stars of chromospherically active and optically variable components.
R Canum Venaticorum is a Mira variable that ranges between magnitudes 6.5 and 12.9 over a period of approximately 329 days.
===Supervoid===
The Giant Void, an extremely large void (part of the universe containing very few galaxies), is within the vicinity of this constellation. It is regarded to be the second largest void ever discovered, slightly larger than the Eridanus Supervoid and smaller than the proposed KBC Void and 1,200 times the volume of expected typical voids. It was discovered in 1988 in a deep-sky survey. Its centre is approximately 1.5 billion light-years away.
===Deep-sky objects===
Canes Venatici contains five Messier objects, including four galaxies. One of the more significant galaxies in Canes Venatici is the Whirlpool Galaxy (M51, NGC 5194) and NGC 5195, a small barred spiral galaxy that is seen face-on. This was the first galaxy recognised as having a spiral structure, this structure being first observed by Lord Rosse in 1845.
Dim and diffuse.jpg| NGC 4242 is a dim galaxy in Canes Venatici.
NGC 4631 HST.jpg| NGC 4631 photographed by the Hubble Space Telescope.
NGC 4707 - HST - Potw1651a.tif| NGC 4707 is a spiral galaxy roughly 22 million light-years from Earth.
Other notable spiral galaxies in Canes Venatici are the Sunflower Galaxy (M63, NGC 5055), M94 (NGC 4736), and M106 (NGC 4258).
M63, the Sunflower Galaxy, was named for its appearance in large amateur telescopes. It is a spiral galaxy with an integrated magnitude of 9.0.
M94 (NGC 4736) is a small face-on spiral galaxy with approximate magnitude 8.0, about 15 million light-years from Earth.
M3 (NGC 5272) is a globular cluster 32,000 light-years from Earth. It is 18′ in diameter, and at magnitude 6.3 is bright enough to be seen with binoculars. It can even be seen with the naked eye under particularly dark skies.
Ton 618 is a hyperluminous quasar and blazar in this constellation, near its border with the neighboring Coma Berenices. It possesses a black hole with a mass 66 billion times that of the Sun, making it one of the most massive black holes ever measured. There is also a Lyman-alpha blob.
== Footnotes ==
|
[
"Hunayn ibn Ishaq",
"Hubble Space Telescope",
"Former constellation",
"Antonín Bečvář",
"blazar",
"Ptolemy",
"R Canum Venaticorum",
"NGC 4242",
"NGC 4631",
"Sunflower Galaxy",
"Messier 3",
"ultraviolet",
"Alpha Canum Venaticorum",
"Peter Apian",
"white dwarf",
"Johannes Hevelius",
"star catalogue",
"AM Canum Venaticorum",
"main sequence star",
"Restoration (England)",
"40th parallel south",
"Messier 94",
"Messier 63",
"Astronomy & Astrophysics",
"Dover Publications",
"Boötes",
"solar mass",
"Coma Berenices",
"NGC 4707",
"RS Canum Venaticorum variable",
"Arabic diacritics",
"PhysOrg.com",
"diminutive",
"right ascension",
"Whirlpool Galaxy",
"void (astronomy)",
"nebula",
"cataclysmic variable star",
"Flamsteed designation",
"equatorial coordinate system",
"Lyman-alpha blob",
"Flamsteed",
"European Space Agency",
"semiregular variable star",
"Ton 618",
"IAU designated constellations",
"binoculars",
"Messier 106",
"NGC 5195",
"globular cluster",
"Gerard of Cremona",
"variable star",
"Eugène Joseph Delporte",
"Charles II of England",
"TON 618",
"star atlas",
"KBC Void",
"American Association of Variable Star Observers",
"Beta Canum Venaticorum",
"Renaissance",
"Mira variable",
"Y Canum Venaticorum",
"double star",
"Almagest",
"NGC 4248",
"La Superba",
"star-forming region",
"List of most massive black holes",
"DG Canum Venaticorum",
"Giant Void",
"Bayer designation",
"galaxies",
"Club (weapon)",
"Magnitude (astronomy)",
"Arabic",
"carbon star",
"Latin",
"Lord Rosse",
"Ursa Major",
"spiral galaxy",
"Cor Caroli",
"Canes Venaticids",
"Messier object",
"Charles I of England",
"William Henry Smyth",
"North Pole",
"Charles Scarborough",
"List of largest cosmic structures",
"quasar",
"Messier 51",
"hunting dog",
"declination",
"barred spiral galaxy",
"medieval times",
"naked-eye",
"International Astronomical Union",
"chromosphere",
"CMB cold spot"
] |
6,436 |
Chamaeleon
|
{{Infobox constellation
| name = Chamaeleon
| abbreviation = Cha
| genitive = Chamaeleontis
| pronounce = , genitive
| symbolism = the Chameleon
| RA = –
| dec= –]]
In 1999, a nearby open cluster was discovered centered on the star η Chamaeleontis. The cluster, known as either
the Eta Chamaeleontis cluster or Mamajek 1, is 8 million years old, and lies 316 light years from Earth.
The constellation contains a number of molecular clouds (the Chamaeleon dark clouds) that are forming low-mass T Tauri stars. The cloud complex lies some 400 to 600 light years from Earth, and contains tens of thousands of solar masses of gas and dust. The most prominent cluster of T Tauri stars and young B-type stars are in the Chamaeleon I cloud, and are associated with the reflection nebula IC 2631.
Chamaeleon contains one planetary nebula, NGC 3195, which is fairly faint. It appears in a telescope at about the same apparent size as Jupiter.
== Equivalents ==
In Chinese astronomy, the stars that form Chamaeleon were classified as the Little Dipper () among the Southern Asterisms () by Xu Guangqi. Chamaeleon is sometimes also called the Frying Pan in Australia.
|
[
"Johann Bayer",
"Volans",
"Alpha Crucis",
"Musca",
"Chinese astronomy",
"Beta Chamaeleontis",
"Eta Chamaeleontis cluster",
"South Pole",
"Chameleon",
"Bayer Family",
"IC 2631",
"lizard",
"Chamaeleon complex",
"Jodocus Hondius",
"Pieter Dirkszoon Keyser",
"double star",
"Frederick de Houtman",
"Petrus Plancius",
"Eta Chamaeleontis",
"chameleon",
"Delta2 Chamaeleontis",
"5th parallel north",
"NGC 3195",
"Apus",
"T Tauri star",
"Amsterdam",
"Chinese constellations",
"open cluster",
"Delta1 Chamaeleontis",
"uranography",
"Cha 110913",
"southern celestial hemisphere",
"Gamma Chamaeleontis",
"Xu Guangqi",
"light years",
"Jupiter",
"south celestial pole",
"Gamma Crucis",
"molecular clouds",
"Octans",
"Chamaeleon (Chinese astronomy)",
"constellation",
"IAU designated constellations",
"International Astronomical Union",
"Delta Chamaeleontis",
"Alpha Chamaeleontis",
"Mensa (constellation)",
"Carina (constellation)"
] |
6,437 |
Cholesterol
|
{{Chembox
| Watchedfields = changed
| verifiedrevid = 477165736
| ImageFile = Cholesterol.svg
| ImageSize = 280
| ImageAlt = Chemical structure of cholesterol
| ImageClass = skin-invert-image
| ImageFile1 = Cholesterol-from-xtal-3D-bs.png
| ImageSize1 = 260
| ImageAlt1 = Ball-and-stick model of cholesterol
| ImageFile2 = Cholesterol-from-xtal-3D-sf.png
| ImageSize2 = 260
| ImageAlt2 = Space-filling model of cholesterol
| ImageFile3 = Sample of Cholesterol.jpg
| ImageSize3 = 200
| ImageAlt3 = Sample of Cholesterol
| IUPACName = Cholest-5-en-3β-ol
| SystematicName = (1R,3aS,3bS,7S,9aR,9bS,11aR)-9a,11a-Dimethyl-1-[(2R)-6-methylheptan-2-yl]-2,3,3a,3b,4,6,7,8,9,9a,9b,10,11,11a-tetradecahydro-1H-cyclopenta[a]phenanthren-7-ol
| OtherNames = Cholesterin, Cholesteryl alcohol
|Section1=
|Section2={{Chembox Properties
| Formula =C27H46O
| MolarMass =386.65 g/mol
| Appearance = white crystalline powder
| Density = 1.052 g/cm3
| MeltingPtC = 148 to 150
| MeltingPt_ref =
Cholesterol is biosynthesized by all animal cells and is an essential structural and signaling component of animal cell membranes. In vertebrates, hepatic cells typically produce the greatest amounts. In the brain, astrocytes produce cholesterol and transport it to neurons. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as Mycoplasma, which require cholesterol for growth. Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D.
Elevated levels of cholesterol in the blood, especially when bound to low-density lipoprotein (LDL, often referred to as "bad cholesterol"), may increase the risk of cardiovascular disease.
== Etymology ==
The word cholesterol comes from Ancient Greek chole- 'bile' and stereos 'solid', followed by the chemical suffix -ol for an alcohol.
==Physiology==
Cholesterol is essential for all animal life. While most cells are capable of synthesizing it, the majority of cholesterol is ingested or synthesized by hepatocytes and transported in the blood to peripheral cells. The levels of cholesterol in peripheral tissues are dictated by a balance of uptake and export. Under normal conditions, brain cholesterol is separate from peripheral cholesterol, i.e., the dietary and hepatic cholesterol do not cross the blood brain barrier. Rather, astrocytes produce and distribute cholesterol in the brain.
De novo synthesis, both in astrocytes and hepatocytes, occurs by a complex 37-step process. This begins with the mevalonate or HMG-CoA reductase pathway, the target of statin drugs, which encompasses the first 18 steps. This is followed by 19 additional steps to convert the resulting lanosterol into cholesterol. A human male weighing 68 kg (150 lb) normally synthesizes about 1 gram (1,000 mg) of cholesterol per day, and his body contains about 35 g, mostly contained within the cell membranes.
Typical daily cholesterol dietary intake for a man in the United States is 307 mg. Most ingested cholesterol is esterified, which causes it to be poorly absorbed by the gut. The body also compensates for absorption of ingested cholesterol by reducing its own cholesterol synthesis. For these reasons, cholesterol in food, seven to ten hours after ingestion, has little, if any effect on concentrations of cholesterol in the blood. Surprisingly, in rats, blood cholesterol is inversely correlated with cholesterol consumption. The more cholesterol a rat eats the lower the blood cholesterol. During the first seven hours after ingestion of cholesterol, as absorbed fats are being distributed around the body within extracellular water by the various lipoproteins (which transport all fats in the water outside cells), the concentrations increase.
Plants make cholesterol in very small amounts. In larger quantities they produce phytosterols, chemically similar substances which can compete with cholesterol for reabsorption in the intestinal tract, thus potentially reducing cholesterol reabsorption. When intestinal lining cells absorb phytosterols, in place of cholesterol, they usually excrete the phytosterol molecules back into the GI tract, an important protective mechanism. The intake of naturally occurring phytosterols, which encompass plant sterols and stanols, ranges between ≈200–300 mg/day depending on eating habits. Specially designed vegetarian experimental diets have been produced yielding upwards of 700 mg/day.
===Function===
====Membranes====
Cholesterol is present in varying degrees in all animal cell membranes, but is absent in prokaryotes. It is required to build and maintain membranes and modulates membrane fluidity over the range of physiological temperatures. The hydroxyl group of each cholesterol molecule interacts with water molecules surrounding the membrane, as do the polar heads of the membrane phospholipids and sphingolipids, while the bulky steroid and the hydrocarbon chain are embedded in the membrane, alongside the nonpolar fatty-acid chain of the other lipids. Through the interaction with the phospholipid fatty-acid chains, cholesterol increases membrane packing, which both alters membrane fluidity and maintains membrane integrity so that animal cells do not need to build cell walls (like plants and most bacteria). The membrane remains stable and durable without being rigid, allowing animal cells to change shape and animals to move.
The structure of the tetracyclic ring of cholesterol contributes to the fluidity of the cell membrane, as the molecule is in a trans conformation making all but the side chain of cholesterol rigid and planar. In this structural role, cholesterol also reduces the permeability of the plasma membrane to neutral solutes, hydrogen ions, and sodium ions.
====Substrate presentation====
Cholesterol regulates the biological process of substrate presentation and the enzymes that use substrate presentation as a mechanism of their activation. Phospholipase D2 (PLD2) is a well-defined example of an enzyme activated by substrate presentation. The enzyme is palmitoylated causing the enzyme to traffic to cholesterol dependent lipid domains sometimes called "lipid rafts". The substrate of phospholipase D is phosphatidylcholine (PC) which is unsaturated and is of low abundance in lipid rafts. PC localizes to the disordered region of the cell along with the polyunsaturated lipid phosphatidylinositol 4,5-bisphosphate (PIP2). PLD2 has a PIP2 binding domain. When PIP2 concentration in the membrane increases, PLD2 leaves the cholesterol-dependent domains and binds to PIP2 where it then gains access to its substrate PC and commences catalysis based on substrate presentation.
====Signaling====
Cholesterol is also implicated in cell signaling processes, assisting in the formation of lipid rafts in the plasma membrane, which brings receptor proteins in close proximity with high concentrations of second messenger molecules. In multiple layers, cholesterol and phospholipids, both electrical insulators, can facilitate speed of transmission of electrical impulses along nerve tissue. For many neuron fibers, a myelin sheath, rich in cholesterol since it is derived from compacted layers of Schwann cell or oligodendrocyte membranes, provides insulation for more efficient conduction of impulses. Demyelination (loss of myelin) is believed to be part of the basis for multiple sclerosis.
Cholesterol binds to and affects the gating of a number of ion channels such as the nicotinic acetylcholine receptor, GABAA receptor, and the inward-rectifier potassium channel. Cholesterol also activates the estrogen-related receptor alpha (ERRα), and may be the endogenous ligand for the receptor. The constitutively active nature of the receptor may be explained by the fact that cholesterol is ubiquitous in the body.
====Epidermis====
The stratum corneum is the outermost layer of the epidermis. Together with ceramides and free fatty acids, cholesterol forms the lipid mortar, a water-impermeable barrier that prevents evaporative water loss. As a rule of thumb, the epidermal lipid matrix is composed of an equimolar mixture of ceramides (≈50% by weight), cholesterol (≈25% by weight), and free fatty acids (≈15% by weight), with smaller quantities of other lipids also being present. The relative abundance of cholesterol sulfate in the epidermis varies across different body sites with the heel of the foot having the lowest concentration.
==Biosynthesis and regulation==
===Biosynthesis===
Almost all animal tissues synthesize cholesterol from acetyl-CoA. All animal cells (exceptions exist within the invertebrates) manufacture cholesterol, for both membrane structure and other uses, with relative production rates varying by cell type and organ function. About 80% of total daily cholesterol production occurs in the liver and the intestines; other sites of higher synthesis rates include the brain, the adrenal glands, and the reproductive organs.
Synthesis within the body starts with the mevalonate pathway where two molecules of acetyl CoA condense to form acetoacetyl-CoA. This is followed by a second condensation between acetyl CoA and acetoacetyl-CoA to form 3-hydroxy-3-methylglutaryl CoA (HMG-CoA).
This molecule is then reduced to mevalonate by the enzyme HMG-CoA reductase. Production of mevalonate is the rate-limiting and irreversible step in cholesterol synthesis and is the site of action for statins (a class of cholesterol-lowering drugs).
Mevalonate is finally converted to isopentenyl pyrophosphate (IPP) through two phosphorylation steps and one decarboxylation step that requires ATP.
Three molecules of isopentenyl pyrophosphate condense to form farnesyl pyrophosphate through the action of geranyl transferase.
Two molecules of farnesyl pyrophosphate then condense to form squalene by the action of squalene synthase in the endoplasmic reticulum.
The final 19 steps to cholesterol contain NADPH and oxygen to help oxidize methyl groups for removal of carbons, mutases to move alkene groups, and NADH to help reduce ketones.
Konrad Bloch and Feodor Lynen shared the Nobel Prize in Physiology or Medicine in 1964 for their discoveries concerning some of the mechanisms and methods of regulation of cholesterol and fatty acid metabolism.
===Regulation of cholesterol synthesis===
Biosynthesis of cholesterol is directly regulated by the cholesterol levels present, though the homeostatic mechanisms involved are only partly understood. A higher intake of food leads to a net decrease in endogenous production, whereas a lower intake of food has the opposite effect. The main regulatory mechanism is the sensing of intracellular cholesterol in the endoplasmic reticulum by the protein SREBP (sterol regulatory element-binding protein 1 and 2). In the presence of cholesterol, SREBP is bound to two other proteins: SCAP (SREBP cleavage-activating protein) and INSIG-1. When cholesterol levels fall, INSIG-1 dissociates from the SREBP-SCAP complex, which allows the complex to migrate to the Golgi apparatus. Here SREBP is cleaved by S1P and S2P (site-1 protease and site-2 protease), two enzymes that are activated by SCAP when cholesterol levels are low.
The cleaved SREBP then migrates to the nucleus and acts as a transcription factor to bind to the sterol regulatory element (SRE), which stimulates the transcription of many genes. Among these are the low-density lipoprotein (LDL) receptor and HMG-CoA reductase. The LDL receptor scavenges circulating LDL from the bloodstream, whereas HMG-CoA reductase leads to an increase in endogenous production of cholesterol. A large part of this signaling pathway was clarified by Dr. Michael S. Brown and Dr. Joseph L. Goldstein in the 1970s. In 1985, they received the Nobel Prize in Physiology or Medicine for their work. Their subsequent work shows how the SREBP pathway regulates the expression of many genes that control lipid formation and metabolism and body fuel allocation.
Cholesterol synthesis can also be turned off when cholesterol levels are high. HMG-CoA reductase contains both a cytosolic domain (responsible for its catalytic function) and a membrane domain. The membrane domain senses signals for its degradation. Increasing concentrations of cholesterol (and other sterols) cause a change in this domain's oligomerization state, which makes it more susceptible to destruction by the proteasome. This enzyme's activity can also be reduced by phosphorylation by an AMP-activated protein kinase. Because this kinase is activated by AMP, which is produced when ATP is hydrolyzed, it follows that cholesterol synthesis is halted when ATP levels are low.
===Plasma transport and regulation of absorption===
As an isolated molecule, cholesterol is only minimally soluble in water, or hydrophilic. Because of this, it dissolves in blood at exceedingly small concentrations. To be transported effectively, cholesterol is instead packaged within lipoproteins, complex discoidal particles with exterior amphiphilic proteins and lipids, whose outward-facing surfaces are water-soluble and inward-facing surfaces are lipid-soluble. This allows it to travel through the blood via emulsification. Unbound cholesterol, being amphipathic, is transported in the monolayer surface of the lipoprotein particle along with phospholipids and proteins. Cholesterol esters bound to fatty acid, on the other hand, are transported within the fatty hydrophobic core of the lipoprotein, along with triglyceride.
There are several types of lipoproteins in the blood. In order of increasing density, they are chylomicrons, very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Lower protein/lipid ratios make for less dense lipoproteins. Cholesterol within different lipoproteins is identical, although some are carried as their native "free" alcohol form (the cholesterol-OH group facing the water surrounding the particles), while others as fatty acyl esters, known also as cholesterol esters, within the particles.) in their shells. Chylomicrons carry fats from the intestine to muscle and other tissues in need of fatty acids for energy or fat production. Unused cholesterol remains in more cholesterol-rich chylomicron remnants and is taken up from here to the bloodstream by the liver. These plaques are the main causes of heart attacks, strokes, and other serious medical problems, leading to the association of so-called LDL cholesterol (actually a lipoprotein) with "bad" cholesterol. Large numbers of HDL particles correlates with better health outcomes, whereas low numbers of HDL particles is associated with atheromatous disease progression in the arteries.
===Metabolism, recycling and excretion===
Cholesterol is susceptible to oxidation and easily forms oxygenated derivatives called oxysterols. Three different mechanisms can form these: autoxidation, secondary oxidation to lipid peroxidation, and cholesterol-metabolizing enzyme oxidation. A great interest in oxysterols arose when they were shown to exert inhibitory actions on cholesterol biosynthesis. This finding became known as the "oxysterol hypothesis". Additional roles for oxysterols in human physiology include their participation in bile acid biosynthesis, function as transport forms of cholesterol, and regulation of gene transcription.
In biochemical experiments, radiolabelled forms of cholesterol, such as tritiated-cholesterol, are used. These derivatives undergo degradation upon storage, and it is essential to purify cholesterol prior to use. Cholesterol can be purified using small Sephadex LH-20 columns.
Cholesterol is oxidized by the liver into a variety of bile acids. These, in turn, are conjugated with glycine, taurine, glucuronic acid, or sulfate. A mixture of conjugated and nonconjugated bile acids, along with cholesterol itself, is excreted from the liver into the bile. Approximately 95% of the bile acids are reabsorbed from the intestines, and the remainder are lost in the feces. The excretion and reabsorption of bile acids forms the basis of the enterohepatic circulation, which is essential for the digestion and absorption of dietary fats. Under certain circumstances, when more concentrated, as in the gallbladder, cholesterol crystallises and is the major constituent of most gallstones (lecithin and bilirubin gallstones also occur, but less frequently). Every day, up to 1 g of cholesterol enters the colon. This cholesterol originates from the diet, bile, and desquamated intestinal cells, and it can be metabolized by the colonic bacteria. Cholesterol is converted mainly into coprostanol, a nonabsorbable sterol that is excreted in the feces.
Although cholesterol is a steroid generally associated with mammals, the human pathogen Mycobacterium tuberculosis is able to completely degrade this molecule and contains a large number of genes that are regulated by its presence. Many of these cholesterol-regulated genes are homologues of fatty acid β-oxidation genes, but have evolved in such a way as to bind large steroid substrates like cholesterol.
==Dietary sources==
Animal fats are complex mixtures of triglycerides, with lesser amounts of both the phospholipids and cholesterol molecules from which all animal (and human) cell membranes are constructed. Since all animal cells manufacture cholesterol, all animal-based foods contain cholesterol in varying amounts. Major dietary sources of cholesterol include red meat, egg yolks and whole eggs, liver, kidney, giblets, fish oil, shellfish, and butter. Human breast milk also contains significant quantities of cholesterol.
Plant cells synthesize cholesterol as a precursor for other compounds, such as phytosterols and steroidal glycoalkaloids, with cholesterol remaining in plant foods only in minor amounts or absent. Some plant foods, such as avocado, flax seeds and peanuts, contain phytosterols, which compete with cholesterol for absorption in the intestines and reduce the absorption of both dietary and bile cholesterol. A typical diet contributes on the order of 0.2 gram of phytosterols, which is not enough to have a significant impact on blocking cholesterol absorption. Phytosterols intake can be supplemented through the use of phytosterol-containing functional foods or dietary supplements that are recognized as having potential to reduce levels of LDL-cholesterol.
===Medical guidelines and recommendations===
In 2015, the scientific advisory panel of U.S. Department of Health and Human Services and U.S. Department of Agriculture for the 2015 iteration of the Dietary Guidelines for Americans dropped the previously recommended limit of consumption of dietary cholesterol to 300 mg per day with a new recommendation to "eat as little dietary cholesterol as possible", thereby acknowledging an association between a diet low in cholesterol and reduced risk of cardiovascular disease.
A 2013 report by the American Heart Association and the American College of Cardiology recommended focusing on healthy dietary patterns rather than specific cholesterol limits, as they are hard for clinicians and consumers to implement. They recommend the DASH and Mediterranean diet, which are low in cholesterol. A 2017 review by the American Heart Association recommends switching saturated fats for polyunsaturated fats to reduce cardiovascular disease risk.
Some supplemental guidelines have recommended doses of phytosterols in the 1.6–3.0 grams per day range (Health Canada, EFSA, ATP III, FDA). A meta-analysis demonstrated a 12% reduction in LDL-cholesterol at a mean dose of 2.1 grams per day. The benefits of a diet supplemented with phytosterols have also been questioned.
==Clinical significance==
===Hypercholesterolemia===
According to the lipid hypothesis, elevated levels of cholesterol in the blood lead to atherosclerosis which may increase the risk of heart attack, stroke, and peripheral artery disease. Since higher blood LDL – especially higher LDL concentrations and smaller LDL particle size – contributes to this process more than the cholesterol content of the HDL particles, LDL particles are often termed "bad cholesterol". High concentrations of functional HDL, which can remove cholesterol from cells and atheromas, offer protection and are commonly referred to as "good cholesterol". These balances are mostly genetically determined, but can be changed by body composition, medications, diet, and other factors. A 2007 study demonstrated that blood total cholesterol levels have an exponential effect on cardiovascular and total mortality, with the association more pronounced in younger subjects. Because cardiovascular disease is relatively rare in the younger population, the impact of high cholesterol on health is larger in older people.
Elevated levels of the lipoprotein fractions, LDL, IDL and VLDL, rather than the total cholesterol level, correlate with the extent and progress of atherosclerosis. Conversely, the total cholesterol can be within normal limits, yet be made up primarily of small LDL and small HDL particles, under which conditions atheroma growth rates are high. A post hoc analysis of the IDEAL and the EPIC prospective studies found an association between high levels of HDL cholesterol (adjusted for apolipoprotein A-I and apolipoprotein B) and increased risk of cardiovascular disease, casting doubt on the cardioprotective role of "good cholesterol".
About one in 250 individuals can have a genetic mutation for the LDL cholesterol receptor that causes them to have familial hypercholesterolemia. Inherited high cholesterol can also include genetic mutations in the PCSK9 gene and the gene for apolipoprotein B.
Elevated cholesterol levels are treatable by a diet that reduces or eliminates saturated fat, and trans fats, There are several international guidelines on the treatment of hypercholesterolemia.
Human trials using HMG-CoA reductase inhibitors, known as statins, have repeatedly confirmed that changing lipoprotein transport patterns from unhealthy to healthier patterns significantly lowers cardiovascular disease event rates, even for people with cholesterol values currently considered low for adults. Studies have shown that reducing LDL cholesterol levels by about 38.7 mg/dL with the use of statins can reduce cardiovascular disease and stroke risk by about 21%. Studies have also found that statins reduce atheroma progression. As a result, people with a history of cardiovascular disease may derive benefit from statins irrespective of their cholesterol levels (total cholesterol below 5.0 mmol/L [193 mg/dL]), and in men without cardiovascular disease, there is benefit from lowering abnormally high cholesterol levels ("primary prevention"). Primary prevention in women was originally practiced only by extension of the findings in studies on men, since, in women, none of the large statin trials conducted prior to 2007 demonstrated a significant reduction in overall mortality or in cardiovascular endpoints. Meta-analyses have demonstrated significant reductions in all-cause and cardiovascular mortality, without significant heterogeneity by sex.
The 1987 report of National Cholesterol Education Program, Adult Treatment Panels suggests the total blood cholesterol level should be: < 200 mg/dL normal blood cholesterol, 200–239 mg/dL borderline-high, > 240 mg/dL high cholesterol. The American Heart Association provides a similar set of guidelines for total (fasting) blood cholesterol levels and risk for heart disease: The average global mean total Cholesterol for humans has remained at about 4.6 mmol/L (178 mg/dL) for men and women, both crude and age standardized, for nearly 40 years from 1980 to 2018, with some regional variations and reduction of total Cholesterol in Western nations.
More current testing methods determine LDL ("bad") and HDL ("good") cholesterol separately, allowing cholesterol analysis to be more nuanced. The desirable LDL level is considered to be less than 100 mg/dL (2.6 mmol/L).
Total cholesterol is defined as the sum of HDL, LDL, and VLDL. Usually, only the total, HDL, and triglycerides are measured. For cost reasons, the VLDL is usually estimated as one-fifth of the triglycerides and the LDL is estimated using the Friedewald formula (or a variant): estimated LDL = [total cholesterol] − [total HDL] − [estimated VLDL]. Direct LDL measures are used when triglycerides exceed 400 mg/dL. The estimated VLDL and LDL have more error when triglycerides are above 400 mg/dL.
In the Framingham Heart Study, each 10 mg/dL (0.6 mmol/L) increase in total cholesterol levels increased 30-year overall mortality by 5% and CVD mortality by 9%. While subjects over the age of 50 had an 11% increase in overall mortality, and a 14% increase in cardiovascular disease mortality per 1 mg/dL (0.06 mmol/L) year drop in total cholesterol levels. The researchers attributed this phenomenon to a different correlation, whereby the disease itself increases risk of death, as well as changes a myriad of factors, such as weight loss and the inability to eat, which lower serum cholesterol. This effect was also shown in men of all ages and women over 50 in the Vorarlberg Health Monitoring and Promotion Programme. These groups were more likely to die of cancer, liver diseases, and mental diseases with very low total cholesterol, of 186 mg/dL (10.3 mmol/L) and lower. This result indicates the low-cholesterol effect occurs even among younger respondents, contradicting the previous assessment among cohorts of older people that this is a marker for frailty occurring with age.
===Hypocholesterolemia===
Abnormally low levels of cholesterol are termed hypocholesterolemia. Research into the causes of this state is relatively limited, but some studies suggest a link with depression, cancer, and cerebral hemorrhage. In general, the low cholesterol levels seem to be a consequence, rather than a cause, of an underlying illness.
===Testing===
The American Heart Association recommends testing cholesterol every 4–6 years for people aged 20 years or older. A separate set of American Heart Association guidelines issued in 2013 indicates that people taking statin medications should have their cholesterol tested 4–12 weeks after their first dose and then every 3–12 months thereafter. For men ages 45 to 65 and women ages 55 to 65, a cholesterol test should occur every 1–2 years, and for seniors over age 65, an annual test should be performed.
==Stereoisomers==
Cholesterol has 256 stereoisomers that arise from its eight stereocenters, although only two of the stereoisomers have biochemical significance (nat-cholesterol and ent-cholesterol, for natural and enantiomer, respectively), and only one occurs naturally (nat-cholesterol).
==Additional images==
File:ConversColest.png|Cholesterol units conversion
File:Steroidogenesis.svg|Steroidogenesis, using cholesterol as building material
File:Cholesterol Spacefill.jpeg|Space-filling model of the Cholesterol molecule
File:Steroid numbering.svg|Numbering of the steroid nuclei
|
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] |
6,438 |
Chromosome
|
A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most important of these proteins are the histones. Aided by chaperone proteins, the histones bind to and condense the DNA molecule to maintain its integrity. These eukaryotic chromosomes display a complex three-dimensional structure that has a significant role in transcriptional regulation.
Normally, chromosomes are visible under a light microscope only during the metaphase of cell division, where all chromosomes are aligned in the center of the cell in their condensed form. Before this stage occurs, each chromosome is duplicated (S phase), and the two copies are joined by a centromere—resulting in either an X-shaped structure if the centromere is located equatorially, or a two-armed structure if the centromere is located distally; the joined copies are called 'sister chromatids'. During metaphase, the duplicated structure (called a 'metaphase chromosome') is highly condensed and thus easiest to distinguish and study. In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation.
Chromosomal recombination during meiosis and subsequent sexual reproduction plays a crucial role in genetic diversity. If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe. This will usually cause the cell to initiate apoptosis, leading to its own death, but the process is occasionally hampered by cell mutations that result in the progression of cancer.
The term 'chromosome' is sometimes used in a wider sense to refer to the individualized portions of chromatin in cells, which may or may not be visible under light microscopy. In a narrower sense, 'chromosome' can be used to refer to the individualized portions of chromatin during cell division, which are visible under light microscopy due to high condensation.
== Etymology ==
The word chromosome () comes from the Greek words (chroma, "colour") and (soma, "body"), describing the strong staining produced by particular dyes. The term was coined by the German anatomist Heinrich Wilhelm Waldeyer, referring to the term 'chromatin', which was introduced by Walther Flemming.
Some of the early karyological terms have become outdated. For example, 'chromatin' (Flemming 1880) and 'chromosom' (Waldeyer 1888) both ascribe color to a non-colored state.
== History of discovery ==
Otto Bütschli was the first scientist to recognize the structures now known as chromosomes.
In a series of experiments beginning in the mid-1880s, Theodor Boveri gave definitive contributions to elucidating that chromosomes are the vectors of heredity, with two notions that became known as 'chromosome continuity' and 'chromosome individuality'.
Wilhelm Roux suggested that every chromosome carries a different genetic configuration, and Boveri was able to test and confirm this hypothesis. Aided by the rediscovery at the start of the 1900s of Gregor Mendel's earlier experimental work, Boveri identified the connection between the rules of inheritance and the behaviour of the chromosomes. Two generations of American cytologists were influenced by Boveri: Edmund Beecher Wilson, Nettie Stevens, Walter Sutton and Theophilus Painter (Wilson, Stevens, and Painter actually worked with him).
In his famous textbook, The Cell in Development and Heredity, Wilson linked together the independent work of Boveri and Sutton (both around 1902) by naming the chromosome theory of inheritance the 'Boveri–Sutton chromosome theory' (sometimes known as the 'Sutton–Boveri chromosome theory'). Ernst Mayr remarks that the theory was hotly contested by some famous geneticists, including William Bateson, Wilhelm Johannsen, Richard Goldschmidt and T.H. Morgan, all of a rather dogmatic mindset. Eventually, absolute proof came from chromosome maps in Morgan's own laboratory.
The number of human chromosomes was published by Painter in 1923. By inspection through a microscope, he counted 24 pairs of chromosomes, giving 48 in total. His error was copied by others, and it was not until 1956 that the true number (46) was determined by Indonesian-born cytogeneticist Joe Hin Tjio.
== Prokaryotes ==
The prokaryotes – bacteria and archaea – typically have a single circular chromosome. The chromosomes of most bacteria (also called genophores), can range in size from only 130,000 base pairs in the endosymbiotic bacteria Candidatus Hodgkinia cicadicola and Candidatus Tremblaya princeps, to more than 14,000,000 base pairs in the soil-dwelling bacterium Sorangium cellulosum.
Some bacteria have more than one chromosome. For instance, Spirochaetes such as Borrelia burgdorferi (causing Lyme disease), contain a single linear chromosome. Vibrios typically carry two chromosomes of very different size. Genomes of the genus Burkholderia carry one, two, or three chromosomes.
=== Structure in sequences ===
Prokaryotic chromosomes have less sequence-based structure than eukaryotes. Bacteria typically have a one-point (the origin of replication) from which replication starts, whereas some archaea contain multiple replication origins. The genes in prokaryotes are often organized in operons and do not usually contain introns, unlike eukaryotes.
=== DNA packaging ===
Prokaryotes do not possess nuclei. Instead, their DNA is organized into a structure called the nucleoid. The nucleoid is a distinct structure and occupies a defined region of the bacterial cell. This structure is, however, dynamic and is maintained and remodeled by the actions of a range of histone-like proteins, which associate with the bacterial chromosome. In archaea, the DNA in chromosomes is even more organized, with the DNA packaged within structures similar to eukaryotic nucleosomes.
Certain bacteria also contain plasmids or other extrachromosomal DNA. These are circular structures in the cytoplasm that contain cellular DNA and play a role in horizontal gene transfer. the DNA is often densely packed and organized; in the case of archaea, by homology to eukaryotic histones, and in the case of bacteria, by histone-like proteins.
Bacterial chromosomes tend to be tethered to the plasma membrane of the bacteria. In molecular biology application, this allows for its isolation from plasmid DNA by centrifugation of lysed bacteria and pelleting of the membranes (and the attached DNA).
Prokaryotic chromosomes and plasmids are, like eukaryotic DNA, generally supercoiled. The DNA must first be released into its relaxed state for access for transcription, regulation, and replication.
== Eukaryotes ==
Each eukaryotic chromosome consists of a long linear DNA molecule associated with proteins, forming a compact complex of proteins and DNA called chromatin. Chromatin contains the vast majority of the DNA in an organism, but a small amount inherited maternally can be found in the mitochondria. It is present in most cells, with a few exceptions, for example, red blood cells.
Histones are responsible for the first and most basic unit of chromosome organization, the nucleosome.
Eukaryotes (cells with nuclei such as those found in plants, fungi, and animals) possess multiple large linear chromosomes contained in the cell's nucleus. Each chromosome has one centromere, with one or two arms projecting from the centromere, although, under most circumstances, these arms are not visible as such. In addition, most eukaryotes have a small circular mitochondrial genome, and some eukaryotes may have additional small circular or linear cytoplasmic chromosomes.
In the nuclear chromosomes of eukaryotes, the uncondensed DNA exists in a semi-ordered structure, where it is wrapped around histones (structural proteins), forming a composite material called chromatin.
=== Interphase chromatin ===
The packaging of DNA into nucleosomes causes a 10 nanometer fibre which may further condense up to 30 nm fibres.
The chromosome scaffold, which is made of proteins such as condensin, TOP2A and KIF4, plays an important role in holding the chromatin into compact chromosomes. Loops of thirty-nanometer structure further condense with scaffold into higher order structures.
This highly compact form makes the individual chromosomes visible, and they form the classic four-arm structure, a pair of sister chromatids attached to each other at the centromere. The shorter arms are called p arms (from the French petit, small) and the longer arms are called q arms (q follows p in the Latin alphabet; q-g "grande"; alternatively it is sometimes said q is short for queue meaning tail in French). This is the only natural context in which individual chromosomes are visible with an optical microscope.
Mitotic metaphase chromosomes are best described by a linearly organized longitudinally compressed array of consecutive chromatin loops.
During mitosis, microtubules grow from centrosomes located at opposite ends of the cell and also attach to the centromere at specialized structures called kinetochores, one of which is present on each sister chromatid. A special DNA base sequence in the region of the kinetochores provides, along with special proteins, longer-lasting attachment in this region. The microtubules then pull the chromatids apart toward the centrosomes, so that each daughter cell inherits one set of chromatids. Once the cells have divided, the chromatids are uncoiled and DNA can again be transcribed. In spite of their appearance, chromosomes are structurally highly condensed, which enables these giant DNA structures to be contained within a cell nucleus.
=== Human chromosomes ===
Chromosomes in humans can be divided into two types: autosomes (body chromosome(s)) and allosome (sex chromosome(s)). Certain genetic traits are linked to a person's sex and are passed on through the sex chromosomes. The autosomes contain the rest of the genetic hereditary information. All act in the same way during cell division. Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes), giving a total of 46 per cell. In addition to these, human cells have many hundreds of copies of the mitochondrial genome. Sequencing of the human genome has provided a great deal of information about each of the chromosomes. Below is a table compiling statistics for the chromosomes, based on the Sanger Institute's human genome information in the Vertebrate Genome Annotation (VEGA) database. Number of genes is an estimate, as it is in part based on gene predictions. Total chromosome length is an estimate as well, based on the estimated size of unsequenced heterochromatin regions.
Based on the micrographic characteristics of size, position of the centromere and sometimes the presence of a chromosomal satellite, the human chromosomes are classified into the following groups:
== Karyotype ==
In general, the karyotype is the characteristic chromosome complement of a eukaryote species. The preparation and study of karyotypes is part of cytogenetics.
Although the replication and transcription of DNA is highly standardized in eukaryotes, the same cannot be said for their karyotypes, which are often highly variable. There may be variation between species in chromosome number and in detailed organization.
In some cases, there is significant variation within species. Often there is:
1. variation between the two sexes
2. variation between the germline and soma (between gametes and the rest of the body)
3. variation between members of a population, due to balanced genetic polymorphism
4. geographical variation between races
5. mosaics or otherwise abnormal individuals.
Also, variation in karyotype may occur during development from the fertilized egg.
The technique of determining the karyotype is usually called karyotyping. Cells can be locked part-way through division (in metaphase) in vitro (in a reaction vial) with colchicine. These cells are then stained, photographed, and arranged into a karyogram, with the set of chromosomes arranged, autosomes in order of length, and sex chromosomes (here X/Y) at the end.
Like many sexually reproducing species, humans have special gonosomes (sex chromosomes, in contrast to autosomes). These are XX in females and XY in males.
=== History and analysis techniques ===
Investigation into the human karyotype took many years to settle the most basic question: How many chromosomes does a normal diploid human cell contain? In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/XO sex determination mechanism. In 1922, Painter was not certain whether the diploid number of man is 46 or 48, at first favouring 46. He revised his opinion later from 46 to 48, and he correctly insisted on humans having an XX/XY system.
New techniques were needed to definitively solve the problem:
Using cells in culture
Arresting mitosis in metaphase by a solution of colchicine
Pretreating cells in a hypotonic solution , which swells them and spreads the chromosomes
Squashing the preparation on the slide forcing the chromosomes into a single plane
Cutting up a photomicrograph and arranging the result into an indisputable karyogram.
It took until 1954 before the human diploid number was confirmed as 46. Considering the techniques of Winiwarter and Painter, their results were quite remarkable. Chimpanzees, the closest living relatives to modern humans, have 48 chromosomes as do the other great apes: in humans two chromosomes fused to form chromosome 2.
== Aberrations ==
Chromosomal aberrations are disruptions in the normal chromosomal content of a cell. They can cause genetic conditions in humans, such as Down syndrome, although most aberrations have little to no effect. Some chromosome abnormalities do not cause disease in carriers, such as translocations, or chromosomal inversions, although they may lead to a higher chance of bearing a child with a chromosome disorder. Abnormal numbers of chromosomes or chromosome sets, called aneuploidy, may be lethal or may give rise to genetic disorders. Genetic counseling is offered for families that may carry a chromosome rearrangement.
The gain or loss of DNA from chromosomes can lead to a variety of genetic disorders. Human examples include:
Cri du chat, caused by the deletion of part of the short arm of chromosome 5. "Cri du chat" means "cry of the cat" in French; the condition was so-named because affected babies make high-pitched cries that sound like those of a cat. Affected individuals have wide-set eyes, a small head and jaw, moderate to severe mental health problems, and are very short.
DiGeorge syndrome, also known as 22q11.2 deletion syndrome. Symptoms are mild learning disabilities in children, with adults having an increased risk of schizophrenia. Infections are also common in children because of problems with the immune system's T cell-mediated response due to an absence of hypoplastic thymus.
Down syndrome, the most common trisomy, usually caused by an extra copy of chromosome 21 (trisomy 21). Characteristics include decreased muscle tone, stockier build, asymmetrical skull, slanting eyes, and mild to moderate developmental disability.
Edwards syndrome, or trisomy-18, the second most common trisomy. Symptoms include motor retardation, developmental disability, and numerous congenital anomalies causing serious health problems. Ninety percent of those affected die in infancy. They have characteristic clenched hands and overlapping fingers.
Isodicentric 15, also called idic(15), partial tetrasomy 15q, or inverted duplication 15 (inv dup 15).
Jacobsen syndrome, which is very rare. It is also called the 11q terminal deletion disorder. Those affected have normal intelligence or mild developmental disability, with poor expressive language skills. Most have a bleeding disorder called Paris-Trousseau syndrome.
Klinefelter syndrome (XXY). Men with Klinefelter syndrome are usually sterile, and tend to be taller than their peers, with longer arms and legs. Boys with the syndrome are often shy and quiet, and have a higher incidence of speech delay and dyslexia. Without testosterone treatment, some may develop gynecomastia during puberty.
Patau Syndrome, also called D-Syndrome or trisomy-13. Symptoms are somewhat similar to those of trisomy-18, without the characteristic folded hand.
Small supernumerary marker chromosome. This means there is an extra, abnormal chromosome. Features depend on the origin of the extra genetic material. Cat-eye syndrome and isodicentric chromosome 15 syndrome (or Idic15) are both caused by a supernumerary marker chromosome, as is Pallister–Killian syndrome.
Triple-X syndrome (XXX). XXX girls tend to be tall and thin, and have a higher incidence of dyslexia.
Turner syndrome (X instead of XX or XY). In Turner syndrome, female sexual characteristics are present but underdeveloped. Females with Turner syndrome often have a short stature, low hairline, abnormal eye features and bone development, and a "caved-in" appearance to the chest.
Wolf–Hirschhorn syndrome, caused by partial deletion of the short arm of chromosome 4. It is characterized by growth retardation, delayed motor skills development, "Greek Helmet" facial features, and mild to profound mental health problems.
XYY syndrome. XYY boys are usually taller than their siblings. Like XXY boys and XXX girls, they are more likely to have learning difficulties.
===Sperm aneuploidy===
Exposure of males to certain lifestyle, environmental and/or occupational hazards may increase the risk of aneuploid spermatozoa. In particular, risk of aneuploidy is increased by tobacco smoking, and occupational exposure to benzene, insecticides, and perfluorinated compounds. Increased aneuploidy is often associated with increased DNA damage in spermatozoa.
== Number in various organisms ==
=== In eukaryotes ===
The number of chromosomes in eukaryotes is highly variable. It is possible for chromosomes to fuse or break and thus evolve into novel karyotypes. Chromosomes can also be fused artificially. For example, when the 16 chromosomes of yeast were fused into one giant chromosome, it was found that the cells were still viable with only somewhat reduced growth rates.
The tables below give the total number of chromosomes (including sex chromosomes) in a cell nucleus for various eukaryotes. Most are diploid, such as humans who have 22 different types of autosomes—each present as two homologous pairs—and two sex chromosomes, giving 46 chromosomes in total. Some other organisms have more than two copies of their chromosome types, for example bread wheat which is hexaploid, having six copies of seven different chromosome types for a total of 42 chromosomes.
| STYLE="vertical-align: top"|
| STYLE="vertical-align: top"|
|}
Normal members of a particular eukaryotic species all have the same number of nuclear chromosomes. Other eukaryotic chromosomes, i.e., mitochondrial and plasmid-like small chromosomes, are much more variable in number, and there may be thousands of copies per cell.
Asexually reproducing species have one set of chromosomes that are the same in all body cells. However, asexual species can be either haploid or diploid.
Sexually reproducing species have somatic cells (body cells) that are diploid [2n], having two sets of chromosomes (23 pairs in humans), one set from the mother and one from the father. Gametes (reproductive cells) are haploid [n], having one set of chromosomes. Gametes are produced by meiosis of a diploid germline cell, during which the matching chromosomes of father and mother can exchange small parts of themselves (crossover) and thus create new chromosomes that are not inherited solely from either parent. When a male and a female gamete merge during fertilization, a new diploid organism is formed.
Some animal and plant species are polyploid [Xn], having more than two sets of homologous chromosomes. Important crops such as tobacco or wheat are often polyploid, compared to their ancestral species. Wheat has a haploid number of seven chromosomes, still seen in some cultivars as well as the wild progenitors. The more common types of pasta and bread wheat are polyploid, having 28 (tetraploid) and 42 (hexaploid) chromosomes, compared to the 14 (diploid) chromosomes in wild wheat.
=== In prokaryotes ===
Prokaryote species generally have one copy of each major chromosome, but most cells can easily survive with multiple copies. For example, Buchnera, a symbiont of aphids has multiple copies of its chromosome, ranging from 10 to 400 copies per cell. However, in some large bacteria, such as Epulopiscium fishelsoni up to 100,000 copies of the chromosome can be present. Plasmids and plasmid-like small chromosomes are, as in eukaryotes, highly variable in copy number. The number of plasmids in the cell is almost entirely determined by the rate of division of the plasmid – fast division causes high copy number.
|
[
"Durum wheat",
"Cultivated tobacco",
"prokaryote",
"aneuploidy",
"Chromosome 8",
"diploid",
"Gorilla",
"Sorangium cellulosum",
"repeated sequence (DNA)",
"bread wheat",
"Common fruit fly",
"Silkworm",
"microscope",
"autosome",
"Theodor Boveri",
"Genetic load",
"Hans von Winiwarter",
"interphase",
"Patau Syndrome",
"centromere",
"Domestic sheep",
"Klinefelter syndrome",
"Joe Hin Tjio",
"Donkey",
"Saccharomyces cerevisiae",
"Paris-Trousseau syndrome",
"Temperature-dependent sex determination",
"Buchnera (proteobacteria)",
"heterochromatin",
"mitosis",
"p arm",
"Chromosome 12",
"light microscope",
"Earthworm",
"condensin",
"Vector (molecular biology)",
"Microchromosome",
"gene",
"chromatin",
"Allopatric speciation",
"Chromosome 6",
"Turner syndrome",
"cytoplasm",
"cell division",
"base pair",
"Locus (genetics)",
"Indian muntjac",
"X chromosome",
"Greek language",
"mitochondrial genome",
"Wolf–Hirschhorn syndrome",
"Einkorn wheat",
"Chromosome 9",
"chromosome 2",
"Laboratory mouse",
"Candidatus Hodgkinia cicadicola",
"Chromosome 19",
"polyploid",
"Ernst Mayr",
"William Bateson",
"TOP2A",
"Down syndrome",
"prometaphase",
"Hypotonicity",
"extrachromosomal DNA",
"metaphase",
"Chromosome 14",
"nucleobase",
"Chromosome 13",
"karyotype",
"Dog",
"Pill millipede",
"Walther Flemming",
"cell cycle",
"Human mitochondrial genetics",
"KIF4A",
"Lampbrush chromosome",
"Chromosome 21",
"Wilhelm Roux",
"DNA sequencing",
"Burkholderia",
"Chromosome 3",
"Centromere",
"Edwards syndrome",
"Tibetan fox",
"Cat-eye syndrome",
"cancer",
"Triple-X syndrome",
"XYY syndrome",
"origin of replication",
"Chromosome 22",
"Wilhelm Johannsen",
"Genome",
"DNA",
"genophore",
"schizophrenia",
"Mitochondrial DNA",
"Guppy",
"dyslexia",
"haploid",
"DNA condensation",
"Vibrio",
"Polymorphism (biology)",
"microtubule",
"transcriptional regulation",
"Sexually reproducing",
"colchicine",
"Chromosome 5",
"Garden snail",
"Oxford University Press",
"Karyotype",
"supercoiled",
"XY sex-determination system",
"isodicentric chromosome 15 syndrome",
"Chromosome 15",
"Genetic recombination",
"Asexually reproducing",
"in vitro",
"chromosome segregation",
"Epulopiscium fishelsoni",
"Epigenetics",
"Transcription (genetics)",
"organism",
"Three-dimensional space",
"mitochondria",
"red blood cell",
"Lyme disease",
"Bread wheat",
"Parasitic chromosome",
"Chimpanzee",
"protein",
"Chromosome 2",
"cytogenetics",
"Chromosome 10",
"Histone-like nucleoid-structuring protein",
"Boveri–Sutton chromosome theory",
"Hare",
"fibroblast",
"trisomy 21",
"dye",
"Domestic pig",
"Cell death",
"Neochromosome",
"Chromosome 16",
"histone",
"gamete",
"Race (classification of human beings)",
"Walter Sutton",
"XO sex-determination system",
"Rabbit",
"plasma membrane",
"Spirochaete",
"Chromosomal crossover",
"apoptosis",
"Minichromosome",
"mitotic catastrophe",
"Satellite chromosome",
"sister chromatids",
"Chromosome 1",
"anaphase",
"Vertebrate and Genome Annotation Project",
"species",
"Laboratory rat",
"syntenic",
"Hedgehog",
"T.H. Morgan",
"cell (biology)",
"speech delay",
"Jacobsen syndrome",
"Pan (genus)",
"chromatid",
"Gamete",
"HOPES",
"plasmid",
"Cri du chat",
"S phase",
"Elephant",
"Rye",
"Syrian hamster",
"Genetic counseling",
"Small supernumerary marker chromosome",
"operon",
"q arm",
"insecticide",
"Chromosome 18",
"kinetochore",
"great apes",
"Goldfish",
"Pallister–Killian syndrome",
"chromosomal inversion",
"Trypanosoma brucei",
"endosymbiotic",
"Isodicentric 15",
"heredity",
"Sanger Institute",
"chromosomal satellite",
"Mosaic (genetics)",
"cytologist",
"genetic diversity",
"archaea",
"Chromosome 7",
"Horse",
"Maternal influence on sex determination",
"Ensembl",
"Human",
"Barr body",
"sex chromosome",
"fertilization",
"circular chromosome",
"Y chromosome",
"Otto Bütschli",
"Chromatid",
"gene prediction",
"cultivar",
"Thale cress",
"Maize",
"sexual reproduction",
"genetic disorder",
"Euchromatin",
"Nondisjunction",
"Heterochromatin",
"germline",
"spermatogonia",
"Cohesin",
"chromosomal instability",
"nucleoid",
"homologous chromosome",
"oogonia",
"meiosis",
"Chromomere",
"eukaryotic",
"Theophilus Painter",
"Chromosome 17",
"Secondary chromosome",
"horizontal gene transfer",
"Genetic genealogy",
"gynecomastia",
"somatic cell",
"Cow",
"Chaperone (protein)",
"chromosome scaffold",
"Nuclear organization",
"Chromosome 20",
"Chromosome 11",
"aphid",
"G banding",
"intron",
"Chromosomal translocation",
"Eukaryote",
"Sex-determination system",
"Gene",
"Histone",
"human genome",
"Genetic deletion",
"Edmund Beecher Wilson",
"nucleosome",
"DNA replication",
"symbiont",
"Adder's tongue fern",
"Polytene chromosome",
"Somatic cell",
"Kingfisher",
"eukaryote",
"Chromosome 4",
"stain",
"Domestic pigeon",
"Richard Goldschmidt",
"DiGeorge syndrome",
"Gregor Mendel",
"Tremblaya princeps",
"Domestic cat",
"cytogeneticist",
"Nettie Stevens",
"Prokaryote",
"Borrelia burgdorferi",
"bacteria",
"Heinrich Wilhelm Waldeyer",
"Guinea pig"
] |
6,439 |
Charge
|
Charge or charged may refer to:
==Arts, entertainment, and media==
===Films===
Charge, Zero Emissions/Maximum Speed, a 2011 documentary
===Music===
Charge (David Ford album)
Charge (Machel Montano album)
Charge!!, an album by The Aquabats
Charged (Nebula album)
Charged (Toshinori Kondo, Eraldo Bernocchi and Bill Laswell album)
===Television===
Charge (TV series)
Charge! (TV network)
"Charged" (Reaper), episode 2 of season one of Reaper
==Companies==
Charge Automotive Limited, an electric-vehicle manufacturer
Charged Productions, an animation studio
Charged Records, a record label
==Finance==
Equitable charge, confers a right on the secured party to look to a particular asset in the event of the debtor's default
Floating charge, a security interest over the assets of a company
==Law==
Criminal charge, a formal accusation made before a court by a prosecuting authority
Legal charge, information or indictment through a formal legal process
==Mathematics, science, and technology==
Charge (physics), the susceptibility (state of being affected) of a body to one of the fundamental forces
Color charge, a property of quarks and gluons, related to their strong interactions
Electric charge, a property which determines the electromagnetic interaction of subatomic particles
Magnetic charge, a property of theoretical magnetic monopoles
Charge, the air and fuel mixture fed into an internal combustion engine
CHARGE syndrome, a specific set of birth defects in children
Explosive charge, a measured quantity of explosive material
Signed, finitely additive measure in mathematics
==Military and iconography ==
Charge (bugle call)
Charge (warfare), a military manoeuvre
Charges (military), ranks used in German-speaking armies
Charge (heraldry), any object depicted on a shield
==Sports==
Charge (basketball), illegal contact by pushing or moving into another player's torso
Charge (ice hockey), illegal contact by taking three or more strides or jumping before hitting an opponent
Charge (fanfare), played at sporting events
Guangzhou Charge, a Chinese esports team in the Overwatch League
Ottawa Charge, a women's hockey team
==Other uses==
Charge of the Goddess, a text often used in the religion Wicca
Charge (student associations), the executive of German student fraternities
Charge (youth), an underage person placed in the care of a medieval nobleman
Charge, a type of pen spinning trick
, two classes of diplomatic agents
Pastoral charge, a group of congregants in some Protestant churches
|
[
"Electric charge",
"Charge (basketball)",
"Charge (heraldry)",
"Charged (Reaper)",
"Guangzhou Charge",
"Charge!!",
"Charged (Nebula album)",
"Floating charge",
"Charge (Machel Montano album)",
"Chargé d'affaires",
"Measure (mathematics)",
"Ottawa Charge",
"Charged Productions",
"Charge (warfare)",
"Charge (fanfare)",
"Charge! (TV network)",
"Charge of the Goddess",
"Information (formal criminal charge)",
"Explosive charge",
"internal combustion engine",
"Charge (student associations)",
"Charge (David Ford album)",
"Charging (ice hockey)",
"Pastoral charge",
"Charged Records",
"Charge, Zero Emissions/Maximum Speed",
"CHARGE syndrome",
"Charge (bugle call)",
"pen spinning",
"Charge (TV series)",
"Charge (youth)",
"Charger (disambiguation)",
"Criminal charge",
"Charges (military)",
"Charge Automotive Limited",
"Supercharge (disambiguation)",
"indictment",
"Charge (physics)",
"Magnetic charge",
"Equitable charge",
"Color charge",
"Charged (Toshinori Kondo, Eraldo Bernocchi and Bill Laswell album)"
] |
6,440 |
Colonna family
|
The House of Colonna is an Italian noble family, forming part of the papal nobility. It played a pivotal role in medieval and Renaissance Rome, supplying one pope (Martin V), 23 cardinals and many other church and political leaders. Other notable family members are Vittoria Colonna, close friend of Michelangelo, Marcantonio II Colonna (Marcantonio Colonna), leader of the papal fleet in the Battle of Lepanto (1571) and Costanza Colonna, patron and protector of Caravaggio. The family was notable for its bitter feud with the Orsini family over their influence in Rome, which was eventually settled by the issuing of the papal bull Pax Romana by Pope Julius II in 1511. In 1571, the heads of both families married nieces of Pope Sixtus V. Thereafter, historians recorded that "no peace had been concluded between the princes of Christendom, in which they had not been included by name". Today, the family is led by Don Prospero Colonna (b.1956).
==History==
===Origins===
According to tradition, the Colonna family is a branch of the Counts of Tusculum — by Peter (1099–1151) son of Gregory III, called Peter "de Columna" from his property the Columna Castle in Colonna, in the Alban Hills. Further back, they trace their lineage past the Counts of Tusculum via Lombard and Italo-Roman nobles, merchants, and clergy through the Early Middle Ages — ultimately claiming origins from the Julio-Claudian dynasty and the gens Julia whose origin is lost in the mists of time but which entered the annals for the first time in 489 BC with the consulship of Gaius Julius Iulus.
The first cardinal from the family was appointed in 1206, when Giovanni Colonna di Carbognano was made Cardinal Deacon of SS. Cosma e Damiano. For many years, Cardinal Giovanni di San Paolo (elevated in 1193) was identified as a member of the Colonna family and therefore its first representative in the College of Cardinals, but modern scholars have established that this was based on false information from the beginning of the 16th century.
Giovanni Colonna (born ) nephew of Cardinal Giovanni Colonna di Carbognano, made his solemn vows as a Dominican around 1228 and received his theological and philosophical training at the Roman studium of Santa Sabina, the forerunner of the Pontifical University of Saint Thomas Aquinas, Angelicum. He served as the Provincial of the Roman province of the Dominican Order and led the provincial chapter of 1248 at Anagni. Colonna was appointed as Archbishop of Messina in 1255.
Margherita Colonna (died 1248) was a member of the Franciscan Order. She was beatified by Pope Pius IX in 1848.
At this time, a rivalry began with the pro-papal Orsini family, leaders of the Guelph faction. This reinforced the pro-Emperor Ghibelline course that the Colonna family followed throughout the period of conflict between the Papacy and the Holy Roman Empire. Ironically according to their own family legend, the Orsini are also descended from the Julio-Claudian dynasty of ancient Rome.
===Colonna versus the Papacy===
In 1297, Cardinal Jacopo disinherited his brothers Ottone, Matteo, and Landolfo of their lands. The latter three appealed to Pope Boniface VIII, who ordered Jacopo to return the land, and furthermore hand over the family's strongholds of Colonna, Palestrina, and other towns to the Papacy. Jacopo refused; in May, Boniface removed him from the College of Cardinals and excommunicated him and his followers.
The Colonna family (aside from the three brothers allied with the Pope) declared that Boniface had been elected illegally following the unprecedented abdication of Pope Celestine V. The dispute led to open warfare, and in September, Boniface appointed Landolfo to the command of his army, to put down the revolt of Landolfo's own Colonna relatives. By the end of 1298, Landolfo had captured Colonna, Palestrina and other towns, and razed them to the ground. The family's lands were distributed among Landolfo and his loyal brothers; the rest of the family fled Italy.
The exiled Colonnas allied with the Pope's other great enemy, Philip IV of France, who in his youth had been tutored by Cardinal Egidio Colonna. In September 1303, Sciarra and Philipp's advisor, Guillaume de Nogaret, led a small force into Anagni to arrest Boniface VIII and bring him to France, where he was to stand trial. The two managed to apprehend the pope, and Sciarra reportedly slapped the pope in the face in the process, which was accordingly dubbed the "Outrage of Anagni". The attempt eventually failed after a few days, when locals freed the pope. However, Boniface VIII died on 11 October, allowing France to dominate his weaker successors during the Avignon papacy.
===Late Middle Ages===
The family remained at the centre of civic and religious life throughout the late Middle Ages. Cardinal Egidio Colonna died at the papal court in Avignon in 1314. An Augustinian, he had studied theology in Paris under St. Thomas of Aquinas to become one of the most authoritative thinkers of his time.
In the 14th century, the family sponsored the decoration of the Church of San Giovanni, most notably the floor mosaics.
In 1328, Louis IV of Germany marched into Italy for his coronation as Holy Roman Emperor. As Pope John XXII was residing in Avignon and had publicly declared that he would not crown Louis, the King decided to be crowned by a member of the Roman aristocracy, who proposed Sciarra Colonna. In honor of this event, the Colonna family was granted the privilege of using the imperial pointed crown on top of their coat of arms.
The poet Petrarch, was a great friend of the family, in particular of Giovanni Colonna and often lived in Rome as a guest of the family. He composed a number of sonnets for special occasions within the Colonna family, including "Colonna the Glorious, the great Latin name upon which all our hopes rest". In this period, the Colonna started claiming they were descendants of the Julio-Claudian dynasty.
At the Council of Constance, the Colonna finally succeeded in their papal ambitions when Oddone Colonna was elected on 14 November 1417. As Martin V, he reigned until his death on 20 February 1431.
===Early modern period===
Vittoria Colonna became famous in the sixteenth century as a poet and a figure in literate circles.
In 1627 Anna Colonna, daughter of Filippo I Colonna, married Taddeo Barberini of the family Barberini; nephew of Pope Urban VIII.
In 1728, the Carbognano branch (Colonna di Sciarra) of the Colonna family added the name Barberini to its family name when Giulio Cesare Colonna di Sciarra married Cornelia Barberini, daughter of the last male Barberini to hold the name and granddaughter of Maffeo Barberini (son of Taddeo Barberini).
===Current status===
The Colonna family have been Prince Assistants to the Papal Throne since 1710.
The family residence in Rome, the Palazzo Colonna, is open to the public every Friday and Saturday morning.
The main 'Colonna di Paliano' line is represented today by Prince Marcantonio Colonna di Paliano, Prince and Duke of Paliano (b. 1948), whose heir is Don Giovanni Andrea Colonna di Paliano (b. 1975), and by Don Prospero Colonna di Paliano, Prince of Avella (b. 1956), whose heir is Don Filippo Colonna di Paliano (b. 1995).
The 'Colonna di Stigliano' line is represented by Don Prospero Colonna di Stigliano, Prince of Stigliano (b. 1938), whose heir is his nephew Don Stefano Colonna di Stigliano (b. 1975).
==Notable members==
Blessed Margherita Colonna ( – 1280)
Stefano Colonna (1265 – ), an influential noble in Medieval Rome and Imperial vicar in the early 14th century
Jacopo Colonna (1250–1318), cardinal
Giacomo Colonna (1270–1329), who took part in the Outrage of Anagni against Pope Boniface VIII
Giovanni Colonna (1295–1348), influential cardinal during the Avignon papacy
Oddone Colonna (1369–1431), whose election as Pope Martin V in 1417 ended the Western Schism
Ludovico Colonna (1390–1436), condottiero
Prospero I Colonna (1410–1463), cardinal
Fabrizio Colonna ( – 1520), the father of Vittoria Colonna, and a general in the Holy League
Prospero Colonna (1452–1523), who fought alongside his cousin Fabrizio Colonna
Francesco Colonna (1453? – 1517?) [La "Pugna d'amore in sogno" di Francesco Colonna Romano, 1996, Maurizio Calvesi], who was credited (along with the monk Francesco Colonna) with the authorship of the Hypnerotomachia Poliphili by an acrostic in the text; also believed to have written the story
Marcantonio I Colonna (1478–1522), condottiero of the 15th–16th centuries
Pompeo Colonna (1479–1532), cardinal, a nephew of Prospero Colonna, mentioned above. Viceroy of Naples from 1530 to 1532
Vittoria Colonna (1490–1547), friend of Michelangelo. Married in 1507 the Spanish-Italian Fernando d'Avalos, marquis of Pescara (deceased 1525), adopting (on becoming a widow) Alfonso d'Avalos, also marquis del Vasto, a nephew of her former husband
Pirro Colonna (1500–1552), 16th century captain under Charles V, Holy Roman Emperor
Marco Antonio Colonna (1523–1597), cardinal
Marcantonio II Colonna the Younger (1535–1584), Duke of Tagliacozzo. Son of Ascanio Colonna and Juana de Aragón. He participated in the naval Battle of Lepanto against the Turks, 7 October 1571 and was Viceroy of Sicily in 1577–1584. Prince of Paliano.
Ascanio Colonna (1560–1608), cardinal
Federico Colonna y Tomacelli, Prince of Butera (1601–1641), Viceroy of Valencia, in Spain, 1640–1641, Viceroy of Catalonia, 1641. He was Great Constable of the kingdom of Naples (1639–1641) as had been his father Filippo I Colonna, (1578 – 11 April 1639).
Marcantonio V Colonna (1606/1610–1659), Prince of Paliano
Lorenzo Onofrio Colonna, Viceroy of Aragon, 1678–1681, in Spain
Prospero II Colonna (1662–1743), cardinal
Carlo Colonna (1665–1739), cardinal, created by Clement XI in 1706
Marcantonio Colonna (1724–1793), cardinal
Giovanni Antonio Colonna (1878–1940), politician
Guido Colonna di Paliano (1908–1982), diplomat and European Commissioner
|
[
"Prince Assistants to the Papal Throne",
"Catholic Church",
"Princes of Paliano",
"Stigliano",
"Viceroy of Aragon",
"Holy Roman Empire",
"Viceroy of Catalonia",
"Council of Constance",
"Tagliacozzo",
"Pope",
"Tusculum",
"papal nobility",
"Marcantonio II Colonna",
"Pope Sixtus V",
"Roman consul",
"Vittoria Colonna",
"Guelphs and Ghibellines",
"Francesco Colonna (writer)",
"Holy Roman Emperor",
"Pontifical University of Saint Thomas Aquinas",
"Prösels Castle",
"Western Schism",
"ancient Rome",
"Pope John XXII",
"Carbognano",
"Pescara",
"Taddeo Barberini",
"Avignon",
"Black nobility",
"Messina",
"Gallicano nel Lazio",
"Marcantonio Colonna",
"Viceroy of Naples",
"Avignon papacy",
"Cardinal Deacon",
"Spain",
"Palazzo Colonna",
"Santa Sabina",
"Alban Hills",
"Ascanio Colonna",
"Pope Julius II",
"Palazzo Colonna (Marino)",
"Costanza Colonna",
"Giacomo Colonna (cardinal)",
"Marco Antonio Colonna",
"Paliano",
"Giovanni di San Paolo",
"Maffeo Barberini (1631-1685)",
"papal abdication",
"Leopold von Ranke",
"Pirro Colonna",
"Thomas of Aquinas",
"Viceroy of Sicily",
"Marcantonio V Colonna",
"Lorenzo Onofrio Colonna, 8th Prince of Paliano",
"Papacy",
"Barberini",
"Egidio Colonna",
"Christendom",
"Margherita Colonna",
"Fernando d'Avalos",
"Cardinal (Catholic Church)",
"Gaius Julius Iulus (consul 489 BC)",
"Giovanni Colonna di Carbognano",
"Pope Celestine V",
"Lombards",
"Wellesley College",
"Sonnino",
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"Guido Colonna di Paliano",
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] |
6,443 |
Ceuta
|
Ceuta (, , ; ) is an autonomous city of Spain on the North African coast. Bordered by Morocco, it lies along the boundary between the Mediterranean Sea and the Atlantic Ocean. Ceuta is one of the special member state territories of the European Union. It was a regular municipality belonging to the province of Cádiz prior to the passing of its Statute of Autonomy in March 1995, as provided by the Spanish Constitution, henceforth becoming an autonomous city.
Ceuta, like Melilla and the Canary Islands, was classified as a free port before Spain joined the European Union. Its population is predominantly Christian and Muslim, with a small minority of Sephardic Jews and Sindhi Hindus, from Pakistan.
Spanish is the official language, while Darija Arabic is also widely spoken.
==Names==
The name Abyla has been said to have been a Punic name ("Lofty Mountain" or "Mountain of God") for Jebel Musa, the southern Pillar of Hercules. The name of the mountain was in fact Habenna (, , "Stone" or "Stele") or ʾAbin-ḥīq (, , "Rock of the Bay"), about the nearby Bay of Benzú. The name was hellenized variously as Ápini (), ). In particular, the Roman stronghold at the site took the name "Fort at the Seven Brothers" (). This was gradually shortened to Septem ( Sépton) or, occasionally, Septum or Septa. These clipped forms continued as Berber Sebta and Arabic Sabtan or Sabtah (), which themselves became in Portuguese () and Spanish (locally ).
==History==
===Ancient===
Controlling access between the Atlantic Ocean and the Mediterranean Sea, the Strait of Gibraltar is an important military and commercial chokepoint. The Phoenicians realized the extremely narrow isthmus joining the Peninsula of Almina to the African mainland made Ceuta eminently defensible and established an outpost there early in the 1st millenniumBC. The Greek geographers record it by variations of Abyla, the ancient name of nearby Jebel Musa. Beside Calpe, the other Pillar of Hercules now known as the Rock of Gibraltar, the Phoenicians established Kart at what is now San Roque, Spain. Other good anchorages nearby became Phoenician and then Carthaginian ports at what are now Tangiers and Cádiz.
After Carthage's destruction in the Punic Wars, most of northwest Africa was left to the Roman client states of Numidia andaround AbylaMauretania. Punic culture continued to thrive in what the Romans knew as "Septem". After the Battle of Thapsus in 46 BC, Caesar and his heirs began annexing North Africa directly as Roman provinces but, as late as Augustus, most of Septem's Berber residents continued to speak and write in Punic.
Caligula assassinated the Mauretanian king Ptolemy in AD40 and seized his kingdom, which Claudius organized in AD 42, placing Septem in the province of Tingitana and raising it to the level of a colony. It subsequently was Romanized and thrived into the late 3rd century, trading heavily with Roman Spain and becoming well known for its salted fish. Roads connected it overland with Tingis (Tangiers) and Volubilis. Under in the late 4th century, Septem still had 10,000 inhabitants, nearly all Christian citizens speaking African Romance, a local dialect of Latin.
===Medieval===
Vandals, probably invited by Count Boniface as protection against the empress dowager, crossed the strait near Tingis around 425 and swiftly overran Roman North Africa. Their king, Gaiseric, focused his attention on the rich lands around Carthage; although the Romans eventually accepted his conquests and he continued to raid them anyway, he soon lost control of Tingis and Septem in a series of Berber revolts. When Justinian decided to reconquer the Vandal lands, his victorious general Belisarius continued along the coast, making Septem a westernmost outpost of the Byzantine Empire around 533. Unlike the former ancient Roman administration, however, Eastern Rome did not push far into the hinterland and made the more defensible Septem their regional capital in place of Tingis.
Epidemics, less capable successors and overstretched supply lines forced a retrenchment and left Septem isolated. It is likely that its count () was obliged to pay homage to the Visigoth Kingdom in Spain in the early 7th century. There are no reliable contemporary accounts of the end of the Islamic conquest of the Maghreb around 710. Instead, the rapid Muslim conquest of Spain produced romances concerning Count Julian of Septem and his betrayal of Christendom in revenge for the dishonor that befell his daughter at King Roderick's court. Allegedly with Julian's encouragement and instructions, the Berber convert and freedman Tariq ibn Ziyad took his garrison from Tangiers across the strait and overran the Spanish so swiftly that both he and his master Musa bin Nusayr fell afoul of a jealous caliph, who stripped them of their wealth and titles.
After the death of Julian, sometimes also described as a king of the Ghomara Berbers, Berber converts to Islam took direct control of what they called Sebta. It was then destroyed during their great revolt against the Umayyad Caliphate around 740. Sebta subsequently remained a small village of Muslims and Christians surrounded by ruins until its resettlement in the 9th century by Mâjakas, chief of the Majkasa Berber tribe, who started the short-lived Banu Isam dynasty. His great-grandson briefly allied his tribe with the Idrisids, but Banu Isam rule ended in 931 when he abdicated in favor of Abd ar-Rahman III, the Umayyad ruler of Córdoba, Spain.
Chaos ensued with the fall of the Caliphate of Córdoba in 1031. Following this, Ceuta and Muslim Iberia were controlled by successive North African dynasties. Starting in 1084, the Almoravid Berbers ruled the region until 1147, when the Almohads conquered the land. Apart from Ibn Hud's rebellion in 1232, they ruled until the Tunisian Hafsids established control. The Hafsids' influence in the west rapidly waned, and Ceuta's inhabitants eventually expelled them in 1249. After this, a period of political instability persisted, under competing interests from the Marinids and Granada as well as autonomous rule under the native Banu al-Azafi. The Fez finally conquered the region in 1387, with assistance from Aragon.
===Portuguese===
On the morning of 21 August 1415, King John I of Portugal led his sons and their assembled forces in a surprise assault that would come to be known as the Conquest of Ceuta. The battle was almost anticlimactic, because the 45,000 men who traveled on 200 Portuguese ships caught the defenders of Ceuta off guard and suffered only eight casualties. By nightfall the town was captured. On the morning of 22 August, Ceuta was in Portuguese hands. Álvaro Vaz de Almada, 1st Count of Avranches was asked to hoist what was to become the flag of Ceuta, which is identical to the flag of Lisbon, but in which the coat of arms derived from that of the Kingdom of Portugal was added to the center; the original Portuguese flag and coat of arms of Ceuta remained unchanged, and the modern-day Ceuta flag features the configuration of the Portuguese shield.
John's son Henry the Navigator distinguished himself in the battle, being wounded during the conquest. The looting of the city proved to be less profitable than expected for John I, so he decided to keep the city to pursue further enterprises in the area.
From 1415 to 1437, Pedro de Meneses became the first governor of Ceuta.
The Marinid Sultanate started the 1419 siege but was defeated by the first governor of Ceuta before reinforcements arrived in the form of John, Constable of Portugal and his brother Henry the Navigator, who were sent with troops to defend Ceuta.
Under King John I's son, Duarte, the city of Ceuta rapidly became a drain on the Portuguese treasury. Trans-Saharan trade journeyed instead to Tangier. It was soon realized that without the city of Tangier, possession of Ceuta was worthless. In 1437, Duarte's brothers Henry the Navigator and Fernando, the Saint Prince persuaded him to launch an attack on the Marinid sultanate. The resulting Battle of Tangier (1437), led by Henry, was a debacle. In the resulting treaty, Henry promised to deliver Ceuta back to the Marinids in return for allowing the Portuguese army to depart unmolested, which he reneged on.
Possession of Ceuta indirectly led to further Portuguese expansion. The main area of Portuguese expansion, at this time, was the coast of the Maghreb, where there was grain, cattle, sugar, and textiles, as well as fish, hides, wax, and honey.
Ceuta had to endure alone for 43 years, until the position of the city was consolidated with the taking of Ksar es-Seghir (1458), Arzila and Tangier (1471) by the Portuguese.
The city was recognized as a Portuguese possession by the Treaty of Alcáçovas (1479) and by the Treaty of Tordesillas (1494).
In the 1540s the Portuguese began building the Royal Walls of Ceuta as they are today including bastions, a navigable moat and a drawbridge. Some of these bastions are still standing, like the bastions of Coraza Alta, Bandera and Mallorquines.
Luís de Camões lived in Ceuta between 1549 and 1551, losing his right eye in battle, which influenced his work of poetry Os Lusíadas.
===Union between Portugal and Spain===
In 1578 King Sebastian of Portugal died at the Battle of Alcácer Quibir (known as the Battle of Three Kings) in what is today northern Morocco, without descendants, triggering the 1580 Portuguese succession crisis. His grand-uncle, the elderly Cardinal Henry, succeeded him as King, but also had no descendants, having taken holy orders. When the cardinal-king died after two years later, three grandchildren of King Manuel I of Portugal claimed the throne:
Infanta Catarina, Duchess of Braganza
António, Prior of Crato
Philip II of Spain, uncle of former King Sebastian of Portugal
Philip prevailed and was crowned King Philip I of Portugal in 1581, uniting the two crowns and overseas empires.
During the Union with Spain, 1580 to 1640, Ceuta attracted many residents of Spanish origin and became the only city of the Portuguese Empire that sided with Spain when Portugal regained its independence in the Portuguese Restoration War of 1640.
===Spanish===
On 1 January 1668, King Afonso VI of Portugal recognised the formal allegiance of Ceuta to Spain and ceded Ceuta to King Carlos II of Spain by the Treaty of Lisbon.
The city was attacked by Moroccan forces under Moulay Ismail during the Siege of Ceuta (1694–1727). During the longest siege in history, the city underwent changes leading to the loss of its Portuguese character. While most of the military operations took place around the Royal Walls of Ceuta, there were also small-scale penetrations by Spanish forces at various points on the Moroccan coast, and seizure of shipping in the Strait of Gibraltar.
During the Napoleonic Wars (1803–1815), Spain allowed Britain to occupy Ceuta. Occupation began in 1810, with Ceuta being returned at the conclusion of the wars. Disagreements regarding the border of Ceuta resulted in the Hispano-Moroccan War (1859–60), which ended at the Battle of Tetuán.
In July 1936, General Francisco Franco took command of the Spanish Army of Africa and rebelled against the Spanish republican government; his military uprising led to the Spanish Civil War of 1936–1939. Franco transported troops to mainland Spain in an airlift using transport aircraft supplied by Germany and Italy. Ceuta became one of the first battlegrounds of the uprising: General Franco's rebel nationalist forces seized Ceuta, while at the same time the city came under fire from the air and sea forces of the official republican government.
The Llano Amarillo monument was erected to honor Francisco Franco; it was inaugurated on 13 July 1940. The tall obelisk has since been abandoned, but the shield symbols of the Falange and Imperial Eagle remain visible.
Following the 1947 Partition of India, a substantial number of Sindhi Hindus from current-day Pakistan settled in Ceuta, adding to a small Hindu community that had existed in Ceuta since 1893, connected to Gibraltar's.
When Spain recognized the independence of Spanish Morocco in 1956, Ceuta and the other remained under Spanish rule. Spain considered them integral parts of the Spanish state, but Morocco has disputed this point.
Culturally, modern Ceuta is part of the Spanish region of Andalusia. It was attached to the province of Cádiz until 1995, the Spanish coast being only 20 km (12.5 miles) away. It is a cosmopolitan city, with a large ethnic Arab-Berber Muslim minority as well as Sephardic Jewish and Hindu minorities.
On 5 November 2007, King Juan Carlos I visited the city, sparking great enthusiasm from the local population and protests from the Moroccan government. It was the first time a Spanish head of state had visited Ceuta in 80 years.
Since 2010, Ceuta (and Melilla) have declared the Muslim holiday of Eid al-Adha, or Feast of the Sacrifice, an official public holiday. It is the first time a non-Christian religious festival has been officially celebrated in Spanish ruled territory since the Reconquista.
==Geography==
Ceuta is separated by from the province of Cádiz on the Spanish mainland by the Strait of Gibraltar and it shares a land border with M'diq-Fnideq Prefecture in the Kingdom of Morocco. It has an area of . It is dominated by Monte Anyera, a hill along its western frontier with Morocco, which is guarded by a Spanish military fort. Monte Hacho on the Peninsula of Almina overlooking the port is one of the possible locations of the southern pillar of the Pillars of Hercules of Greek legend (the other possibility being Jebel Musa).
===Important Bird Area===
The Ceuta Peninsula has been recognised as an Important Bird Area (IBA) by BirdLife International because the site is part of a migratory bottleneck, or choke point, at the western end of the Mediterranean for large numbers of raptors, storks and other birds flying between Europe and Africa. These include European honey buzzards, black kites, short-toed snake eagles, Egyptian vultures, griffon vultures, black storks, white storks and Audouin's gulls.
===Climate===
Ceuta has a maritime-influenced Mediterranean climate, similar to nearby Spanish and Moroccan cities such as Tarifa, Algeciras or Tangiers. The average diurnal temperature variation is relatively low; the average annual temperature is with average yearly highs of and lows of though the Ceuta weather station has only been in operation since 2003. Ceuta has relatively mild winters for the latitude, while summers are warm yet milder than in the interior of Southern Spain, due to the moderating effect of the Straits of Gibraltar. Summers are very dry, but yearly precipitation is still at ,
}}
== Government and administration ==
Since 1995, Ceuta is, along with Melilla, one of the two autonomous cities of Spain.
Ceuta is known officially in Spanish as (English: Autonomous City of Ceuta), with a rank between a standard municipality and an autonomous community. Ceuta is part of the territory of the European Union. The city was a free port before Spain joined the European Union in 1986. Now it has a low-tax system within the Economic and Monetary Union of the European Union.
Since 1979, Ceuta has held elections to its 25-seat assembly every four years. The leader of its government was the Mayor until the Autonomy Statute provided for the new title of Mayor-President. , the People's Party (PP) won 18 seats, keeping Juan Jesús Vivas as Mayor-President, which he has been since 2001. The remaining seats are held by the regionalist Caballas Coalition (4) and the Socialist Workers' Party (PSOE, 3).
Owing to its small population, Ceuta elects only one member of the Congress of Deputies, the lower house of the Cortes Generales (the Spanish Parliament). election, this post is held by María Teresa López of Vox.
Ceuta is subdivided into 63 ("neighborhoods"), such as Barriada de Berizu, Barriada de P. Alfonso, Barriada del Sarchal, and El Hacho.
Ceuta maintains its own police force.
== Defence and Civil Guard ==
The defence of the enclave is the responsibility of the Spanish Armed Forces' General Command of Ceuta (COMGECEU). The Spanish Army's combat components of the command include:
54th Regulares Infantry Regiment based in González Tablas barracks;
2nd Tercio Duke of Alba Regiment of the Spanish Legion based in the Seraglio-Recarga cantonment;
3rd "Montesa" Cavalry Regiment (RC-3) located in the Colonel Galindo barracks and equipped with Leopard 2 main battle tanks and Pizarro infantry fighting vehicles
30th Mixed Artillery Regiment, one group equipped with 155/52mm towed howitzers and the other with Mistral short-range SAMs and 35/90 SKYDOR/35/90 GDF-007 anti-aircraft guns fulfilling an air defence role; and
7th Engineer Regiment
The command also includes its headquarters battalion as well as logistics elements.
Ceuta itself is only distant from the main Spanish naval base at Rota on the Spanish mainland. The Spanish Air Force's Morón Air Base is also within proximity.
The Civil Guard is responsible for border security and protects both the territory's fortified land border as well as its maritime approaches against frequent, and sometimes significant, migrant incursions.
==Economy==
The official currency of Ceuta is the euro. It is part of a special low tax zone in Spain. Ceuta is one of two Spanish port cities on the northern shore of Africa, along with Melilla. They are historically military strongholds, free ports, oil ports, and also fishing ports. Today the economy of the city depends heavily on its port (now in expansion) and its industrial and retail centres.
===Transport===
The city's Port of Ceuta is connected to the Port of Algeciras across the Strait of Gibraltar by multiple daily sailings of ferries.
A single road border checkpoint to the south of Ceuta near Fnideq allows for cars and pedestrians to travel between Morocco and Spain. An additional border crossing for pedestrians exists between Benzú and Belyounech on the northern coast. The rest of the border is closed and inaccessible.
There is a bus service throughout the city, and while it does not pass into neighbouring Morocco, it services both frontier crossings.
===Hospitals===
The following hospitals are located within Ceuta:
University Hospital of Ceuta, established in 2010, 252 beds
Primary Care Emergency Services Jose Lafont
Ceuta Medical Centre
Spanish Military Hospital (500 beds in 1929, 2020 listed as a clinic)
==Demographics==
As of 2024, its population was 83,299.
Due to its location, Ceuta is home to a mixed ethnic and religious population. The two main religious groups are Christians and Muslims. As of 2006 approximately 50% of the population was Christian and approximately 48% Muslim. As of a 2018 estimate, around 67.8% of the city's population were born in Ceuta.
Spanish is the primary and official language of the enclave. Moroccan Arabic (Darija) is widely spoken. In 2021, the Council of Europe demanded that Spain formally recognize the language by 2023.
===Religion===
Christianity has been present in Ceuta continuously from late antiquity, as evidenced by the ruins of a basilica in downtown Ceuta and accounts of the martyrdom of St. Daniel Fasanella and his Franciscans in 1227 during the Almohad Caliphate.
The town's Grand Mosque had been built over a Byzantine-era church. In 1415, the year of the city's conquest, the Portuguese converted the Grand Mosque into Ceuta Cathedral. The present form of the cathedral dates to refurbishments undertaken in the late 17th century, combining baroque and neoclassical elements. It was dedicated to StMary of the Assumption in 1726.
The Roman Catholic Diocese of Ceuta was established in 1417. It incorporated the suppressed Diocese of Tanger in 1570. The Diocese of Ceuta was a suffragan of Lisbon until 1675, when it became a suffragan of Seville. In 1851, Ceuta's administration was notionally merged into the Diocese of Cádiz and Ceuta as part of a concordat between Spain and the Holy See; the union was not actually accomplished, however, until 1879.
Small Jewish and Hindu minorities are also present in the city.
===Migration===
Like Melilla, Ceuta attracts African migrants who try to use it as an entry to Europe. As a result, the enclave is surrounded by double fences that are high, and hundreds of migrants congregate near the fences waiting for a chance to cross them. The fences are regularly stormed by migrants trying to claim asylum once they enter Ceuta.
==Education==
The University of Granada offers undergraduate programmes at their campus in Ceuta. Like all areas of Spain, Ceuta is also served by the National University of Distance Education (UNED).
While primary and secondary education are generally offered in Spanish only, a growing number of schools are entering the Bilingual Education Programme.
==Notable people from Ceuta==
=== up to 1800 ===
Qadi Ayyad (1083 in Ceuta 1149) born in Ceuta, then belonging to the Almoravids was the great imam of that city
Muhammad al-Idrisi (1100 in Ceuta 1165 in Ceuta) was a Muslim geographer, cartographer and Egyptologist. He lived in Palermo at the court of King Roger II of Sicily, known for the .
Abu al-Abbas as-Sabti (1129 in Ceuta 1204 in Marrakesh) the main Wali of Marrakesh
Joseph ben Judah of Ceuta ( 1226) a Jewish physician and poet, and disciple of Moses Maimonides
Abu al-Abbas al-Azafi (1162 in Ceuta 1236) a religious and legal scholar, member of the Banu al-Azafi who ruled Ceuta
Mohammed ibn Rushayd (1259 in Sabta 1321) a judge, writer and scholar of Hadith
Álvaro of Braganza (1440–1504) a president of Council of Castile.
George Camocke (1666–1732) a Royal Navy captain and former admiral for Spain who was exiled to Ceuta to live out the last years of his life.
Don Fernando de Leyba (1734 in Ceuta 1780) a Spanish officer who served as the third governor of Upper Louisiana from 1778 until his death.
Brigadier General Francisco Antonio García Carrasco Díaz (1742 in Ceuta 1813 in Lima, Peru) a Spanish soldier and Royal Governor of Chile
Sebastián Kindelán y O'Regan (1757 in Ceuta 1826 in Santiago de Cuba) a colonel in the Spanish Army who served as governor of East Florida 1812/1815, of Santo Domingo 1818/1821 and was provisional governor of Cuba 1822/1823
Isidro de Alaix Fábregas Count of Vergara and Viscount of Villarrobledo, (1790 in Ceuta 1853 in Madrid) a Spanish general of the First Carlist War who backed Isabella II of Spain
=== since 1800 ===
General Francisco Llano de la Encomienda (1879 in Ceuta 1963 in Mexico City), a Spanish soldier. During the Spanish Civil War (1936–1939) he remained loyal to the Second Spanish Republic
General Antonio Escobar Huertas (1879 in Ceuta executed 1940 in Barcelona), a Spanish military officer
África de las Heras Gavilán (1909 in Ceuta 1988 in Moscow), a Spanish Communist, naturalized Soviet citizen, and KGB spy who went by the code name Patria
Eugenio Martín (born 1925 in Ceuta), a Spanish film director and screenwriter
Jacob Hassan, PhD (1936 in Ceuta 2006 in Madrid), a Spanish philologist of Sephardic Jewish descent
Manuel Chaves González (born 1945 in Ceuta), a Spanish politician of the Spanish Socialist Workers' Party. He served as the Third Vice President of the Spanish Government from 2009 to 2011
Ramón Castellano de Torres (born 1947 in Ceuta), a Spanish artist, thought by some to be an expressionist painter
Ignacio Velázquez Rivera (born 1953), first Mayor-President of Melilla
Juan Jesús Vivas Lara (born 1953 in Ceuta), became the Mayor-President of Ceuta in Spain in 2001
Pedro Avilés Gutiérrez (born 1956 in Ceuta), a Spanish novelist from Madrid.
Eva María Isanta Foncuberta (born 1971 in Ceuta), a Spanish actress
Mohamed Taieb Ahmed (born 1975 in Ceuta), a Spanish-Moroccan drug lord responsible for trafficking hashish across the Strait of Gibraltar and into Spain.
===Sport ===
Francisco Lesmes (1924–2005) and Rafael Lesmes (1926–2012), brothers and Spanish footballers.
José Martínez Sánchez (born 1945 in Ceuta), nicknamed Pirri, a retired Spanish footballer, mainly played for Real Madrid, appearing in 561 competitive games and scoring 172 goals
José Ramón López (born 1950), a sprint canoer, silver medallist at the 1976 Summer Olympics
Miguel Bernardo Bianquetti (born 1951 in Ceuta), known as Migueli, a Spanish retired footballer, 391 caps for FC Barcelona and 32 for Spain
Nayim (born 1966 in Ceuta), a retired Spanish footballer; he scored a last-minute goal for Real Zaragoza in the 1995 UEFA Cup Winners' Cup Final.
Lorena Miranda (born 1991 in Ceuta), a Spanish female water polo player, silver medallist at the 2012 Summer Olympics.
Anuar Tuhami (born 1995 in Ceuta), a Spanish-Moroccan footballer, played one game for Morocco
==Twin towns and sister cities==
Ceuta is twinned with:
Aci Catena, Italy
Algeciras, Spain (since 1997)
Buenos Aires, Argentina
Cádiz, Spain (since 2007)
Melilla, Spain
Santarém, Portugal
==Dispute with Morocco==
The Moroccan government has repeatedly called for Spain to transfer the sovereignty of Ceuta, Melilla and the plazas de soberanía to Morocco, with Spain's refusal to do so serving as a major source of tension in Morocco–Spain relations. In Morocco, Ceuta is frequently referred to as the "occupied Sebtah", and the Moroccan government has argued that the city, along with other Spanish territories in the region, are colonies. One of the major arguments used by Morocco in their attempts to acquire sovereignty over Ceuta refers to the geographical position of the city, as Ceuta is an exclave surrounded by Moroccan territory and the Mediterranean Sea and has no territorial continuity with the rest of Spain. This argument was originally developed by one of the founders of the Moroccan Istiqlal Party, Alal-El Faasi, who openly advocated for Morocco to invade and occupy Ceuta and other North African territories under Spanish rule. Spain, in line with the majority of nations in the rest of the world, has never recognized Morocco's claim over Ceuta. The official position of the Spanish government is that Ceuta is an integral part of Spain, and has been since the 16th century, centuries prior to Morocco's independence from Spain and France in 1956. The majority of Ceuta's population support continued Spanish sovereignty and are opposed to Moroccan control over the territory.
In 1986, Spain joined NATO. However, Ceuta is not under NATO protection since Article 6 of the North Atlantic Treaty limits such coverage to Europe and North America and islands north of the Tropic of Cancer. However, French Algeria was explicitly included in the treaty upon France's entry. Legal experts have claimed that other articles of the treaty could cover Spanish territories in North Africa but this interpretation has not been tested in practice. During the 2022 Madrid summit, the issue of the protection of Ceuta was raised by Spain, with NATO Secretary General Jens Stoltenberg stating: "On which territories NATO protects and Ceuta and Melilla, NATO is there to protect all Allies against any threats. At the end of the day, it will always be a political decision to invoke Article 5, but rest assured NATO is there to protect and defend all Allies". On 21 December 2020, following statements made by Moroccan Prime Minister Saadeddine Othmani that Ceuta is "Moroccan as the Sahara", the Spanish government summoned the Moroccan ambassador, Karima Benyaich, to convey that Spain expects all its partners to respect the sovereignty and territorial integrity of its territory in Africa and asked for an explanation for Othmani's words.
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"Important Bird Area",
"Count Julian",
"Abu Sa'id Uthman II",
"Mauretania",
"Ptolemy's Geography",
"El País",
"Trans-Saharan trade",
"John, Constable of Portugal",
"Roman Catholic Archdiocese of Seville",
"Spanish Federation of Municipalities and Provinces",
"Abu al-Abbas al-Azafi",
"chokepoint",
"medieval romance",
"Caballas Coalition",
"Spain",
"Monumento del Llano Amarillo",
"Portuguese Empire",
"Hispania",
"Berbers",
"Qadi Ayyad",
"Isabella II of Spain",
"Mohamed Taieb Ahmed",
"Rock of Gibraltar",
"Punic Wars",
"Council of Europe",
"Eid al-Adha",
"António, Prior of Crato",
"Berber Revolt",
"Hotel Tryp Ceuta",
"Islamic conquest of the Maghreb",
"Punics",
"Euro sign",
"coat of arms",
"Carteia",
"Phoenician colonies",
"List of sovereign states",
"ASCOD",
"Byzantine Empire",
"Philip I of Portugal",
"Sindhi Hindus",
"Christianity",
"Roman citizenship",
"Kingdom of Portugal",
"plazas de soberanía",
"National University of Distance Education",
"Tabula Rogeriana",
"Ceuta border fence",
"BirdLife International",
"Mediterranean climate",
"Ancient Carthage",
"2022 Madrid summit",
"1580 Portuguese succession crisis",
"Battle of Tétouan",
"Moroccan Darija",
"northwest Africa",
"Jacob Hassan",
"Spanish Air Force",
"Anuar Tuhami",
"Francisco Franco",
"Port of Algeciras",
"Musa bin Nusayr",
"Buenos Aires",
"University of Granada",
"Napoleonic Wars",
"Flag of Portugal",
"Banu Isam",
"Portuguese Restoration War",
"Spanish Army",
"municipalities in Spain",
"Arabic language",
"Marrakesh",
"bird of prey",
"Assembly of Ceuta",
"Marinid",
"Morocco national football team",
"Oerlikon GDF",
"Sephardic Jews",
"Carthaginian Empire",
"North Africa",
"Portuguese language",
"Sephardic",
"People's Party (Spain)",
"Ranked lists of Spanish autonomous communities",
"Saadeddine Othmani",
"Reconquista",
"Perejil Island",
"religious festival",
"bastion",
"Pomponius Mela",
"Autonomous community",
"List of Spanish autonomous communities by Human Development Index",
"Civil Guard (Spain)",
"Spanish Legion",
"Holy See",
"Almohad Caliphate",
"Spanish Senate",
"baroque architecture",
"Spanish Morocco",
"Regulares",
"Gibraltar",
"Morón Air Base",
"Pedro Aviles",
"Galla Placidia",
"José Ramón López",
"Nazi Germany",
"Francisco Lesmes",
"flag of Ceuta",
"BBC",
"Belyounech",
"Siege of Ceuta (1419)",
"Moses Maimonides",
"Hispano-Moroccan War (1859–60)",
"ISO 4217",
"Congress of Deputies (Spain)",
"First Carlist War",
"Hinduism",
"Afonso VI of Portugal",
"Early Christianity",
"North Atlantic Treaty",
"Conquest of Ceuta",
"Monte Hacho",
"Morocco",
"Augustus",
"Azulejo",
"Infanta Catarina, Duchess of Braganza",
"Vox (political party)",
"National Statistics Institute (Spain)",
"Muhammad al-Idrisi",
"Economic and Monetary Union of the European Union",
"short-toed snake eagle",
"FC Barcelona",
"Roman Republic",
"Gaiseric",
"Roderic",
"Treaty of Tordesillas",
"National Institute of Statistics (Spain)",
"Tingis",
"Muslim conquest of Spain",
"flag of Lisbon",
"Ceuta Cathedral",
"Philip II of Spain",
"Christian",
"Wali",
"Tariq ibn Ziyad",
"Illustrious Generation (Portugal)",
"Central European Time",
"Official language",
"Atlantic Ocean",
"European honey buzzard",
"Falangism",
"Roman province",
"Agencia Estatal de Meteorología",
"World Socialist Web Site",
"Patriarchate of Lisbon",
"São Bento railway station",
"Muslim holiday",
"Sebastián Kindelán y O'Regan",
"Cortes Generales",
"Enclave and exclave",
"Punic language",
"African Romance",
"Egyptian vulture",
"Benzú",
"Vandalic War",
"Carthage",
"Crown of Aragon",
"Tangier",
"Government of Spain",
"Umayyad Caliphate",
"Pillars of Hercules",
"Stele",
"Andalusia",
"Islam",
"free port",
"Naval Station Rota",
"Romanization (cultural)",
"Aci Catena",
"black stork",
"Cádiz",
"Sebastian of Portugal",
"Roman road",
"KGB",
"Blackwell Publishing",
"Almoravids",
"Fernando, the Saint Prince",
"Battle of Alcácer Quibir",
"Ramón Castellano de Torres",
"Tangiers",
"Fernando de Leyba",
"Iberian Union",
"Universidad de Sevilla",
"Istiqlal Party",
"NATO",
"Jebel Musa (Morocco)",
"Military occupation",
"hinterland",
"Dedication (ritual)",
"Abu al-Abbas as-Sabti",
"white stork",
"Edward, King of Portugal",
"Arab-Berber",
"Nayim",
"holy orders",
"concordat of 1851",
"European Union",
"Ceuta Heliport",
"Royal Governor of Chile",
"Decathlon (retailer)",
"Spanish Armed Forces",
"philologist",
"Atlantic mackerel",
"Treaty of Alcáçovas",
"Roman Catholicism",
"Almohad",
"euro",
"Port of Ceuta",
"Ibn Hud",
"Spanish Navy",
"Volubilis",
"Justinian I",
"Spanish language",
"Almoravid",
"Idrisid",
"Abd ar-Rahman III",
"Euro",
"Islam in Spain",
"Ignacio Velázquez Rivera",
"diurnal temperature variation",
"Antonio Escobar Huertas",
"Tingitana",
"Treaty of Lisbon (1668)",
"Battle of Tangier (1437)",
"M'diq-Fnideq Prefecture",
"Leopard 2",
"Byzantine architecture",
"Calpe",
"Autonomous city of Spain",
"El Corte Inglés",
"Eugenio Martín",
"Henry the Navigator",
"casino",
"Marinids",
"Socialist Workers' Party (Spain)",
"Daniel and companions",
"ancient Greek geography",
"Christian martyrdom",
"Latin",
"Manuel Chaves González",
"Roman colonia",
"client state",
"Carlos II of Spain",
"Migueli",
"Tercio \"Duque de Alba\" No. 2 of the Legion",
"Judaism",
"Morocco–Spain border",
"Hindu",
"George Camocke",
"Central European Summer Time",
"Ksar es-Seghir",
"Belisarius",
"Audouin's gull",
"Mohammed ibn Rushayd",
"Hafsid",
"griffon vulture",
"Eva Isanta",
"Juan Carlos I",
"Morocco–Spain relations",
"Numidia"
] |
6,444 |
Cleopatra (disambiguation)
|
Cleopatra (69–30 BC) was the last active Ptolemaic ruler of Egypt before it became a Roman province.
Cleopatra may also refer to:
== Given name ==
Cleopatra (given name), a list of people and fictional characters
Cleopatra (Greek singer) (born 1963), who represented Greece in the 1992 Eurovision Song Contest
Cleopatra (Greek myth), a list of mythological figures
== Arts and entertainment ==
=== Film ===
Cleopatra (1912 film), an American silent film
Cleopatra (1917 film), an American silent film
Cleopatra (1928 film), an American silent short film
Cleopatra (1934 film), an American film by Cecil B. DeMille
Cleopatra (1963 film), an American film by Joseph L. Mankiewicz starring Elizabeth Taylor and Richard Burton
Cleopatra (1970 film), a Japanese anime film
Cleopatra (2003 film), an Argentine film
Cleopatra (2005 film), an Indian Tamil-language film
Cleopatra (2007 film), a Brazilian film by Júlio Bressane
Cleopatra (2013 film), an Indian Malayalam-language film
Foxxy Cleopatra, a major character in the 2002 film Austin Powers in Goldmember
=== Literature ===
Cleopatra (Rider Haggard novel) (1889)
Cleopatra (Gardner novel), a 1962 novel by Jeffrey K. Gardner
La Cleopatra (poem), an epic poem by Girolamo Graziani
the title character of Cleopatra in Space, an American graphic novel series for children by Mike Maihack
=== Classical music ===
Cleopatra (Cimarosa), a 1789 opera seria by Domenico Cimarosa
Cleopatra (Rossi), an 1876 opera by Lauro Rossi
Cleopatra, an opera by Johann Mattheson
Cleopatra, a composition by Luigi Mancinelli
Cleopatra, a symphonic poem by George Whitefield Chadwick
=== Popular music ===
Cleopatra Records, an American record label
Cleopatra (group), a British girl group
==== Albums ====
Cleopatra (album), a 2016 album by The Lumineers
Cleopatra (1963 soundtrack), a soundtrack by Alex North
Cleopatra, a 2004 album by Isabel Bayrakdarian
Handel: Cleopatra, a 2011 album by Natalie Dessay
==== Songs ====
"Cleopatra" (Frankie Avalon song) (1963)
"Cleopatra" (Jerome Kern song) (1917)
"Cleopatra" (Samira Efendi song), Azerbaijan's 2020 Eurovision song submission.
"Cleopatra" (The Lumineers song) (2016)
"Cleopatra" (Weezer song) (2014)
"Cleopatra (I've Got to Get You Off My Mind)", a song by The Tennors
"Cleopatra", a song by Adam and the Ants from their 1979 album Dirk Wears White Sox
"Cleopatra", a song by Nico Fidenco
"Cleopatra", a song by David Vendetta
"Cleopatra", a song by Train from AM Gold (album), 2022
=== Paintings ===
Cleopatra (Artemisia Gentileschi, Ferrara), by Artemisia Gentileschi, c. 1620
Cleopatra (Artemisia Gentileschi, Milan), by Artemisia Gentileschi, 1613 or 1621–1622
Cleopatra (Artemisia Gentileschi, Rome), by Artemisia Gentileschi, c. 1633–5
=== Television ===
Cleopatra (miniseries), a 1999 American miniseries produced by Hallmark Entertainment
Cleopatra 2525, an American science fiction television series
The Cleopatras, a 1983 British series
== Places ==
Cleopatra (neighborhood), a neighborhood of Alexandria, Egypt
Cleopatra, Kentucky, United States, an unincorporated community
Cleopatra, Missouri, United States, an unincorporated community
Cleopatra (crater), an impact crater on Venus
== Plants and animals ==
Cleopatra (horse), an American racehorse
Cleopatra (gastropod), a genus of freshwater snails
Gonepteryx cleopatra or cleopatra, a species of butterfly
Neoguillauminia cleopatra, a species of tree from New Caledonia
== Ships ==
, various Royal Navy ships
, an East India Company paddle frigate built in 1839 and sunk by a tropical cyclone in 1847
Cleopatra (cylinder ship), a vessel constructed to convey Cleopatra's Needle from Alexandria to London in 1877
, originally named Cleopatra, a mixed passenger liner and animal carrier which sank in 1898
, a World War II Victory cargo ship renamed Cleopatra in 1956
== Other uses ==
Cleopatra (cigarette), an Egyptian brand
|
[
"David Vendetta",
"Cleopatra (2007 film)",
"Cleopatra (Gardner novel)",
"Cleopatra (1970 film)",
"Cleopatra (neighborhood)",
"Nico Fidenco",
"Cleopatra (gastropod)",
"Cleopatra (Greek singer)",
"Cleopatra",
"Cleopatra (horse)",
"Cleopatra 2525",
"Cleopatra (1963 soundtrack)",
"Cleopatra (1963 film)",
"Cleopatra (miniseries)",
"Cleopatra (2005 film)",
"Cleopatra (cylinder ship)",
"Cleopatra (Jerome Kern song)",
"La Cleopatra (poem)",
"Cleopatra (Cimarosa)",
"Cleopatra (1917 film)",
"Cleopatra Records",
"Cleopatra, Missouri",
"The Cleopatras",
"Cleopatra (crater)",
"Cleopatra (The Lumineers song)",
"Cleopatra (1928 film)",
"Cleopatra (Samira Efendi song)",
"Cleopatra (album)",
"Cleopatra (Frankie Avalon song)",
"Gonepteryx cleopatra",
"Cleopatra in Space",
"Cleopatra (given name)",
"Johann Mattheson",
"Dirk Wears White Sox",
"Cleopatra (2003 film)",
"Cleopatra (Artemisia Gentileschi, Rome)",
"Cleopatra's Needle",
"Foxxy Cleopatra",
"Cleopatra, Kentucky",
"Cleopatra (1934 film)",
"Isabel Bayrakdarian",
"Cleopatra (1912 film)",
"Cleopatra (cigarette)",
"Cleopatra (Rossi)",
"Neoguillauminia cleopatra",
"Luigi Mancinelli",
"Kleopatra (disambiguation)",
"Cleopatra (Greek myth)",
"Natalie Dessay",
"The Tennors",
"AM Gold (album)",
"Cleopatra (Haggard novel)",
"Cleopatra (group)",
"George Whitefield Chadwick",
"Cleopatra (2013 film)",
"Cleopatra Algemene Studentenvereniging Groningen",
"Cleopatra (Artemisia Gentileschi, Milan)",
"Cleopatra (Artemisia Gentileschi, Ferrara)",
"Cleopatra (Weezer song)"
] |
6,445 |
Carcinogen
|
A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and biologic agents such as viruses and bacteria.
The specific mechanisms for carcinogenic activity is unique to each agent and cell type. Carcinogens can be broadly categorized, however, as activation-dependent and activation-independent which relate to the agent's ability to engage directly with DNA. Activation-dependent agents are relatively inert in their original form, but are bioactivated in the body into metabolites or intermediaries capable of damaging human DNA. These are also known as "indirect-acting" carcinogens. Examples of activation-dependent carcinogens include polycyclic aromatic hydrocarbons (PAHs), heterocyclic aromatic amines, and mycotoxins. Activation-independent carcinogens, or "direct-acting" carcinogens, are those that are capable of directly damaging DNA without any modification to their molecular structure. These agents typically include electrophilic groups that react readily with the net negative charge of DNA molecules. For blood cancers, the latency period may be as short as two. Other organizations that evaluate the carcinogenicity of substances include the National Toxicology Program of the US Public Health Service, NIOSH, the American Conference of Governmental Industrial Hygienists and others.
There are numerous sources of exposures to carcinogens including ultraviolet radiation from the sun, radon gas emitted in residential basements, environmental contaminants such as chlordecone, cigarette smoke and ingestion of some types of foods such as alcohol and processed meats. Occupational exposures represent a major source of carcinogens with an estimated 666,000 annual fatalities worldwide attributable to work related cancers. According to NIOSH, 3-6% of cancers worldwide are due to occupational exposures.
=== Non-ionizing radiation ===
Not all types of electromagnetic radiation are carcinogenic. Low-energy waves on the electromagnetic spectrum including radio waves, microwaves, infrared radiation and visible light are thought not to be, because they have insufficient energy to break chemical bonds. Evidence for carcinogenic effects of non-ionizing radiation is generally inconclusive, though there are some documented cases of radar technicians with prolonged high exposure experiencing significantly higher cancer incidence.
Higher-energy radiation, including ultraviolet radiation (present in sunlight) generally is carcinogenic, if received in sufficient doses. For most people, ultraviolet radiations from sunlight is the most common cause of skin cancer. In Australia, where people with pale skin are often exposed to strong sunlight, melanoma is the most common cancer diagnosed in people aged 15–44 years.
Substances or foods irradiated with electrons or electromagnetic radiation (such as microwave, X-ray or gamma) are not carcinogenic. In contrast, non-electromagnetic neutron radiation produced inside nuclear reactors can produce secondary radiation through nuclear transmutation.
== Common carcinogens associated with food ==
=== Alcohol ===
Alcohol is a carcinogen of the head and neck, esophagus, liver, colon and rectum, and breast. It has a synergistic effect with tobacco smoke in the development of head and neck cancers. In the United States approximately 6% of cancers and 4% of cancer deaths are attributable to alcohol use.
=== Processed meats ===
Chemicals used in processed and cured meat such as some brands of bacon, sausages and ham may produce carcinogens. For example, nitrites used as food preservatives in cured meat such as bacon have also been noted as being carcinogenic with demographic links, but not causation, to colon cancer.
=== Meats cooked at high temperatures ===
Cooking food at high temperatures, for example grilling or barbecuing meats, may also lead to the formation of minute quantities of many potent carcinogens that are comparable to those found in cigarette smoke (i.e., [[benzo(a)pyrene|benzo[a]pyrene]]). Charring of food looks like coking and tobacco pyrolysis, and produces carcinogens. There are several carcinogenic pyrolysis products, such as polynuclear aromatic hydrocarbons, which are converted by human enzymes into epoxides, which attach permanently to DNA. Pre-cooking meats in a microwave oven for 2–3 minutes before grilling shortens the time on the hot pan, and removes heterocyclic amine (HCA) precursors, which can help minimize the formation of these carcinogens.
=== Acrylamide in foods ===
Frying, grilling or broiling food at high temperatures, especially starchy foods, until a toasted crust is formed generates acrylamides. This discovery in 2002 led to international health concerns. Subsequent research has however found that it is not likely that the acrylamides in burnt or well-cooked food cause cancer in humans; Cancer Research UK categorizes the idea that burnt food causes cancer as a "myth".
== Biologic Agents ==
Several biologic agents are known carcinogens.
Aflatoxin B1, a toxin produced by the fungus Aspergillus flavus which is a common contaminant of stored grains and nuts is a known cause of hepatocellular cancer. The bacteria H. Pylori is known to cause stomach cancer and MALT lymphoma. Hepatitis B and C are associated with the development of hepatocellular cancer. HPV is the primary cause of cervical cancer.
== Cigarette smoke ==
Tobacco smoke contains at least 70 known carcinogens and is implicated in the development of numerous types of cancers including cancers of the lung, larynx, esophagus, stomach, kidney, pancreas, liver, bladder, cervix, colon, rectum and blood. Potent carcinogens found in cigarette smoke include polycyclic aromatic hydrocarbons (PAH, such as benzo(a)pyrene), benzene, and nitrosamine.
== Occupational carcinogens ==
Given that populations of workers are more likely to have consistent, often high level exposures to chemicals rarely encountered in normal life, much of the evidence for the carcinogenicity of specific agents is derived from studies of workers.
|
Lung
|
Lightweight alloys
Aerospace applications
Nuclear reactors
|-
! Cadmium and its compounds
|
Prostate
|
Yellow pigments
Phosphors
Solders
Batteries
Metal paintings and coatings
|-
! Hexavalent chromium(VI) compounds
|
Lung
|
Paints
Pigments
Preservatives
|-
! Nitrosamines
|
Lung
Esophagus
Liver
|
cigarette smoke
nitrite-treated foods (cured meats)
|-
! Ethylene oxide
|
Leukemia
|
commodity chemical
Sterilant for hospital equipment
|-
! Nickel
|
Nose
Lung
|
Nickel plating
Ferrous alloys
Ceramics
Batteries
Stainless-steel welding byproduct
|-
! Radon and its decay products
|
Lung
|
Uranium decay
Quarries and mines
Cellars and poorly ventilated places
|-
! Vinyl chloride
|
Hemangiosarcoma
Liver
|
Production of polyvinyl chloride
|-
! Shift work that involves
circadian disruption
|
Breast
|
|-
! Involuntary smoking (Passive smoking)
|
Lung
|
|-
! Radium-226, Radium-224, Plutonium-238, Plutonium-239 and other alpha particle emitters with high atomic weight
|
Bone (they are bone seekers)
Liver
|
Nuclear fuel processing
Radium dial manufacturing
|-
| col span="3" | Unless otherwise specified, ref is:
|}
=== Others ===
Gasoline (contains aromatics)
Lead and its compounds
Alkylating antineoplastic agents (e.g., mechlorethamine)
Styrene
Other alkylating agents (e.g., dimethyl sulfate)
Ultraviolet radiation from the sun and UV lamps
Other ionizing radiation (X-rays, gamma rays, etc.)
Low refining or unrefined mineral oils
== Mechanisms of carcinogenicity ==
Carcinogens can be classified as genotoxic or nongenotoxic. Genotoxins cause irreversible genetic damage or mutations by binding to DNA. Genotoxins include chemical agents like N-nitroso-N-methylurea (NMU) or non-chemical agents such as ultraviolet light and ionizing radiation. Certain viruses can also act as carcinogens by interacting with DNA.
Nongenotoxins do not directly affect DNA but act in other ways to promote growth. These include hormones and some organic compounds.
== Classification ==
=== International Agency for Research on Cancer ===
The International Agency for Research on Cancer (IARC) is an intergovernmental agency established in 1965, which forms part of the World Health Organization of the United Nations. It is based in Lyon, France. Since 1971 it has published a series of Monographs on the Evaluation of Carcinogenic Risks to Humans that have been highly influential in the classification of possible carcinogens.
Group 1: the agent (mixture) is carcinogenic to humans. The exposure circumstance entails exposures that are carcinogenic to humans.
Group 2A: the agent (mixture) is most likely (product more likely to be) carcinogenic to humans. The exposure circumstance entails exposures that are probably carcinogenic to humans.
Group 2B: the agent (mixture) is possibly (chance of product being) carcinogenic to humans. The exposure circumstance entails exposures that are possibly carcinogenic to humans.
Group 3: the agent (mixture or exposure circumstance) is not classifiable as to its carcinogenicity to humans.
Group 4: the agent (mixture) is most likely not carcinogenic to humans.
=== Globally Harmonized System ===
The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a United Nations initiative to attempt to harmonize the different systems of assessing chemical risk which currently exist (as of March 2009) around the world. It classifies carcinogens into two categories, of which the first may be divided again into subcategories if so desired by the competent regulatory authority:
Category 1: known or presumed to have carcinogenic potential for humans
Category 1A: the assessment is based primarily on human evidence
Category 1B: the assessment is based primarily on animal evidence
Category 2: suspected human carcinogens
=== U.S. National Toxicology Program ===
The National Toxicology Program of the U.S. Department of Health and Human Services is mandated to produce a biennial Report on Carcinogens. As of August 2024, the latest edition was the 15th report (2021). It classifies carcinogens into two groups:
Known to be a human carcinogen
Reasonably anticipated to be a human carcinogen
=== American Conference of Governmental Industrial Hygienists ===
The American Conference of Governmental Industrial Hygienists (ACGIH) is a private organization best known for its publication of threshold limit values (TLVs) for occupational exposure and monographs on workplace chemical hazards. It assesses carcinogenicity as part of a wider assessment of the occupational hazards of chemicals.
Group A1: Confirmed human carcinogen
Group A2: Suspected human carcinogen
Group A3: Confirmed animal carcinogen with unknown relevance to humans
Group A4: Not classifiable as a human carcinogen
Group A5: Not suspected as a human carcinogen
=== European Union ===
The European Union classification of carcinogens is contained in the Regulation (EC) No 1272/2008. It consists of three categories:
Category 1A: Carcinogenic
Category 1B: May cause cancer
Category 2: Suspected of causing cancer
The former European Union classification of carcinogens was contained in the Dangerous Substances Directive and the Dangerous Preparations Directive. It also consisted of three categories:
Category 1: Substances known to be carcinogenic to humans.
Category 2: Substances which should be regarded as if they are carcinogenic to humans.
Category 3: Substances which cause concern for humans, owing to possible carcinogenic effects but in respect of which the available information is not adequate for making a satisfactory assessment.
This assessment scheme is being phased out in favor of the GHS scheme (see above), to which it is very close in category definitions.
=== Safe Work Australia ===
Under a previous name, the NOHSC, in 1999 Safe Work Australia published the Approved Criteria for Classifying Hazardous Substances [NOHSC:1008(1999)].
Section 4.76 of this document outlines the criteria for classifying carcinogens as approved by the Australian government. This classification consists of three categories:
Category 1: Substances known to be carcinogenic to humans.
Category 2: Substances that should be regarded as if they were carcinogenic to humans.
Category 3: Substances that have possible carcinogenic effects in humans but about which there is insufficient information to make an assessment.
==Major carcinogens implicated in the four most common cancers worldwide==
In this section, the carcinogens implicated as the main causative agents of the four most common cancers worldwide are briefly described. These four cancers are lung, breast, colon, and stomach cancers. Together they account for about 41% of worldwide cancer incidence and 42% of cancer deaths (for more detailed information on the carcinogens implicated in these and other cancers, see references).
===Lung cancer===
Lung cancer (pulmonary carcinoma) is the most common cancer in the world, both in terms of cases (1.6 million cases; 12.7% of total cancer cases) and deaths (1.4 million deaths; 18.2% of total cancer deaths). Lung cancer is largely caused by tobacco smoke. Risk estimates for lung cancer in the United States indicate that tobacco smoke is responsible for 90% of lung cancers. Other factors are implicated in lung cancer, and these factors can interact synergistically with smoking so that total attributable risk adds up to more than 100%. These factors include occupational exposure to carcinogens (about 9-15%), radon (10%) and outdoor air pollution (1-2%).
Tobacco smoke is a complex mixture of more than 5,300 identified chemicals. The most important carcinogens in tobacco smoke have been determined by a "Margin of Exposure" approach. Using this approach, the most important tumorigenic compounds in tobacco smoke were, in order of importance, acrolein, formaldehyde, acrylonitrile, 1,3-butadiene, cadmium, acetaldehyde, ethylene oxide, and isoprene. Most of these compounds cause DNA damage by forming DNA adducts or by inducing other alterations in DNA. DNA damages are subject to error-prone DNA repair or can cause replication errors. Such errors in repair or replication can result in mutations in tumor suppressor genes or oncogenes leading to cancer.
===Breast cancer===
Breast cancer is the second most common cancer [(1.4 million cases, 10.9%), but ranks 5th as cause of death (458,000, 6.1%)]. Estrogen appears to contribute to breast carcinogenesis by three processes; (1) the metabolism of estrogen to genotoxic, mutagenic carcinogens, (2) the stimulation of tissue growth, and (3) the repression of phase II detoxification enzymes that metabolize ROS leading to increased oxidative DNA damage.
The major estrogen in humans, estradiol, can be metabolized to quinone derivatives that form adducts with DNA. These derivatives can cause depurination, the removal of bases from the phosphodiester backbone of DNA, followed by inaccurate repair or replication of the apurinic site leading to mutation and eventually cancer. This genotoxic mechanism may interact in synergy with estrogen receptor-mediated, persistent cell proliferation to ultimately cause breast cancer.
===Colon cancer===
Colorectal cancer is the third most common cancer [1.2 million cases (9.4%), 608,000 deaths (8.0%)]. In addition, substantial evidence implicates bile acids as an important factor in colon cancer. Twelve studies (summarized in Bernstein et al.) indicate that the bile acids deoxycholic acid (DCA) or lithocholic acid (LCA) induce production of DNA-damaging reactive oxygen species or reactive nitrogen species in human or animal colon cells. Furthermore, 14 studies showed that DCA and LCA induce DNA damage in colon cells. Also 27 studies reported that bile acids cause programmed cell death (apoptosis).
Increased apoptosis can result in selective survival of cells that are resistant to induction of apoptosis. Overall, the available evidence indicates that DCA and LCA are centrally important DNA-damaging carcinogens in colon cancer.
===Stomach cancer===
Stomach cancer is the fourth most common cancer [990,000 cases (7.8%), 738,000 deaths (9.7%)]. ROS cause oxidative DNA damage including the major base alteration 8-hydroxydeoxyguanosine (8-OHdG). 8-OHdG resulting from ROS is increased in chronic gastritis. The altered DNA base can cause errors during DNA replication that have mutagenic and carcinogenic potential. Thus H. pylori-induced ROS appear to be the major carcinogens in stomach cancer because they cause oxidative DNA damage leading to carcinogenic mutations.
Diet is also thought to be a contributing factor in stomach cancer: in Japan, where very salty pickled foods are popular, the incidence of stomach cancer is high. Preserved meat such as bacon, sausages, and ham increases the risk, while a diet rich in fresh fruit, vegetables, peas, beans, grains, nuts, seeds, herbs, and spices will reduce the risk. The risk also increases with age.
|
[
"Aspergillus flavus",
"threshold limit value",
"Genotoxin",
"Ultraviolet",
"Mutagen",
"Lung cancer",
"fuel oil",
"France",
"Skin",
"CERCLA",
"acrolein",
"estradiol",
"estrogen",
"infrared radiation",
"hemangiosarcoma",
"epoxide",
"ultraviolet",
"Lung",
"Solder",
"neutron radiation",
"bile acid",
"asbestos",
"US Public Health Service",
"benzene",
"bladder cancer",
"cereal",
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] |
6,446 |
Camouflage
|
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and octopuses, are capable of actively changing their skin pattern and colours, whether for camouflage or for signalling. It is possible that some plants use camouflage to evade being eaten by herbivores.
Military camouflage was spurred by the increasing range and accuracy of firearms in the 19th century. In particular the replacement of the inaccurate musket with the rifle made personal concealment in battle a survival skill. In the 20th century, military camouflage developed rapidly, especially during the World War I. On land, artists such as André Mare designed camouflage schemes and observation posts disguised as trees. At sea, merchant ships and troop carriers were painted in dazzle patterns that were highly visible, but designed to confuse enemy submarines as to the target's speed, range, and heading. During and after World War II, a variety of camouflage schemes were used for aircraft and for ground vehicles in different theatres of war. The use of radar since the mid-20th century has largely made camouflage for fixed-wing military aircraft obsolete.
Non-military use of camouflage includes making cell telephone towers less obtrusive and helping hunters to approach wary game animals. Patterns derived from military camouflage are frequently used in fashion clothing, exploiting their strong designs and sometimes their symbolism. Camouflage themes recur in modern art, and both figuratively and literally in science fiction and works of literature.
== History ==
=== Classical antiquity ===
In ancient Greece, Aristotle (384–322 BC) commented on the colour-changing abilities, both for camouflage and for signalling, of cephalopods including the octopus, in his Historia animalium:
Poulton's "general protective resemblance" was at that time considered to be the main method of camouflage, as when Frank Evers Beddard wrote in 1892 that "tree-frequenting animals are often green in colour. Among vertebrates numerous species of parrots, iguanas, tree-frogs, and the green tree-snake are examples". Beddard did however briefly mention other methods, including the "alluring coloration" of the flower mantis and the possibility of a different mechanism in the orange tip butterfly. He wrote that "the scattered green spots upon the under surface of the wings might have been intended for a rough sketch of the small flowerets of the plant [an umbellifer], so close is their mutual resemblance." He also explained the coloration of sea fish such as the mackerel: "Among pelagic fish it is common to find the upper surface dark-coloured and the lower surface white, so that the animal is inconspicuous when seen either from above or below."
The artist Abbott Handerson Thayer formulated what is sometimes called Thayer's Law, the principle of countershading. However, he overstated the case in the 1909 book Concealing-Coloration in the Animal Kingdom, arguing that "All patterns and colors whatsoever of all animals that ever preyed or are preyed on are under certain normal circumstances obliterative" (that is, cryptic camouflage), and that "Not one 'mimicry' mark, not one 'warning color'... nor any 'sexually selected' color, exists anywhere in the world where there is not every reason to believe it the very best conceivable device for the concealment of its wearer", and using paintings such as Peacock in the Woods (1907) to reinforce his argument. Thayer was roundly mocked for these views by critics including Teddy Roosevelt.
The English zoologist Hugh Cott's 1940 book Adaptive Coloration in Animals corrected Thayer's errors, sometimes sharply: "Thus we find Thayer straining the theory to a fantastic extreme in an endeavour to make it cover almost every type of coloration in the animal kingdom." Cott built on Thayer's discoveries, developing a comprehensive view of camouflage based on "maximum disruptive contrast", countershading and hundreds of examples. The book explained how disruptive camouflage worked, using streaks of boldly contrasting colour, paradoxically making objects less visible by breaking up their outlines. While Cott was more systematic and balanced in his view than Thayer, and did include some experimental evidence on the effectiveness of camouflage, his 500-page textbook was, like Thayer's, mainly a natural history narrative which illustrated theories with examples.
Experimental evidence that camouflage helps prey avoid being detected by predators was first provided in 2016, when ground-nesting birds (plovers and coursers) were shown to survive according to how well their egg contrast matched the local environment.
== Evolution ==
As there is a lack of evidence for camouflage in the fossil record, studying the evolution of camouflage strategies is very difficult. Furthermore, camouflage traits must be both adaptable (provide a fitness gain in a given environment) and heritable (in other words, the trait must undergo positive selection). Thus, studying the evolution of camouflage strategies requires an understanding of the genetic components and various ecological pressures that drive crypsis.
=== Fossil history ===
Camouflage is a soft-tissue feature that is rarely preserved in the fossil record, but rare fossilised skin samples from the Cretaceous period show that some marine reptiles were countershaded. The skins, pigmented with dark-coloured eumelanin, reveal that both leatherback turtles and mosasaurs had dark backs and light bellies. There is fossil evidence of camouflaged insects going back over 100 million years, for example lacewings larvae that stick debris all over their bodies much as their modern descendants do, hiding them from their prey. Dinosaurs appear to have been camouflaged, as a 120 million year old fossil of a Psittacosaurus has been preserved with countershading.
=== Genetics ===
Camouflage does not have a single genetic origin. However, studying the genetic components of camouflage in specific organisms illuminates the various ways that crypsis can evolve among lineages. Many cephalopods have the ability to actively camouflage themselves, controlling crypsis through neural activity. For example, the genome of the common cuttlefish includes 16 copies of the reflectin gene, which grants the organism remarkable control over coloration and iridescence. The reflectin gene is thought to have originated through transposition from symbiotic Aliivibrio fischeri bacteria, which provide bioluminescence to its hosts. While not all cephalopods use active camouflage, ancient cephalopods may have inherited the gene horizontally from symbiotic A. fischeri, with divergence occurred through subsequent gene duplication (such as in the case of Sepia officinalis) or gene loss (as with cephalopods with no active camouflage capabilities).[3] This is unique as an instance of camouflage arising as an instance of horizontal gene transfer from an endosymbiont. However, other methods of horizontal gene transfer are common in the evolution of camouflage strategies in other lineages. Peppered moths and walking stick insects both have camouflage-related genes that stem from transposition events.
The Agouti genes are orthologous genes involved in camouflage across many lineages. They produce yellow and red coloration (phaeomelanin), and work in competition with other genes that produce black (melanin) and brown (eumelanin) colours. In eastern deer mice, over a period of about 8000 years the single agouti gene developed 9 mutations that each made expression of yellow fur stronger under natural selection, and largely eliminated melanin-coding black fur coloration. On the other hand, all black domesticated cats have deletions of the agouti gene that prevent its expression, meaning no yellow or red color is produced. The evolution, history and widespread scope of the agouti gene shows that different organisms often rely on orthologous or even identical genes to develop a variety of camouflage strategies.
=== Ecology ===
While camouflage can increase an organism's fitness, it has genetic and energetic costs. There is a trade-off between detectability and mobility. Species camouflaged to fit a specific microhabitat are less likely to be detected when in that microhabitat, but must spend energy to reach, and sometimes to remain in, such areas. Outside the microhabitat, the organism has a higher chance of detection. Generalized camouflage allows species to avoid predation over a wide range of habitat backgrounds, but is less effective. The development of generalized or specialized camouflage strategies is highly dependent on the biotic and abiotic composition of the surrounding environment.
There are many examples of the tradeoffs between specific and general cryptic patterning. Phestilla melanocrachia, a species of nudibranch that feeds on stony coral, utilizes specific cryptic patterning in reef ecosystems. The nudibranch syphons pigments from the consumed coral into the epidermis, adopting the same shade as the consumed coral. This allows the nudibranch to change colour (mostly between black and orange) depending on the coral system that it inhabits. However, P. melanocrachia can only feed and lay eggs on the branches of host-coral, Platygyra carnosa, which limits the geographical range and efficacy in nudibranch nutritional crypsis. Furthermore, the nudibranch colour change is not immediate, and switching between coral hosts when in search for new food or shelter can be costly.
The costs associated with distractive or disruptive crypsis are more complex than the costs associated with background matching. Disruptive patterns distort the body outline, making it harder to precisely identify and locate. However, disruptive patterns result in higher predation. Disruptive patterns that specifically involve visible symmetry (such as in some butterflies) reduce survivability and increase predation. Some researchers argue that because wing-shape and color pattern are genetically linked, it is genetically costly to develop asymmetric wing colorations that would enhance the efficacy of disruptive cryptic patterning. Symmetry does not carry a high survival cost for butterflies and moths that their predators views from above on a homogeneous background, such as the bark of a tree. On the other hand, natural selection drives species with variable backgrounds and habitats to move symmetrical patterns away from the centre of the wing and body, disrupting their predators' symmetry recognition.
== Principles ==
Camouflage can be achieved by different methods, described below. Most of the methods help to hide against a background; but mimesis and motion dazzle protect without hiding. Methods may be applied on their own or in combination. Many mechanisms are visual, but some research has explored the use of techniques against olfactory (scent) and acoustic (sound) detection. Methods may also apply to military equipment.
=== Background matching ===
Some animals' colours and patterns match a particular natural background. This is an important component of camouflage in all environments. For instance, tree-dwelling parakeets are mainly green; woodcocks of the forest floor are brown and speckled; reedbed bitterns are streaked brown and buff; in each case the animal's coloration matches the hues of its habitat. Similarly, desert animals are almost all desert coloured in tones of sand, buff, ochre, and brownish grey, whether they are mammals like the gerbil or fennec fox, birds such as the desert lark or sandgrouse, or reptiles like the skink or horned viper. Military uniforms, too, generally resemble their backgrounds; for example khaki uniforms are a muddy or dusty colour, originally chosen for service in South Asia. Many moths show industrial melanism, including the peppered moth which has coloration that blends in with tree bark. The coloration of these insects evolved between 1860 and 1940 to match the changing colour of the tree trunks on which they rest, from pale and mottled to almost black in polluted areas. This is taken by zoologists as evidence that camouflage is influenced by natural selection, as well as demonstrating that it changes where necessary to resemble the local background.
File:Lion-in-tall-grass.jpg|Lion in Kruger National Park, South Africa, blending in with the tall grass
File:Tanzania 0607 cropped Nevit.jpg|Black-faced sandgrouse is coloured like its desert background.
File:Caprimulgus aegyptius.jpg|Egyptian nightjar nests in open sand with only its camouflaged plumage to protect it.
File:Katydid camouflaged in basil plant.jpg|Bright green katydid has the colour of fresh vegetation.
=== Disruptive coloration ===
Disruptive patterns use strongly contrasting, non-repeating markings such as spots or stripes to break up the outlines of an animal or military vehicle, or to conceal telltale features, especially by masking the eyes, as in the common frog. Disruptive patterns may use more than one method to defeat visual systems such as edge detection. Predators like the leopard use disruptive camouflage to help them approach prey, while potential prey use it to avoid detection by predators. Disruptive patterning is common in military usage, both for uniforms and for military vehicles. Disruptive patterning, however, does not always achieve crypsis on its own, as an animal or a military target may be given away by factors like shape, shine, and shadow.
The presence of bold skin markings does not in itself prove that an animal relies on camouflage, as that depends on its behaviour. For example, although giraffes have a high contrast pattern that could be disruptive coloration, the adults are very conspicuous when in the open. Some authors have argued that adult giraffes are cryptic, since when standing among trees and bushes they are hard to see at even a few metres' distance. However, adult giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves, even from lions, rather than on camouflage.
File:Great male Leopard in South Afrika-JD.JPG|Leopard: a disruptively camouflaged predator
File:T-90 main battle tank (2).jpg|Russian T-90 battle tank painted in bold disruptive pattern of sand and green
File:Gaboon viper (4530693343).jpg|Gaboon viper's bold markings are powerfully disruptive.
File:Ptarmigan and five chicks.JPG|A ptarmigan and five chicks exhibit exceptional disruptive camouflage
File:Jumping spider with prey.jpg|Jumping spider: a disruptively camouflaged invertebrate predator
File:Smilax bona-nox, Colt Creek State Park, Lakeland, Florida.jpg|Many understory plants such as the saw greenbriar, Smilax bona-nox have pale markings, possibly disruptive camouflage.
=== Countershading ===
Countershading uses graded colour to counteract the effect of self-shadowing, creating an illusion of flatness. Self-shadowing makes an animal appear darker below than on top, grading from light to dark; countershading 'paints in' tones which are darkest on top, lightest below, making the countershaded animal nearly invisible against a suitable background. Thayer observed that "Animals are painted by Nature, darkest on those parts which tend to be most lighted by the sky's light, and vice versa". Accordingly, the principle of countershading is sometimes called Thayer's Law. Countershading is widely used by terrestrial animals, such as gazelles and grasshoppers; marine animals, such as sharks and dolphins; and birds, such as snipe and dunlin.
Countershading is less often used for military camouflage, despite Second World War experiments that showed its effectiveness. English zoologist Hugh Cott encouraged the use of methods including countershading, but despite his authority on the subject, failed to persuade the British authorities. Soldiers often wrongly viewed camouflage netting as a kind of invisibility cloak, and they had to be taught to look at camouflage practically, from an enemy observer's viewpoint. At the same time in Australia, zoologist William John Dakin advised soldiers to copy animals' methods, using their instincts for wartime camouflage.
The term countershading has a second meaning unrelated to "Thayer's Law". It is that the upper and undersides of animals such as sharks, and of some military aircraft, are different colours to match the different backgrounds when seen from above or from below. Here the camouflage consists of two surfaces, each with the simple function of providing concealment against a specific background, such as a bright water surface or the sky. The body of a shark or the fuselage of an aircraft is not gradated from light to dark to appear flat when seen from the side. The camouflage methods used are the matching of background colour and pattern, and disruption of outlines. The theory that the body shape of the horned lizards which live in open desert is adapted to minimise shadow is supported by the one species which lacks fringe scales, the roundtail horned lizard, which lives in rocky areas and resembles a rock. When this species is threatened, it makes itself look as much like a rock as possible by curving its back, emphasizing its three-dimensional shape.
File:Ibexes.jpg|Three countershaded and cryptically coloured ibex almost invisible in the Israeli desert
File:Armoured personnel carriers, Eriboll - geograph.org.uk - 1316295.jpg|"Shape, shine, shadow" make these 'camouflaged' military vehicles easily visible.
File:Phrynosoma mcallii.jpg|The flat-tail horned lizard's body is flattened and fringed to minimise its shadow.
File:Øvelse på Evjemoen Tropp 4.2 - camouflage nettings.jpg|Camouflage netting is draped away from a military vehicle to reduce its shadow.
File:Perfect Camouflage (Caterpillar on teakwood branch).jpg|A caterpillar's fringe of bristles conceals its shadow.
=== Distraction ===
Many prey animals have conspicuous high-contrast markings which paradoxically attract the predator's gaze. These distractive markings may serve as camouflage by distracting the predator's attention from recognising the prey as a whole, for example by keeping the predator from identifying the prey's outline. Experimentally, search times for blue tits increased when artificial prey had distractive markings.
=== Cryptic behaviour ===
Movement catches the eye of prey animals on the lookout for predators, and of predators hunting for prey. Most methods of crypsis therefore also require suitable cryptic behaviour, such as lying down and keeping still to avoid being detected, or in the case of stalking predators such as the tiger, moving with extreme stealth, both slowly and quietly, watching its prey for any sign they are aware of its presence. As an example of the combination of behaviours and other methods of crypsis involved, young giraffes seek cover, lie down, and keep still, often for hours until their mothers return; their skin pattern blends with the pattern of the vegetation, while the chosen cover and lying position together hide the animals' shadows. In the ocean, the leafy sea dragon sways mimetically, like the seaweeds amongst which it rests, as if rippled by wind or water currents. Swaying is seen also in some insects, like Macleay's spectre stick insect, Extatosoma tiaratum. The behaviour may be motion crypsis, preventing detection, or motion masquerade, promoting misclassification (as something other than prey), or a combination of the two.
=== Motion camouflage ===
Most forms of camouflage are ineffective when the camouflaged animal or object moves, because the motion is easily seen by the observing predator, prey or enemy. However, insects such as hoverflies and dragonflies use motion camouflage: the hoverflies to approach possible mates, and the dragonflies to approach rivals when defending territories. Motion camouflage is achieved by moving so as to stay on a straight line between the target and a fixed point in the landscape; the pursuer thus appears not to move, but only to loom larger in the target's field of vision.
Some insects sway while moving to appear to be blown back and forth by the breeze.
The same method can be used for military purposes, for example by missiles to minimise their risk of detection by an enemy.
File:Hoverfly August 2007-8.jpg|Male Syritta pipiens hoverflies use motion camouflage to approach females
File:Australian Emperor mating and laying.jpg|Male Australian Emperor dragonflies use motion camouflage to approach rivals.
File:Motion Camouflage.webm|thumbtime=2|Preying mantises exhibiting motion camouflage.
=== Mimesis ===
In mimesis (also called masquerade), the camouflaged object looks like something else which is of no special interest to the observer. Mimesis is common in prey animals, for example when a peppered moth caterpillar mimics a twig, or a grasshopper mimics a dry leaf. It is also found in nest structures; some eusocial wasps, such as Leipomeles dorsata, build a nest envelope in patterns that mimic the leaves surrounding the nest.
Mimesis is also employed by some predators and parasites to lure their prey. For example, a flower mantis mimics a particular kind of flower, such as an orchid. This tactic has occasionally been used in warfare, for example with heavily armed Q-ships disguised as merchant ships.
The common cuckoo, a brood parasite, provides examples of mimesis both in the adult and in the egg. The female lays her eggs in nests of other, smaller species of bird, one per nest. The female mimics a sparrowhawk. The resemblance is sufficient to make small birds take action to avoid the apparent predator. The female cuckoo then has time to lay her egg in their nest without being seen to do so. The cuckoo's egg itself mimics the eggs of the host species, reducing its chance of being rejected.
File:Biston betularia.png|Peppered moth caterpillars mimic twigs
File:Insect camouflage PP08338.png|Flower mantis lures its insect prey by mimicking a Phalaenopsis orchid blossom
File:Hooded Grasshopper (Teratodus monticollis) W IMG 0525.jpg|Hooded grasshopper Teratodus monticollis, superbly mimics a leaf with a bright orange border
File:Gumleaf grasshopper.jpg|This grasshopper hides from predators by mimicking a dry leaf
File:IWM-E-18461-Crusader-camouflaged-19421026.jpg|WWII tank concealed in Operation Bertram by mimicking a truck
File:HMS President - geograph.org.uk - 659583.jpg|Armed WW1 Q-ship lured enemy submarines by mimicking a merchantman
File:European Cuckoo Mimics Sparrowhawk.jpg|Cuckoo adult mimics sparrowhawk, giving female time to lay eggs parasitically
File:Cuckoo Eggs Mimicking Reed Warbler Eggs.JPG|Cuckoo eggs mimicking smaller eggs, in this case of reed warbler
File:Wrap-around spider in the genus Dolophones (Family Araneidae) Camouflage View.JPG|Wrap-around spider Dolophones mimicking a stick
=== Motion dazzle ===
Most forms of camouflage are made ineffective by movement: a deer or grasshopper may be highly cryptic when motionless, but instantly seen when it moves. But one method, motion dazzle, requires rapidly moving bold patterns of contrasting stripes. Motion dazzle distorts speed perception and is most effective at high speeds; stripes can also distort perception of size (and so, perceived range to the target). As of 2011, motion dazzle had been proposed for military vehicles, but never applied. Since motion dazzle patterns would make animals more difficult to locate accurately when moving, but easier to see when stationary, there would be an evolutionary trade-off between motion dazzle and crypsis. an experimental study by Tim Caro suggested in 2012 that the pattern reduces the attractiveness of stationary models to biting flies such as horseflies and tsetse flies. However, a simulation study by Martin How and Johannes Zanker in 2014 suggests that when moving, the stripes may confuse observers, such as mammalian predators and biting insects, by two visual illusions: the wagon-wheel effect, where the perceived motion is inverted, and the barberpole illusion, where the perceived motion is in a wrong direction.
== Mechanisms ==
Animals can camouflage themselves by one or more principles using a variety of mechanisms. For example, some animals achieve background matching by changing their skin coloration to resemble their current background.
=== Changeable skin coloration ===
Animals such as chameleon, frog, flatfish such as the peacock flounder, squid, octopus and even the isopod idotea balthica actively change their skin patterns and colours using special chromatophore cells to resemble their current background, or, as in most chameleons, for signalling. However, Smith's dwarf chameleon does use active colour change for camouflage.
Each chromatophore contains pigment of only one colour. In fish and frogs, colour change is mediated by a type of chromatophore known as melanophores that contain dark pigment. A melanophore is star-shaped; it contains many small pigmented organelles which can be dispersed throughout the cell, or aggregated near its centre. When the pigmented organelles are dispersed, the cell makes a patch of the animal's skin appear dark; when they are aggregated, most of the cell, and the animal's skin, appears light. In frogs, the change is controlled relatively slowly, mainly by hormones. In fish, the change is controlled by the brain, which sends signals directly to the chromatophores, as well as producing hormones.
The skins of cephalopods such as the octopus contain complex units, each consisting of a chromatophore with surrounding muscle and nerve cells. The cephalopod chromatophore has all its pigment grains in a small elastic sac, which can be stretched or allowed to relax under the control of the brain to vary its opacity. By controlling chromatophores of different colours, cephalopods can rapidly change their skin patterns and colours.
On a longer timescale, animals like the Arctic hare, Arctic fox, stoat, and rock ptarmigan have snow camouflage, changing their coat colour (by moulting and growing new fur or feathers) from brown or grey in the summer to white in the winter; the Arctic fox is the only species in the dog family to do so. However, Arctic hares which live in the far north of Canada, where summer is very short, remain white year-round.
The principle of varying coloration either rapidly or with the changing seasons has military applications. Active camouflage could in theory make use of both dynamic colour change and counterillumination. Simple methods such as changing uniforms and repainting vehicles for winter have been in use since World War II. In 2011, BAE Systems announced their Adaptiv infrared camouflage technology. It uses about 1,000 hexagonal panels to cover the sides of a tank. The Peltier plate panels are heated and cooled to match either the vehicle's surroundings (crypsis), or an object such as a car (mimesis), when viewed in infrared.
File:Rock Ptarmigan (Lagopus Muta).jpg|Rock ptarmigan, changing colour in springtime. The male is still mostly in winter plumage
File:Norwegian Winter War Volunteers.jpg|Norwegian volunteer soldiers in Winter War, 1940, with white camouflage overalls over their uniforms
File:Arctic Hare.jpg|Arctic hares in the low arctic change from brown to white in winter
File:Bundesarchiv Bild 101III-Roth-173-01, Russland, Raum Charkow, Jagdpanzer.jpg|Snow-camouflaged German Marder III jagdpanzer and white-overalled crew and infantry in Russia, 1943
File:Yemen Chameleon (cropped).jpg|Veiled chameleon, Chamaeleo calyptratus, changes colour mainly in relation to mood and for signalling.
File:Adaptiv infrared camouflage demo hiding tank as car.jpg|Adaptiv infrared camouflage lets an armoured vehicle mimic a car.
=== Self-decoration ===
Some animals actively seek to hide by decorating themselves with materials such as twigs, sand, or pieces of shell from their environment, to break up their outlines, to conceal the features of their bodies, and to match their backgrounds. For example, a caddisfly larva builds a decorated case and lives almost entirely inside it; a decorator crab covers its back with seaweed, sponges, and stones. The nymph of the predatory masked bug uses its hind legs and a 'tarsal fan' to decorate its body with sand or dust. There are two layers of bristles (trichomes) over the body. On these, the nymph spreads an inner layer of fine particles and an outer layer of coarser particles. The camouflage may conceal the bug from both predators and prey.
Similar principles can be applied for military purposes, for instance when a sniper wears a ghillie suit designed to be further camouflaged by decoration with materials such as tufts of grass from the sniper's immediate environment. Such suits were used as early as 1916, the British army having adopted "coats of motley hue and stripes of paint" for snipers. Cott takes the example of the larva of the blotched emerald moth, which fixes a screen of fragments of leaves to its specially hooked bristles, to argue that military camouflage uses the same method, pointing out that the "device is ... essentially the same as one widely practised during the Great War for the concealment, not of caterpillars, but of caterpillar-tractors, [gun] battery positions, observation posts and so forth."
File:Hyastenus elatus.jpg|This decorator crab has covered its body with sponges.
File:IDF-CombatEngineeringSniper001.jpg|Sniper in a Ghillie suit with plant materials
File:Reduvius personatus, Masked Hunter Bug nymph camouflaged with sand grains.JPG|Reduvius personatus, masked hunter bug nymph, camouflaged with sand grains
File:Battle of Lake Khasan-Camouflaged soviet tanks.jpg|Soviet tanks under netting dressed with vegetation, 1938
=== Transparency ===
Many marine animals that float near the surface are highly transparent, giving them almost perfect camouflage. However, transparency is difficult for bodies made of materials that have different refractive indices from seawater. Some marine animals such as jellyfish have gelatinous bodies, composed mainly of water; their thick mesogloea is acellular and highly transparent. This conveniently makes them buoyant, but it also makes them large for their muscle mass, so they cannot swim fast, making this form of camouflage a costly trade-off with mobility. Gelatinous planktonic animals are between 50 and 90 percent transparent. A transparency of 50 percent is enough to make an animal invisible to a predator such as cod at a depth of ; better transparency is required for invisibility in shallower water, where the light is brighter and predators can see better. For example, a cod can see prey that are 98 percent transparent in optimal lighting in shallow water. Therefore, sufficient transparency for camouflage is more easily achieved in deeper waters.
Some tissues such as muscles can be made transparent, provided either they are very thin or organised as regular layers or fibrils that are small compared to the wavelength of visible light. A familiar example is the transparency of the lens of the vertebrate eye, which is made of the protein crystallin, and the vertebrate cornea which is made of the protein collagen. Other structures cannot be made transparent, notably the retinas or equivalent light-absorbing structures of eyes – they must absorb light to be able to function. The camera-type eye of vertebrates and cephalopods must be completely opaque. Finally, some structures are visible for a reason, such as to lure prey. For example, the nematocysts (stinging cells) of the transparent siphonophore Agalma okenii resemble small copepods. Examples of transparent marine animals include a wide variety of larvae, including radiata (coelenterates), siphonophores, salps (floating tunicates), gastropod molluscs, polychaete worms, many shrimplike crustaceans, and fish; whereas the adults of most of these are opaque and pigmented, resembling the seabed or shores where they live. Adult comb jellies and jellyfish obey the rule, often being mainly transparent. Cott suggests this follows the more general rule that animals resemble their background: in a transparent medium like seawater, that means being transparent. The small Amazon River fish Microphilypnus amazonicus and the shrimps it associates with, Pseudopalaemon gouldingi, are so transparent as to be "almost invisible"; further, these species appear to select whether to be transparent or more conventionally mottled (disruptively patterned) according to the local background in the environment.
=== Silvering ===
Where transparency cannot be achieved, it can be imitated effectively by silvering to make an animal's body highly reflective. At medium depths at sea, light comes from above, so a mirror oriented vertically makes animals such as fish invisible from the side. Most fish in the upper ocean such as sardine and herring are camouflaged by silvering.
The marine hatchetfish is extremely flattened laterally, leaving the body just millimetres thick, and the body is so silvery as to resemble aluminium foil. The mirrors consist of microscopic structures similar to those used to provide structural coloration: stacks of between 5 and 10 crystals of guanine spaced about of a wavelength apart to interfere constructively and achieve nearly 100 per cent reflection. In the deep waters that the hatchetfish lives in, only blue light with a wavelength of 500 nanometres percolates down and needs to be reflected, so mirrors 125 nanometres apart provide good camouflage.
In fish such as the herring which live in shallower water, the mirrors must reflect a mixture of wavelengths, and the fish accordingly has crystal stacks with a range of different spacings. A further complication for fish with bodies that are rounded in cross-section is that the mirrors would be ineffective if laid flat on the skin, as they would fail to reflect horizontally. The overall mirror effect is achieved with many small reflectors, all oriented vertically. Silvering is found in other marine animals as well as fish. The cephalopods, including squid, octopus and cuttlefish, have multilayer mirrors made of protein rather than guanine.
=== Counter-illumination ===
Counter-illumination means producing light to match a background that is brighter than an animal's body or military vehicle; it is a form of active camouflage. It is notably used by some species of squid, such as the firefly squid and the midwater squid. The latter has light-producing organs (photophores) scattered all over its underside; these create a sparkling glow that prevents the animal from appearing as a dark shape when seen from below. Counterillumination camouflage is the likely function of the bioluminescence of many marine organisms, though light is also produced to attract or to detect prey and for signalling.
Counterillumination has rarely been used for military purposes. "Diffused lighting camouflage" was trialled by Canada's National Research Council during the Second World War. It involved projecting light on to the sides of ships to match the faint glow of the night sky, requiring awkward external platforms to support the lamps. The Canadian concept was refined in the American Yehudi lights project, and trialled in aircraft including B-24 Liberators and naval Avengers. The planes were fitted with forward-pointing lamps automatically adjusted to match the brightness of the night sky.
== Applications ==
=== Military ===
==== Before 1800 ====
Ship camouflage was occasionally used in ancient times. Philostratus () wrote in his Imagines that Mediterranean pirate ships could be painted blue-gray for concealment. Vegetius () says that "Venetian blue" (sea green) was used in the Gallic Wars, when Julius Caesar sent his speculatoria navigia (reconnaissance boats) to gather intelligence along the coast of Britain; the ships were painted entirely in bluish-green wax, with sails, ropes and crew the same colour. There is little evidence of military use of camouflage on land before 1800, but two unusual ceramics show men in Peru's Mochica culture from before 500 AD, hunting birds with blowpipes which are fitted with a kind of shield near the mouth, perhaps to conceal the hunters' hands and faces. Another early source is a 15th-century French manuscript, The Hunting Book of Gaston Phebus, showing a horse pulling a cart which contains a hunter armed with a crossbow under a cover of branches, perhaps serving as a hide for shooting game. Jamaican Maroons are said to have used plant materials as camouflage in the First Maroon War ().
==== 19th-century origins ====
The development of military camouflage was driven by the increasing range and accuracy of infantry firearms in the 19th century. In particular the replacement of the inaccurate musket with weapons such as the Baker rifle made personal concealment in battle essential. Two Napoleonic War skirmishing units of the British Army, the 95th Rifle Regiment and the 60th Rifle Regiment, were the first to adopt camouflage in the form of a rifle green jacket, while the Line regiments continued to wear scarlet tunics. A contemporary study in 1800 by the English artist and soldier Charles Hamilton Smith provided evidence that grey uniforms were less visible than green ones at a range of 150 yards.
In the American Civil War, rifle units such as the 1st United States Sharp Shooters (in the Federal army) similarly wore green jackets while other units wore more conspicuous colours. The first British Army unit to adopt khaki uniforms was the Corps of Guides at Peshawar, when Sir Harry Lumsden and his second in command, William Hodson introduced a "drab" uniform in 1848. Hodson wrote that it would be more appropriate for the hot climate, and help make his troops "invisible in a land of dust". Later they improvised by dyeing cloth locally. Other regiments in India soon adopted the khaki uniform, and by 1896 khaki drill uniform was used everywhere outside Europe; by the Second Boer War six years later it was used throughout the British Army.
During the late 19th century camouflage was applied to British coastal fortifications. The fortifications around Plymouth, England were painted in the late 1880s in "irregular patches of red, brown, yellow and green." From 1891 onwards British coastal artillery was permitted to be painted in suitable colours "to harmonise with the surroundings" and by 1904 it was standard practice that artillery and mountings should be painted with "large irregular patches of different colours selected to suit local conditions."
==== First World War ====
In the First World War, the French army formed a camouflage corps, led by Lucien-Victor Guirand de Scévola, employing artists known as camoufleurs to create schemes such as tree observation posts and covers for guns. Other armies soon followed them. The term camouflage probably comes from camoufler, a Parisian slang term meaning to disguise, and may have been influenced by camouflet, a French term meaning smoke blown in someone's face. The English zoologist John Graham Kerr, artist Solomon J. Solomon and the American artist Abbott Thayer led attempts to introduce scientific principles of countershading and disruptive patterning into military camouflage, with limited success. In early 1916 the Royal Naval Air Service began to create dummy air fields to draw the attention of enemy planes to empty land. They created decoy homes and lined fake runways with flares, which were meant to help protect real towns from night raids. This strategy was not common practice and did not succeed at first, but in 1918 it caught the Germans off guard multiple times.
Ship camouflage was introduced in the early 20th century as the range of naval guns increased, with ships painted grey all over. In April 1917, when German U-boats were sinking many British ships with torpedoes, the marine artist Norman Wilkinson devised dazzle camouflage, which paradoxically made ships more visible but harder to target. In Wilkinson's own words, dazzle was designed "not for low visibility, but in such a way as to break up her form and thus confuse a submarine officer as to the course on which she was heading".
File:USS West Mahomet (ID-3681) cropped.jpg|USS West Mahomet in dazzle camouflage
File:CamouflagedAustralian9.2inchHowitzerYpres1917.jpeg|Siege howitzer camouflaged against observation from the air, 1917
File:Austro-Hungarian ski patrol on Italian front in snow camouflage 1915-1918.jpg|Austro-Hungarian ski patrol in two-part snow uniforms with improvised head camouflage on Italian front, 1915–1918
==== Second World War ====
In the Second World War, the zoologist Hugh Cott, a protégé of Kerr, worked to persuade the British army to use more effective camouflage methods, including countershading, but, like Kerr and Thayer in the First World War, with limited success. For example, he painted two rail-mounted coastal guns, one in conventional style, one countershaded. In aerial photographs, the countershaded gun was essentially invisible. The power of aerial observation and attack led every warring nation to camouflage targets of all types. The Soviet Union's Red Army created the comprehensive doctrine of Maskirovka for military deception, including the use of camouflage. For example, during the Battle of Kursk, General Katukov, the commander of the Soviet 1st Tank Army, remarked that the enemy "did not suspect that our well-camouflaged tanks were waiting for him. As we later learned from prisoners, we had managed to move our tanks forward unnoticed". The tanks were concealed in previously prepared defensive emplacements, with only their turrets above ground level. In the air, Second World War fighters were often painted in ground colours above and sky colours below, attempting two different camouflage schemes for observers above and below. Bombers and night fighters were often black, while maritime reconnaissance planes were usually white, to avoid appearing as dark shapes against the sky. For ships, dazzle camouflage was mainly replaced with plain grey in the Second World War, though experimentation with colour schemes continued. writing the practical Home Guard Manual of Camouflage. The film-maker Geoffrey Barkas ran the Middle East Command Camouflage Directorate during the 1941–1942 war in the Western Desert, including the successful deception of Operation Bertram. Hugh Cott was chief instructor; the artist camouflage officers, who called themselves camoufleurs, included Steven Sykes and Tony Ayrton. In Australia, artists were also prominent in the Sydney Camouflage Group, formed under the chairmanship of Professor William John Dakin, a zoologist from Sydney University. Max Dupain, Sydney Ure Smith, and William Dobell were among the members of the group, which worked at Bankstown Airport, RAAF Base Richmond and Garden Island Dockyard. In the United States, artists like John Vassos took a certificate course in military and industrial camouflage at the American School of Design with Baron Nicholas Cerkasoff, and went on to create camouflage for the Air Force.
File:Catalina Góraszka 2008 204.JPG|Maritime patrol Catalina, painted white to minimise visibility against the sky
File:SS Platanenmuster Sommer.jpg|1937 summer variant of Waffen SS Flecktarn Plane tree pattern
File:USS Duluth (CL-87) underway in Hampton Roads on 10 October 1944 (NH 98363).jpg|USS Duluth in naval camouflage Measure 32, Design 11a, one of many dazzle schemes used on warships
File:Spitfire.planform.arp.jpg|A Spitfire's underside 'azure' paint scheme, meant to hide it against the sky
File:Royal Air Force 1939-1945- Fighter Command CL3979.jpg|A Luftwaffe aircraft hangar built to resemble a street of village houses, Belgium, 1944
File:Bundesarchiv Bild 183-E0406-0022-001, Russland, Kesselschlacht Stalingrad.jpg|Red Army soldiers in the Battle of Stalingrad in snow camouflage overalls, January 1943
==== After 1945 ====
Camouflage has been used to protect military equipment such as vehicles, guns, ships, aircraft and buildings as well as individual soldiers and their positions.
Vehicle camouflage methods begin with paint, which offers at best only limited effectiveness. Other methods for stationary land vehicles include covering with improvised materials such as blankets and vegetation, and erecting nets, screens and soft covers which may suitably reflect, scatter or absorb near infrared and radar waves. Some military textiles and vehicle camouflage paints also reflect infrared to help provide concealment from night vision devices.
After the Second World War, radar made camouflage generally less effective, though coastal boats are sometimes painted like land vehicles.
Many camouflaged textile patterns have been developed to suit the need to match combat clothing to different kinds of terrain (such as woodland, snow, and desert). The design of a pattern effective in all terrains has proved elusive. The American Universal Camouflage Pattern of 2004 attempted to suit all environments, but was withdrawn after a few years of service. Terrain-specific patterns have sometimes been developed but are ineffective in other terrains. The problem of making a pattern that works at different ranges has been solved with multiscale designs, often with a pixellated appearance and designed digitally, that provide a fractal-like range of patch sizes so they appear disruptively coloured both at close range and at a distance. The first genuinely digital camouflage pattern was the Canadian Disruptive Pattern (CADPAT), issued to the army in 2002, soon followed by the American Marine pattern (MARPAT). A pixellated appearance is not essential for this effect, though it is simpler to design and to print.
File:CADPAT digital camouflage pattern (Temperate Woodland variant).jpg|CADPAT was the first pixellated digital camouflage pattern to be issued, in 2002.
File:British dpm2.jpg|British Disruptive Pattern Material, issued to special forces in 1963 and universally by 1968
File:M05 snow pattern.jpg|2007 2-colour snow variant of Finnish Defence Forces M05 pattern
File:Pla camo.svg|Main (4-colour woodland) variant of Chinese People's Liberation Army Type 99 pattern,
File:Flecktarn.jpg|Modern German Flecktarn 1990, developed from a 1938 pattern, a non-digital pattern which works at different distances
File:Six-Color Desert Pattern.jpg|US "Chocolate Chip" Six-Color Desert Pattern developed in 1962, widely used in Gulf War
=== Hunting ===
Hunters of game have long made use of camouflage in the form of materials such as animal skins, mud, foliage, and green or brown clothing to enable them to approach wary game animals. Field sports such as driven grouse shooting conceal hunters in hides (also called blinds or shooting butts). Modern hunting clothing makes use of fabrics that provide a disruptive camouflage pattern; for example, in 1986 the hunter Bill Jordan created cryptic clothing for hunters, printed with images of specific kinds of vegetation such as grass and branches.
=== Civil structures ===
Camouflage is occasionally used to make built structures less conspicuous: for example, in South Africa, towers carrying cell telephone antennae are sometimes camouflaged as tall trees with plastic branches, in response to "resistance from the community". Since this method is costly (a figure of three times the normal cost is mentioned), alternative forms of camouflage can include using neutral colours or familiar shapes such as cylinders and flagpoles. Conspicuousness can also be reduced by siting masts near, or on, other structures.
Automotive manufacturers often use patterns to disguise upcoming products. This camouflage is designed to obfuscate the vehicle's visual lines, and is used along with padding, covers, and decals. The patterns' purpose is to prevent visual observation (and to a lesser degree photography), that would subsequently enable reproduction of the vehicle's form factors.
=== Fashion, art and society ===
Military camouflage patterns influenced fashion and art from the time of the First World War onwards. Gertrude Stein recalled the cubist artist Pablo Picasso's reaction in around 1915:
In 1919, the attendants of a "dazzle ball", hosted by the Chelsea Arts Club, wore dazzle-patterned black and white clothing. The ball influenced fashion and art via postcards and magazine articles. The Illustrated London News announced:
More recently, fashion designers have often used camouflage fabric for its striking designs, its "patterned disorder" and its symbolism. Camouflage clothing can be worn largely for its symbolic significance rather than for fashion, as when, during the late 1960s and early 1970s in the United States, anti-war protestors often ironically wore military clothing during demonstrations against the American involvement in the Vietnam War.
Modern artists such as Ian Hamilton Finlay have used camouflage to reflect on war. His 1973 screenprint of a tank camouflaged in a leaf pattern, Arcadia, is described by the Tate as drawing "an ironic parallel between this idea of a natural paradise and the camouflage patterns on a tank". The title refers to the Utopian Arcadia of poetry and art, and the memento mori Latin phrase Et in Arcadia ego which recurs in Hamilton Finlay's work. In science fiction, Camouflage is a novel about shapeshifting alien beings by Joe Haldeman. The word is used more figuratively in works of literature such as Thaisa Frank's collection of stories of love and loss, A Brief History of Camouflage.
In 1986, Andy Warhol began a series of monumental camouflage paintings, which helped to transform camouflage into a popular print pattern. A year later, in 1987, New York designer Stephen Sprouse used Warhol's camouflage prints as the basis for his Autumn Winter 1987 collection.
File:André_Mare_1885-1932_Camouflaged_280_Gun_sketch_in_ink_and_watercolour.jpg|André Mare's Cubist sketch, , of a 280 calibre gun illustrates the interplay of art and war, as artists like Mare contributed their skills as wartime camoufleurs.
File:Vietnam War protest in Washington DC April 1971.jpg|Camouflage clothing in an anti-war protest, 1971
File:Aline Campos 1c.jpg|A camouflage skirt as a fashion item, 2007
|
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"nematocyst",
"French language",
"Pterocles decoratus",
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"Scleractinia",
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"Jon Latimer",
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"The Colours of Animals",
"List of camoufleurs",
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"Charles Hamilton Smith",
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"countershading",
"Actinopterygii",
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"shapeshifting",
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"Ship camouflage",
"HMS Largs",
"herbivore"
] |
6,449 |
Clock
|
A clock or chronometer is a device that measures and displays time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia.
Some predecessors to the modern clock may be considered "clocks" that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface. There is a range of duration timers, a well-known example being the hourglass. Water clocks, along with sundials, are possibly the oldest time-measuring instruments. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1300 in Europe, which kept time with oscillating timekeepers like balance wheels.
Traditionally, in horology (the study of timekeeping), the term clock was used for a striking clock, while a clock that did not strike the hours audibly was called a timepiece. This distinction is not generally made any longer. Watches and other timepieces that can be carried on one's person are usually not referred to as clocks. Spring-driven clocks appeared during the 15th century. During the 15th and 16th centuries, clockmaking flourished. The next development in accuracy occurred after 1656 with the invention of the pendulum clock by Christiaan Huygens. A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time-keeping for navigation. The mechanism of a timepiece with a series of gears driven by a spring or weights is referred to as clockwork; the term is used by extension for a similar mechanism not used in a timepiece. The electric clock was patented in 1840, and electronic clocks were introduced in the 20th century, becoming widespread with the development of small battery-powered semiconductor devices.
The timekeeping element in every modern clock is a harmonic oscillator, a physical object (resonator) that vibrates or oscillates at a particular frequency. so the English word came from the Middle Low German and Middle Dutch .
The word is also derived from the Middle English , Old North French , or Middle Dutch , all of which mean 'bell'.
==History of time-measuring devices==
===Sundials===
The apparent position of the Sun in the sky changes over the course of each day, reflecting the rotation of the Earth. Shadows cast by stationary objects move correspondingly, so their positions can be used to indicate the time of day. A sundial shows the time by displaying the position of a shadow on a (usually) flat surface that has markings that correspond to the hours. Sundials can be horizontal, vertical, or in other orientations. Sundials were widely used in ancient times. With knowledge of latitude, a well-constructed sundial can measure local solar time with reasonable accuracy, within a minute or two. Sundials continued to be used to monitor the performance of clocks until the 1830s, when the use of the telegraph and trains standardized time and time zones between cities.
===Devices that measure duration, elapsed time and intervals===
Many devices can be used to mark the passage of time without respect to reference time (time of day, hours, minutes, etc.) and can be useful for measuring duration or intervals. Examples of such duration timers are candle clocks, incense clocks, and the hourglass. Both the candle clock and the incense clock work on the same principle, wherein the consumption of resources is more or less constant, allowing reasonably precise and repeatable estimates of time passages. In the hourglass, fine sand pouring through a tiny hole at a constant rate indicates an arbitrary, predetermined passage of time. The resource is not consumed, but re-used.
===Water clocks===
Water clocks, along with sundials, are possibly the oldest time-measuring instruments, with the only exception being the day-counting tally stick. Given their great antiquity, where and when they first existed is not known and is perhaps unknowable. The bowl-shaped outflow is the simplest form of a water clock and is known to have existed in Babylon and Egypt around the 16th century BC. Other regions of the world, including India and China, also have early evidence of water clocks, but the earliest dates are less certain. Some authors, however, write about water clocks appearing as early as 4000 BC in these regions of the world.
The Macedonian astronomer Andronicus of Cyrrhus supervised the construction of the Tower of the Winds in Athens in the 1st century BC, which housed a large clepsydra inside as well as multiple prominent sundials outside, allowing it to function as a kind of early clocktower. The Greek and Roman civilizations advanced water clock design with improved accuracy. These advances were passed on through Byzantine and Islamic times, eventually making their way back to Europe. Independently, the Chinese developed their own advanced water clocks () by 725 AD, passing their ideas on to Korea and Japan.
Some water clock designs were developed independently, and some knowledge was transferred through the spread of trade. Pre-modern societies do not have the same precise timekeeping requirements that exist in modern industrial societies, where every hour of work or rest is monitored and work may start or finish at any time regardless of external conditions. Instead, water clocks in ancient societies were used mainly for astrological reasons. These early water clocks were calibrated with a sundial. While never reaching the level of accuracy of a modern timepiece, the water clock was the most accurate and commonly used timekeeping device for millennia until it was replaced by the more accurate pendulum clock in 17th-century Europe.
Islamic civilization is credited with further advancing the accuracy of clocks through elaborate engineering. In 797 (or possibly 801), the Abbasid caliph of Baghdad, Harun al-Rashid, presented Charlemagne with an Asian elephant named Abul-Abbas together with a "particularly elaborate example" of a water clock. Pope Sylvester II introduced clocks to northern and western Europe around 1000 AD.
=== Mechanical water clocks ===
The first known geared clock was invented by the great mathematician, physicist, and engineer Archimedes during the 3rd century BC. Archimedes created his astronomical clock, which was also a cuckoo clock with birds singing and moving every hour. It is the first carillon clock as it plays music simultaneously with a person blinking his eyes, surprised by the singing birds. The Archimedes clock works with a system of four weights, counterweights, and strings regulated by a system of floats in a water container with siphons that regulate the automatic continuation of the clock. The principles of this type of clock are described by the mathematician and physicist Hero, who says that some of them work with a chain that turns a gear in the mechanism. Another Greek clock probably constructed at the time of Alexander was in Gaza, as described by Procopius. The Gaza clock was probably a Meteoroskopeion, i.e., a building showing celestial phenomena and the time. It had a pointer for the time and some automations similar to the Archimedes clock. There were 12 doors opening one every hour, with Hercules performing his labors, the Lion at one o'clock, etc., and at night a lamp becomes visible every hour, with 12 windows opening to show the time.
The Tang dynasty Buddhist monk Yi Xing along with government official Liang Lingzan made the escapement in 723 (or 725) to the workings of a water-powered armillary sphere and clock drive, which was the world's first clockwork escapement. The Song dynasty polymath and genius Su Song (1020–1101) incorporated it into his monumental innovation of the astronomical clock tower of Kaifeng in 1088. His astronomical clock and rotating armillary sphere still relied on the use of either flowing water during the spring, summer, and autumn seasons or liquid mercury during the freezing temperatures of winter (i.e., hydraulics).
In Su Song's waterwheel linkwork device, the action of the escapement's arrest and release was achieved by gravity exerted periodically as the continuous flow of liquid-filled containers of a limited size. In a single line of evolution, Su Song's clock therefore united the concepts of the clepsydra and the mechanical clock into one device run by mechanics and hydraulics. In his memorial, Su Song wrote about this concept:
According to your servant's opinion there have been many systems and designs for astronomical instruments during past dynasties all differing from one another in minor respects. But the principle of the use of water-power for the driving mechanism has always been the same. The heavens move without ceasing but so also does water flow (and fall). Thus if the water is made to pour with perfect evenness, then the comparison of the rotary movements (of the heavens and the machine) will show no discrepancy or contradiction; for the unresting follows the unceasing.
Song was also strongly influenced by the earlier armillary sphere created by Zhang Sixun (976 AD), who also employed the escapement mechanism and used liquid mercury instead of water in the waterwheel of his astronomical clock tower. The mechanical clockworks for Su Song's astronomical tower featured a great driving-wheel that was 11 feet in diameter, carrying 36 scoops, into each of which water was poured at a uniform rate from the "constant-level tank". The main driving shaft of iron, with its cylindrical necks supported on iron crescent-shaped bearings, ended in a pinion, which engaged a gear wheel at the lower end of the main vertical transmission shaft. This great astronomical hydromechanical clock tower was about ten metres high (about 30 feet), featured a clock escapement, and was indirectly powered by a rotating wheel either with falling water or liquid mercury. A full-sized working replica of Su Song's clock exists in the Republic of China (Taiwan)'s National Museum of Natural Science, Taichung city. This full-scale, fully functional replica, approximately 12 meters (39 feet) in height, was constructed from Su Song's original descriptions and mechanical drawings. The Chinese escapement spread west and was the source for Western escapement technology.
In the 12th century, Al-Jazari, an engineer from Mesopotamia (lived 1136–1206) who worked for the Artuqid king of Diyar-Bakr, Nasir al-Din, made numerous clocks of all shapes and sizes. The most reputed clocks included the elephant, scribe, and castle clocks, some of which have been successfully reconstructed. As well as telling the time, these grand clocks were symbols of the status, grandeur, and wealth of the Urtuq State. Knowledge of these mercury escapements may have spread through Europe with translations of Arabic and Spanish texts.
===Fully mechanical===
The word (from the Greek —'hour', and —'to tell') was used to describe early mechanical clocks, but the use of this word (still used in several Romance languages) for all timekeepers conceals the true nature of the mechanisms. For example, there is a record that in 1176, Sens Cathedral in France installed an 'horologe', but the mechanism used is unknown. According to Jocelyn de Brakelond, in 1198, during a fire at the abbey of St Edmundsbury (now Bury St Edmunds), the monks "ran to the clock" to fetch water, indicating that their water clock had a reservoir large enough to help extinguish the occasional fire. The word clock (via Medieval Latin from Old Irish , both meaning 'bell'), which gradually supersedes "horologe", suggests that it was the sound of bells that also characterized the prototype mechanical clocks that appeared during the 13th century in Europe.
In Europe, between 1280 and 1320, there was an increase in the number of references to clocks and horologes in church records, and this probably indicates that a new type of clock mechanism had been devised. Existing clock mechanisms that used water power were being adapted to take their driving power from falling weights. This power was controlled by some form of oscillating mechanism, probably derived from existing bell-ringing or alarm devices. This controlled release of power – the escapement – marks the beginning of the true mechanical clock, which differed from the previously mentioned cogwheel clocks. The verge escapement mechanism appeared during the surge of true mechanical clock development, which did not need any kind of fluid power, like water or mercury, to work.
These mechanical clocks were intended for two main purposes: for signalling and notification (e.g., the timing of services and public events) and for modeling the solar system. The former purpose is administrative; the latter arises naturally given the scholarly interests in astronomy, science, and astrology and how these subjects integrated with the religious philosophy of the time. The astrolabe was used both by astronomers and astrologers, and it was natural to apply a clockwork drive to the rotating plate to produce a working model of the solar system.
Simple clocks intended mainly for notification were installed in towers and did not always require faces or hands. They would have announced the canonical hours or intervals between set times of prayer. Canonical hours varied in length as the times of sunrise and sunset shifted. The more sophisticated astronomical clocks would have had moving dials or hands and would have shown the time in various time systems, including Italian hours, canonical hours, and time as measured by astronomers at the time. Both styles of clocks started acquiring extravagant features, such as automata.
In 1283, a large clock was installed at Dunstable Priory in Bedfordshire in southern England; its location above the rood screen suggests that it was not a water clock. In 1292, Canterbury Cathedral installed a 'great horloge'. Over the next 30 years, there were mentions of clocks at a number of ecclesiastical institutions in England, Italy, and France. In 1322, a new clock was installed in Norwich, an expensive replacement for an earlier clock installed in 1273. This had a large (2 metre) astronomical dial with automata and bells. The costs of the installation included the full-time employment of two clockkeepers for two years. and modern reproductions have been made.
Wallingford's clock had a large astrolabe-type dial, showing the sun, the moon's age, phase, and node, a star map, and possibly the planets. In addition, it had a wheel of fortune and an indicator of the state of the tide at London Bridge. Bells rang every hour, the number of strokes indicating the time.
===Spring-driven===
Matthew Norman carriage clock with winding key.jpg|Matthew Norman carriage clock with winding key
1908 Gilbert mantel clock decorated with Memento Mori decoupage.JPG|Decorated William Gilbert mantel clock
Clockmakers developed their art in various ways. Building smaller clocks was a technical challenge, as was improving accuracy and reliability. Clocks could be impressive showpieces to demonstrate skilled craftsmanship, or less expensive, mass-produced items for domestic use. The escapement in particular was an important factor affecting the clock's accuracy, so many different mechanisms were tried.
Spring-driven clocks appeared during the 15th century, although they are often erroneously credited to Nuremberg watchmaker Peter Henlein (or Henle, or Hele) around 1511. The earliest existing spring driven clock is the chamber clock given to Phillip the Good, Duke of Burgundy, around 1430, now in the Germanisches Nationalmuseum. and some 15th-century clocks in Germany indicated minutes and seconds.
An early record of a seconds hand on a clock dates back to about 1560 on a clock now in the Fremersdorf collection.
During the 15th and 16th centuries, clockmaking flourished, particularly in the metalworking towns of Nuremberg and Augsburg, and in Blois, France. Some of the more basic table clocks have only one time-keeping hand, with the dial between the hour markers being divided into four equal parts making the clocks readable to the nearest 15 minutes. Other clocks were exhibitions of craftsmanship and skill, incorporating astronomical indicators and musical movements. The cross-beat escapement was invented in 1584 by Jost Bürgi, who also developed the remontoire. Bürgi's clocks were a great improvement in accuracy as they were correct to within a minute a day. These clocks helped the 16th-century astronomer Tycho Brahe to observe astronomical events with much greater precision than before.
=== Pendulum ===
The next development in accuracy occurred after 1656 with the invention of the pendulum clock. Galileo had the idea to use a swinging bob to regulate the motion of a time-telling device earlier in the 17th century. Christiaan Huygens, however, is usually credited as the inventor. He determined the mathematical formula that related pendulum length to time (about 99.4 cm or 39.1 inches for the one second movement) and had the first pendulum-driven clock made. The first model clock was built in 1657 in the Hague, but it was in England that the idea was taken up. The longcase clock (also known as the grandfather clock) was created to house the pendulum and works by the English clockmaker William Clement in 1670 or 1671. It was also at this time that clock cases began to be made of wood and clock faces to use enamel as well as hand-painted ceramics.
In 1670, William Clement created the anchor escapement, an improvement over Huygens' crown escapement. Clement also introduced the pendulum suspension spring in 1671. The concentric minute hand was added to the clock by Daniel Quare, a London clockmaker and others, and the second hand was first introduced.
===Hairspring===
In 1675, Huygens and Robert Hooke invented the spiral balance spring, or the hairspring, designed to control the oscillating speed of the balance wheel. This crucial advance finally made accurate pocket watches possible. The great English clockmaker Thomas Tompion, was one of the first to use this mechanism successfully in his pocket watches, and he adopted the minute hand which, after a variety of designs were trialled, eventually stabilised into the modern-day configuration. The rack and snail striking mechanism for striking clocks, was introduced during the 17th century and had distinct advantages over the 'countwheel' (or 'locking plate') mechanism. During the 20th century there was a common misconception that Edward Barlow invented rack and snail striking. In fact, his invention was connected with a repeating mechanism employing the rack and snail. The repeating clock, that chimes the number of hours (or even minutes) on demand was invented by either Quare or Barlow in 1676. George Graham invented the deadbeat escapement for clocks in 1720.
===Marine chronometer===
A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time-keeping for navigation. The position of a ship at sea could be determined with reasonable accuracy if a navigator could refer to a clock that lost or gained less than about 10 seconds per day. This clock could not contain a pendulum, which would be virtually useless on a rocking ship. In 1714, the British government offered large financial rewards to the value of 20,000 pounds for anyone who could determine longitude accurately. John Harrison, who dedicated his life to improving the accuracy of his clocks, later received considerable sums under the Longitude Act.
In 1735, Harrison built his first chronometer, which he steadily improved on over the next thirty years before submitting it for examination. The clock had many innovations, including the use of bearings to reduce friction, weighted balances to compensate for the ship's pitch and roll in the sea and the use of two different metals to reduce the problem of expansion from heat. The chronometer was tested in 1761 by Harrison's son and by the end of 10 weeks the clock was in error by less than 5 seconds.
===Mass production===
The British had dominated watch manufacture for much of the 17th and 18th centuries, but maintained a system of production that was geared towards high quality products for the elite. Although there was an attempt to modernise clock manufacture with mass-production techniques and the application of duplicating tools and machinery by the British Watch Company in 1843, it was in the United States that this system took off. In 1816, Eli Terry and some other Connecticut clockmakers developed a way of mass-producing clocks by using interchangeable parts. Aaron Lufkin Dennison started a factory in 1851 in Massachusetts that also used interchangeable parts, and by 1861 was running a successful enterprise incorporated as the Waltham Watch Company.
===Early electric===
In 1815, the English scientist Francis Ronalds published the first electric clock powered by dry pile batteries. Alexander Bain, a Scottish clockmaker, patented the electric clock in 1840. The electric clock's mainspring is wound either with an electric motor or with an electromagnet and armature. In 1841, he first patented the electromagnetic pendulum. By the end of the nineteenth century, the advent of the dry cell battery made it feasible to use electric power in clocks. Spring or weight-driven clocks that use electricity, either alternating current (AC) or direct current (DC), to rewind the spring or raise the weight of a mechanical clock would be classified as an electromechanical clock. This classification would also apply to clocks that employ an electrical impulse to propel the pendulum. In electromechanical clocks, electricity serves no time-keeping function. These types of clocks were made as individual timepieces but are more commonly used in synchronized time installations in schools, businesses, factories, railroads and government facilities as a master clock and slave clocks.
Where an AC electrical supply of stable frequency is available, timekeeping can be maintained very reliably by using a synchronous motor, essentially counting the cycles. The supply current alternates with an accurate frequency of 50 hertz in many countries, and 60 hertz in others. While the frequency may vary slightly during the day as the load changes, generators are designed to maintain an accurate number of cycles over a day, so the clock may be a fraction of a second slow or fast at any time, but will be perfectly accurate over a long time. The rotor of the motor rotates at a speed that is related to the alternation frequency. Appropriate gearing converts this rotation speed to the correct ones for the hands of the analog clock. Time in these cases is measured in several ways, such as by counting the cycles of the AC supply, vibration of a tuning fork, the behaviour of quartz crystals, or the quantum vibrations of atoms. Electronic circuits divide these high-frequency oscillations into slower ones that drive the time display.
===Quartz===
The piezoelectric properties of crystalline quartz were discovered by Jacques and Pierre Curie in 1880. The first crystal oscillator was invented in 1917 by Alexander M. Nicholson, after which the first quartz crystal oscillator was built by Walter G. Cady in 1921. In 1969, Seiko produced the world's first quartz wristwatch, the Astron. Their inherent accuracy and low cost of production resulted in the subsequent proliferation of quartz clocks and watches. Atomic clocks were first theorized by Lord Kelvin in 1879. In the 1930s the development of magnetic resonance created practical method for doing this. A prototype ammonia maser device was built in 1949 at the U.S. National Bureau of Standards (NBS, now NIST). Although it was less accurate than existing quartz clocks, it served to demonstrate the concept. The first accurate atomic clock, a caesium standard based on a certain transition of the caesium-133 atom, was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. Calibration of the caesium standard atomic clock was carried out by the use of the astronomical time scale ephemeris time (ET). As of 2013, the most stable atomic clocks are ytterbium clocks, which are stable to within less than two parts in 1 quintillion (). which had the potential for more accuracy. All modern clocks use oscillation.
Although the mechanisms they use vary, all oscillating clocks, mechanical, electric, and atomic, work similarly and can be divided into analogous parts. They consist of an object that repeats the same motion over and over again, an oscillator, with a precisely constant time interval between each repetition, or 'beat'. Attached to the oscillator is a controller device, which sustains the oscillator's motion by replacing the energy it loses to friction, and converts its oscillations into a series of pulses. The pulses are then counted by some type of counter, and the number of counts is converted into convenient units, usually seconds, minutes, hours, etc. Finally some kind of indicator displays the result in human readable form.
===Power source===
===Oscillator===
The timekeeping element in every modern clock is a harmonic oscillator, a physical object (resonator) that vibrates or oscillates repetitively at a precisely constant frequency.
In mechanical clocks, this is either a pendulum or a balance wheel.
In some early electronic clocks and watches such as the Accutron, they use a tuning fork.
In quartz clocks and watches, it is a quartz crystal.
In atomic clocks, it is the vibration of electrons in atoms as they emit microwaves.
In early mechanical clocks before 1657, it was a crude balance wheel or foliot which was not a harmonic oscillator because it lacked a balance spring. As a result, they were very inaccurate, with errors of perhaps an hour a day.
The advantage of a harmonic oscillator over other forms of oscillator is that it employs resonance to vibrate at a precise natural resonant frequency or "beat" dependent only on its physical characteristics, and resists vibrating at other rates. The possible precision achievable by a harmonic oscillator is measured by a parameter called its Q, or quality factor, which increases (other things being equal) with its resonant frequency. This is why there has been a long-term trend toward higher frequency oscillators in clocks. Balance wheels and pendulums always include a means of adjusting the rate of the timepiece. Quartz timepieces sometimes include a rate screw that adjusts a capacitor for that purpose. Atomic clocks are primary standards, and their rate cannot be adjusted.
====Synchronized or slave clocks====
Some clocks rely for their accuracy on an external oscillator; that is, they are automatically synchronized to a more accurate clock:
Slave clocks, used in large institutions and schools from the 1860s to the 1970s, kept time with a pendulum, but were wired to a master clock in the building, and periodically received a signal to synchronize them with the master, often on the hour. Later versions without pendulums were triggered by a pulse from the master clock and certain sequences used to force rapid synchronization following a power failure.
Synchronous electric clocks do not have an internal oscillator, but count cycles of the 50 or 60 Hz oscillation of the AC power line, which is synchronized by the utility to a precision oscillator. The counting may be done electronically, usually in clocks with digital displays, or, in analog clocks, the AC may drive a synchronous motor which rotates an exact fraction of a revolution for every cycle of the line voltage, and drives the gear train. Although changes in the grid line frequency due to load variations may cause the clock to temporarily gain or lose several seconds during the course of a day, the total number of cycles per 24 hours is maintained extremely accurately by the utility company, so that the clock keeps time accurately over long periods.
Computer real-time clocks keep time with a quartz crystal, but can be periodically (usually weekly) synchronized over the Internet to atomic clocks (UTC), using the Network Time Protocol (NTP).
Radio clocks keep time with a quartz crystal, but are periodically synchronized to time signals transmitted from dedicated standard time radio stations or satellite navigation signals, which are set by atomic clocks.
===Controller===
This has the dual function of keeping the oscillator running by giving it 'pushes' to replace the energy lost to friction, and converting its vibrations into a series of pulses that serve to measure the time.
In mechanical clocks, this is the escapement, which gives precise pushes to the swinging pendulum or balance wheel, and releases one gear tooth of the escape wheel at each swing, allowing all the clock's wheels to move forward a fixed amount with each swing.
In electronic clocks this is an electronic oscillator circuit that gives the vibrating quartz crystal or tuning fork tiny 'pushes', and generates a series of electrical pulses, one for each vibration of the crystal, which is called the clock signal.
In atomic clocks the controller is an evacuated microwave cavity attached to a microwave oscillator controlled by a microprocessor. A thin gas of caesium atoms is released into the cavity where they are exposed to microwaves. A laser measures how many atoms have absorbed the microwaves, and an electronic feedback control system called a phase-locked loop tunes the microwave oscillator until it is at the frequency that causes the atoms to vibrate and absorb the microwaves. Then the microwave signal is divided by digital counters to become the clock signal.
In mechanical clocks, the low Q of the balance wheel or pendulum oscillator made them very sensitive to the disturbing effect of the impulses of the escapement, so the escapement had a great effect on the accuracy of the clock, and many escapement designs were tried. The higher Q of resonators in electronic clocks makes them relatively insensitive to the disturbing effects of the drive power, so the driving oscillator circuit is a much less critical component.
In digital clocks a series of integrated circuit counters or dividers add the pulses up digitally, using binary logic. Often pushbuttons on the case allow the hour and minute counters to be incremented and decremented to set the time.
===Indicator===
This displays the count of seconds, minutes, hours, etc. in a human readable form.
The earliest mechanical clocks in the 13th century did not have a visual indicator and signalled the time audibly by striking bells. Many clocks to this day are striking clocks which strike the hour.
Analog clocks display time with an analog clock face, which consists of a dial with the numbers 1 through 12 or 24, the hours in the day, around the outside. The hours are indicated with an hour hand, which makes one or two revolutions in a day, while the minutes are indicated by a minute hand, which makes one revolution per hour. In mechanical clocks a gear train drives the hands; in electronic clocks the circuit produces pulses every second which drive a stepper motor and gear train, which move the hands.
Digital clocks display the time in periodically changing digits on a digital display. A common misconception is that a digital clock is more accurate than an analog wall clock, but the indicator type is separate and apart from the accuracy of the timing source.
Talking clocks and the speaking clock services provided by telephone companies speak the time audibly, using either recorded or digitally synthesized voices.
==Types==
Clocks can be classified by the type of time display, as well as by the method of timekeeping.
===Time display methods===
====Analog====
Analog clocks usually use a clock face which indicates time using rotating pointers called "hands" on a fixed numbered dial or dials. The standard clock face, known universally throughout the world, has a short "hour hand" which indicates the hour on a circular dial of 12 hours, making two revolutions per day, and a longer "minute hand" which indicates the minutes in the current hour on the same dial, which is also divided into 60 minutes. It may also have a "second hand" which indicates the seconds in the current minute. The only other widely used clock face today is the 24 hour analog dial, because of the use of 24 hour time in military organizations and timetables. Before the modern clock face was standardized during the Industrial Revolution, many other face designs were used throughout the years, including dials divided into 6, 8, 10, and 24 hours. During the French Revolution the French government tried to introduce a 10-hour clock, as part of their decimal-based metric system of measurement, but it did not achieve widespread use. An Italian 6 hour clock was developed in the 18th century, presumably to save power (a clock or watch striking 24 times uses more power).
Another type of analog clock is the sundial, which tracks the sun continuously, registering the time by the shadow position of its gnomon. Because the sun does not adjust to daylight saving time, users must add an hour during that time. Corrections must also be made for the equation of time, and for the difference between the longitudes of the sundial and of the central meridian of the time zone that is being used (i.e. 15 degrees east of the prime meridian for each hour that the time zone is ahead of GMT). Sundials use some or part of the 24 hour analog dial. There also exist clocks which use a digital display despite having an analog mechanism—these are commonly referred to as flip clocks. Alternative systems have been proposed. For example, the "Twelv" clock indicates the current hour using one of twelve colors, and indicates the minute by showing a proportion of a circular disk, similar to a moon phase.
====Digital====
Kanazawa Station Water Clock.jpg|Digital clock displaying time by controlling valves on the fountain
Digital-clock-radio-basic hf.jpg|Simplistic digital clock radio
Analog clock with digital display.png|Diagram of a mechanical digital display of a flip clock
Cifra 5 digital flip clock designed by Gino Valle (1957).jpg|Cifra 5 digital flip clock (1957)
SAMSUNG Galaxy S22 Ultra BLACK.jpg|A digital clock on a Samsung Galaxy smartphone
Digital clocks display a numeric representation of time. Two numeric display formats are commonly used on digital clocks:
the 24-hour notation with hours ranging 00–23;
the 12-hour notation with AM/PM indicator, with hours indicated as 12AM, followed by 1AM–11AM, followed by 12PM, followed by 1PM–11PM (a notation mostly used in domestic environments).
Most digital clocks use electronic mechanisms and LCD, LED, or VFD displays; many other display technologies are used as well (cathode-ray tubes, nixie tubes, etc.). After a reset, battery change or power failure, these clocks without a backup battery or capacitor either start counting from 12:00, or stay at 12:00, often with blinking digits indicating that the time needs to be set. Some newer clocks will reset themselves based on radio or Internet time servers that are tuned to national atomic clocks. Since the introduction of digital clocks in the 1960s, there has been a notable decline in the use of analog clocks.
Some clocks, called 'flip clocks', have digital displays that work mechanically. The digits are painted on sheets of material which are mounted like the pages of a book. Once a minute, a page is turned over to reveal the next digit. These displays are usually easier to read in brightly lit conditions than LCDs or LEDs. Also, they do not go back to 12:00 after a power interruption. Flip clocks generally do not have electronic mechanisms. Usually, they are driven by AC-synchronous motors.
====Hybrid (analog-digital)====
Clocks with analog quadrants, with a digital component, usually minutes and hours displayed analogously and seconds displayed in digital mode.
====Auditory====
For convenience, distance, telephony or blindness, auditory clocks present the time as sounds. The sound is either spoken natural language, (e.g. "The time is twelve thirty-five"), or as auditory codes (e.g. number of sequential bell rings on the hour represents the number of the hour like the bell, Big Ben). Most telecommunication companies also provide a speaking clock service as well.
====Word====
Word clocks are clocks that display the time visually using sentences. E.g.: "It's about three o'clock." These clocks can be implemented in hardware or software.
====Projection====
Some clocks, usually digital ones, include an optical projector that shines a magnified image of the time display onto a screen or onto a surface such as an indoor ceiling or wall. The digits are large enough to be easily read, without using glasses, by persons with moderately imperfect vision, so the clocks are convenient for use in their bedrooms. Usually, the timekeeping circuitry has a battery as a backup source for an uninterrupted power supply to keep the clock on time, while the projection light only works when the unit is connected to an A.C. supply. Completely battery-powered portable versions resembling flashlights are also available.
====Tactile====
Auditory and projection clocks can be used by people who are blind or have limited vision. There are also clocks for the blind that have displays that can be read by using the sense of touch. Some of these are similar to normal analog displays, but are constructed so the hands can be felt without damaging them. Another type is essentially digital, and uses devices that use a code such as Braille to show the digits so that they can be felt with the fingertips.
====Multi-display====
Some clocks have several displays driven by a single mechanism, and some others have several completely separate mechanisms in a single case. Clocks in public places often have several faces visible from different directions, so that the clock can be read from anywhere in the vicinity; all the faces show the same time. Other clocks show the current time in several time-zones. Watches that are intended to be carried by travellers often have two displays, one for the local time and the other for the time at home, which is useful for making pre-arranged phone calls. Some equation clocks have two displays, one showing mean time and the other solar time, as would be shown by a sundial. Some clocks have both analog and digital displays. Clocks with Braille displays usually also have conventional digits so they can be read by sighted people.
==Purposes==
Clocks are in homes, offices and many other places; smaller ones (watches) are carried on the wrist or in a pocket; larger ones are in public places, e.g. a railway station or church. A small clock is often shown in a corner of computer displays, mobile phones and many MP3 players.
The primary purpose of a clock is to display the time. Clocks may also have the facility to make a loud alert signal at a specified time, typically to waken a sleeper at a preset time; they are referred to as alarm clocks. The alarm may start at a low volume and become louder, or have the facility to be switched off for a few minutes then resume. Alarm clocks with visible indicators are sometimes used to indicate to children too young to read the time that the time for sleep has finished; they are sometimes called training clocks.
A clock mechanism may be used to control a device according to time, e.g. a central heating system, a VCR, or a time bomb (see: digital counter). Such mechanisms are usually called timers. Clock mechanisms are also used to drive devices such as solar trackers and astronomical telescopes, which have to turn at accurately controlled speeds to counteract the rotation of the Earth.
Most digital computers depend on an internal signal at constant frequency to synchronize processing; this is referred to as a clock signal. (A few research projects are developing CPUs based on asynchronous circuits.) Some equipment, including computers, also maintains time and date for use as required; this is referred to as time-of-day clock, and is distinct from the system clock signal, although possibly based on counting its cycles.
===Time standards===
For some scientific work timing of the utmost accuracy is essential. It is also necessary to have a standard of the maximum accuracy against which working clocks can be calibrated. An ideal clock would give the time to unlimited accuracy, but this is not realisable. Many physical processes, in particular including some transitions between atomic energy levels, occur at exceedingly stable frequency; counting cycles of such a process can give a very accurate and consistent time—clocks which work this way are usually called atomic clocks. Such clocks are typically large, very expensive, require a controlled environment, and are far more accurate than required for most purposes; they are typically used in a standards laboratory.
===Navigation===
Until advances in the late twentieth century, navigation depended on the ability to measure latitude and longitude. Latitude can be determined through celestial navigation; the measurement of longitude requires accurate knowledge of time. This need was a major motivation for the development of accurate mechanical clocks. John Harrison created the first highly accurate marine chronometer in the mid-18th century. The Noon gun in Cape Town still fires an accurate signal to allow ships to check their chronometers. Many buildings near major ports used to have (some still do) a large ball mounted on a tower or mast arranged to drop at a pre-determined time, for the same purpose. While satellite navigation systems such as GPS require unprecedentedly accurate knowledge of time, this is supplied by equipment on the satellites; vehicles no longer need timekeeping equipment.
===Sports and games===
Clocks can be used to measure varying periods of time in games and sports. Stopwatches can be used to time the performance of track athletes. Chess clocks are used to limit the board game players' time to make a move. In various sports, measure the duration the game or subdivisions of the game, while other clocks may be used for tracking different durations; these include play clocks, shot clocks, and pitch clocks.
== Culture ==
=== Folklore and superstition ===
In the United Kingdom, clocks are associated with various beliefs, many involving death or bad luck. In legends, clocks have reportedly stopped of their own accord upon a nearby person's death, especially those of monarchs. The clock in the House of Lords supposedly stopped at "nearly" the hour of George III's death in 1820, the one at Balmoral Castle stopped during the hour of Queen Victoria's death, and similar legends are related about clocks associated with William IV and Elizabeth I. Many superstitions exist about clocks. One stopping before a person has died may foretell coming death. Similarly, if a clock strikes during a church hymn or a marriage ceremony, death or calamity is prefigured for the parishioners or a spouse, respectively. Death or ill events are foreshadowed if a clock strikes the wrong time. It may also be unlucky to have a clock face a fire or to speak while a clock is striking.
In Chinese culture, giving a clock () is often taboo, especially to the elderly, as it is a homophone of the act of attending another's funeral ().
==Specific types==
==Awards==
(GPHG)
|
[
"horology",
"Watchmaker",
"goldleaf",
"capacitor",
"Astronomical",
"Electronic transition",
"Artuqid",
"Tide clock",
"Cathédrale Saint-Étienne de Sens",
"digital computer",
"track athlete",
"Internet",
"Telescope mount",
"flip clock",
"Babylon",
"Daedalus (journal)",
"harmonic oscillator",
"chain drive",
"Hour",
"clockmaking",
"slave clocks",
"pendulum",
"digital clock",
"Water clock",
"LED",
"Voltaic pile",
"Balloon clock",
"Quantum clock",
"Clockarium",
"ephemeris time",
"satellite navigation",
"Musical clock",
"cognate",
"Jost Bürgi",
"Verge escapement",
"flashlight",
"Pendulum clock",
"cathode-ray tube",
"Q factor",
"sand",
"London Bridge",
"interchangeable parts",
"Samsung Galaxy",
"Germanisches Nationalmuseum",
"Republic of China",
"rood screen",
"Tower of the Winds",
"counter (digital)",
"hour",
"timer",
"Jens Olsen's World Clock",
"hydraulics",
"tally stick",
"Kaifeng",
"Doll's head clock",
"Millennium",
"Clock face",
"LCD",
"Date and time representation by country",
"Conical pendulum",
"Walter Guyton Cady",
"Mora clock",
"Elephant clock",
"Candle clock",
"Japanese clock",
"Colgate Clock (Indiana)",
"Balmoral Castle",
"Quartz clock",
"resonance",
"American Watchmakers-Clockmakers Institute",
"List of biggest clock faces",
"repeater (horology)",
"Charlemagne",
"Atmos clock",
"Harun al-Rashid",
"Blois",
"Faux pas derived from Chinese pronunciation",
"Chess clock",
"Lighthouse clock",
"National Museum of Natural Science",
"Binary clock",
"Stopwatch",
"shot clock",
"Time clock",
"Joella Yoder",
"lunar month",
"Kit-Cat Klock",
"Iron Ring Clock",
"BaselWorld",
"longitude",
"Ancient Rome",
"Hourglass",
"Pulsar clock",
"tuning fork",
"GMT",
"drive wheel",
"Big Ben",
"Clock network",
"quartz clock",
"resonant frequency",
"National Bureau of Standards",
"Abul-Abbas",
"equation clock",
"French Empire mantel clock",
"Salisbury Cathedral clock",
"Peter Henlein",
"Clockmaker",
"Alexander M. Nicholson",
"caesium",
"clockkeeper",
"Cyrrhus (Macedonia)",
"Nuclear magnetic resonance",
"movement (clockwork)",
"speaking clock",
"Donald Routledge Hill",
"astrolabe",
"MP3 player",
"Ancient Greece",
"synchronous motor",
"asynchronous circuit",
"Cosmo Clock 21",
"Mains power",
"atom",
"The clock as herald of the Industrial Revolution",
"Nuremberg",
"Moveable feast",
"Noon gun",
"Robert Hooke",
"French Revolution",
"oscillator",
"Master clock",
"longcase clock",
"Solar time",
"Local mean time",
"Doomsday Clock",
"List of international common standards",
"wheel train (horology)",
"Francis Ronalds",
"Low Countries",
"Archimedes",
"Padua, Italy",
"equation of time",
"Solar tracker",
"Rotor (electric)",
"time zone",
"mantel clock",
"canonical hours",
"World clock",
"Cavity resonator",
"Speaking clock",
"Tycho Brahe",
"pitch clock",
"Steam clock",
"Incense clock",
"verge escapement",
"Byzantine Empire",
"gear train",
"sundial",
"Chronometer watch",
"castle clock",
"St Albans",
"Analog clock with digital display",
"Banjo clock",
"Christiaan Huygens",
"stackfreed",
"Digital data",
"Canterbury Cathedral",
"Augsburg",
"Andronicus of Cyrrhus",
"Elizabeth I",
"Padua",
"William IV",
"longitude prize",
"incense clock",
"ancient Greek astronomy",
"Derek J. de Solla Price",
"day",
"Seiko",
"energy level",
"minute hand",
"Middle Dutch",
"remontoire",
"Aaron Lufkin Dennison",
"pendulum clock",
"ammonia",
"George Graham (clockmaker)",
"second",
"Cape Town",
"24 hour analog dial",
"Time ball",
"play clock",
"phase-locked loop",
"Dunstable Priory",
"Pope Sylvester II",
"rack and snail",
"Physical Review Letters",
"Alarm clock",
"Cuckoo clock",
"ancient times",
"alarm clock",
"stepper motor",
"Bell Telephone Laboratories",
"Clock of the Long Now",
"Edward Barlow (priest)",
"the Hague",
"Invention",
"Bracket clock",
"Nasrudin",
"Norwich cathedral astronomical clock",
"Astronomical clock",
"NIST",
"Escapement",
"VCR",
"Grandfather clock",
"Museu de Belles Arts de València",
"Battery (electricity)",
"Jewel bearing",
"Observatory chronometer",
"Clock tower",
"Singing bird box",
"Roman Athens",
"vacuum fluorescent display",
"Mercury (element)",
"Pre-modern",
"hourglass",
"Oil-lamp clock",
"master clock",
"Slave clock",
"fr:Discussion:Horloge",
"Colgate Clock (New Jersey)",
"American Institute of Physics",
"Alexander Bain (inventor)",
"Metrology",
"Abbasid",
"Taichung",
"Corpus Clock",
"24-hour analog dial",
"clocktower",
"Carriage clock",
"Pierre Curie",
"Lantern clock",
"Le Défenseur du Temps",
"Bedfordshire",
"Primum Mobile",
"Industrial Revolution",
"anchor escapement",
"Taiwan",
"National Institute of Standards and Technology",
"balance wheel",
"American clock",
"Railroad chronometer",
"Duodecimal",
"Mandalay",
"Massachusetts",
"waterwheel",
"alternating current",
"direct current",
"Oxford University Press",
"pocket watch",
"Tomar",
"24-hour clock",
"Vitreous enamel",
"semiconductor device",
"10-hour clock",
"United Kingdom",
"House of Lords",
"Hertz",
"escapement",
"Replica watch",
"Braille watch",
"solar time",
"Clock drift",
"Ancient Macedonia",
"electron",
"Radio clock",
"maser",
"Chariot clock",
"Circadian rhythm",
"gnomon",
"Striking clock",
"Accutron",
"mercury (element)",
"Bury St Edmunds",
"Image projector",
"Equation clock",
"time",
"Turret clock",
"Lunar phase",
"Homophonic puns in Mandarin Chinese",
"prime meridian",
"John Harrison",
"Cambridge University Press",
"Vacuum fluorescent display",
"friction",
"Queen Victoria",
"Galileo Galilei",
"candle clock",
"Automaton clock",
"Tang dynasty",
"Old French",
"National Physical Laboratory, UK",
"Earth clock",
"Braille",
"Rolling ball clock",
"Astron (wristwatch)",
"Electric clock",
"hertz",
"ytterbium",
"time bomb",
"Eli Terry",
"System time",
"Torsion pendulum clock",
"Richard of Wallingford",
"celestial navigation",
"barrel (horology)",
"Talking clock",
"real-time clock",
"12-hour notation",
"automata",
"Allen-Bradley Clock Tower at Rockwell Automation Headquarters Building",
"electromechanical clock",
"Cox's timepiece",
"clock face",
"Daniel Quare",
"balance spring",
"piezoelectric",
"clock signal",
"hour hand",
"Middle English",
"Debt clock",
"armillary sphere",
"horologe",
"Jacques Curie",
"astrology",
"Ibn al-Razzaz Al-Jazari",
"Lord Kelvin",
"Royal Observatory, Greenwich",
"latitude",
"Song dynasty",
"caliph",
"D. Reidel",
"Flying pendulum clock",
"Clock ident",
"Spring Drive",
"Waltham Watch Company",
"caesium standard",
"integrated circuit",
"atomic clock",
"polymath",
"Guard tour patrol system",
"radio time signal",
"Cartel clock",
"Star clock",
"Projection clock",
"Congreve clock",
"Al-Jazari",
"Liang Lingzan",
"crystal oscillator",
"Baghdad",
"Coordinated Universal Time",
"caesium-133",
"year",
"Zhang Sixun",
"Medieval Latin",
"mainspring",
"Jocelyn de Brakelond",
"nixie tube",
"Islamic",
"12-hour time",
"microwave",
"Rubik's Clock",
"Cuckooland Museum",
"24 hour time",
"metric system",
"clockwork",
"sprocket",
"Giovanni Dondi dell'Orologio",
"Timeline of time measurement technology",
"binary numeral system",
"Voice synthesis",
"Lamport timestamp",
"Routledge",
"Ahmad Y Hassan",
"electric clock",
"Sundial",
"Louis Essen",
"striking clock",
"Floral clock",
"Alternating current",
"Rota Fortunae",
"24-hour notation",
"St Albans Abbey",
"Electromagnetism",
"Mantel clock",
"fusee (horology)",
"quartz",
"marine chronometer",
"Federation of the Swiss Watch Industry FH",
"Game clock",
"Kanazawa Station",
"The British Museum",
"Electronic oscillator",
"gear",
"Old Irish",
"digital counter",
"George III",
"pulley",
"Latin",
"Yi Xing",
"National Association of Watch and Clock Collectors",
"resonator",
"Romance languages",
"Department of Defense master clock",
"electromagnet",
"vacuum tube",
"Allan variance",
"Watch",
"Su Song",
"Standard (technical)",
"time server",
"Network Time Protocol",
"spiral balance",
"Atomic clock",
"microprocessor",
"Thomas Tompion",
"Skeleton clock",
"Mechanical watch",
"List of largest cuckoo clocks",
"Asian elephant",
"Digital clock"
] |
6,451 |
Charles Proteus Steinmetz
|
Charles Proteus Steinmetz (born Karl August Rudolph Steinmetz; April 9, 1865 – October 26, 1923) was an American mathematician and electrical engineer and professor at Union College. He fostered the development of alternating current that made possible the expansion of the electric power industry in the United States, formulating mathematical theories for engineers. He made ground-breaking discoveries in the understanding of hysteresis that enabled engineers to design better electromagnetic apparatus equipment, especially electric motors for use in industry.{{efn|Quoting from Alger, "Steinmetz was truly the patron saint of the GE motor business." A genius in both mathematics and electronics, he did work that earned him the nicknames "Forger of Thunderbolts" and "The Wizard of Schenectady". Steinmetz's equation, Steinmetz solids, Steinmetz curves, and Steinmetz equivalent circuit are all named after him, as are numerous honors and scholarships, including the IEEE Charles Proteus Steinmetz Award, one of the highest technical recognitions given by the Institute of Electrical and Electronics Engineers professional society.
==Early life and education==
Steinmetz was born Karl August Rudolph Steinmetz on April 9, 1865, in Breslau, Province of Silesia, Prussia (now Wrocław, Poland), the son of Caroline (Neubert) and Karl Heinrich Steinmetz. He was baptized as a Lutheran into the Evangelical Church of Prussia. Steinmetz, who stood only tall as an adult,
Following Gymnasium, Steinmetz studied at the University of Breslau to begin work on his undergraduate degree in 1883. Nearing completion of his doctorate in 1888, he was forced to flee to Zurich, Switzerland, as the German government was preparing to prosecute him for his socialist activities.
==Political persecution and emigration==
As socialist meetings and press had been banned in Germany, Steinmetz fled to Zurich in 1889 to escape possible arrest. Cornell University Professor Ronald R. Kline, author of Steinmetz: Engineer and Socialist, points to other factors which reinforced Steinmetz's decision to leave his homeland such as financial problems and the prospect of a more harmonious life with his socialist friends and supporters than the stressful domestic circumstances of his father's household.
==Political activism and beliefs==
Steinmetz was politically active in the US as a technocratic socialist for over thirty years. Following the Bolshevik introduction of a technocratic plan to electrify Russia, Steinmetz spoke of Lenin alongside Albert Einstein as the "two greatest minds of our time."
==Electrical engineering==
Steinmetz is known for his contribution in three major fields of alternating current (AC) systems theory: hysteresis, steady-state analysis, and transients.
===AC hysteresis theory===
Shortly after arriving in the United States, Steinmetz went to work for Rudolf Eickemeyer in Yonkers, New York, and published in the field of magnetic hysteresis, earning worldwide professional recognition. Eickemeyer's firm developed transformers for use in the transmission of electrical power among many other mechanical and electrical devices. In 1893 Eickemeyer's company, along with all of its patents and designs, was bought by the newly formed General Electric Company, where Steinmetz quickly became known as the engineering wizard in GE's engineering community. His seminal books and many other AIEE papers "taught a whole generation of engineers how to deal with AC phenomena".
===AC transient theory===
Steinmetz also greatly advanced the understanding of lightning. His systematic experiments resulted in the first laboratory created "man-made lightning", earning him the nickname the "Forger of Thunderbolts".
==Professional life==
Steinmetz acted in the following professional capacities:
At Union College, as chair of electrical engineering from 1902 to 1913 and as faculty member thereafter until his death in 1923
First vice-president of the International Association of Municipal Electricians (IAME) {which later became the International Municipal Signal Association (IMSA)} from 1913 until his death in 1923.
He was granted an honorary degree from Harvard University in 1901 Steinmetz was also an elected member of both the American Academy of Arts and Sciences and the American Philosophical Society.
Steinmetz wrote 13 books and 60 articles, not exclusively about engineering. He was a member and adviser to the fraternity Phi Gamma Delta at Union College, whose chapter house was one of the first electrified residences.
While serving as president of the Schenectady Board of Education, Steinmetz introduced numerous progressive reforms, including extended school hours, school meals, school nurses, special classes for the children of immigrants, and the distribution of free textbooks.]]
Steinmetz was affected by kyphosis, as were his father and grandfather. In spite of his love for children and family life, Steinmetz remained unmarried, to prevent his spinal deformity from being passed to any offspring.{{efn|He founded the Mohawk Aerial Navigation Company, Ltd.{{efn|Quoting from Hammond, "This has placed him before the public as an atheist.* The title he did not deny. The writer put him down as a confirmed agnostic, for an atheist is a person who knows there is no God, and Steinmetz was not of that..."
One of the highest technical recognitions given by the Institute of Electrical and Electronics Engineers, the "IEEE Charles Proteus Steinmetz Award", is given for major contributions to standardization within the field of electrical and electronics engineering.
The Charles P. Steinmetz Memorial Lecture series was begun in his honor in 1925, sponsored by the Schenectady branch of the IEEE. Through 2017 seventy-three gatherings have taken place, held almost exclusively at Union College, featuring notable figures such as Nobel laureate experimental physicist Robert A. Millikan, helicopter inventor Igor Sikorsky, nuclear submarine pioneer Admiral Hyman G. Rickover (1963), Nobel-winning semiconductor inventor William Shockley, and Internet "founding father" Leonard Kleinrock.
Steinmetz's connection to Union is further celebrated with the annual Steinmetz Symposium, a day-long event in which Union undergraduates give presentations on research they have done. Steinmetz Hall, which houses the Union College computer center, is named after him.
The Charles P. Steinmetz Scholarship is awarded annually by the college, underwritten since its inception in 1923 by the General Electric Company.
A 1914 "Duplex Drive Brougham" Detroit Electric automobile that once belonged to Steinmetz was purchased by Union College in 1971, and restored for use in campus ceremonies. The Steinmetz car is permanent displayed in the first-floor corridor between the Wold Center and F.W. Olin building.
A Chicago public high school, Steinmetz College Prep, is named for him, as well as a Schenectady public school, the Steinmetz Career and Leadership Academy, formerly Steinmetz Middle-School.
A public park in north Schenectady, New York, was named for him in 1931.
In 1983, the US Post Office included Steinmetz in a series of postage stamps commemorating American inventors.
In May 2015, a life-size bronze statue of Charles Steinmetz meeting Thomas Edison by sculptor and caster Dexter Benedict was unveiled on a plaza on the corner of Erie Boulevards and South Ferry Street in Schenectady.
Charles Steinmetz's Mohawk River cabin is preserved and on display in the outdoor collection of historic structures in Greenfield Village, part of the Henry Ford Museum complex in Dearborn, Michigan.
==In popular culture==
Steinmetz is featured in John Dos Passos's U.S.A. trilogy in one of the biographies. He also serves as a major character in Starling Lawrence's The Lightning Keeper.
Steinmetz is a major character in the novel Electric City by Elizabeth Rosner.
In the 1944 Three Stooges short "Busy Buddies", Moe Howard references Steinmetz.
Steinmetz was portrayed in 1959 by the actor Rod Steiger in the CBS television anthology series, The Joseph Cotten Show. The episode focused on his socialist activities in Germany.
A famous anecdote about Steinmetz concerns a troubleshooting consultation at Henry Ford's River Rouge Plant. A humorous aspect of the story is the "itemized bill" he submitted for the work performed.
|
[
"hysteresis",
"Mathematician",
"American Philosophical Society",
"American Institute of Electrical Engineers",
"Charles P. Steinmetz Academic Centre",
"US Post Office",
"Institute of Electrical and Electronics Engineers",
"school nurse",
"Thorstein Veblen",
"de:Steinmetzschaltung",
"Electrical engineering",
"Poland",
"William Shockley",
"Induction motor",
"Hysteresis",
"Proteus",
"lightning",
"semiconductor",
"Thomas Edison",
"Steinmetz College Prep",
"Robert A. Millikan",
"phasor",
"Leonard Kleinrock",
"Transmission line",
"Schenectady, New York",
"University of Wrocław",
"Elliott Cresson Medal",
"Network synthesis filters",
"Cedergren Medal",
"kyphosis",
"Electric power industry",
"Technical Alliance",
"Igor Sikorsky",
"Albert Einstein",
"Leland Olds",
"standardization",
"Network analysis (electrical circuits)",
"Harvard University",
"alternating current",
"Hyman G. Rickover",
"Charles P. Steinmetz Memorial Lecture",
"transient (oscillation)",
"voltage",
"Detroit Electric",
"Kyphosis",
"John Dos Passos",
"River Rouge Plant",
"transformer",
"electric power transmission",
"Nobel Prize",
"International Electrotechnical Vocabulary",
"Zurich",
"complex number",
"IEEE Charles Proteus Steinmetz Award",
"Yonkers, New York",
"dwarfism",
"Lutheran",
"Rod Steiger",
"Union College",
"Phi Gamma Delta",
"Elizabeth Rosner",
"Kingdom of Prussia",
"University of Breslau",
"Philip Langdon Alger",
"Engineering education",
"Franklin Institute",
"Vale Cemetery and Vale Park",
"Mechanicville Hydroelectric Plant",
"Alternating current",
"calculus",
"mathematician",
"American Academy of Arts and Sciences",
"Moe Howard",
"steady state (electronics)",
"Vladimir Lenin",
"General Electric",
"Wrocław",
"International Electrotechnical Commission",
"induction motor",
"Gymnasium (school)",
"Steinmetz solid",
"Three Stooges",
"Evangelical Church of Prussia",
"Switzerland",
"electrification",
"Province of Silesia",
"agnostic",
"rotation (mathematics)",
"Cornell University",
"magnetic hysteresis",
"The Joseph Cotten Show (TV series)",
"lower-case letter",
"Hip dysplasia (human)",
"U.S.A. (trilogy)",
"Metal-halide lamp",
"International Municipal Signal Association",
"Prussia",
"Steinmetz curve",
"Phasor measurement unit",
"The Henry Ford",
"electrical machine",
"electric power industry",
"Thunderbolt",
"Odyssey",
"PBS",
"Edison Tech Center",
"Steinmetz's equation",
"IEEE",
"Analogue filter",
"Schenectady",
"CBS television",
"anthology series",
"Wireless power",
"Albert A. Michelson Medal",
"greenhouse"
] |
6,452 |
Charles Martel
|
Charles Martel (; – 22 October 741), Martel being a sobriquet in Old French for "The Hammer", was a Frankish political and military leader who, as Duke and Prince of the Franks and Mayor of the Palace, was the de facto ruler of the Franks from 718 until his death. He was a son of the Frankish statesman Pepin of Herstal and a noblewoman named Alpaida. Charles successfully asserted his claims to power as successor to his father as the power behind the throne in Frankish politics. Continuing and building on his father's work, he restored centralized government in Francia and began the series of military campaigns that re-established the Franks as the undisputed masters of all Gaul. According to a near-contemporary source, the Liber Historiae Francorum, Charles was "a warrior who was uncommonly ... effective in battle".
Charles gained a victory against an Umayyad invasion of Aquitaine at the Battle of Tours, at a time when the Umayyad Caliphate controlled most of the Iberian Peninsula. Alongside his military endeavours, Charles has been traditionally credited with an influential role in the development of the Frankish system of feudalism.
At the end of his reign, Charles divided Francia between his sons, Carloman and Pepin. The latter became the first king of the Carolingian dynasty. Pepin's son Charlemagne, grandson of Charles, extended the Frankish realms and became the first emperor in the West since the Fall of the Western Roman Empire.
== Background ==
Charles, nicknamed "Martel" ("the Hammer") in later chronicles, was a son of Pepin of Herstal and his mistress, possible second wife, Alpaida. He had a brother named Childebrand, who later became the Frankish dux (that is, duke) of Burgundy. And is the great grandson of Arnulf of Metz.
Older historiography commonly describes Charles as "illegitimate", but the dividing line between wives and concubines was not clear-cut in eighth-century Francia. It is likely that the accusation of "illegitimacy" derives from the desire of Pepin's first wife Plectrude to see her progeny as heirs to Pepin's throne.
By Charles's lifetime the Merovingians had ceded power to the Mayors of the Palace, who controlled the royal treasury, dispensed patronage, and granted land and privileges in the name of the figurehead king. Charles's father, Pepin of Herstal, had united the Frankish realm by conquering Neustria and Burgundy. Pepin was the first to call himself Duke and Prince of the Franks, a title later taken up by Charles.
== Contesting for power ==
In December 714, Pepin of Herstal died. A few months before his death and shortly after the murder of his son Grimoald the Younger, he had taken the advice of his wife Plectrude to designate as his sole heir Theudoald, his grandson by their deceased son Grimoald. This was immediately opposed by the Austrasian nobles because Theudoald was a child of only eight years of age. To prevent Charles using this unrest to his own advantage, Plectrude had him imprisoned in Cologne, the city which was intended to be her capital. This prevented an uprising on his behalf in Austrasia, but not in Neustria.
=== Civil war of 715–718 ===
Pepin's death occasioned open conflict between his heirs and the Neustrian nobles who sought political independence from Austrasian control. In 715, Dagobert III named Raganfrid mayor of the palace. On 26 September 715, Raganfrid's Neustrians met the young Theudoald's forces at the Battle of Compiègne. Theudoald was defeated and fled back to Cologne. Before the end of the year, Charles had escaped from prison and been acclaimed mayor by the nobles of Austrasia. The Battle of Cologne is the only defeat of Charles's career.
==== Battle of Amblève ====
Charles retreated to the hills of the Eifel to gather and train men. In April 716, he fell upon the triumphant army near Malmedy as it was returning to Neustria. In the ensuing Battle of Amblève, Charles attacked as the enemy rested at midday. According to one source, he split his forces into several groups which fell at them from many sides. Another suggests that while this was his intention, he then decided, given the enemy's unpreparedness, this was not necessary. In any event, the suddenness of the assault led them to believe they were facing a much larger host. Many of the enemy fled and Charles's troops gathered the spoils of the camp. His reputation increased considerably as a result, and he attracted more followers. This battle is often considered by historians as the turning point in Charles's struggle.
==== Battle of Vincy ====
Richard Gerberding points out that up to this time, much of Charles's support was probably from his mother's kindred in the lands around Liege. After Amblève, he seems to have won the backing of the influential Willibrord, founder of the Abbey of Echternach. The abbey had been built on land donated by Plectrude's mother, Irmina of Oeren, but most of Willibrord's missionary work had been carried out in Frisia. In joining Chilperic and Raganfrid, Radbod of Frisia sacked Utrecht, burning churches and killing many missionaries. Willibrord and his monks were forced to flee to Echternach. Gerberding suggests that Willibrord had decided that the chances of preserving his life's work were better with a successful field commander like Charles than with Plectrude in Cologne. Willibrord subsequently baptized Charles's son Pepin. Gerberding suggests a likely date of Easter 716. Charles also received support from bishop Pepo of Verdun.
Charles took time to rally more men and prepare. By the following spring, he had attracted enough support to invade Neustria. Charles sent an envoy who proposed a cessation of hostilities if Chilperic would recognize his rights as mayor of the palace in Austrasia. The refusal was not unexpected but served to impress upon Charles's forces the unreasonableness of the Neustrians. They met near Cambrai at the Battle of Vincy on 21 March 717. The victorious Charles pursued the fleeing king and mayor to Paris, but as he was not yet prepared to hold the city, he turned back to deal with Plectrude and Cologne. He took the city and dispersed her adherents. Plectrude was allowed to retire to a convent. Theudoald lived to 741 under his uncle's protection.
== Consolidation of power ==
Upon this success, Charles proclaimed Chlothar IV king in Austrasia in opposition to Chilperic and deposed Rigobert, archbishop of Reims, replacing him with Milo, a lifelong supporter.
In 718, Chilperic responded to Charles's new ascendancy by making an alliance with Odo the Great (or Eudes, as he is sometimes known), the duke of Aquitaine, who had become independent during the civil war in 715, but was again defeated, at the Battle of Soissons, by Charles. Chilperic fled with his ducal ally to the land south of the Loire and Raganfrid fled to Angers. Soon Chlotar IV died and Odo surrendered King Chilperic in exchange for Charles recognizing his dukedom. Charles recognized Chilperic as king of the Franks in return for legitimate royal affirmation of his own mayoralty over all the kingdoms.
=== Wars of 718–732 ===
Between 718 and 732, Charles secured his power through a series of victories. Having unified the Franks under his banner, Charles was determined to punish the Saxons who had invaded Austrasia. Therefore, late in 718, he laid waste their country to the banks of the Weser, the Lippe, and the Ruhr. It is more likely that this invasion or raid took place in revenge for Odo's support for a rebel Berber leader named Munnuza.
Whatever the precise circumstances were, it is clear that an army under the leadership of Abd al-Rahman al-Ghafiqi headed north, and after some minor engagements marched on the wealthy city of Tours. According to British medieval historian Paul Fouracre, "Their campaign should perhaps be interpreted as a long-distance raid rather than the beginning of a war". They were, however, defeated by the army of Charles at the Battle of Tours (known in France as the Battle of Poitiers), at a location between the French cities of Tours and Poitiers, in a victory described by the Continuations of Fredegar. According to the historian Bernard Bachrach, the Arab army, mostly mounted, failed to break through the Frankish infantry. News of this battle spread, and may be recorded in Bede's Ecclesiastical History (Book V, ch. 23). However, it is not given prominence in Arabic sources from the period.
Despite his victory, Charles did not gain full control of Aquitaine, and Odo remained duke until 735.
== Wars of 732–737 ==
Between his victory of 732 and 735, Charles reorganized the kingdom of Burgundy, replacing the counts and dukes with his loyal supporters, thus strengthening his hold on power. He was forced, by the ventures of Bubo, Duke of the Frisians, to invade independent-minded Frisia again in 734. In that year, he slew the duke at the Battle of the Boarn. Charles ordered the Frisian pagan shrines destroyed, and so wholly subjugated the populace that the region was peaceful for twenty years after.
In 735, Duke Odo of Aquitaine died. Though Charles wished to rule the duchy directly and went there to elicit the submission of the Aquitanians, the aristocracy proclaimed Odo's son, Hunald I of Aquitaine, as duke, and Charles and Hunald eventually recognised each other's position.
== Interregnum (737–741) ==
In 737, at the tail end of his campaigning in Provence and Septimania, the Merovingian king, Theuderic IV, died. Charles, titling himself maior domus and princeps et dux Francorum, did not appoint a new king and nobody acclaimed one. The throne lay vacant until Charles' death. The interregnum, the final four years of Charles' life, was relatively peaceful although in 738 he compelled the Saxons of Westphalia to submit and pay tribute and in 739 he checked an uprising in Provence where some rebels united under the leadership of Maurontus.
Charles used the relative peace to set about integrating the outlying realms of his empire into the Frankish church. He erected four dioceses in Bavaria (Salzburg, Regensburg, Freising, and Passau) and gave them Boniface as archbishop and metropolitan over all Germany east of the Rhine, with his seat at Mainz. Boniface had been under his protection from 723 on. Indeed, the saint himself explained to his old friend, Daniel of Winchester, that without it he could neither administer his church, defend his clergy nor prevent idolatry.
In 739, Pope Gregory III begged Charles for his aid against Liutprand, but Charles was loath to fight his onetime ally and ignored the plea. Nonetheless, the pope's request for Frankish protection showed how far Charles had come from the days when he was tottering on excommunication, and set the stage for his son and grandson to assert themselves in the peninsula.
== Death and transition in rule ==
Charles died on 22 October 741, at Quierzy-sur-Oise in what is today the Aisne département in the Picardy region of France. He was buried at Saint Denis Basilica in Paris.
His territories had been divided among his adult sons a year earlier: to Carloman he gave Austrasia, Alemannia, and Thuringia, and to Pippin the Younger Neustria, Burgundy, Provence, and Metz and Trier in the "Mosel duchy". Grifo was given several lands throughout the kingdom, but at a later date, just before Charles died.
== Legacy ==
Earlier in his life Charles had many internal opponents and felt the need to appoint his own kingly claimant, Chlotar IV. Later, however, the dynamics of rulership in Francia had changed, and no hallowed Merovingian ruler was required. Charles divided his realm among his sons without opposition (though he ignored his young son Bernard). For many historians, Charles laid the foundations for his son Pepin's rise to the Frankish throne in 751, and his grandson Charlemagne's imperial acclamation in 800. However, for Paul Fouracre, while Charles was "the most effective military leader in Francia", his career "finished on a note of unfinished business".
===Family and children===
Charles married twice, his first wife being Rotrude of Treves, daughter either of Lambert II, Count of Hesbaye, or of Leudwinus, Count of Treves. They had the following children:
Hiltrud
Carloman However, alongside this there soon developed a darker reputation, for his alleged abuse of church property. A ninth-century text, the Visio Eucherii, possibly written by Hincmar of Reims, portrayed Charles as suffering in hell for this reason. According to British medieval historian Paul Fouracre, this was "the single most important text in the construction of Charles's reputation as a seculariser or despoiler of church lands".
By the eighteenth century, historians such as Edward Gibbon had begun to portray the Frankish leader as the saviour of Christian Europe from a full-scale Islamic invasion.
In the nineteenth century, the German historian Heinrich Brunner argued that Charles had confiscated church lands in order to fund military reforms that allowed him to defeat the Arab conquests, in this way brilliantly combining two traditions about the ruler. However, Fouracre argued that "...there is not enough evidence to show that there was a decisive change either in the way in which the Franks fought, or in the way in which they organised the resources needed to support their warriors."
Many twentieth-century European historians continued to develop Gibbon's perspectives, such as French medievalist Christian Pfister, who wrote in 1911 that
And in 1993, the influential political scientist Samuel Huntington saw the battle of Tours as marking the end of the "Arab and Moorish surge west and north".
Other recent historians, however, argue that the importance of the battle is dramatically overstated, both for European history in general and for Charles's reign in particular. This view is typified by Alessandro Barbero, who in 2004 wrote,
Similarly, in 2002 Tomaž Mastnak wrote:
More recently, the memory of Charles has been appropriated by far right and white nationalist groups, such as the 'Charles Martel Group' in France, and by the perpetrator of the Christchurch mosque shootings at Al Noor Mosque and Linwood Islamic Centre in Christchurch, New Zealand, in 2019. The memory of Charles is a topic of debate in contemporary French politics on both the right and the left.
=== Order of the Genet ===
In the seventeenth century, a legend emerged that Charles had formed the first regular order of knights in France. In 1620, Andre Favyn stated (without providing a source) that among the spoils Charles's forces captured after the Battle of Tours were many genets (raised for their fur) and several of their pelts. Charles gave these furs to leaders amongst his army, forming the first order of knighthood, the Order of the Genet. Favyn's claim was then repeated and elaborated in later works in English, for instance by Elias Ashmole in 1672, and James Coats in 1725.
|
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"Abbey of Echternach",
"Bernard Bachrach",
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"sobriquet",
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"Chilperic II",
"Umayyad Caliphate",
"Malmedy",
"Linwood Islamic Centre",
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"metropolitan bishop",
"Richard Gerberding",
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"Al Noor Mosque, Christchurch",
"Plectrude",
"Departments of France",
"Sigramnus, Count of Hesbaye",
"Edward Gibbon",
"Chronicle of 754",
"Battle of the Boarn",
"Daniel of Winchester",
"Prince-Bishopric of Freising",
"Paul Fouracre",
"Theudoald",
"Carloman, son of Charles Martel",
"Roman Catholic Archdiocese of Rouen",
"Tours",
"Alessandro Barbero",
"Weser",
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"Childebrand I",
"Irmina of Oeren",
"power behind the throne",
"Pepin II the Middle",
"Saracen",
"Loire",
"Hunald I",
"Battle of Compiègne",
"Internet Medieval Sourcebook",
"Odo the Great",
"Quierzy",
"Odilo, Duke of Bavaria",
"Bernard, son of Charles Martel",
"Christchurch",
"Abd al-Rahman ibn Abd Allah al-Ghafiqi",
"Paul the Deacon",
"Palace of Versailles",
"Mainz",
"Carolman, son of Charles Martel",
"Munuza",
"Lantfrid",
"Pepin the Short",
"Childeric II",
"Thierry IV",
"Fall of the Western Roman Empire",
"Westphalia",
"Roman Catholic Archdiocese of Reims",
"Hieronymus, son of Charles Martel",
"centralized government",
"BBC Radio 4",
"Elias Ashmole",
"Auda of France",
"Duke and Prince of the Franks",
"Gaul",
"Battle of Tours",
"Rigobert",
"Cologne",
"Neustria",
"Mayor of the Palace",
"Christchurch mosque shootings",
"White nationalism",
"Ragenfrid",
"Pepin of Herstal",
"Iberian Peninsula",
"Battle of Soissons (718)",
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"feudalism",
"archbishop",
"Ruhr (river)",
"Picardy",
"Septimania",
"Roman Catholic Diocese of Passau",
"Abdul Rahman Al Ghafiqi",
"List of rulers of Bavaria",
"Jean Baptiste Joseph De Bay père",
"Arnulfings",
"Grifo (noble)",
"Carolingian dynasty",
"Bourges",
"Theuderic IV",
"Agilolfings",
"Far-right politics",
"Carloman (mayor of the palace)",
"Roi fainéant",
"Grimoald the Younger",
"Pope Gregory III",
"Alemanni",
"Hincmar",
"Lippe (district)",
"hell",
"In Our Time (radio series)",
"List of Mayors of the Palaces",
"Samuel P. Huntington",
"William E. Watson",
"Frisians",
"Maurontus",
"Muhammad",
"Eifel",
"Milo (bishop of Trier)",
"Ecclesiastical History of the English People",
"Guillaume Rouillé",
"Battle of Cologne",
"Bubo, Duke of the Frisians",
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"Charlemagne",
"Mayors of the Palace",
"Willibrord",
"Herstal",
"Arnulf of Metz",
"Raganfrid",
"Hugbert of Bavaria",
"Teutoburg Forest",
"Archbishopric of Salzburg",
"Ruodhaid",
"Burgundy",
"Austrasia",
"Liber Historiae Francorum",
"Angers",
"Liutprand, King of the Lombards",
"Hiltrud",
"Battle of Amblève",
"Alpaida",
"Battle of Toulouse (721)",
"Liber Pontificalis",
"Saint Boniface",
"Roman Catholic Diocese of Regensburg",
"Leudwinus",
"Swanachild",
"Chlothar IV",
"Basilica of St Denis",
"Dagobert III",
"Paris",
"Poitiers",
"duke of Aquitaine",
"Franks",
"Heinrich Brunner",
"Christian Pfister"
] |
6,456 |
Charles Edward Jones
|
Charles Edward "Chuck" Jones (November 8, 1952 – September 11, 2001) was a United States Air Force officer, an aeronautical engineer, computer programmer, and an astronaut in the USAF Manned Spaceflight Engineer Program. He was killed during the September 11 attacks, aboard American Airlines Flight 11.
== Life ==
Charles Edward Jones was born November 8, 1952, in Clinton, Indiana. He graduated from Wichita East High School in 1970, earned a Bachelor of Science degree in Astronautical Engineering from the United States Air Force Academy in 1974, and received a Master of Science degree in Astronautics from Massachusetts Institute of Technology in 1980. He entered the USAF Manned Spaceflight Engineer program in 1982, and was scheduled to fly on mission STS-71-B in December 1986, but the mission was canceled after the Challenger Disaster in January 1986. He left the Manned Spaceflight Engineer program in 1987.
He later worked for Defense Intelligence Agency, Bolling Air Force Base in Washington, D.C., and was Systems Program Director for Intelligence and Information Systems, Hanscom Air Force Base, Massachusetts.
Jones was killed at the age of 48 in the attacks of September 11, 2001, aboard American Airlines Flight 11. Jones was flying that day on a routine business trip for BAE Systems, and had been living as a retired U.S. Air Force colonel in Bedford, Massachusetts, at the time of his death. He was survived by his wife Jeanette.
==Military decorations==
His awards include:
Senior Missile Badge
|
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"computer programmer",
"Wichita East High School",
"Manned Spaceflight Engineer",
"Parachutist Badge (United States)",
"BAE Systems",
"service star",
"September 11 attacks",
"Washington, D.C.",
"United States Air Force",
"List of astronauts by selection",
"oak leaf cluster",
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"Bolling Air Force Base",
"Massachusetts",
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"Bedford, Massachusetts",
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"Casualties of the September 11 attacks",
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"Canceled Space Shuttle missions",
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"Colonel",
"Marksmanship Ribbon",
"Space Shuttle Challenger",
"Manned Spaceflight Engineer Program",
"National 9/11 Memorial",
"aeronautical engineer",
"Defense Superior Service Medal",
"Missile Badge",
"Air Force Achievement Medal",
"Computer programmer",
"Bachelor of Science",
"USAF",
"New York (state)",
"Defense Intelligence Agency",
"New York City",
"American Airlines Flight 11",
"Defense Meritorious Service Medal",
"National Defense Service Medal",
"Air Force Organizational Excellence Award",
"Air Force Training Ribbon",
"Massachusetts Institute of Technology",
"Lake North Pole",
"Hanscom Air Force Base",
"Clinton, Indiana",
"Joint Meritorious Unit Award"
] |
6,458 |
Ceramic
|
A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick.
The earliest ceramics made by humans were fired clay bricks used for building house walls and other structures. Other pottery objects such as pots, vessels, vases and figurines were made from clay, either by itself or mixed with other materials like silica, hardened by sintering in fire. Later, ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, amorphous ceramic coatings on top of the crystalline ceramic substrates. Ceramics now include domestic, industrial, and building products, as well as a wide range of materials developed for use in advanced ceramic engineering, such as semiconductors.
The word ceramic comes from the Ancient Greek word (), meaning "of or for pottery" (). The earliest known mention of the root ceram- is the Mycenaean Greek , workers of ceramic, written in Linear B syllabic script. The word ceramic can be used as an adjective to describe a material, product, or process, or it may be used as a noun, either singular or, more commonly, as the plural noun ceramics.
==Materials==
Ceramic material is an inorganic, metallic oxide, nitride, or carbide material. Some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, and weak in shearing and tension. They withstand the chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand very high temperatures, ranging from 1,000 °C to 1,600 °C (1,800 °F to 3,000 °F).
The crystallinity of ceramic materials varies widely. Most often, fired ceramics are either vitrified or semi-vitrified, as is the case with earthenware, stoneware, and porcelain. Varying crystallinity and electron composition in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators (researched in ceramic engineering). With such a large range of possible options for the composition/structure of a ceramic (nearly all of the elements, nearly all types of bonding, and all levels of crystallinity), the breadth of the subject is vast, and identifiable attributes (hardness, toughness, electrical conductivity) are difficult to specify for the group as a whole. General properties such as high melting temperature, high hardness, poor conductivity, high moduli of elasticity, chemical resistance, and low ductility are the norm, with known exceptions to each of these rules (piezoelectric ceramics, low glass transition temperature ceramics, superconductive ceramics).
Composites such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family.
Highly oriented crystalline ceramic materials are not amenable to a great range of processing. Methods for dealing with them tend to fall into one of two categories: either making the ceramic in the desired shape by reaction in situ or "forming" powders into the desired shape and then sintering to form a solid body. Ceramic forming techniques include shaping by hand (sometimes including a rotation process called "throwing"), slip casting, tape casting (used for making very thin ceramic capacitors), injection molding, dry pressing, and other variations.
Many ceramics experts do not consider materials with an amorphous (noncrystalline) character (i.e., glass) to be ceramics, even though glassmaking involves several steps of the ceramic process and its mechanical properties are similar to those of ceramic materials. However, heat treatments can convert glass into a semi-crystalline material known as glass-ceramic.
Traditional ceramic raw materials include clay minerals such as kaolinite, whereas more recent materials include aluminium oxide, more commonly known as alumina. Modern ceramic materials, which are classified as advanced ceramics, include silicon carbide and tungsten carbide. Both are valued for their abrasion resistance and are therefore used in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are also used in the medical, electrical, electronics, and armor industries.
==History==
Human beings appear to have been making their own ceramics for at least 26,000 years, subjecting clay and silica to intense heat to fuse and form ceramic materials. The earliest found so far were in southern central Europe and were sculpted figures, not dishes. The earliest known pottery was made by mixing animal products with clay and firing it at up to . While pottery fragments have been found up to 19,000 years old, it was not until about 10,000 years later that regular pottery became common. An early people that spread across much of Europe is named after its use of pottery: the Corded Ware culture. These early Indo-European peoples decorated their pottery by wrapping it with rope while it was still wet. When the ceramics were fired, the rope burned off but left a decorative pattern of complex grooves on the surface.
The invention of the wheel eventually led to the production of smoother, more even pottery using the wheel-forming (throwing) technique, like the pottery wheel. Early ceramics were porous, absorbing water easily. It became useful for more items with the discovery of glazing techniques, which involved coating pottery with silicon, bone ash, or other materials that could melt and reform into a glassy surface, making a vessel less pervious to water.
===Archaeology===
Ceramic artifacts have an important role in archaeology for understanding the culture, technology, and behavior of peoples of the past. They are among the most common artifacts to be found at an archaeological site, generally in the form of small fragments of broken pottery called sherds. The processing of collected sherds can be consistent with two main types of analysis: technical and traditional.
The traditional analysis involves sorting ceramic artifacts, sherds, and larger fragments into specific types based on style, composition, manufacturing, and morphology. By creating these typologies, it is possible to distinguish between different cultural styles, the purpose of the ceramic, and the technological state of the people, among other conclusions. Besides, by looking at stylistic changes in ceramics over time, it is possible to separate (seriate) the ceramics into distinct diagnostic groups (assemblages). A comparison of ceramic artifacts with known dated assemblages allows for a chronological assignment of these pieces.
The technical approach to ceramic analysis involves a finer examination of the composition of ceramic artifacts and sherds to determine the source of the material and, through this, the possible manufacturing site. Key criteria are the composition of the clay and the temper used in the manufacture of the article under study: the temper is a material added to the clay during the initial production stage and is used to aid the subsequent drying process. Types of temper include shell pieces, granite fragments, and ground sherd pieces called 'grog'. Temper is usually identified by microscopic examination of the tempered material. Clay identification is determined by a process of refiring the ceramic and assigning a color to it using Munsell Soil Color notation. By estimating both the clay and temper compositions and locating a region where both are known to occur, an assignment of the material source can be made. Based on the source assignment of the artifact, further investigations can be made into the site of manufacture.
==Properties==
The physical properties of any ceramic substance are a direct result of its crystalline structure and chemical composition. Solid-state chemistry reveals the fundamental connection between microstructure and properties, such as localized density variations, grain size distribution, type of porosity, and second-phase content, which can all be correlated with ceramic properties such as mechanical strength σ by the Hall-Petch equation, hardness, toughness, dielectric constant, and the optical properties exhibited by transparent materials.
Ceramography is the art and science of preparation, examination, and evaluation of ceramic microstructures. Evaluation and characterization of ceramic microstructures are often implemented on similar spatial scales to that used commonly in the emerging field of nanotechnology: from nanometers to tens of micrometers (µm). This is typically somewhere between the minimum wavelength of visible light and the resolution limit of the naked eye.
The microstructure includes most grains, secondary phases, grain boundaries, pores, micro-cracks, structural defects, and hardness micro indentions. Most bulk mechanical, optical, thermal, electrical, and magnetic properties are significantly affected by the observed microstructure. The fabrication method and process conditions are generally indicated by the microstructure. The root cause of many ceramic failures is evident in the cleaved and polished microstructure. Physical properties which constitute the field of materials science and engineering include the following:
===Mechanical properties===
Mechanical properties are important in structural and building materials as well as textile fabrics. In modern materials science, fracture mechanics is an important tool in improving the mechanical performance of materials and components. It applies the physics of stress and strain, in particular the theories of elasticity and plasticity, to the microscopic crystallographic defects found in real materials in order to predict the macroscopic mechanical failure of bodies. Fractography is widely used with fracture mechanics to understand the causes of failures and also verify the theoretical failure predictions with real-life failures.
Ceramic materials are usually ionic or covalent bonded materials. A material held together by either type of bond will tend to fracture before any plastic deformation takes place, which results in poor toughness in these materials. Additionally, because these materials tend to be porous, the pores and other microscopic imperfections act as stress concentrators, decreasing the toughness further, and reducing the tensile strength. These combine to give catastrophic failures, as opposed to the more ductile failure modes of metals.
These materials do show plastic deformation. However, because of the rigid structure of crystalline material, there are very few available slip systems for dislocations to move, and so they deform very slowly.
To overcome the brittle behavior, ceramic material development has introduced the class of ceramic matrix composite materials, in which ceramic fibers are embedded and with specific coatings are forming fiber bridges across any crack. This mechanism substantially increases the fracture toughness of such ceramics. Ceramic disc brakes are an example of using a ceramic matrix composite material manufactured with a specific process.
Scientists are working on developing ceramic materials that can withstand significant deformation without breaking. A first such material that can deform in room temperature was found in 2024.
====Ice-templating for enhanced mechanical properties====
If a ceramic is subjected to substantial mechanical loading, it can undergo a process called ice-templating, which allows some control of the microstructure of the ceramic product and therefore some control of the mechanical properties. Ceramic engineers use this technique to tune the mechanical properties to their desired application. Specifically, the strength is increased when this technique is employed. Ice templating allows the creation of macroscopic pores in a unidirectional arrangement. The applications of this oxide strengthening technique are important for solid oxide fuel cells and water filtration devices.
To process a sample through ice templating, an aqueous colloidal suspension is prepared to contain the dissolved ceramic powder evenly dispersed throughout the colloid, for example yttria-stabilized zirconia (YSZ). The solution is then cooled from the bottom to the top on a platform that allows for unidirectional cooling. This forces ice crystals to grow in compliance with the unidirectional cooling, and these ice crystals force the dissolved YSZ particles to the solidification front of the solid-liquid interphase boundary, resulting in pure ice crystals lined up unidirectionally alongside concentrated pockets of colloidal particles. The sample is then heated and at the same the pressure is reduced enough to force the ice crystals to sublime and the YSZ pockets begin to anneal together to form macroscopically aligned ceramic microstructures. The sample is then further sintered to complete the evaporation of the residual water and the final consolidation of the ceramic microstructure.
During ice-templating, a few variables can be controlled to influence the pore size and morphology of the microstructure. These important variables are the initial solids loading of the colloid, the cooling rate, the sintering temperature and duration, and the use of certain additives which can influence the microstructural morphology during the process. A good understanding of these parameters is essential to understanding the relationships between processing, microstructure, and mechanical properties of anisotropically porous materials.
===Electrical properties===
====Semiconductors====
Some ceramics are semiconductors. Most of these are transition metal oxides that are II-VI semiconductors, such as zinc oxide. While there are prospects of mass-producing blue light-emitting diodes (LED) from zinc oxide, ceramicists are most interested in the electrical properties that show grain boundary effects. One of the most widely used of these is the varistor. These are devices that exhibit the property that resistance drops sharply at a certain threshold voltage. Once the voltage across the device reaches the threshold, there is a breakdown of the electrical structure in the vicinity of the grain boundaries, which results in its electrical resistance dropping from several megohms down to a few hundred ohms. The major advantage of these is that they can dissipate a lot of energy, and they self-reset; after the voltage across the device drops below the threshold, its resistance returns to being high. This makes them ideal for surge-protection applications; as there is control over the threshold voltage and energy tolerance, they find use in all sorts of applications. The best demonstration of their ability can be found in electrical substations, where they are employed to protect the infrastructure from lightning strikes. They have rapid response, are low maintenance, and do not appreciably degrade from use, making them virtually ideal devices for this application. Semiconducting ceramics are also employed as gas sensors. When various gases are passed over a polycrystalline ceramic, its electrical resistance changes. With tuning to the possible gas mixtures, very inexpensive devices can be produced.
====Superconductivity====
Under some conditions, such as extremely low temperatures, some ceramics exhibit high-temperature superconductivity (in superconductivity, "high temperature" means above 30 K). The reason for this is not understood, but there are two major families of superconducting ceramics.
====Ferroelectricity and supersets====
Piezoelectricity, a link between electrical and mechanical response, is exhibited by a large number of ceramic materials, including the quartz used to measure time in watches and other electronics. Such devices use both properties of piezoelectrics, using electricity to produce a mechanical motion (powering the device) and then using this mechanical motion to produce electricity (generating a signal). The unit of time measured is the natural interval required for electricity to be converted into mechanical energy and back again.
The piezoelectric effect is generally stronger in materials that also exhibit pyroelectricity, and all pyroelectric materials are also piezoelectric. These materials can be used to inter-convert between thermal, mechanical, or electrical energy; for instance, after synthesis in a furnace, a pyroelectric crystal allowed to cool under no applied stress generally builds up a static charge of thousands of volts. Such materials are used in motion sensors, where the tiny rise in temperature from a warm body entering the room is enough to produce a measurable voltage in the crystal.
In turn, pyroelectricity is seen most strongly in materials that also display the ferroelectric effect, in which a stable electric dipole can be oriented or reversed by applying an electrostatic field. Pyroelectricity is also a necessary consequence of ferroelectricity. This can be used to store information in ferroelectric capacitors, elements of ferroelectric RAM.
The most common such materials are lead zirconate titanate and barium titanate. Aside from the uses mentioned above, their strong piezoelectric response is exploited in the design of high-frequency loudspeakers, transducers for sonar, and actuators for atomic force and scanning tunneling microscopes.
====Positive thermal coefficient====
Temperature increases can cause grain boundaries to suddenly become insulating in some semiconducting ceramic materials, mostly mixtures of heavy metal titanates. The critical transition temperature can be adjusted over a wide range by variations in chemistry. In such materials, current will pass through the material until joule heating brings it to the transition temperature, at which point the circuit will be broken and current flow will cease. Such ceramics are used as self-controlled heating elements in, for example, the rear-window defrost circuits of automobiles.
At the transition temperature, the material's dielectric response becomes theoretically infinite. While a lack of temperature control would rule out any practical use of the material near its critical temperature, the dielectric effect remains exceptionally strong even at much higher temperatures. Titanates with critical temperatures far below room temperature have become synonymous with "ceramic" in the context of ceramic capacitors for just this reason.
===Optical properties===
Optically transparent materials focus on the response of a material to incoming light waves of a range of wavelengths. Frequency selective optical filters can be utilized to alter or enhance the brightness and contrast of a digital image. Guided lightwave transmission via frequency selective waveguides involves the emerging field of fiber optics and the ability of certain glassy compositions as a transmission medium for a range of frequencies simultaneously (multi-mode optical fiber) with little or no interference between competing wavelengths or frequencies. This resonant mode of energy and data transmission via electromagnetic (light) wave propagation, though low powered, is virtually lossless. Optical waveguides are used as components in Integrated optical circuits (e.g. light-emitting diodes, LEDs) or as the transmission medium in local and long haul optical communication systems. Also of value to the emerging materials scientist is the sensitivity of materials to radiation in the thermal infrared (IR) portion of the electromagnetic spectrum. This heat-seeking ability is responsible for such diverse optical phenomena as night-vision and IR luminescence.
Thus, there is an increasing need in the military sector for high-strength, robust materials which have the capability to transmit light (electromagnetic waves) in the visible (0.4 – 0.7 micrometers) and mid-infrared (1 – 5 micrometers) regions of the spectrum. These materials are needed for applications requiring transparent armor, including next-generation high-speed missiles and pods, as well as protection against improvised explosive devices (IED).
In the 1960s, scientists at General Electric (GE) discovered that under the right manufacturing conditions, some ceramics, especially aluminium oxide (alumina), could be made translucent. These translucent materials were transparent enough to be used for containing the electrical plasma generated in high-pressure sodium street lamps. During the past two decades, additional types of transparent ceramics have been developed for applications such as nose cones for heat-seeking missiles, windows for fighter aircraft, and scintillation counters for computed tomography scanners. Other ceramic materials, generally requiring greater purity in their make-up than those above, include forms of several chemical compounds, including:
Barium titanate: (often mixed with strontium titanate) displays ferroelectricity, meaning that its mechanical, electrical, and thermal responses are coupled to one another and also history-dependent. It is widely used in electromechanical transducers, ceramic capacitors, and data storage elements. Grain boundary conditions can create PTC effects in heating elements.
Sialon (silicon aluminium oxynitride) has high strength; resistance to thermal shock, chemical and wear resistance, and low density. These ceramics are used in non-ferrous molten metal handling, weld pins, and the chemical industry.
Silicon carbide (SiC) is used as a susceptor in microwave furnaces, a commonly used abrasive, and as a refractory material.
Silicon nitride (Si3N4) is used as an abrasive powder.
Steatite (magnesium silicates) is used as an electrical insulator.
Titanium carbide Used in space shuttle re-entry shields and scratchproof watches.
Uranium oxide (UO2), used as fuel in nuclear reactors.
Yttrium barium copper oxide (YBa2Cu3O7−x), a high-temperature superconductor.
Zinc oxide (ZnO), which is a semiconductor, and used in the construction of varistors.
Zirconium dioxide (zirconia), which in pure form undergoes many phase changes between room temperature and practical sintering temperatures, can be chemically "stabilized" in several different forms. Its high oxygen ion conductivity recommends it for use in fuel cells and automotive oxygen sensors. In another variant, metastable structures can impart transformation toughening for mechanical applications; most ceramic knife blades are made of this material. Partially stabilised zirconia (PSZ) is much less brittle than other ceramics and is used for metal forming tools, valves and liners, abrasive slurries, kitchen knives and bearings subject to severe abrasion.
==Products==
===By usage===
For convenience, ceramic products are usually divided into four main types; these are shown below with some examples:
Structural, including bricks, pipes, floor and roof tiles, vitrified tile
Refractories, such as kiln linings, gas fire radiants, steel and glass making crucibles
Whitewares, including tableware, cookware, wall tiles, pottery products and sanitary ware
Technical, also known as engineering, advanced, special, and fine ceramics. Such items include:
gas burner nozzles
ballistic protection, vehicle armor
nuclear fuel uranium oxide pellets
biomedical implants
coatings of jet engine turbine blades
ceramic matrix composite gas turbine parts
reinforced carbon–carbon ceramic disc brakes
missile nose cones
bearings
thermal insulation tiles used on the Space Shuttle orbiter
===Ceramics made with clay===
Frequently, the raw materials of modern ceramics do not include clays.
Those that do have been classified as:
Earthenware, fired at lower temperatures than other types
Stoneware, vitreous or semi-vitreous
Porcelain, which contains a high content of kaolin
Bone china
===Classification===
Ceramics can also be classified into three distinct material categories:
Oxides: alumina, beryllia, ceria, zirconia
Non-oxides: carbide, boride, nitride, silicide
Composite materials: particulate reinforced, fiber reinforced, combinations of oxides and non-oxides.
Each one of these classes can be developed into unique material properties.
==Applications==
Knife blades: the blade of a ceramic knife will stay sharp for much longer than that of a steel knife, although it is more brittle and susceptible to breakage.
Carbon-ceramic brake disks for vehicles: highly resistant to brake fade at high temperatures.
Advanced composite ceramic and metal matrices have been designed for most modern armoured fighting vehicles because they offer superior penetrating resistance against shaped charge (HEAT rounds) and kinetic energy penetrators.
Ceramics such as alumina and boron carbide have been used as plates in ballistic armored vests to repel high-velocity rifle fire. Such plates are known commonly as small arms protective inserts, or SAPIs. Similar low-weight material is used to protect the cockpits of some military aircraft.
Ceramic ball bearings can be used in place of steel. Their greater hardness results in lower susceptibility to wear. Ceramic bearings typically last triple the lifetime of steel bearings. They deform less than steel under load, resulting in less contact with the bearing retainer walls and lower friction. In very high-speed applications, heat from friction causes more problems for metal bearings than ceramic bearings. Ceramics are chemically resistant to corrosion and are preferred for environments where steel bearings would rust. In some applications their electricity-insulating properties are advantageous. Drawbacks to ceramic bearings include significantly higher cost, susceptibility to damage under shock loads, and the potential to wear steel parts due to ceramics' greater hardness.
In the early 1980s Toyota researched production of an adiabatic engine using ceramic components in the hot gas area. The use of ceramics would have allowed temperatures exceeding 1650 °C. Advantages would include lighter materials and a smaller cooling system (or no cooling system at all), leading to major weight reduction. The expected increase of fuel efficiency (due to higher operating temperatures, demonstrated in Carnot's theorem) could not be verified experimentally. It was found that heat transfer on the hot ceramic cylinder wall was greater than the heat transfer to a cooler metal wall. This is because the cooler gas film on a metal surface acts as a thermal insulator. Thus, despite the desirable properties of ceramics, prohibitive production costs and limited advantages have prevented widespread ceramic engine component adoption. In addition, small imperfections in ceramic material along with low fracture toughness can lead to cracking and potentially dangerous equipment failure. Such engines are possible experimentally, but mass production is not feasible with current technology.
Experiments with ceramic parts for gas turbine engines are being conducted. Currently, even blades made of advanced metal alloys used in the engines' hot section require cooling and careful monitoring of operating temperatures. Turbine engines made with ceramics could operate more efficiently, providing for greater range and payload.
Recent advances have been made in ceramics which include bioceramics such as dental implants and synthetic bones. Hydroxyapatite, the major mineral component of bone, has been made synthetically from several biological and chemical components and can be formed into ceramic materials. Orthopedic implants coated with these materials bond readily to bone and other tissues in the body without rejection or inflammatory reaction. They are of great interest for gene delivery and tissue engineering scaffolding. Most hydroxyapatite ceramics are quite porous and lack mechanical strength and are therefore used solely to coat metal orthopedic devices to aid in forming a bond to bone or as bone fillers. They are also used as fillers for orthopedic plastic screws to aid in reducing inflammation and increase the absorption of these plastic materials. Work is being done to make strong, fully dense nanocrystalline hydroxyapatite ceramic materials for orthopedic weight bearing devices, replacing foreign metal and plastic orthopedic materials with a synthetic but naturally occurring bone mineral. Ultimately, these ceramic materials may be used as bone replacement, or with the incorporation of protein collagens, the manufacture of synthetic bones.
Applications for actinide-containing ceramic materials include nuclear fuels for burning excess plutonium (Pu), or a chemically inert source of alpha radiation in power supplies for uncrewed space vehicles or microelectronic devices. Use and disposal of radioactive actinides require immobilization in a durable host material. Long half-life radionuclides such as actinide are immobilized using chemically durable crystalline materials based on polycrystalline ceramics and large single crystals.
High-tech ceramics are used for producing watch cases. The material is valued by watchmakers for its light weight, scratch resistance, durability, and smooth touch. IWC is one of the brands that pioneered the use of ceramic in watchmaking.
Ceramics are used in the design of mobile phone bodies due to their high hardness, resistance to scratches, and ability to dissipate heat. Ceramic's thermal management properties help in maintaining optimal device temperatures during heavy use enhancing performance. Additionally, ceramic materials can support wireless charging and offer better signal transmission compared to metals, which can interfere with antennas. Companies like Apple and Samsung have incorporated ceramic in their devices.
Ceramics made of silicon carbide are used in pump and valve components because of their corrosion resistance characteristics. It is also used in nuclear reactors as fuel cladding materials due to their ability to withstand radiation and thermal stress. Other uses of Silicon carbide ceramics include paper manufacturing, ballistics, chemical production, and as pipe system components.
|
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] |
6,459 |
Wuxing (Chinese philosophy)
|
(), usually translated as Five Phases or Five Agents, is a fivefold conceptual scheme used in many traditional Chinese fields of study to explain a wide array of phenomena, including terrestrial and celestial relationships, influences and cycles, that characterise the interactions and relationships within science, medicine, politics, religion and social relationships and education within Chinese culture.
The agents are more commonly observed in there heavenly stems generative cycle running consecutively clockwise starting with Wood, Fire, Earth,Metal and Water as depicted by the diagram above, or in their across the cycle formation as the earthly stems arrangement of Fire, Water, Wood, Metal, and Earth. When in their overactive destructive arrangement of Wood, Earth, Water, Fire and Metal natural disasters, calamity and illnesses and disease will ensure.
The wuxing system has been in use since it was systemized in the second or first century BCE during the Han dynasty. It appears in many seemingly disparate fields of early Chinese thought, including music, feng shui, alchemy, astrology, martial arts, military strategy, I Ching divination, religion and traditional medicine, serving as a metaphysics based on cosmic analogy.
==Etymology==
Wuxing originally referred to the five classical planets (from brightest to dimmest: Venus, Jupiter, Mercury, Mars, Saturn), which were with the combination of the Sun and the Moon, conceived as creating yang and yin of the five forces of earthly life. This is why the word is composed of Chinese characters meaning "five" () and "moving" (). "Moving" is shorthand for "planets", since the word for planets in Chinese has been translated as "moving stars" (). Some of the Mawangdui Silk Texts (before 168 BC) also connect the wuxing to the wude (), the Five Virtues and Five Emotions . Scholars believe that various predecessors to the concept of wuxing were merged into one system of many interpretations in the Han dynasty.
Wuxing was first translated into English as "the Five Elements", drawing parallels with the Greek and Indian Vedic static, solid or formative arrangement of the four elements. However, this analogy could be misleading as the four elements are concerned with form, substance and quantity, whereas the post heaven arrangement of the wuxing are "primarily concerned with process, change, and quality". For example, the wuxing element "Wood" is more accurately thought of as the "vital essence" of trees rather than the physical substance wood. This led sinologist Nathan Sivin to propose the alternative translation "five phases" in 1987. But "phase" also fails to capture the full meaning of wuxing. In some contexts, the wuxing are indeed associated with physical substances. Historian of Chinese medicine Manfred Porkert proposed the (somewhat unwieldy) term "Evolutive Phase".
==Cycles==
In traditional doctrine, the five phases are connected in two cycles of interactions: a generating or creation ( shēng) cycle, also known as "mother-son"; and an overacting or destructive ( kè) cycle, also known as "grandfather-grandson" (see diagram). Each of the two cycles can be analyzed going forward or reversed. There is also an "overacting" or excessive version of the destructive cycle.
===Inter-promoting===
The generating cycle ( xiāngshēng) is:
Wood feeds Fire
Fire produces Earth (ash, lava)
Earth bears Metal (geological processes produce minerals)
Metal collects Water (water vapor condenses on metal, for example)
Water nourishes Wood (Water flowers, plants and other changes in forest)
===Weakening===
The reverse generating cycle (/ xiāngxiè) is:
Wood depletes Water
Water rusts Metal
Metal impoverishes Earth (erosion, destructive mining of minerals)
Earth smothers Fire
Fire burns Wood (forest fires)
===Inter-regulating===
The destructive cycle ( xiāngkè) is:
Wood grasps (or stabilizes) Earth (roots of trees can prevent soil erosion)
Earth contains (or directs) Water (dams or river banks)
Water dampens (or regulates) Fire
Fire melts (or refines or shapes) Metal
Metal chops (or carves) Wood
===Overacting===
The excessive destructive cycle ( xiāngchéng) is:
Wood depletes Earth (depletion of nutrients in soil, over-farming, overcultivation)
Earth obstructs Water (over-damming)
Water extinguishes Fire
Fire melts Metal (affecting its integrity)
Metal makes Wood rigid to easily snap.
===Counteracting===
A reverse or deficient destructive cycle ( xiāngwǔ or xiānghào) is:
Wood dulls Metal
Metal de-energizes Fire (conducting heat away)
Fire evaporates Water
Water muddies (or destabilizes) Earth
Earth rots Wood (buried wood rots)
==Celestial stem==
===Ming nayin===
In Ziwei divination, nayin () further classifies the Five Elements into 60 ming (), or life orders, based on the ganzhi. Similar to the astrology zodiac, the ming is used by fortune-tellers to analyse individual personality and destiny.
==Applications==
The wuxing schema is applied to explain phenomena in various fields.
===Phases of the year===
The five phases are around 73 days each and are usually used to describe the transformations of nature rather than their formative states.
Wood/Spring: a period of growth, expanding which generates abundant vitality, movement and as a consequence is associated with wind.
Fire/Summer: a period of fruition, ripening flowering, and associated with heat.
Earth can be seen as a period of stability and stillness transitioning between the other phases or seasons or when relating to transformative seasonal periods it can be seen as late Summer. This period is associated with centralisation, leveling and dampness.
Metal/Autumn: a period of moving inward it is associated with collection, harvesting, transmuting, contracting, loss and dryness.
Water/Winter: a period of reclusivness, stillness, consolidation and coolness.
===Cosmology and feng shui===
The art of feng shui (Chinese geomancy) is based on wuxing, with the structure of the cosmos mirroring the five phases, as well as the eight trigrams. Each phase has a complex network of associations with different aspects of nature (see table): colors, seasons and shapes all interact according to the cycles.
An interaction or energy flow can be expansive, destructive, or exhaustive, depending on the cycle to which it belongs. By understanding these energy flows, a feng shui practitioner attempts to rearrange energy to benefit the client.
===Dynastic transitions===
According to the Warring States period political philosopher Zou Yan ( BCE), each of the five elements possesses a personified virtue (), which indicates the foreordained destiny () of a dynasty; hence the cyclic succession of the elements also indicates dynastic transitions. Zou Yan claims that the Mandate of Heaven sanctions the legitimacy of a dynasty by sending self-manifesting auspicious signs in the ritual color (white, green, black, red, and yellow) that matches the element of the new dynasty (Metal, Wood, Water, Fire, and Earth). From the Qin dynasty onward, most Chinese dynasties invoked the theory of the Five Elements to legitimize their reign.
In order to explain the integrity and complexity of the human body, Chinese medical scientists and physicians use the Five Elements theory to classify the human body's endogenous influences on organs, physiological activities, pathological reactions, and environmental or exogenous (external, environmental) influences. This diagnostic capacity is extensively used in traditional five phase acupuncture today, as opposed to the modern Confucian styled eight principles based Traditional Chinese medicine. In combination the two systems are a formative and functional study of postnatal and prenatal influencing on genetics, psychology, sociology and ecology.
===Music===
The Huainanzi and the Yueling chapter () of the Book of Rites make the following correlations:
Qing is a Chinese color word used for both green and blue. Modern Mandarin has separate words for each, but like many other languages, older forms of Chinese did not distinguish between green and blue.
In most modern music, various five note or seven note scales (e.g., the major scale) are defined by selecting five or seven frequencies from the set of twelve semi-tones in the Equal tempered tuning. The Chinese shi'er lü system of tuning is closest to the ancient Greek tuning of Pythagoras.
===Martial arts===
Wuxing being an influential philosophical concept, there are several Chinese martial arts and a few other east Asian styles that incorporate five phases concepts into their systems.
Tai chi trains and focuses on five basic qualities as part of its overarching strategy.
The Five Steps () are:
Lǎo Jìnbù (老進步) – always step forward
Juébù Tuìbù (絕不退步) – never step backward
Yòupàn (右盼) – watch right
Zuǒgù (左顧) – beware left
Zhōngdìng (中定) – center pole, point, pivot neutral posture, maintain balance, maintain equilibrium.
These five steps are not mutable states in tai chi.
Xingyi Quan uses the five elements metaphorically to represent ideally five different energies, but energy work is subtle, so normally one starts out learning five basic techniques with complementary footwork to teach the basic concepts behind the energies. Ideally one can use any technique with any kind of energy, but there are different levels of skill one must go through.
In Xingyi Quan, realization of the five energies has three basic levels: Obvious power, subtle power, mysterious power.
The Five Animals in Shaolin martial arts are a extension of the Wuxing theory as their qualities are the embodiment and representation of the energetic qualities of the five phases in the animal kingdom. They are the,
Tiger - Fire (fierce and powerful)
Monkey - Metal (hunched over)
Snake - Water (flexible)
Crane - Wind (evasive)
Mantis - Earth (steady and rooted)
Wuxing Heqidao, (Gogyo Aikido 五行合气道) is a life art with roots in Confucian, Taoists and Buddhist theory. It centers around applied peace and health studies rather than defence or physical action. It emphasizes the unification of mind, body and environment using the physiological theory of yin, yang and five-element Traditional Chinese medicine. Its movements, exercises, and teachings cultivate, direct, and harmonise the qi.
== Gogyo==
The Japanese term is gogyo (Japanese: , romanized: gogyō). During the 5th and 6th centuries (Kofun period), Japan adopted various philosophical disciplines such as Taoism, Chinese Buddhism and Confucianism through monks and physicians from China helping to evolve the Onmyōdō system. As opposed to theory of Godai that is form based philosophy that was introduced to Japan through India and Tibetan Buddhism. These theories have been extensively practiced in Japanese acupuncture and traditional Kampo medicine.
|
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"ganzhi",
"Nanhua University",
"Joseph Needham",
"shi'er lü",
"Wuxing painting",
"wikt:agreeableness",
"San Jiao",
"Taste",
"Life",
"Emotion",
"Urinary bladder (Chinese medicine)",
"Mandate of Heaven",
"Chinese alchemy",
"Feng Youlan",
"pinyin",
"Visual perception",
"south",
"Chen Menglei",
"Venus",
"Onmyōdō",
"eight principles",
"bone",
"Qi",
"urine",
"curiosity",
"Small intestine (Chinese medicine)",
"De (Chinese)",
"sinologist",
"Guoyu (book)",
"Equal tempered",
"Human eye",
"planning",
"Chinese culture",
"Shiming",
"Japanese language",
"The Art of War",
"Animal styles in Chinese martial arts",
"middle finger",
"Mandarin Chinese",
"index finger",
"Mercury (planet)",
"Chinese Journal of Integrative Medicine",
"Complete Classics Collection of Ancient China",
"Nathan Sivin",
"wikt:erudition",
"wikt:scorched",
"Chinese cosmology",
"Righteousness",
"Huainanzi",
"Wood (wuxing)",
"Cihai",
"north",
"Humorism",
"xingyiquan",
"sweat",
"Pericardium (Chinese medicine)",
"prudence",
"Decomposition",
"saliva",
"Metal (wuxing)",
"Flying Star Feng Shui",
"Fertilisation",
"thumb",
"ear"
] |
6,462 |
Church of Christ, Scientist
|
The Church of Christ, Scientist was founded in 1879 in Boston, Massachusetts, by Mary Baker Eddy, author of Science and Health with Key to the Scriptures, and founder of Christian Science. The church was founded "to commemorate the word and works of Christ Jesus" and "reinstate primitive Christianity and its lost element of healing".
In the early decades of the 20th century, Christian Science churches were founded in communities around the world, though in the last several decades of that century, there was a marked decline in membership, except in Africa, where there has been growth. Headquartered in Boston, the church does not officially report membership, and estimates as to worldwide membership range from under 100,000 to about 400,000. In 2010, there were 1,153 churches in the United States.
==History==
The church was incorporated by Mary Baker Eddy in 1879, following a claimed personal healing in 1866, which she said resulted from reading the Bible. The Bible and Eddy's textbook on Christian healing, Science and Health with Key to the Scriptures, are together the church's key doctrinal sources and have been ordained as the church's "dual impersonal pastor".
The First Church of Christ, Scientist publishes the weekly newspaper The Christian Science Monitor in print and online.
==Beliefs and practices==
Christian Scientists believe that prayer is effective for healing diseases. The Church has collected over 50,000 testimonies of incidents that it considers healing through Christian Science treatment alone. While most of these testimonies represent ailments neither diagnosed nor treated by medical professionals, the Church requires three other people to vouch for any testimony published in any of its official organs, including the Christian Science Journal, Christian Science Sentinel, and Herald of Christian Science; verifiers say that they witnessed the healing or know the testifier well enough to vouch for them.
A Christian Science practitioner is someone who devotes their full time to prayer for others, but they do not use drugs or make medical diagnoses. Christian Scientists may take an intensive two-week "Primary" class from an authorized Christian Science teacher. Those who wish to become "Journal-listed" (accredited) practitioners, devoting themselves full-time to the practice of healing, must first have Primary class instruction. When they have what the church regards as a record of healing, they may submit their names for publication in the directory of practitioners and teachers in the Christian Science Journal. A practitioner who has been listed for at least three years may apply for "Normal" class instruction, given once every three years. Those who receive a certificate are authorized to teach. Both Primary and Normal classes are based on the Bible and the writings of Mary Baker Eddy. The Primary class focuses on the chapter "Recapitulation" in Science and Health with Key to the Scriptures. This chapter uses the Socratic method of teaching and contains the "Scientific Statement of Being". The "Normal" class focuses on the platform of Christian Science, contained on pages 330-340 of Science and Health.
==Organization==
The First Church of Christ, Scientist is the legal title of The Mother Church and administrative headquarters of the Christian Science Church. The Mary Baker Eddy Library for the Betterment of Humanity is housed in an 11-story structure originally built for The Christian Science Publishing Society.
An international newspaper, The Christian Science Monitor, founded by Eddy in 1908 and winner of seven Pulitzer Prizes, is published by the church through the Christian Science Publishing Society.
===Board of directors===
The Christian Science Board of Directors is a five-person executive entity created by Mary Baker Eddy to conduct the business of the Christian Science Church under the terms defined in the by-laws of the Church Manual. Its functions and restrictions are defined by the Manual.
==Controversies==
===Broadcasting===
Beginning in the mid-1980s, church executives undertook a controversial and ambitious foray into electronic broadcast media. The first significant effort was to create a weekly half-hour syndicated television program, The Christian Science Monitor Reports. "Monitor Reports" was anchored in its first season by newspaper veteran Rob Nelson. He was replaced in the second by the Christian Science Monitor's former Moscow correspondent, David Willis.
In October 1991, Christian Science Monitor anchor John Hart, who is not a Christian Scientist, resigned following professional disputes with the Monitor regarding Christian Science teachings and his journalistic independence.
The hundreds of millions lost on broadcasting brought the church to the brink of bankruptcy. However, with the 1991 publication of The Destiny of The Mother Church by the late Bliss Knapp, the church secured a $90 million bequest from the Knapp trust. The trust dictated that the book be published as "Authorized Literature", with neither modification nor comment. Historically, the church had censured Knapp for deviating at several points from Eddy's teaching, and had refused to publish the work. The church's archivist, fired in anticipation of the book's publication, wrote to branch churches to inform them of the book's history. Many Christian Scientists thought the book violated the church's by-laws, and the editors of the church's religious periodicals and several other church employees resigned in protest. Alternate beneficiaries subsequently sued to contest the church's claim it had complied fully with the will's terms, and the church ultimately received only half of the original sum.
The fallout of the broadcasting debacle also sparked a minor revolt among some prominent church members. In late 1993, a group of Christian Scientists filed suit against the Board of Directors, alleging a willful disregard for the Manual of The Mother Church in its financial dealings. The suit was thrown out by the Supreme Judicial Court of Massachusetts in 1997, but a lingering discontent with the church's financial matters persists to this day. The Destiny Of The Mother Church ceased publication in September 2023.
===Membership decline and financial setbacks===
In spite of its early meteoric rise, church membership has declined over the past eight decades, according to the church's former treasurer, J. Edward Odegaard. Though the Church is prohibited by the Manual from publishing membership figures, the number of branch churches in the United States has fallen steadily since World War II. In 2009, for the first time in church history, more new members came from Africa than the United States.
In 2005, The Boston Globe reported that the church was considering consolidating Boston operations into fewer buildings and leasing out space in buildings it owned. Church official Philip G. Davis noted that the administration and Colonnade buildings had not been fully used for many years and that vacancy increased after staff reductions in 2004. The church posted an $8 million financial loss in fiscal 2003, and in 2004 cut 125 jobs, a quarter of the staff, at the Christian Science Monitor. Conversely, Davis noted that "the financial situation right now is excellent" and stated that the church was not facing financial problems.
=== Use of spiritual healing in place of medical treatment ===
The use of prayer, often in place of medical treatment, has been an area of controversy since the founding of the church; and the legality of practicing Christian Science was raised as early as 1887, when some Christian Science practitioners were charged with practicing medicine without a license. Avoidance of medical care is not a doctrinal obligation and is considered a personal choice. However, during the 1980s and 1990s in the United States, a number of Christian Scientist parents whose children died from lack of access to medical treatment were the subject of considerable controversy and were charged with manslaughter or even murder, but the outcomes of the cases were inconsistent. The lack of consensus regarding medical care is reflected in the laws of various U.S. states, which have also been inconsistent regarding religious exemptions from medical care.
|
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"faith healing",
"ailment",
"Nontrinitarianism",
"Mary Baker Eddy",
"Boston"
] |
6,466 |
Connecticut
|
{{Infobox U.S. state
| name = Connecticut
| image_flag = Flag of Connecticut.svg
| image_seal = Seal of Connecticut.svg
| flag_link = Flag of Connecticut
| image_map = Connecticut in United States (zoom).svg
| nickname =
| motto = {{plainlist|
(Latin)
He who transplanted still sustains
| LargestMetro = New York (combined)Greater Hartford (metro and urban)
| LargestCity = Bridgeport
| LargestCounty = Capitol (Hartford County)
| population_demonym = (colloquial)
Connecticuter
Connecticutian
| Governor =
| Lieutenant Governor =
| Legislature = General Assembly
| Upperhouse = Senate
| Lowerhouse = House of Representatives
| Judiciary = Connecticut Supreme Court
| Senators =
| Representative = 5 Democrats
| postal_code = CT
| OfficialLang = None
| area_rank = 48th
| area_total_km2 = 14,356
| area_total_sq_mi = 5,543
| area_land_km2 = 12,559
| area_land_sq_mi = 4,849
| area_water_km2 = 1,809
| area_water_sq_mi = 698
| area_water_percent = 12.6
| population_rank = 29th
| population_as_of = 2024
| 2010Pop = 3,675,069
| population_density_rank = 4th
| 2020Density = 288
| 2020DensityUS = 745
| MedianHouseholdIncome = $ (2023)
| IncomeRank = 10th
| AdmittanceOrder = 5th
| AdmittanceDate = January 9, 1788
| timezone1 = Eastern
| utc_offset1 = −05:00
| timezone1_DST = EDT
| utc_offset1_DST = −04:00
| Longitude = 71°47′ W to 73°44′ W
| Latitude = 40°58′ N to 42°03′ N
| width_km = 177
| width_mi = 110
| length_km = 113
| length_mi = 70
| elevation_max_point = Massachusetts border on south slope of Mount Frissell
| elevation_max_m = 725
| elevation_max_ft = 2,379
| elevation_m = 150
| elevation_ft = 500
| elevation_min_point = Long Island Sound is a state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capital is Hartford, and its most populous city is Bridgeport. Connecticut lies between the major hubs of New York City and Boston along the Northeast Corridor, where the New York-Newark Combined Statistical Area, which includes four of Connecticut's seven largest cities, extends into the southwestern part of the state. Connecticut is the third-smallest state by area after Rhode Island and Delaware, and the 29th most populous with more than 3.6 million residents as of 2024, ranking it fourth among the most densely populated U.S. states.
The state is named after the Connecticut River, the longest in New England, which roughly bisects the state and drains into the Long Island Sound between the towns of Old Saybrook and Old Lyme. The name of the river is in turn derived from anglicized spellings of , a Mohegan-Pequot word for "long tidal river". Before the arrival of the first European settlers, the region was inhabited by various Algonquian tribes. In 1633, the Dutch West India Company established a small, short-lived settlement called House of Hope in Hartford. Half of Connecticut was initially claimed by the Dutch colony New Netherland, which included much of the land between the Connecticut and Delaware Rivers, although the first major settlements were established by the English around the same time. Thomas Hooker led a band of followers from the Massachusetts Bay Colony to form the Connecticut Colony, while other settlers from Massachusetts founded the Saybrook Colony and the New Haven Colony; both had merged into the first by 1664.
Connecticut's official nickname, the "Constitution State", refers to the Fundamental Orders adopted by the Connecticut Colony in 1639, which is considered by some to be the first written constitution in Western history. As one of the Thirteen Colonies that rejected British rule during the American Revolution, Connecticut was influential in the development of the federal government of the United States. In 1787, Roger Sherman and Oliver Ellsworth, state delegates to the Constitutional Convention, proposed a compromise between the Virginia and New Jersey Plans; its bicameral structure for Congress, with a respectively proportional and equal representation of the states in the House of Representatives and Senate, was adopted and remains to this day. In January 1788, Connecticut became the fifth state to ratify the Constitution.
Connecticut is a developed and affluent state, performing well on the Human Development Index and on different metrics of income except for equality. It is home to a number of prestigious educational institutions, including Yale University in New Haven, as well as other liberal arts colleges and private boarding schools in and around the "Knowledge Corridor". Due to its geography, Connecticut has maintained a strong maritime tradition; the United States Coast Guard Academy is located in New London by the Thames River. The state is also associated with the aerospace industry through major companies Pratt & Whitney and Sikorsky Aircraft headquartered in East Hartford and Stratford, respectively. Historically a manufacturing center for arms, hardware, and timepieces, Connecticut, as with the rest of the region, had transitioned into an economy based on the financial, insurance, and real estate sectors; many multinational firms providing such services can be found concentrated in the state capital of Hartford and along the Gold Coast in Fairfield County.
==History==
===First people===
The name Connecticut is derived from the Mohegan-Pequot word that has been translated as "long tidal river" and "upon the long river", both referring to the Connecticut River. Evidence of human presence in the Connecticut region dates to as far back as 10,000 years ago. Stone tools were used for hunting, fishing, and woodworking. Semi-nomadic in lifestyle, these peoples moved seasonally to take advantage of various resources in the area. They shared languages based on Algonquian. The Connecticut region was inhabited by many Native American tribes that can be grouped into the Nipmuc, the Sequin or "River Indians" (which included the Tunxis, Schaghticoke, Podunk, Wangunk, Hammonasset, and Quinnipiac), the Mattabesec or "Wappinger Confederacy" and the Pequot-Mohegan. Some of these groups still reside in Connecticut, including the Mohegans, the Pequots, and the Paugusetts.
===Colonial period===
Dutchman Adriaen Block was the first European explorer in Connecticut. He explored the region in 1614. Dutch fur traders then sailed up the Connecticut River, calling it Versche Rivier ("Fresh River") and building a fort at Dutch Point in Hartford, which they named "House of Hope" ().
The Connecticut Colony originally consisted of several smaller settlements in Windsor, Wethersfield, Saybrook, Hartford, and New Haven. The first English settlers came in 1633 and settled at Windsor, then at Wethersfield the following year. John Winthrop the Younger of Massachusetts received a commission to create Saybrook Colony at the mouth of the Connecticut River in 1635.
A large group of Puritans arrived in 1636 from Massachusetts Bay Colony, led by Thomas Hooker, who established the Connecticut Colony at Hartford. The Fundamental Orders of Connecticut were adopted in January 1639, and have been described as the first constitutional document in America.
The Quinnipiack Colony was established by John Davenport, Theophilus Eaton, and others at New Haven in March 1638. The New Haven Colony had its own constitution called "The Fundamental Agreement of the New Haven Colony", signed on June 4, 1639.
Each settlement was an independent political entity, established without official sanction of the English Crown. In 1662, Winthrop traveled to England and obtained a charter from CharlesII which united the settlements of Connecticut. Historically significant colonial settlements included Windsor (1633), Wethersfield (1634), Saybrook (1635), Hartford (1636), New Haven (1638), Fairfield (1639), Guilford (1639), Milford (1639), Stratford (1639), Farmington (1640), Stamford (1641), and New London (1646).
The Pequot War marked the first significant clash between colonists and Native Americans in New England. The Pequot had been aggressively extending their area of control at the expense of the Wampanoag to the north, Narragansett (east), Connecticut River Valley Algonquian tribes and the Mohegan (west), and Lenape Algonquian people (south). Meanwhile, the Pequot had been reacting with increasing aggression to colonial territorial expansion. In response to the 1636 murder of an English privateer and his crew, followed by the murder of a trader,
Connecticut's original Charter in 1662 granted it all the land to the "South Sea"—that is, to the Pacific Ocean. The Hartford Treaty with the Dutch was signed on September 19, 1650, but never ratified by the British, stated the western boundary of Connecticut ran north from Greenwich Bay for a distance of , "provided the said line come not within of Hudson River".
Yale College was established in 1701, providing Connecticut with an important institution to educate clergy and civil leaders. The Congregational church dominated religious life in the colony and, by extension, town affairs in many parts.
With more than of coastline including along its navigable rivers, Connecticut developed during its colonial years the antecedents of a maritime tradition that would later produce booms in shipbuilding, marine transport, naval support, seafood production, and leisure boating.
Historical records list the Tryall as the first vessel built in Connecticut Colony, in 1649 at a site on the Connecticut River in present-day Wethersfield. In the two decades leading up to 1776 and the American Revolution, Connecticut boatyards launched about 100 sloops, schooners and brigs according to a database of U.S. customs records maintained online by the Mystic Seaport Museum, the largest being the 180-ton Patient Mary launched in New Haven in 1763. Connecticut's first lighthouse was constructed in 1760 at the mouth of the Thames River with the New London Harbor Lighthouse.
====American Revolution====
Connecticut designated four delegates to the Second Continental Congress who signed the Declaration of Independence: Samuel Huntington, Roger Sherman, William Williams, and Oliver Wolcott. Connecticut's legislature authorized the outfitting of six new regiments in 1775, in the wake of the clashes between British regulars and Massachusetts militia at Lexington and Concord. There were some 1,200 Connecticut troops on hand at the Battle of Bunker Hill in June 1775. In 1775, David Bushnell invented the Turtle which the following year launched the first submarine attack in history, unsuccessfully against a British warship at anchor in New York Harbor.
In 1777, the British got word of Continental Army supplies in Danbury, and they landed an expeditionary force of some 2,000 troops in Westport. This force then marched to Danbury and destroyed homes and much of the depot. Continental Army troops and militia led by General David Wooster and General Benedict Arnold engaged them on their return march at Ridgefield in 1777. For the winter of 1778–79, General George Washington decided to split the Continental Army into three divisions encircling New York City, where British General Sir Henry Clinton had taken up winter quarters. Major General Israel Putnam chose Redding as the winter encampment quarters for some 3,000 regulars and militia under his command. The Redding encampment allowed Putnam's soldiers to guard the replenished supply depot in Danbury and to support any operations along Long Island Sound and the Hudson River Valley. Some of the men were veterans of the winter encampment at Valley Forge, Pennsylvania, the previous winter. Soldiers at the Redding camp endured supply shortages, cold temperatures, and significant snow, with some historians dubbing the encampment "Connecticut's Valley Forge".
The state was also the launching site for a number of raids against Long Island orchestrated by Samuel Holden Parsons and Benjamin Tallmadge, and provided soldiers and material for the war effort, especially to Washington's army outside New York City. General William Tryon raided the Connecticut coast in July 1779, focusing on New Haven, Norwalk, and Fairfield. New London and Groton Heights were raided in September 1781 by Benedict Arnold, who had turned traitor to the British.
At the outset of the American Revolution, the Continental Congress assigned Nathaniel Shaw Jr. of New London as its naval agent in charge of recruiting privateers to seize British vessels as opportunities presented, with nearly 50 operating out of the Thames River which eventually drew the reprisal from the British force led by Arnold.
=== Early statehood ===
====Early national period and industrial revolution====
Connecticut ratified the U.S. Constitution on January 9, 1788, becoming the fifth state. and fisheries. After Congress established in 1790 the predecessor to the U.S. Revenue Cutter Service that would evolve into the U.S. Coast Guard, President Washington assigned Jonathan Maltbie as one of seven masters to enforce customs regulations, with Maltbie monitoring the southern New England coast with a 48-foot cutter sloop named Argus.
In 1786, Connecticut ceded territory to the U.S. government that became part of the Northwest Territory. The state retained land extending across the northern part of present-day Ohio called the Connecticut Western Reserve. The Western Reserve section was settled largely by people from Connecticut, and they brought Connecticut place names to Ohio.
Connecticut made agreements with Pennsylvania and New York which extinguished the land claims within those states' boundaries and created the Connecticut Panhandle. The state then ceded the Western Reserve in 1800 to the federal government, The cessation of imports from Britain stimulated the construction of factories to manufacture textiles and machinery. Connecticut came to be recognized as a major center for manufacturing, due in part to the inventions of Eli Whitney and other early innovators of the Industrial Revolution.
The war led to the development of fast clippers that helped extend the reach of New England merchants to the Pacific and Indian oceans. The first half of the 19th century saw as well a rapid rise in whaling, with New London emerging as one of the New England industry's three biggest home ports after Nantucket and New Bedford.
The state was known for its political conservatism, typified by its Federalist party and the Yale College of Timothy Dwight. The foremost intellectuals were Dwight and Noah Webster, who compiled his great dictionary in New Haven. Religious tensions polarized the state, as the Congregational Church struggled to maintain traditional viewpoints, in alliance with the Federalists. The failure of the Hartford Convention in 1814 hurt the Federalist cause, with the Democratic-Republican Party gaining control in 1817.
Connecticut had been governed under the "Fundamental Orders" since 1639, but the state adopted a new constitution in 1818.
====Civil War era====
Connecticut manufacturers played a major role in supplying the Union forces with weapons and supplies during the Civil War. The state furnished 55,000 men, formed into thirty full regiments of infantry, including two in the U.S. Colored Troops, with several Connecticut men becoming generals. The Navy attracted 250 officers and 2,100 men, and Glastonbury native Gideon Welles was Secretary of the Navy. James H. Ward of Hartford was the first U.S. Naval Officer killed in the Civil War. Connecticut casualties included 2,088 killed in combat, 2,801 dying from disease, and 689 dying in Confederate prison camps.
A surge of national unity in 1861 brought thousands flocking to the colors from every town and city. However, as the war became a crusade to end slavery, many Democrats (especially Irish Catholics) pulled back. The Democrats took a pro-slavery position and included many Copperheads willing to let the South secede. The intensely fought 1863 election for governor was narrowly won by the Republicans.
====Second industrial revolution====
Connecticut's extensive industry, dense population, flat terrain, and wealth encouraged the construction of railroads starting in 1839. By 1840, of line were in operation, growing to in 1850 and in 1860.
The New York, New Haven and Hartford Railroad, called the New Haven or "The Consolidated", became the dominant Connecticut railroad company after 1872. J. P. Morgan began financing the major New England railroads in the 1890s, dividing territory so that they would not compete. The New Haven purchased 50 smaller companies, including steamship lines, and built a network of light rails (electrified trolleys) that provided inter-urban transportation for all of southern New England. By 1912, the New Haven operated over of track with 120,000 employees.
As steam-powered passenger ships proliferated after the Civil War, Noank would produce the two largest built in Connecticut during the 19th century, with the 332-foot wooden steam paddle wheeler Rhode Island launched in 1882, and the 345-foot paddle wheeler Connecticut seven years later. Connecticut shipyards would launch more than 165 steam-powered vessels in the 19th century.
===20th century===
====World War I====
When World War I broke out in 1914, Connecticut became a major supplier of weaponry to the U.S. military; by 1918, 80% of the state's industries were producing goods for the war effort. Remington Arms in Bridgeport produced half the small-arms cartridges used by the U.S. Army, with other major suppliers including Winchester in New Haven and Colt in Hartford.
Connecticut was also an important U.S. Navy supplier, with Electric Boat receiving orders for 85 submarines, Lake Torpedo Boat building more than 20 subs, and the Groton Iron Works building freighters. On June 21, 1916, the Navy made Groton the site for its East Coast submarine base and school.
The state enthusiastically supported the American war effort in 1917 and 1918 with large purchases of war bonds, a further expansion of industry, and an emphasis on increasing food production on the farms. Thousands of state, local, and volunteer groups mobilized for the war effort and were coordinated by the Connecticut State Council of Defense. Manufacturers wrestled with manpower shortages; Waterbury's American Brass and Manufacturing Company was running at half capacity, so the federal government agreed to furlough soldiers to work there.
====Interwar period====
In 1919, J. Henry Roraback started the Connecticut Light & Power Co. which became the state's dominant electric utility. In 1925, Frederick Rentschler spurred the creation of Pratt & Whitney in Hartford to develop engines for aircraft; the company became an important military supplier in World WarII and one of the three major manufacturers of jet engines in the world.
On September 21, 1938, the most destructive storm in New England history struck eastern Connecticut, killing hundreds of people. The eye of the "Long Island Express" passed just west of New Haven and devastated the Connecticut shoreline between Old Saybrook and Stonington from the full force of wind and waves, even though they had partial protection by Long Island. The hurricane caused extensive damage to infrastructure, homes, and businesses. In New London, a sailing ship was driven into a warehouse complex, causing a major fire. Heavy rainfall caused the Connecticut River to flood downtown Hartford and East Hartford. An estimated 50,000 trees fell onto roadways.
====World War II====
The advent of lend-lease in support of Britain helped lift Connecticut from the Great Depression, with the state a major production center for weaponry and supplies used in World WarII. Connecticut manufactured 4.1% of total U.S. military armaments produced during the war, ranking ninth among the 48 states, with major factories including Colt for firearms, Pratt & Whitney for aircraft engines, Chance Vought for fighter planes, Hamilton Standard for propellers, and Electric Boat for submarines and PT boats. In Bridgeport, General Electric produced a significant new weapon to combat tanks: the bazooka.
On May 13, 1940, Igor Sikorsky made an untethered flight of the first practical helicopter. The helicopter saw limited use in World War II, but future military production made Sikorsky Aircraft's Stratford plant Connecticut's largest single manufacturing site by the start of the 21st century.
====Post-World War II economic expansion====
Connecticut lost some wartime factories following the end of hostilities, but the state shared in a general post-war expansion that included the construction of highways and resulting in middle-class growth in suburban areas.
Prescott Bush represented Connecticut in the U.S. Senate from 1952 to 1963; his son George H. W. Bush and grandson George W. Bush both became presidents of the United States. In 1965, Connecticut ratified its current constitution, replacing the document that had served since 1818.
In 1968, commercial operation began for the Connecticut Yankee Nuclear Power Plant in Haddam; in 1970, the Millstone Nuclear Power Station began operations in Waterford. In 1974, Connecticut elected Democratic Governor Ella T. Grasso, who became the first woman in any state to be elected governor without being the wife or widow of a previous governor.
====Late 20th century====
Connecticut's dependence on the defense industry posed an economic challenge at the end of the Cold War. The resulting budget crisis helped elect Lowell Weicker as governor on a third-party ticket in 1990. Weicker's remedy was a state income tax which proved effective in balancing the budget, but only for the short-term. He did not run for a second term, in part because of this politically unpopular move.
In 1992, initial construction was completed on Foxwoods Casino at the Mashantucket Pequots reservation in eastern Connecticut, which became the largest casino in the Western Hemisphere. Mohegan Sun followed four years later.
===Early 21st century===
In 2000, presidential candidate Al Gore chose Senator Joe Lieberman as his running mate, marking the first time that a major party presidential ticket included someone of the Jewish faith. Gore and Lieberman fell five votes short of George W. Bush and Dick Cheney in the Electoral College. In the terrorist attacks of September 11, 2001, 65 state residents were killed, mostly Fairfield County residents who were working in the World Trade Center. In 2004, Republican Governor John G. Rowland resigned during a corruption investigation, later pleading guilty to federal charges.
Connecticut was hit by three major storms in just over 14 months in 2011 and 2012, with all three causing extensive property damage and electric outages. Hurricane Irene struck Connecticut August 28, and damage totaled $235 million. Two months later, the "Halloween nor'easter" dropped extensive snow onto trees, resulting in snapped branches and trunks that damaged power lines; some areas were without electricity for 11 days. Hurricane Sandy hit New Jersey and passed over Connecticut with hurricane-force winds and tides up to 12 feet above normal. Many coastal buildings were damaged or destroyed. Sandy's winds drove storm surges into streets and cut power to 98% of homes and businesses, with more than $360 million in damage.
On December 14, 2012, Adam Lanza shot and killed 26 people at Sandy Hook Elementary School in Newtown, and then killed himself. The massacre spurred renewed efforts by activists for tighter laws on gun ownership nationally.
In the summer and fall of 2016, Connecticut experienced a drought in many parts of the state, causing some water-use bans. As of , 45% of the state was listed at Severe Drought by the U.S. Drought Monitor, including almost all of Hartford and Litchfield counties. All the rest of the state was in Moderate Drought or Severe Drought, including Middlesex, Fairfield, New London, New Haven, Windham, and Tolland counties. This affected the agricultural economy in the state.
==Geography==
Connecticut is bordered on the south by Long Island Sound, on the west by New York, on the north by Massachusetts, and on the east by Rhode Island. The state capital and fourth largest city is Hartford, and other major cities and towns (by population) include Bridgeport, New Haven, Stamford, Waterbury, Norwalk, Danbury, New Britain, Greenwich, and Bristol. There are 169 incorporated towns in Connecticut, with cities and villages included within some towns.
The highest peak in Connecticut is Bear Mountain in Salisbury in the northwest corner of the state. The highest point is just east of where Connecticut, Massachusetts, and New York meet (42°3′ N, 73°29′ W), on the southern slope of Mount Frissell, whose peak lies nearby in Massachusetts. At the opposite extreme, many of the coastal towns have areas that are less than above sea level.
Connecticut has a long maritime history and a reputation based on that history—yet the state has no direct oceanfront (technically speaking). The coast of Connecticut sits on Long Island Sound, which is an estuary. The state's access to the open Atlantic Ocean is both to the west (toward New York City) and to the east (toward the "race" near Rhode Island). Due to this unique geography, Long Island Sound and the Connecticut shoreline are relatively protected from high waves from storms.
The Connecticut River cuts through the center of the state, flowing into Long Island Sound. The most populous metropolitan region centered within the state lies in the Connecticut River Valley. Despite Connecticut's relatively small size, it features wide regional variations in its landscape; for example, in the northwestern Litchfield Hills, it features rolling mountains and horse farms, whereas in areas to the east of New Haven along the coast, the landscape features coastal marshes, beaches, and large scale maritime activities.
Connecticut's rural areas and small towns in the northeast and northwest corners of the state contrast sharply with its industrial cities such as Stamford, Bridgeport, and New Haven, located along the coastal highways from the New York border to New London, then northward up the Connecticut River to Hartford. Many towns in northeastern and northwestern Connecticut center around a green. Near the green typically stand historical visual symbols of New England towns, such as a white church, a colonial meeting house, a colonial tavern or inn, several colonial houses, and so on, establishing a scenic historical appearance maintained for both historic preservation and tourism. Many of the areas in southern and coastal Connecticut have been built up and rebuilt over the years, and look less visually like traditional New England.
The northern boundary of the state with Massachusetts is marked by the Southwick Jog or Granby Notch, an approximately square detour into Connecticut. The origin of this anomaly is clearly established in a long line of disputes and temporary agreements which were finally concluded in 1804, when southern Southwick's residents sought to leave Massachusetts, and the town was split in half.
The southwestern border of Connecticut where it abuts New York State is marked by a panhandle in Fairfield County and the Western Connecticut Planning Region, containing the towns of Greenwich, Stamford, New Canaan, Darien, and parts of Norwalk and Wilton. This irregularity in the boundary is the result of territorial disputes in the late 17th century, culminating with New York giving up its claim to the area, whose residents considered themselves part of Connecticut, in exchange for an equivalent area extending northwards from Ridgefield to the Massachusetts border, as well as undisputed claim to Rye, New York.
Areas maintained by the National Park Service include Appalachian National Scenic Trail, Quinebaug and Shetucket Rivers Valley National Heritage Corridor, and Weir Farm National Historic Site.
===Climate===
Connecticut lies at the rough transition zone between the southern end of the humid continental climate, and the northern portion of the humid subtropical climate. Northern Connecticut generally experiences a climate with hot, humid summers and moderataely cold winters with periodic snowfall. Far southern and coastal Connecticut has a climate with cool winters with a mix of rain and infrequent snow, and the long hot and humid summers typical of the middle and lower East Coast.
==== Precipitation ====
Connecticut sees a fairly even precipitation pattern with rainfall/snowfall spread throughout the 12 months. Connecticut averages 56% of possible sunshine (higher than the U.S. national average), averaging 2,400 hours of sunshine annually. Although summers are sunny in Connecticut, quick moving summer thunderstorms can bring brief downpours with thunder and lightning. Occasionally these thunderstorms can be severe, and the state usually averages one tornado per year. During hurricane season, the remains of tropical cyclones occasionally affect the region, though a direct hit is rare. Some notable hurricanes to impact the state include the 1938 New England hurricane, Hurricane Carol in 1954, Hurricane Sandy in 2012, and Hurricane Isaias in 2020.
Weather commonly associated with the fall season typically begins in October and lasts to the first days of December. Daily high temperatures in October and November range from the 50s to 60s F. Winters (December through mid-March) are moderately generally cold from south to north in Connecticut. The coldest month (January) has average high temperatures ranging from in the coastal lowlands to in the inland and northern portions on the state. The lowest temperature recorded in Connecticut is which has been observed twice: in Falls Village on February 16, 1943, and in Coventry on January 22, 1961. Although rare, Ice storms also occur on occasion, such as the Southern New England ice storm of 1973.
===Flora===
Forests consist of a mix of Northeastern coastal forests of oak in southern areas of the state, to the upland New England-Acadian forests in the northwestern parts of the state. Mountain Laurel (Kalmia latifolia) is the state flower and is native to low ridges in several parts of Connecticut. Rosebay rhododendron (Rhododendron maximum) is also native to eastern uplands of Connecticut and Pachaug State Forest is home to the Rhododendron Sanctuary Trail. Atlantic white cedar (Chamaecyparis thyoides), is found in wetlands in the southern parts of the state. Connecticut has one native cactus (Opuntia humifusa), found in sandy coastal areas and low hillsides. Several types of beach grasses and wildflowers are also native to Connecticut. Connecticut spans USDA Plant Hardiness Zones 5b to 7a. Coastal Connecticut is the broad transition zone where more southern and subtropical plants are cultivated.
===Fauna===
=== Largest cities and towns ===
==Demographics==
As of the 2020 United States census, Connecticut has a population of 3,605,944, an increase of 31,847 people (0.9%) from the 2010 United States census. Among the census records, 20.4% of the population was under 18.
In 1790, 97% of the population in Connecticut was classified as "rural". The first census in which less than half the population was classified as rural was 1890. In the 2000 census, only 12.3% was considered rural. Most of western and southern Connecticut (particularly the Gold Coast) is strongly associated with New York City; this area is the most affluent and populous region of the state and has high property costs and high incomes. The center of population of Connecticut is located in the town of Cheshire.
According to HUD's 2022 Annual Homeless Assessment Report, there were an estimated 2,930 homeless people in Connecticut.
In common with the majority of the United States, non-Hispanic whites have remained the dominant racial and ethnic group in Connecticut. From being 98% of the population in 1940, however, they have declined to 63% of the population as of the 2020 census. These statistics have represented fewer Americans identifying as non-Hispanic white, which has given rise to the Hispanic and Latino American population and Asian American population overall. , 46.1% of Connecticut's population younger than age1 were minorities. As of 2004, 11.4% of the population (400,000) was foreign-born. In 1870, native-born Americans had accounted for 75% of the state's population, but that had dropped to 35% by 1918. Also as of 2000, 81.69% of Connecticut residents age5 and older spoke English at home and 8.42% spoke Spanish, followed by Italian at 1.59%, French at 1.31%, and Polish at 1.20%.
The largest ancestry groups since 2010 were: 19.3% Italian, 17.9% Irish, 10.7% English, 10.4% German, 8.6% Polish, 6.6% French, 3.0% French Canadian, 2.7% American, 2.0% Scottish, and 1.4% Scotch Irish.
The top countries of origin for Connecticut's immigrants in 2018 were India, Jamaica, the Dominican Republic, Poland and Ecuador.
===Birth data===
Note: Births in table do not add up because Hispanics are counted both by their ethnicity and by their race, giving a higher overall number.
{{bar box
|title = Religion in Connecticut (2014) Protestant 35%, Roman Catholic 33%, non-religious 28%, Jewish 3%, Mormonism 1%, Orthodox 1%, Jehovah's Witness 1%, Hinduism 1%, Buddhism 1% and Islam 1%. Jewish congregations had 108,280 (3.2%) members in 2000.
The Jewish population is concentrated in the towns near Long Island Sound between Greenwich and New Haven, in Greater New Haven and in Greater Hartford, especially the suburb of West Hartford. According to the Association of Religion Data Archives, the largest Christian denominations, by number of adherents, in 2010 were: the Catholic Church, with 1,252,936; the United Church of Christ, with 96,506; and non-denominational Evangelical Protestants, with 72,863. It found the state to be 21% non-religious and specifically 19% white mainline Protestant, 19% white Catholic, 9% white evangelical Protestant, 7% black Protestant, and 7% Hispanic Catholic. In contrast to the 2014 Pew survey, the 2020 PRRI survey found Connecticut to be 40% Protestant and 28% Catholic (with the remainder of Christians being Mormon at 2%, and Orthodox at 1%). The PRRI survey found Jewish citizens to be 2% of the population and, like the Pew survey: Hindus, Buddhists, and Muslims to be 1% each.
== Economy ==
The total 2023 gross state product for Connecticut was $345.9 billion, up from $321.7 billion in 2022.
Connecticut's adjusted per capita personal income in 2022 was estimated at $77,940, third-highest among states. There is a large disparity in incomes throughout the state; Connecticut was tied with California and Massachusetts for the second highest (after New York's 0.52) Gini coefficient, at 0.50, as of 2020. According to a 2018 study by Phoenix Marketing International, Connecticut had the third-largest number of millionaires per capita in the United States, with a ratio of 7.75%. New Canaan is the wealthiest town in Connecticut, with a per capita income of $105,846. Hartford is the poorest municipality in Connecticut, with a per capita income of $16,798 in 2020. At the county level, per capita income ranged from $48,295 in Fairfield County to $26,585 in Windham County, which is close to the United States average. but economists expected record new levels of layoffs as a result of business closures in the spring of 2020 due to the coronavirus pandemic.
===Taxation===
Tax is collected by the Connecticut Department of Revenue Services and by local municipalities.
As of 2012, Connecticut residents had the second highest rate in the nation of combined state and local taxes after New York, at 12.6% of income compared to the national average of 9.9% as reported by the Tax Foundation.
Before 1991, Connecticut had an investment-only income tax system. Income from employment was untaxed, but income from investments was taxed at 13%, the highest rate in the U.S., with no deductions allowed for costs of producing the investment income, such as interest on borrowing.
In 1991, under Governor Lowell P. Weicker Jr., an independent, the system was changed to one in which the taxes on employment income and investment income were equalized at a maximum rate of 4%. The new tax policy drew investment firms to Connecticut; , Fairfield County was home to the headquarters for 16 of the 200 largest hedge funds in the world.
, the income tax rates on Connecticut individuals were divided into seven tax brackets of 3% (on income up to $10,000); 5% ($10,000–$50,000); 5.5% ($50,000–$100,000); 6% ($100,000–$200,000); 6.5% ($200,000–$250,000); 6.9% ($250,000–$500,000); and 6.99% above $500,000, with additional amounts owed depending on the bracket.
All wages of Connecticut residents are subject to the state's income tax, even if earned outside the state. However, in those cases, Connecticut income tax must be withheld only to the extent the Connecticut tax exceeds the amount withheld by the other jurisdiction. Since New York has higher income tax rates than Connecticut, this effectively means that Connecticut residents who work in New York have no Connecticut income tax withheld. Connecticut permits a credit for taxes paid to other jurisdictions, but since residents who work in other states are still subject to Connecticut income taxation, they may owe taxes if the jurisdictional credit does not fully offset the Connecticut tax amount. Some items and services in general are not subject to sales and use taxes unless specifically enumerated as taxable by statute. A provision excluding clothing under $50 from sales tax was repealed .
State law authorizes municipalities to tax property, including real estate, vehicles and other personal property, with state statute providing varying exemptions, credits and abatements. All assessments are at 70% of fair market value. and any excess may not be refunded or carried forward. According to the Tax Foundation, on a per capita basis in the 2017 fiscal year Connecticut residents paid the 3rd highest average property taxes in the nation after New Hampshire and New Jersey.
, gasoline taxes and fees in Connecticut were 40.13 cents per gallon, 11th highest in the United States which had a nationwide average of 36.13 cents a gallon excluding federal taxes. Diesel taxes and fees as of January 2020 in Connecticut were 46.50 cents per gallon, ninth highest nationally with the U.S. average at 37.91 cents.
===Real estate===
In 2019, sales of single-family homes in Connecticut totaled 33,146 units, a 2.1 percent decline from the 2018 transaction total. The median home sold in 2019 recorded a transaction amount of $260,000, up 0.4 percent from 2018.
Connecticut had the seventh highest rate of home foreclosure activity in the country in 2019 at 0.53 percent of the total housing stock.
===Industries===
Finance, insurance and real estate was Connecticut's largest industry in 2018 as ranked by gross domestic product, generating $75.7 billion in GDP that year. Major employers include The Hartford, Travelers, Harman International, Cigna, the Aetna subsidiary of CVS Health, Mass Mutual, People's United Financial, Bank of America, Realogy, Bridgewater Associates, GE Capital, William Raveis Real Estate, and Berkshire Hathaway through reinsurance and residential real estate subsidiaries.
The combined educational, health and social services sector was the largest single industry as ranked by employment, with a combined workforce of 342,600 people at the end of 2019, ranking fourth the year before in GDP at $28.3 billion.
The broad business and professional services sector had the second highest GDP total in Connecticut in 2018 at an estimated $33.7 billion. Lockheed Martin subsidiary Sikorsky Aircraft operates Connecticut's single largest manufacturing plant in Stratford,
Other major manufacturers include the Electric Boat division of General Dynamics, which makes submarines in Groton, Boehringer Ingelheim, a pharmaceuticals manufacturer with its U.S. headquarters in Ridgefield,
Connecticut historically was a center of gun manufacturing, and four gun-manufacturing firms continued to operate in the state , employing 2,000 people: Colt, Stag, Ruger, and Mossberg. Marlin, owned by Remington, closed in April 2011.
Other large components of the Connecticut economy in 2018 included wholesale trade ($18.1 billion in GDP); information services ($13.8 billion); retail ($13.7 billion); arts, entertainment and food services ($9.1 billion); and construction ($8.3 billion). Foxwoods Resort Casino and Mohegan Sun are the two biggest tourist draws and number among the state's largest employers; both are located on Native American reservations in the southeastern Connecticut.
Connecticut's agricultural production totaled $580 million in 2017, with just over half of that revenue the result of nursery stock production. Milk production totaled $81 million that year, with other major product categories including eggs, vegetables and fruit, tobacco and shellfish.
===Energy===
Connecticut's economy uses less energy to produce each dollar of GDP than all other states except California, Massachusetts, and New York. It uses less energy on a per-capita basis than all but six other states. It has no fossil-fuel resources, but does have renewable resources. Average retail electricity prices are the highest among the 48 contiguous states. While most of the state's energy consumption is generated using fossil fuels, nuclear power delivered over 40% of state's electricity generation in 2019. Refuse-derived fuels and other biomass provided the largest share of renewable electricity at about a 3% share. Solar and wind generation have grown in recent years. More than three-quarters of solar generation came from distributed small-scale installations such as rooftop solar in 2019, and there is planning underway to significantly increase renewable generation with the state's offshore wind resource.
==Transport==
===Roads===
The Interstate highways in the state are Interstate 95 (I-95) traveling southwest to northeast along the coast, I-84 traveling southwest to northeast in the center of the state, I-91 traveling north to south in the center of the state, and I-395 traveling north to south near the eastern border of the state. The other major highways in Connecticut are the Merritt Parkway and Wilbur Cross Parkway, which together form Connecticut Route 15 (Route 15), traveling from the Hutchinson River Parkway in New York parallel to I-95 before turning north of New Haven and traveling parallel to I-91, finally becoming a surface road in Berlin. I-95 and Route 15 were originally toll roads; they relied on a system of toll plazas at which all traffic stopped and paid fixed tolls. A series of major crashes at these plazas eventually contributed to the decision to remove the tolls in 1988. Other major arteries in the state include U.S. Route7 (US7) in the west traveling parallel to the New York state line, Route8 farther east near the industrial city of Waterbury and traveling north–south along the Naugatuck River Valley nearly parallel with US7, and Route9 in the east.
Between New Haven and New York City, I-95 is one of the most congested highways in the United States. Although I-95 has been widened in several spots, some areas are only three lanes and this strains traffic capacity, resulting in frequent and lengthy rush hour delays. Frequently, the congestion spills over to clog the parallel Merritt Parkway and even US1. The state has encouraged traffic reduction schemes, including rail use and ride-sharing.
Connecticut also has a very active bicycling community, with one of the highest rates of bicycle ownership and use in the United States, particularly in New Haven. According to the U.S. Census 2006 American Community Survey, New Haven has the highest percentage of commuters who bicycle to work of any major metropolitan center on the East Coast.
===Rail===
Rail is a popular travel mode between New Haven and New York City's Grand Central Terminal. Southwestern Connecticut is served by the Metro-North Railroad's New Haven Line, operated by the Metropolitan Transportation Authority. Metro-North provides commuter service between New York City and New Haven, with branches to New Canaan, Danbury, and Waterbury. Connecticut lies along Amtrak's Northeast Corridor, which features frequent Northeast Regional and Acela Express service from New Haven south to New York City, Philadelphia, Baltimore, Washington, DC, and Norfolk, VA, as well as north to New London, Providence and Boston. Since 1990, coastal cities and towns between New Haven and New London are also served by the Shore Line East commuter line.
In June 2018, a commuter rail service called the Hartford Line began operating between New Haven and Springfield on Amtrak's New Haven-Springfield Line. Hartford Line service is provided by both Amtrak and the Connecticut Department of Transportation's CT Rail, and in addition to its termini serves New Haven State Street, Wallingford, Meriden, Berlin, Hartford, Windsor, and Windsor Locks. Several infill stations are planned to be added in the near future as of 2021. Amtrak's Vermonter runs from Washington to St. Albans, Vermont via the same line. In July 2019, Amtrak launched the Valley Flyer, which runs between New Haven and Greenfield, Massachusetts.
A proposed commuter rail service, the Central Corridor Rail Line, would connect New London with Norwich, Willimantic, Storrs via the main campus of the University of Connecticut, and Stafford Springs, with service continuing into Massachusetts and Brattleboro, Vermont. The proposal also adds stops to service popular tourist destinations Foxwoods Resort Casino and Mohegan Sun.
===Bus===
Statewide bus service is supplied by Connecticut Transit, owned by the Connecticut Department of Transportation, with smaller municipal authorities providing local service. Bus networks are an important part of the transportation system in Connecticut, especially in urban areas like Hartford, Stamford, Norwalk, Bridgeport and New Haven. Connecticut Transit also operates CTfastrak, a bus rapid transit service between New Britain and Hartford, which opened to the public on March 28, 2015.
===Air===
Connecticut's largest airport is Bradley International Airport in Windsor Locks, north of Hartford. Many residents of central and southern Connecticut also make heavy use of JFK International Airport and Newark International Airports, especially for international travel. Smaller regional air service is provided at Tweed New Haven Regional Airport. Larger civil airports include Danbury Municipal Airport and Waterbury-Oxford Airport in western Connecticut, Hartford–Brainard Airport in central Connecticut, and Groton-New London Airport in eastern Connecticut. Sikorsky Memorial Airport is located in Stratford and mostly services cargo, helicopter and private aviation.
===Ferry===
Several ferry services cross Long Island Sound and connect the state to Long Island. The Bridgeport & Port Jefferson Ferry travels between Bridgeport, Connecticut, and Port Jefferson, New York. Ferry service also operates out of New London to Orient, New York; Fishers Island, New York; and Block Island, Rhode Island, which are popular tourist destinations. and Susan Bysiewicz is the Lieutenant Governor; both are Democrats. From 1639 until the adoption of the 1818 constitution, the governor presided over the General Assembly. In 1974, Ella Grasso was elected as the governor of Connecticut. This was the first time in United States history when a woman was a governor without her husband being governor first.
In addition to the governor and lieutenant governor, there are four other executive officers named in the state constitution that are elected directly by voters: secretary of the state, treasurer, comptroller, and attorney general. All executive officers are elected to four-year terms. , Matthew Ritter is the Speaker of the House of Connecticut.
, Connecticut's United States Senators are Richard Blumenthal (Democrat) and Chris Murphy (Democrat). Connecticut has five representatives in the U.S. House, all of whom are Democrats.
Locally elected representatives also develop local ordinances to govern cities and towns. The town ordinances often include noise control and zoning guidelines. However, the State of Connecticut also provides statewide ordinances for noise control as well.
===Judicial===
The highest court of Connecticut's judicial branch is the Connecticut Supreme Court, headed by the Chief Justice of Connecticut. The Supreme Court is responsible for deciding on the constitutionality of laws, or cases as they relate to the law. Its proceedings are similar to those of the United States Supreme Court: no testimony is given by witnesses, and the lawyers of the two sides each present oral arguments no longer than thirty minutes. Following a court proceeding, the court may take several months to arrive at a judgment. , the Chief Justice is Richard A. Robinson.
In 1818, the court became a separate entity, independent of the legislative and executive branches. The Connecticut Appellate Court is a lesser statewide court, and the Superior Courts are lower courts that resemble county courts of other states.
===Local government===
Connecticut does not have county government, unlike all other states except Rhode Island. Connecticut county governments were mostly eliminated in 1960, with the exception of sheriffs elected in each county. In 2000, the county sheriff was abolished and replaced with the state marshal system, which has districts that follow the old county territories. The judicial system is divided into judicial districts at the trial-court level which largely follow the old county lines. The eight counties are still widely used for purely geographical and statistical purposes, such as weather reports and census reporting, although the latter will cease using the counties in 2024.
The state is divided into nine regional councils of government defined by the state Office of Planning and Management, which facilitate regional planning and coordination of services between member towns. The Intragovernmental Policy Division of this Office coordinates regional planning with the administrative bodies of these regions. Each region has an administrative body made up chief executive officers of the member towns. The regions are established for the purpose of planning "coordination of regional and state planning activities; redesignation of logical planning regions and promotion of the continuation of regional planning organizations within the state; and provision for technical aid and the administration of financial assistance to regional planning organizations". This proposal was approved by the Census Bureau in 2022, and will be fully implemented by 2024.
Connecticut shares with the rest of New England a governmental institution called the New England town. The state is divided into 169 towns which serve as the fundamental political jurisdictions. Naugatuck is a consolidated town and borough.
==Politics==
Connecticut is a blue state. As of 2024, both of its U.S. Senators, all five of its U.S. House representatives, as well as its Governor, Lt. Governor, Attorney General, and Secretary of State, are members of the Democratic Party. The last Republican presidential candidate to win Connecticut's votes in the Electoral College was George H. W. Bush in 1988.
===Registered voters===
Connecticut residents who register to vote may declare an affiliation to a political party, may become unaffiliated at will, and may change affiliations subject to certain waiting periods. , around 58% of registered voters are enrolled in a political party. The Democratic Party of Connecticut is the largest party in the state by voter registration, with 36% of voters, followed by the Connecticut Republican Party with approximately 21%. An additional 1.6% are registered to third parties. As of 2022, 4 third parties have statewide enrollment privileges (meaning any state resident may register as a member), including the Libertarian Party of Connecticut, the Independent Party of Connecticut, the Connecticut Green Party, and the Connecticut Working Families Party. Connecticut allows electoral fusion, where the same candidate can run on the ballot of more than one political party; this is often used by the Connecticut Working Families Party to cross-endorse Democratic candidates.
===Voting===
In July 2009, the Connecticut legislature overrode a veto by Governor M. Jodi Rell to pass SustiNet, the first significant public-option health care reform legislation in the nation.
In April 2012, both houses of the Connecticut state legislature passed a bill (20 to 16 and 86 to 62) that abolished capital punishment for all future crimes, while 11 inmates who were waiting on the death row at the time could still be executed.
==Education==
Connecticut ranked third in the nation for educational performance, according to Education Week's Quality Counts 2018 report. It earned an overall score of 83.5 out of 100 points. On average, the country received a score of 75.2. Connecticut posted a B-plus in the Chance-for-Success category, ranking fourth on factors that contribute to a person's success both within and outside the K-12 education system. Connecticut received a mark of B-plus and finished fourth for School Finance. It ranked 12th with a grade of C on the K-12 Achievement Index.
Notable private schools include Choate Rosemary Hall, The Hotchkiss School, Loomis Chaffee School, and Taft School.
===Colleges and universities===
Connecticut was home to the nation's first law school, Litchfield Law School, which operated from 1773 to 1833 in Litchfield. Well known universities in the state include Yale University, Wesleyan University, Trinity College, Sacred Heart University, Fairfield University, Quinnipiac University, and the University of Connecticut. The Connecticut State University System includes 4 state universities, and the state also has 12 community colleges. The United States Coast Guard Academy is located in New London.
==Sports==
There are two Connecticut teams in the American Hockey League. The Bridgeport Islanders is a farm team for the New York Islanders which competes at the Total Mortgage Arena in Bridgeport. The Hartford Wolf Pack is an affiliate of the New York Rangers; they play in the XL Center in Hartford.
The Hartford Yard Goats of the Double-A Northeast are a AA affiliate of the Colorado Rockies. Also, the Norwich Sea Unicorns play in the Futures Collegiate Baseball League. The New Britain Bees play in the Atlantic League of Professional Baseball. The Connecticut Sun of the WNBA currently play at the Mohegan Sun Arena in Uncasville. In soccer, Hartford Athletic began play in the USL Championship in 2019.
The state hosts several major sporting events. Since 1952, a PGA Tour golf tournament has been played in the Hartford area. It was originally called the "Insurance City Open" and later the "Greater Hartford Open" and is now known as the Travelers Championship.
Lime Rock Park in Salisbury is a road racing course, home to the International Motor Sports Association, SCCA, United States Auto Club, and K&N Pro Series East races. Thompson International Speedway, Stafford Motor Speedway, and Waterford Speedbowl are oval tracks holding weekly races for NASCAR Modifieds and other classes, including the NASCAR Whelen Modified Tour. The state also hosts several major mixed martial arts events for Bellator MMA and the Ultimate Fighting Championship.
===Professional sports teams===
The Hartford Whalers of the National Hockey League played in Hartford from 1975 to 1997 at the Hartford Civic Center. They departed to Raleigh, North Carolina, after disputes with the state over the construction of a new arena, and they are now known as the Carolina Hurricanes. A baseball team known as the Hartfords (or Hartford Dark Blues) played in the National Association from 1874 to 1875, before becoming charter members of the National League in 1876. The team moved to Brooklyn, New York, and then disbanded one season later. In 1926, Hartford also had a franchise in the National Football League known as the Hartford Blues. From 2000 until 2006 the city was home to the Hartford FoxForce of World TeamTennis.
===College sports===
The Connecticut Huskies are the team of the University of Connecticut (UConn); they play NCAA Division I sports. Both the men's basketball and women's basketball teams have won multiple national championships. In 2004, UConn became the first school in NCAA DivisionI history to have its men's and women's basketball programs win the national title in the same year; they repeated the feat in 2014 and are still the only DivisionI school to win both titles in the same year. The UConn women's basketball team holds the record for the longest consecutive winning streak in NCAA college basketball at 111 games, a streak that ended in 2017. Both teams play in the historic Harry A. Gampel Pavilion and XL Center in Hartford. The UConn Huskies football team has played in the Football Bowl Subdivision since 2002, and has played in four bowl games.
New Haven biennially hosts "The Game" between the Yale Bulldogs and the Harvard Crimson, the country's second-oldest college football rivalry. Yale alumnus Walter Camp is deemed the "Father of American Football", and he helped develop modern football while living in New Haven. Other Connecticut universities which feature DivisionI sports teams are Quinnipiac University, Fairfield University, Central Connecticut State University and Sacred Heart University.
==Etymology and symbols==
The name "Connecticut" originated with the Mohegan word quonehtacut, meaning "place of long tidal river". Connecticut's official nickname is "The Constitution State", adopted in 1959 and based on its colonial constitution of 1638–1639 which was the first in America and, arguably, the world. Connecticut is also unofficially known as "The Nutmeg State", "Nutmegger" is sometimes used, as is "Yankee".
The official state song is "Yankee Doodle". The traditional abbreviation of the state's name is "Conn."; the official postal abbreviation is CT.
Commemorative stamps issued by the United States Postal Service with Connecticut themes include Nathan Hale, Eugene O'Neill, Josiah Willard Gibbs, Noah Webster, Eli Whitney, the whaling ship the Charles W. Morgan, which is docked at Mystic Seaport, and a decoy of a broadbill duck.
File:Charter Oak in Hartford CT.jpg|The Charter Oak
File:SS-571-Nautilus-trials.gif|The
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"Oxford University Press",
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"Football Bowl Subdivision",
"Westmoreland County, Connecticut",
"Bridgeport & Port Jefferson Ferry",
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"Vought",
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"sloop",
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"Mormon",
"center of population",
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"2011 Halloween nor'easter",
"Connecticut Supreme Court",
"Adriaen Block",
"New Haven Line",
"M. Jodi Rell",
"Groton-New London Airport",
"Independent school",
"Protestant",
"Councils of governments in Connecticut",
"Union (American Civil War)",
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"sales tax",
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"Connecticut House of Representatives",
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"Connecticut Route 15",
"Interstate 395 in Connecticut",
"New London County, Connecticut",
"Tweed New Haven Regional Airport",
"inn",
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"Metro-North Railroad",
"Berkshire Hathaway",
"Outline of Connecticut",
"USRC Argus",
"Connecticut Compromise",
"Raleigh, North Carolina",
"Orient, New York",
"Fairfield County, Connecticut",
"United States Auto Club",
"noise pollution",
"Democratic Party of Connecticut",
"Winsted, Connecticut",
"Hartford Public High School",
"WNBA",
"John Davenport (clergyman)",
"clipper",
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"Roger Sherman",
"Prudence Crandall",
"African Americans",
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"Buddhism",
"Travelers Championship",
"humid subtropical climate",
"Ultimate Fighting Championship",
"Rhode Island",
"Harvard Crimson",
"National Association of Professional Base Ball Players",
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"carpool",
"Samuel Huntington (statesman)",
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"Harvard–Yale football rivalry",
"List of states and territories of the United States by population density",
"Foxwoods Resort Casino",
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"Catholic Church",
"Metropolitan Transportation Authority",
"United States House of Representatives",
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"Stafford Springs, CT",
"New England",
"New Haven Colony",
"Connecticut State Troubadour",
"ASML Holding",
"Homelessness in Connecticut",
"Newtown, Connecticut",
"Bradley International Airport",
"Islam",
"cronyism",
"SUNY Press",
"tavern",
"AC Connecticut",
"mainline Protestant",
"list of Connecticut counties",
"Groton (town), Connecticut",
"CTfastrak",
"church (building)",
"WNPR",
"George W. Bush",
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"Italian American",
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] |
6,468 |
Country Liberal Party
|
The Country Liberal Party of the Northern Territory (CLP), commonly known as the Country Liberals, is a centre-right and conservative political party in Australia's Northern Territory. In territory politics, it operates in a two-party system with the Australian Labor Party (ALP). It also contests federal elections as an affiliate of the Liberal Party of Australia and National Party of Australia, the two partners in the federal coalition.
The CLP originated in 1971 as a division of the Country Party (later renamed the National Party), the first local branches of which were formed in 1966. It adopted its current name in 1974 to attract Liberal Party supporters, but maintained a sole affiliation with the Country Party until 1979, when it acquired observer status with the Liberals while maintaining full voting rights in the Country Party. The party dominated the Northern Territory Legislative Assembly from the inaugural election in 1974 through to its defeat at the 2001 election, winning eight consecutive elections and providing the territory's first seven chief ministers. Following its defeat in 2001, the party did not return to power until 2012, but was defeated at the 2016 election. It remained in opposition until the 2024 election, in which it regained government in a landslide and the party's leader Lia Finocchiaro, who was elected party leader and leader of the opposition in February 2020, became Chief Minister.
At federal level, the CLP contests elections for the Northern Territory's House of Representatives and Senate seats, which also cover the Australian Indian Ocean Territories. It is registered with the Australian Electoral Commission (AEC). Its candidates do not form a separate parliamentary party but instead join either the Liberal or National party rooms – for instance, CLP senator Nigel Scullion was a long-serving deputy leader of the Nationals. Its sole current federal legislator Jacinta Nampijinpa Price, also a senator, sits with the National Party.
The CLP's constitution describes it as an "independent conservative" party and commits it to Northern Territory statehood. It has typically prioritised economic development of the territory and originally drew most of its support from Outback towns and the pastoral industry. It later developed a voter base among the urban middle-class populations of Darwin, Palmerston and Alice Springs (the latter two of which are strongholds for the party). The CLP party provided the territory's first Indigenous MP (Hyacinth Tungutalum) and Australia's first Indigenous head of government (Adam Giles).
==History==
===Origins===
A party system did not develop in the Northern Territory until the 1960s, due to its small population and lack of regular elections. The Australian Labor Party (ALP) contested elections as early as 1905, but rarely faced an organised opposition; anti-Labor candidates usually stood as independents. The regionalist North Australia Party (NAP), established by Lionel Rose for the 1965 Legislative Council election, has been cited as a predecessor of the CLP.
A Darwin branch of the Country Party was established on 20 July 1966, following by an Alice Springs branch on 29 July. The creation of the branches was spurred by the upcoming 1966 federal election and the announcement by the Northern Territory's federal MP Jock Nelson that he would be retiring from politics. The Country Party achieved its first electoral success with the election of Sam Calder as Nelson's replacement. It subsequently won four out of eleven seats at the 1968 Legislative Council election. A third branch of the party was established in Katherine in February 1971. The branches affiliated with the Federal Council of the Australian Country Party in July 1971, establishing a formal entity with a central council, executive and annual conference. The party was formally named the "Australian Country Party – Northern Territory".
The Country Party primarily drew its support from Alice Springs, small towns, and the pastoral industry, including "a fair proportion of the non-urban Aboriginal vote". The party did not have a strong presence in Darwin. A branch of the Liberal Party, the Country Party's coalition partner at a federal level, had been established in Darwin in 1966, representing commercial interests and urban professionals. The Liberals fielded candidates at the 1968 Legislative Council elections, but by 1970 the local branch had ceased to function. In 1973, the Country Party began actively working to include Liberal supporters within its organisation, spurred by the Whitlam government's announcement of a fully elective Northern Territory Legislative Assembly. Following informal negotiations led by Goff Letts, a joint committee was established to determine changes to the Country Party's constitution and policy. These were officially approved, along with the adoption of the name Country Liberal Party, at the party's annual conference in Alice Springs on 20 July 1974. Per its 2018 constitution, the party reckons 1974 as its founding date.
===1974–2001: Foundation and early dominance===
The Whitlam government passed legislation in 1974 to establish a fully elected unicameral Northern Territory Legislative Assembly, replacing the previous partly elected Legislative Council, which had been in existence since 1947. The CLP won 17 out of 19 seats at the inaugural elections in October 1974, with independents holding the other two seats. Goff Letts became the inaugural majority leader, a title changed to chief minister after the granting of self-government in 1978. The CLP governed the Northern Territory from 1974 until the 2001 election. During this time, it never faced more than nine opposition members. Indeed, the CLP's dominance was so absolute that its internal politics were seen as a bigger threat than any opposition party. This was especially pronounced in the mid-1980s, when a series of party-room coups resulted in the Territory having three Chief Ministers during the 1983–87 term and also saw the creation of the Northern Territory Nationals as a short-lived splinter group under the leadership of former CLP chief minister Ian Tuxworth. According to ABC election analyst Antony Green, the CLP weathered these severe ructions because Territory Labor was "unelectable" at the time.
The Whitlam government also passed legislation to give the Northern Territory and Australian Capital Territory (ACT) representation in the federal Senate, with each territory electing two senators. Bernie Kilgariff was elected as the CLP's first senator at the 1975 federal election, sitting alongside Sam Calder in the parliamentary National Country Party. On 3 February 1979 a special conference of the CLP resolved that "the Federal CLP Parliamentarians be permitted to sit in the Party Rooms of their choice in Canberra". Despite personal misgivings, Kilgariff chose to sit with the parliamentary Liberal Party from 8 March 1979 in order that the CLP have representation in both parties, a practice which has been maintained where possible.
===2001–2012: In opposition===
At the 2001 election, the Australian Labor Party won government by one seat, ending 27 years of CLP government.
In the 2004 federal election, the CLP held one seat in the House of Representatives, and one seat in the Senate. The CLP lost its federal lower house seat in the 2007 federal election, defeating the incumbent Labor government led by Paul Henderson. In the lead up to the Territory election, CLP Senator Nigel Scullion sharply criticised the Federal Labor government for its suspension of the live cattle trade to Indonesia - an economic mainstay of the territory.
The election victory ended 11 years of ALP rule in the Northern Territory. The victory was also notable for the support it achieved from indigenous people in pastoral and remote electorates. Large swings were achieved in remote Territory electorates (where the indigenous population comprised around two-thirds of voters) and a total of five Aboriginal CLP candidates won election to the Assembly. Among the indigenous candidates elected were high-profile Aboriginal activist Bess Price and former ALP member Alison Anderson. Anderson was appointed Minister for Indigenous Advancement. In a nationally reported speech in November 2012, Anderson condemned welfare dependency and a culture of entitlement in her first ministerial statement on the status of Aboriginal communities in the Territory and said the CLP would focus on improving education and on helping create real jobs for indigenous people.
====Leadership spills====
Adam Giles replaced Mills as Chief Minister of the Northern Territory and party leader at the 2013 CLP leadership ballot on 13 March while Mills was on a trade mission in Japan. Giles was sworn in as Chief Minister on 14 March, becoming the first indigenous head of government of an Australian state or territory.
Willem Westra van Holthe challenged Giles at the 2015 CLP leadership ballot on 2 February and was elected leader by the party room in a late night vote conducted by phone. However, Giles refused to resign as Chief Minister following the vote. On 3 February, ABC News reported that officials were preparing an instrument for Giles' removal by the Administrator. The swearing-in of Westra van Holthe, which had been scheduled for 11:00 local time (01:30 UTC), was delayed. After a meeting of the parliamentary wing of the CLP, Giles announced that he would remain as party leader and Chief Minister, and that Westra van Holthe would be his deputy.
====Defections and minority government====
After four defections during the parliamentary term, the CLP was reduced to minority government by July 2015. Giles raised the possibility of an early election on 20 July stating that he would "love" to call a snap poll, but that it was "pretty much impossible to do". Crossbenchers dismissed the notion of voting against a confidence motion to bring down the government.
Federally, a MediaReach seat-level opinion poll of 513 voters in the seat of Solomon conducted 22−23 June ahead of the 2016 federal election held on 2 July surprisingly found Labor candidate Luke Gosling heavily leading two-term CLP incumbent Natasha Griggs 61–39 on the two-party vote from a large 12.4 percent swing. The CLP lost Solomon to Labor at the election, with Gosling defeating Griggs 56–44 on the two-party vote from a 7.4 percent swing.
Polling ahead of the 2016 Territory election indicated a large swing against the CLP, including a near-total collapse in Darwin/Palmerston. By the time the writs were dropped, commentators had almost universally written off the CLP. At 27 August Territory election, the CLP was swept from power in a massive Labor landslide, suffering easily the worst defeat of a sitting government in Territory history and one of the worst defeats a governing party has ever suffered at the state or territory level in Australia. The party not only lost all of the bush seats it picked up in 2012, but was all but shut out of Darwin/Palmerston, winning only one seat there. All told, the CLP only won two seats, easily its worst showing in an election. Giles himself lost his own seat, becoming the second Majority Leader/Chief Minister to lose his own seat. Even before Giles' defeat was confirmed, second-term MP Gary Higgins—the only surviving member of the Giles cabinet—was named the party's new leader, with Lia Finocchiaro as his deputy. On 20 January 2020, Higgins announced his resignation as party leader and announced his retirement at the next election. Finocchiaro succeeded him as CLP leader and leader of the opposition on 1 February 2020.
Finocchiaro led the CLP to a modest recovery at the 2020 Territory election. The CLP picked up a six-seat swing, boosting its seat count to eight. However, it failed to make significant inroads in the Darwin/Palmerston area, winning only two seats there, including that of Finocchiaro.
The CLP lost the seat of Daly to Labor in a 2021 by-election, the first time an incumbent government had won a seat from the opposition in territory history.
The CLP won a landslide victory in the 2024 Northern Territory general election.
===2024–present: Return to government===
==Ideology==
The CLP stands for office in the Northern Territory Assembly and Federal Parliament of Australia and primarily concerns itself with representing Territory interests. It is a regionally based party, that has parliamentary representation in both the Federal Parliament and at the territory level. It brands as a party with strong roots in the Territory.
The CLP competes against the Territory Labor Party (the local branch of Australia's largest social democratic party). It is closely affiliated with, but is independent from the Liberal Party of Australia (a mainly urban, pro-business party comprising mainly liberal membership) and the National Party of Australia (a conservative and regional interests party).
The foreword to the constitution of the party describes it as an "independent conservative political party". The party promotes traditional Liberal Party values such as individualism and private enterprise, and what it describes as "progressive" political policy such as full statehood for the Northern Territory.
==Voter base==
Traditionally, the CLP's voting base has been mostly concentrated in Palmerston, Alice Springs, Katherine and parts of Darwin, as well as in rural towns where the majority of people are white.
Initially, remote Indigenous communities around Australia voted strongly for Labor, but in recent years, Indigenous Australians have been more frequently voting for the Coalition, particularly in remote communities. At the same time, Labor has become stronger in Darwin and Palmerston. At the 2012 general election, the CLP won government by gaining five remote seats where the majority of the population identify as Aboriginal and that were traditionally considered safe seats for Labor. In 2016, the CLP was defeated by Labor in a landslide, and thus lost most of its ground territory-wide. However, in 2020, the CLP gained back some of its ground in remote areas (including narrowly gaining the seat of Barkly, which they did not win in 2012, with a huge swing to them).
The CLP's rule was once so tight, that a former minister once said the CLP had a "'rightful inheritance of being the party that runs this place'".
===Demographics===
A 2023 poll conducted by the Redbridge Group, which found that the CLP would win the 2024 general election in a landslide, looked at demographics by voting intention in the Northern Territory. The poll found that the CLP has a support base among many demographics. The poll found that the CLP is overwhelmingly more popular than Labor among middle and high-income earners and people over 40, and that the CLP had more support than Labor among both Indigenous and non-Indigenous people, English and non-English speakers, and both men and women. The poll found that people aged between 18 and 40 are still more likely to vote for the CLP than they are any party, but by a smaller margin than people over 40.
As less parties and candidates contest Northern Territory general elections than they do Australian federal elections in the Northern Territory, the CLP, Labor and independents usually have a higher vote share at territory elections than at federal elections in the Northern Territory due to the absence of right-wing minor parties such as Pauline Hanson's One Nation and the fact that the Greens do not run in every seat at territory elections. On the territory level, the Redbridge poll found that 25% of One Nation supporters would vote for the CLP on the territory level, second to only the Shooters, Fishers and Farmers Party (SFF) at 33%.
}}
|
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"House of Representatives (Australia)",
"Indigenous Voice to Parliament",
"Landslide victory",
"2024 Northern Territory general election",
"Katherine, Northern Territory",
"Jodeen Carney",
"Gerry Wood",
"Two-party-preferred vote",
"unicameral",
"parliamentary party",
"Administrator of the Northern Territory",
"Shane Stone",
"1968 Northern Territory Legislative Council election",
"Country Liberal Party leadership spill, 2015",
"conservatism",
"2001 Northern Territory general election",
"Independent politician",
"Alice Springs",
"Alfred Lionel Rose",
"full-preferential voting",
"indigenous Australians",
"AM (Australian radio series)",
"social democracy",
"1965 Northern Territory Legislative Council election",
"Jingili, Northern Territory",
"2004 Australian federal election",
"National Party of Australia",
"Charles Darwin University",
"Australian Labor Party (Northern Territory Branch)",
"Populism",
"2016 Australian federal election",
"Paul Henderson (politician)",
"Bernie Kilgariff",
"Gillard government",
"majority-minority",
"Ian Tuxworth",
"North Australia Party",
"ABC News (Australia)",
"Outback",
"Country Liberal Party leadership spill, 2013",
"Chief minister",
"Proposed Northern Territory statehood",
"Northern Territory statehood",
"Jacinta Nampijinpa Price",
"1966 Australian federal election",
"Stephen Hatton",
"1997 Northern Territory general election",
"Conservatism in Australia",
"NT Greens",
"2007 Australian federal election",
"2016 Northern Territory general election",
"Statutory Instrument",
"Alison Anderson",
"Luke Gosling",
"Shooters, Fishers and Farmers Party",
"Nigel Scullion",
"voter base",
"Coalition (Australia)",
"Liberal Party of Australia",
"Adam Giles",
"Indigenous Australians",
"Lia Finocchiaro",
"1990 Northern Territory general election",
"Northern Territory Legislative Assembly",
"Electoral division of Daly",
"Opinion polling for the Australian federal election, 2016",
"1974 Northern Territory general election",
"2020 Northern Territory general election",
"Gary Higgins",
"pre-selection",
"Conservatism",
"Marshall Perron",
"Federal Parliament of Australia",
"Chief Minister of the Northern Territory",
"Natasha Griggs",
"private enterprise",
"1977 Northern Territory general election",
"2005 Northern Territory general election",
"Leader of the Opposition (Australia)",
"Gerard Maley",
"minority government",
"Darwin, Northern Territory",
"Australia",
"safe seat",
"Palmerston, Northern Territory",
"Pauline Hanson's One Nation",
"Swing (Australian politics)",
"Whitlam government",
"Electoral division of Barkly",
"liberalism",
"Aboriginal Australians",
"2001 Australian federal election",
"Australian Senate",
"landslide victory",
"Sam Calder",
"Crossbencher",
"2021 Daly by-election",
"1983 Northern Territory general election",
"Australian Capital Territory",
"confidence motion",
"Goff Letts",
"two-party system",
"Antony Green",
"Australian Country Party",
"Paul Everingham",
"Northern Territory Nationals",
"Hyacinth Tungutalum",
"1980 Northern Territory general election"
] |
6,469 |
Canon law
|
Canon law (from , , a 'straight measuring rod, ruler') is a set of ordinances and regulations made by ecclesiastical authority (church leadership) for the government of a Christian organization or church and its members. The way that such church law is legislated, interpreted and at times adjudicated varies widely among these four bodies of churches. In all three traditions, a canon was originally a rule adopted by a church council; these canons formed the foundation of canon law.
==Etymology==
Greek / , Arabic / , Hebrew / , 'straight'; a rule, code, standard, or measure; the root meaning in all these languages is 'reed'; see also the Romance-language ancestors of the English word cane.
In the fourth century, the First Council of Nicaea (325) calls canons the disciplinary measures of the church: the term canon, κανὠν, means in Greek, a rule. There is a very early distinction between the rules enacted by the church and the legislative measures taken by the state called , Latin for laws. or Ecclesiastical Canons of the Same Holy Apostles is a collection of ancient ecclesiastical decrees (eighty-five in the Eastern, fifty in the Western Church) concerning the government and discipline of the Early Christian Church, incorporated with the Apostolic Constitutions which are part of the Ante-Nicene Fathers.
==Catholic Church==
In the Catholic Church, canon law is the system of laws and legal principles made and enforced by the church's hierarchical authorities to regulate its external organization and government and to order and direct the activities of Catholics toward the mission of the church. It was the first modern Western legal system and is the oldest continuously functioning legal system in the West.
In the Latin Church, positive ecclesiastical laws, based directly or indirectly upon immutable divine law or natural law, derive formal authority in the case of universal laws from the supreme legislator (i.e., the Supreme Pontiff), who possesses the totality of legislative, executive, and judicial power in his person, while particular laws derive formal authority from a legislator inferior to the supreme legislator. The actual subject material of the canons is not just doctrinal or moral in nature, but all-encompassing of the human condition, and therefore extending beyond what is taken as revealed truth.
The Catholic Church also includes the main five rites (groups) of churches which are in full union with the Holy See and the Latin Church:
Alexandrian Rite Churches which include the Coptic Catholic Church, Eritrean Catholic Church, and Ethiopian Catholic Church.
West Syriac Rite which includes the Maronite Church, Syriac Catholic Church and the Syro-Malankara Catholic Church.
Armenian Rite Church which includes the Armenian Catholic Church.
Byzantine Rite Churches which include the Albanian Greek Catholic Church, Belarusian Greek Catholic Church, Bulgarian Greek Catholic Church, Greek Catholic Church of Croatia and Serbia, Greek Byzantine Catholic Church, Hungarian Greek Catholic Church, Italo-Albanian Catholic Church, Macedonian Greek Catholic Church, Melkite Greek Catholic Church, Romanian Greek Catholic Church, Russian Greek Catholic Church, Ruthenian Greek Catholic Church, Slovak Greek Catholic Church and Ukrainian Greek Catholic Church.
East Syriac Rite Churches which includes the Chaldean Catholic Church and Syro-Malabar Church.
All of these church groups are in full communion with the Supreme Pontiff and are subject to the Code of Canons of the Eastern Churches.
===History, sources of law, and codifications===
The Catholic Church has what is claimed to be the oldest continuously functioning internal legal system in Western Europe, much later than Roman law but predating the evolution of modern European civil law traditions.
The history of Latin canon law can be divided into four periods: the jus antiquum, the jus novum, the jus novissimum and the Code of Canon Law. In relation to the Code, history can be divided into the jus vetus (all law before the Code) and the jus novum (the law of the Code, or jus codicis).
===Catholic canon law as legal system===
Roman Catholic canon law is a fully developed legal system, with all the necessary elements: courts, lawyers, judges, a fully articulated legal code, principles of legal interpretation, and coercive penalties, though it lacks civilly-binding force in most secular jurisdictions. One example where conflict between secular and canon law occurred was in the English legal system, as well as systems, such as the U.S., that derived from it. Here criminals could apply for the benefit of clergy. Being in holy orders, or fraudulently claiming to be, meant that criminals could opt to be tried by ecclesiastical rather than secular courts. The ecclesiastical courts were generally more lenient. Under the Tudors, the scope of clerical benefit was steadily reduced by Henry VII, Henry VIII, and Elizabeth I. The papacy disputed secular authority over priests' criminal offenses. The benefit of clergy was systematically removed from English legal systems over the next 200 years, although it still occurred in South Carolina in 1855.
In English Law, the use of this mechanism, which by that point was a legal fiction used for first offenders, was abolished by the Criminal Law Act 1827.
The academic degrees in Catholic canon law are the J.C.B. (Juris Canonici Baccalaureatus, Bachelor of Canon Law, normally taken as a graduate degree), J.C.L. (Juris Canonici Licentiatus, Licentiate of Canon Law) and the J.C.D. (Juris Canonici Doctor, Doctor of Canon Law). Because of its specialized nature, advanced degrees in civil law or theology are normal prerequisites for the study of canon law.
Much of Catholic canon law's legislative style was adapted from the Roman Code of Justinian. As a result, Roman ecclesiastical courts tend to follow the Roman Law style of continental Europe with some variation, featuring collegiate panels of judges and an investigative form of proceeding, called "inquisitorial", from the Latin "inquirere", to enquire. This is in contrast to the adversarial form of proceeding found in the common law system of English and U.S. law, which features such things as juries and single judges.
The institutions and practices of Catholic canon law paralleled the legal development of much of Europe, and consequently, both modern civil law and common law bear the influences of canon law. As Edson Luiz Sampel, a Brazilian expert in Catholic canon law, says, canon law is contained in the genesis of various institutes of civil law, such as the law in continental Europe and Latin American countries. Indirectly, canon law has significant influence in contemporary society.
Catholic Canonical jurisprudential theory generally follows the principles of Aristotelian-Thomistic legal philosophy. the Catechism of the Catholic Church cites Aquinas in defining law as "an ordinance of reason for the common good, promulgated by the one who is in charge of the community" and reformulates it as "a rule of conduct enacted by competent authority for the sake of the common good".
===Code for the Eastern Churches===
The law of the Eastern Catholic Churches in full communion with the Roman papacy was in much the same state as that of the Latin Church before 1917; much more diversity in legislation existed in the various Eastern Catholic Churches. Each had its own special law, in which custom still played an important part. One major difference in Eastern Europe however, specifically in the Eastern Orthodox Christian churches, was in regards to divorce. Divorce started to slowly be allowed in specific instances such as adultery being committed, abuse, abandonment, impotence, and barrenness being the primary justifications for divorce. Eventually, the church began to allow remarriage to occur (for both spouses) post-divorce. but finalized nearly 30 years later. After the Second Vatican Council (1962 - 1965), the Vatican produced the Code of Canons of the Eastern Churches which became the first code of Eastern Catholic Canon Law.
==Eastern Orthodox Church==
The Eastern Orthodox Church, principally through the work of 18th-century Athonite monastic scholar Nicodemus the Hagiorite, has compiled canons and commentaries upon them in a work known as the (, 'Rudder'), so named because it is meant to "steer" the church in her discipline. The dogmatic determinations of the Councils are to be applied rigorously since they are considered to be essential for the church's unity and the faithful preservation of the Gospel.
==Anglican Communion==
In the Church of England, the ecclesiastical courts that formerly decided many matters such as disputes relating to marriage, divorce, wills, and defamation, still have jurisdiction of certain church-related matters (e.g. discipline of clergy, alteration of church property, and issues related to churchyards). Their separate status dates back to the 12th century when the Normans split them off from the mixed secular/religious county and local courts used by the Saxons. In contrast to the other courts of England, the law used in ecclesiastical matters is at least partially a civil law system, not common law, although heavily governed by parliamentary statutes. Since the Reformation, ecclesiastical courts in England have been royal courts. The teaching of canon law at the Universities of Oxford and Cambridge was abrogated by Henry VIII; thereafter practitioners in the ecclesiastical courts were trained in civil law, receiving a Doctor of Civil Law (D.C.L.) degree from Oxford, or a Doctor of Laws (LL.D.) degree from Cambridge. Such lawyers (called "doctors" and "civilians") were centered at "Doctors Commons", a few streets south of St Paul's Cathedral in London, where they monopolized probate, matrimonial, and admiralty cases until their jurisdiction was removed to the common law courts in the mid-19th century.
Other churches in the Anglican Communion around the world (e.g., the Episcopal Church in the United States and the Anglican Church of Canada) still function under their own private systems of canon law.
In 2002 a Legal Advisors Consultation meeting at Canterbury concluded:(1) There are principles of canon law common to the churches within the Anglican Communion; (2) Their existence can be factually established; (3) Each province or church contributes through its own legal system to the principles of canon law common within the Communion; (4) these principles have strong persuasive authority and are fundamental to the self-understanding of each of the member churches; (5) These principles have a living force, and contain within themselves the possibility for further development; and (6) The existence of the principles both demonstrates and promotes unity in the Communion.
==Presbyterian and Reformed churches==
In Presbyterian and Reformed churches, canon law is known as "practice and procedure" or "church order", and includes the church's laws respecting its government, discipline, legal practice, and worship.
Roman canon law had been criticized by the Presbyterians as early as 1572 in the Admonition to Parliament. The protest centered on the standard defense that canon law could be retained so long as it did not contradict the civil law. According to Polly Ha, the Reformed church government refuted this, claiming that the bishops had been enforcing canon law for 1500 years.
==Lutheranism==
The Book of Concord is the historic doctrinal statement of the Lutheran Church, consisting of ten credal documents recognized as authoritative in Lutheranism since the 16th century. However, the Book of Concord is a confessional document (stating orthodox belief) rather than a book of ecclesiastical rules or discipline, like canon law. Each Lutheran national church establishes its own system of church order and discipline, though these are referred to as "canons".
==United Methodist Church==
The Book of Discipline contains the laws, rules, policies, and guidelines for The United Methodist Church. Its latest edition was published in 2024.
|
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"Anglican Church of Canada",
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"Doctor of both laws",
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"Albanian Greek Catholic Church",
"East Syriac Rite",
"Nicodemus the Hagiorite",
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"Western world",
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"Akribeia",
"Admiralty law",
"GlobaLex",
"church council",
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"common law",
"Codex iuris civilis",
"wikt:cane",
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"House of Tudor",
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"Melkite Greek Catholic Church",
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"benefit of clergy",
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"Fetha Nagast",
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"Canon law (Church of England)",
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"University of Oxford",
"Common law",
"Episcopal Church in the United States",
"Doctor of Laws",
"Maronite Church",
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"Doctors' Commons",
"Aristotelianism",
"Code of Canons of the Eastern Churches",
"Roman law",
"legal system",
"Supreme Pontiff",
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"legal fiction",
"Armenian Catholic Church",
"Ecclesiastical court",
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"Chaldean Catholic Church",
"English Reformation",
"Hebrew language",
"Hungarian Greek Catholic Church",
"Summa Theologica",
"Licentiate of Canon Law",
"University of Cambridge",
"Collections of ancient canons",
"Eritrean Catholic Church",
"Doctor of Canon Law",
"Normans",
"Canonical Inquisition",
"Syro-Malankara Catholic Church",
"Arabic language",
"qaanoon",
"Sharia",
"Doctor of Civil Law",
"Armenian Rite",
"Mount Athos",
"Ius remonstrandi",
"Abrogation of Old Covenant laws",
"Byzantine Rite",
"Ante-Nicene Fathers",
"Ruthenian Greek Catholic Church",
"probate",
"State religion",
"canon (canon law)",
"Romanian Greek Catholic Church",
"John Baker (legal historian)",
"legislative power",
"Church of England",
"Dr. Edward N. Peters"
] |
6,501 |
Columbanus
|
Saint Columbanus (; 543 – 23 November 615) was an Irish missionary notable for founding a number of monasteries after 590 in the Frankish and Lombard kingdoms, most notably Luxeuil Abbey in present-day France and Bobbio Abbey in present-day Italy.
Columbanus taught an Irish monastic rule and penitential practices for those repenting of sins, which emphasised private confession to a priest, followed by penances imposed by the priest in reparation for the sins. Columbanus is one of the earliest identifiable Hiberno-Latin writers.
|
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"San Colombano Belmonte",
"Comgall",
"Saint Kilian",
"Holy See",
"Eastern Orthodox Church",
"Seán MacBride",
"Chlothar II",
"Pope Gregory I",
"penance",
"Theudebert II",
"Hiberno-Scottish mission",
"Roman Martyrology",
"Sigebert I",
"Suitbert of Kaiserwerdt",
"Luxeuil Abbey",
"Wettingen-Mehrerau Abbey",
"monastery",
"Jonas of Bobbio",
"Catholic Encyclopedia",
"Lake Constance",
"Brunhilda of Austrasia",
"Tours",
"Martin of Tours",
"heresy",
"John A. Costello",
"San Colombano Certénoli",
"Oratory (worship)",
"Kingdom of Meath",
"Luxeuil",
"Saint-Malo",
"The Name of the Rose",
"s:The ancient Irish church/Chapter 6",
"Loire",
"San Colombano al Lambro",
"Wilfrid",
"Vosges Mountains",
"Fontaine-lès-Luxeuil",
"Pope Boniface IV",
"Aleteia",
"Mainz",
"La Voivre, Haute-Saône",
"Arianism",
"Saint Peter",
"Bobbio Abbey",
"Bangor Abbey",
"Capital punishment",
"Aurelia of Strasbourg",
"Civil parish of Arney",
"Agilulf",
"Vatican News",
"Columba",
"Pope John XXIII",
"Neustria",
"Saint-Coulomb",
"Nones (liturgy)",
"Saint",
"Leinster",
"Annegray",
"Metz",
"Fourth Council of Mâcon",
"St. Gallen",
"Childebert II",
"Lombards",
"Trebbia",
"Nestorianism",
"Milan",
"Rule of Saint Benedict",
"Free Imperial City of Besançon",
"cuculla",
"County Fermanagh",
"Kingdom of the Lombards",
"Ursicinus of Saint-Ursanne",
"Tuggen",
"Corpus of Electronic Texts",
"Vergilius of Salzburg",
"Lake Zurich",
"Bobbio",
"laus perennis",
"John Oliver (bishop)",
"Guntram",
"Theuderic II",
"Alemanni",
"Luxeuil-les-Bains",
"Victorius of Aquitaine",
"Nantes",
"Suebi",
"Abbey of St Gall",
"satchel (bag)",
"Umberto Eco",
"Celtic Christianity",
"Lough Erne",
"Pope Gregory the Great",
"Three-Chapter Controversy",
"Theodelinda",
"squirrel",
"Lent",
"Saint Gall",
"Willibrord",
"Bishop Augustalis",
"Apennine Mountains",
"Aar",
"Soissons",
"Burgundy",
"Austrasia",
"computus",
"manual labour",
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"Bregenz",
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"Deicolus",
"Saint Boniface",
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"Limmat",
"Rhine",
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"Robert Schuman",
"Nevers",
"Franks",
"Psalms",
"quartodecimanism",
"defile (geography)",
"Missionary Society of Saint Columban"
] |
6,503 |
Concord, New Hampshire
|
Concord () is the capital city of the U.S. state of New Hampshire and the seat of Merrimack County. As of the 2020 United States census the population was 43,976, making it the 3rd most populous city in New Hampshire after Manchester and Nashua.
The area was first settled by Europeans in 1659.
Interstate 89 and Interstate 93 are the two main interstate highways serving the city, and general aviation access is via Concord Municipal Airport. The nearest airport with commercial air service is Manchester–Boston Regional Airport, to the south. There has been no passenger rail service to Concord since 1981. The tribe fished for migrating salmon, sturgeon, and alewives with nets strung across the rapids of the Merrimack River. The stream was also the transportation route for their birch bark canoes, which could travel from Lake Winnipesaukee to the Atlantic Ocean. The broad sweep of the Merrimack River valley floodplain provided good soil for farming beans, gourds, pumpkins, melons and maize.
The area was first settled by Europeans in 1659 as Penacook, after the Abenaki word "pannukog" meaning "bend in the river," referencing the steep bends of the Merrimack River through the area. Citizens displaced by the resulting border adjustment were given land elsewhere as compensation. In 1779, New Pennacook Plantation was granted to Timothy Walker Jr. and his associates at what would be incorporated in 1800 as Rumford, Maine, the site of Pennacook Falls.
Concord grew in prominence throughout the 18th century, and some of the earliest houses from this period survive at the northern end of Main Street. In the years following the Revolution, Concord's central geographical location made it a logical choice for the state capital, particularly after Samuel Blodget in 1807 opened a canal and lock system to allow vessels passage around the Amoskeag Falls downriver, connecting Concord with Boston by way of the Middlesex Canal. In 1808, Concord was named the official seat of state government, Construction on the State House was completed in 1819, and it remains the oldest capitol in the nation in which the state's legislative branches meet in their original chambers. Concord was also named the seat of Merrimack County in 1823, and the Merrimack County Courthouse was constructed in 1857 in the North End at the site of the Old Town House.
In the early 19th century, much of the city's economy was dominated by furniture-making, printing, and granite quarrying; granite had become a popular building material for many monumental halls in the early United States, and Concord granite was used in the construction of both the New Hampshire State House and the Library of Congress in Washington, D.C. In 1828, Lewis Downing joined J. Stephens Abbot to form Abbot and Downing. The State Hospital continued to expand throughout the following decades, and in 1891 Concord Hospital opened its doors as Margaret Pillsbury General Hospital, the first general hospital in the state of New Hampshire.
Concord's economy changed once again in the 20th century with the declining railroad and textile industry. The city developed into a center for national politics due to New Hampshire's first-in-the-nation primary, and many presidential candidates still visit the Concord area during campaign season. The city also developed an identity within the emerging space industry, with the McAuliffe-Shepard Discovery Center opening in 1990 to commemorate Alan Shepard, the first American in space from nearby Derry, and Christa McAuliffe, a teacher at Concord High School who died in the 1986 Space Shuttle Challenger disaster. Today, Concord remains a center for politics, law, healthcare, and insurance companies.
Image:First Concord Bridge.GIF| First Concord Bridge, 1795
Image:State House, Concord, NH.jpg|State House
Image:Main Street, Concord, NH.jpg|Main Street
Image:City Hall, Concord, NH.jpg|City Hall in 1913
Image:Old Library, Concord, NH.jpg|Old Library
Image:Post Office, Concord, NH.jpg|Old Post Office in 1910
==Geography==
Concord is located in south-central New Hampshire at (43.2070, −71.5371). It is north of the Massachusetts border, west of the Maine border, east of the Vermont border, and south of the Canadian border at Pittsburg.
According to the United States Census Bureau, the city has a total area of . of it are land and of it are water, comprising 4.81% of the city. Concord is drained by the Merrimack River. Penacook Lake, the largest lake in the city and its main source of water, is in the west. The highest point in Concord is above sea level on Oak Hill, just west of the hill's summit in neighboring Loudon.
Concord lies fully within the Merrimack River watershed and is centered on the river, which runs from northwest to southeast through the city. Downtown is located on a low terrace to the west of the river, with residential neighborhoods climbing hills to the west and extending southwards towards the town of Bow. To the east of the Merrimack, atop a bluff, is a flat, sandy plain known as Concord Heights, which has seen most of the city's commercial development since 1960. The eastern boundary of Concord (with the town of Pembroke) is formed by the Soucook River, a tributary of the Merrimack. The Turkey River winds through the southwestern quarter of the city, passing through the campus of St. Paul's School before entering the Merrimack River in Bow. In the northern part of the city, the Contoocook River enters the Merrimack at the village of Penacook.
Concord is north of Manchester, New Hampshire's largest city, and north of Boston.
===Villages===
The city of Concord is made up of its downtown, including its North End and South End neighborhoods, plus the four distinct villages of Penacook, Concord Heights, East Concord, and West Concord.
=== Adjacent municipalities ===
Canterbury (north)
Loudon (northeast)
Pembroke (southeast)
Bow (south)
Hopkinton (west)
Webster (northwest)
Boscawen (north-northwest)
===Climate===
Concord, as with much of New England, is within the humid continental climate zone (Köppen Dfb), with long, cold, snowy winters, warm (and at times humid) summers, and relatively brief autumns and springs. In winter, successive storms deliver moderate to at times heavy snowfall amounts, contributing to the relatively reliable snow cover. In addition, lows reach below on an average 15 nights per year, and the city straddles the border between USDA Hardiness Zone 5b and 6a. However, thaws are frequent, with one to three days per month with + highs from December to February. Summer can bring stretches of humid conditions as well as thunderstorms, and there is an average of 12 days of + highs annually. The window for freezing temperatures on average begins on September 27 and expires on May 14. Population estimate
U.S. Decennial Census
1767-1786: NH Provincial & State Papers
}}
As of the 2020 United States census, there were 43,976 people residing in the city. The population density was . At the 2010 Census there were 42,695 residents and 10,052 families in the city, as well as 18,852 housing units at an average density of . The racial makeup of the city in 2020 was 84.5% White, 4.9% Black or African American, 1.0% Native American, 4.9% Asian, 0.1% Pacific Islander, 0.4% from some other race, and 1.8% from two or more races. 4.9% of the population were Hispanic or Latino of any race.
In 2010 there were 17,592 households, out of which 28.7% had children under the age of 18 living with them, 41.3% were headed by married couples living together, 11.6% had a female householder with no husband present, and 42.9% were non-families. 33.6% of all households were made up of individuals, and 12.0% were someone living alone who was 65 years of age or older. The average household size was 2.26, and the average family size was 2.90.
==Economy==
===Top employers===
In 2020, the top employer in the city remained the State of New Hampshire, with over 6,000 employed workers, while the largest private employer was Concord Hospital, with just under 3,000 employees. According to the City of Concord's Comprehensive Annual Financial Report, the top 10 employers in the city for the Fiscal Year 2020 were:
==Transportation==
===Highways===
Interstate 89 and Interstate 93 are the two main interstate highways serving Concord, and join just south of the city limits. Interstate 89 links Concord with Lebanon and the state of Vermont to the northwest, while Interstate 93 connects the city to Plymouth, Littleton, and the White Mountains to the north and Manchester and Boston to the south. Interstate 393 is a spur highway leading east from Concord and merging with U.S. Route 4 as a direct route to New Hampshire's Seacoast region. North-south U.S. Route 3 serves as Concord's Main Street, while U.S. Route 202 and New Hampshire Route 9 cross the city from east to west. State routes 13 and 132 also serve the city: Route 13 leads southwest out of Concord towards Goffstown and Milford, while Route 132 travels north parallel to Interstate 93. New Hampshire Route 106 passes through the easternmost part of Concord, crossing I-393 and NH 9 before crossing the Soucook River south into the town of Pembroke. To the north, NH 106 leads to Loudon, Belmont and Laconia.
=== Railroads ===
Historically, Concord served as an important railroad terminal and station for the Boston and Maine Railroad. The former Concord Station was located at what is now a Burlington department store on Storrs Street. The station itself was built in 1860, but the fourth and most famous iteration of the station was built in 1885, which had a brick head house designed by Bradford L. Gilbert. The head house was demolished in 1959 and replaced by a smaller "McGinnis Era" station. By 1967, all passenger rail services to Concord had been discontinued. For 13 months in 1980 and 1981, MBTA Commuter Rail ran two round trips a day between Boston and Concord. Since then, there has not been any passenger rail service to Concord.
In 2021, Amtrak announced their plan to implement new service between Boston and Concord by 2035.
===Bus===
Local bus service is provided by Concord Area Transit (CAT), with three routes through the city. Regional bus service provided by Concord Coach Lines and Greyhound Lines is available from the Concord Transportation Center at 30 Stickney Avenue next to Exit 14 on Interstate 93, with service south to Boston and points in between, as well as north to Littleton and northeast to Berlin.
===Other modes===
General aviation services are available through Concord Municipal Airport, located east of downtown. There is no commercial air service within the city limits; the nearest such airport is Manchester–Boston Regional Airport, to the south.
=== Complete Streets Improvement Project ===
Concord's downtown underwent a significant renovation between 2015 and 2016, during the city's "Complete Streets Improvement Project". At a proposed cost of $12 million, the project promised to deliver on categories of maintenance to aging infrastructure, improved accessibility, increased sustainability, a safer experience for walkers, bikers and motorists alike, and to stimulate economic growth in an increasingly idle downtown. The main infrastructural change was reducing the four-lane street (two in each direction) to two lanes plus a turning lane in the center. The freed-up space would contribute to extra width for bikes to ride in either direction, increased curb size and an added median where there is no need for a turning lane. Concord opted to add shared lane markings for bikes, rather than a dedicated protected bike lane.
By adding curb space, this project created new opportunities for pedestrians to enjoy the downtown. Many power lines were buried, and street trees, colorful benches, art installations, and other green spaces were added, all allowing people to reclaim a space long dominated by cars. Another aspect of the new construction was adding heated sidewalk capabilities, utilizing excess steam from the local Concord Steam plant, and minimizing sand and snow blowing needed during the winter months. After scrapping some of the most expensive offenders, the budget ended up at $14.2 million, with the project actually coming in $1.1 million below that. Although adding final aesthetic touches with the extra money were debated, the city council ended up deciding to save for financially straining years ahead.
==Notable people==
==Government==
Concord is governed via the council-manager system. The city council consists of a mayor and 14 councilors, ten of which are elected to two-year terms representing each of the city wards, while the other four are elected at-large to four-year terms. The mayor is elected directly every two years. The current mayor as of 2024 is Byron Champlin, who was elected on November 7, 2023, with more than 75% of the vote.
According to the Concord city charter, the mayor chairs the council, currently Thomas J. Aspell Jr. The current police chief is Bradley S. Osgood.
In the New Hampshire Senate, Concord is in the 15th District, represented by Democrat Becky Whitley since December 2020. On the New Hampshire Executive Council, Concord is in the 2nd District, represented by Cinde Warmington, the sole Democrat on the council. In the United States House of Representatives, Concord is in New Hampshire's 2nd congressional district, represented by Democrat Maggie Goodlander.
New Hampshire Department of Corrections operates the New Hampshire State Prison for Men and New Hampshire State Prison for Women in Concord.
Concord leans strongly Democratic in presidential elections; the last Republican nominee to carry the city was then Vice President George H. W. Bush in 1988. Voter turnout was 72.7% in the 2020 general election, down from 76.2% in 2016, but still above the 2020 national turnout of 66.7%.
==Media==
Newspapers and journals
Concord Monitor (daily)
Concord NH Patch (daily)
New Hampshire Bulletin (daily)
The Concord Insider (weekly)
The Hippo (weekly)
Radio
WKXL 1450 AM (News Talk Information)
WNHN-LP 94.7 FM (Jazz, Blues, Progressive Talk)
WEVO 89.1 FM (Public radio)
WCNH 90.5 FM (Classical Music)
WJYY 105.5 FM (Top 40)
WAKC 102.3 FM (Contemporary Christian)
WICX 102.7 FM (Catholic Radio)
The city is otherwise served by Manchester area stations. New Hampshire Public Radio is headquartered in Concord.
Television
WPXG-TV (Channel 21) (Ion Television)
Concord TV Public-access television cable TV station
==Sites of interest==
The New Hampshire State House, designed by architect Stuart Park and constructed between 1815 and 1818, is the oldest state house in which the legislature meets in its original chambers. The building was remodeled in 1866, and the third story and west wing were added in 1910.
Across from the State House is the Eagle Hotel on Main Street, which has been a downtown landmark since its opening in 1827. U.S. Presidents Ulysses S. Grant, Rutherford Hayes, and Benjamin Harrison all dined there, and Franklin Pierce spent the night before departing for his inauguration. Other well-known guests included Jefferson Davis, Charles Lindbergh, Eleanor Roosevelt, Richard M. Nixon (who carried New Hampshire in all three of his presidential bids), and Thomas E. Dewey. The hotel closed in 1961.
South from the Eagle Hotel on Main Street is Phenix Hall, which replaced "Old" Phenix Hall, which burned in 1893. Both the old and new buildings featured multi-purpose auditoriums used for political speeches, theater productions, and fairs. Abraham Lincoln spoke at the old hall in 1860; Theodore Roosevelt, at the new hall in 1912.
North on Main Street is the Walker-Woodman House, also known as the Reverend Timothy Walker House, the oldest standing two-story house in Concord. It was built for the Reverend Timothy Walker between 1733 and 1735.
On the north end of Main Street is the Pierce Manse, in which President Franklin Pierce lived in Concord before and following his presidency. The mid-1830s Greek Revival house was moved from Montgomery Street to North Main Street in 1971 to prevent its demolition.
Beaver Meadow Golf Course, located in the northern part of Concord, is one of the oldest golf courses in New England. Besides this golf course, other important sporting venues in Concord include Everett Arena and Memorial Field.
The SNOB (Somewhat North Of Boston) Film Festival, started in the fall of 2002, brings independent films and filmmakers to Concord and has provided an outlet for local filmmakers to display their films. SNOB Film Festival was a catalyst for the building in 2007 of Red River Theatres, a locally owned, nonprofit, independent cinema named after the 1948 film featuring John Wayne.
Other sites of interest include the Capitol Center for the Arts, the New Hampshire Historical Society, which has two facilities in Concord, and the McAuliffe-Shepard Discovery Center, a science museum named after Christa McAuliffe, the Concord teacher who died during the Space Shuttle Challenger disaster in 1986, and Alan Shepard, the Derry-born astronaut who was the second person and first American in space as well as the fifth and oldest person to walk on the Moon.
==Education==
===Public schools===
Concord's public schools are within the Concord School District, except for schools in the Penacook area of the city, which are within the Merrimack Valley School District, a district which also includes several towns north of Concord. The only public high school in the Concord School District is Concord High School, which had about 1,450 students as of Fall 2023. The only public middle school in the Concord School District is Rundlett Middle School, which had roughly 770 students as of Fall 2023. Concord School District's elementary schools underwent a major re-configuration in 2012, with three newly constructed schools opening and replacing six previous schools. Kimball School and Walker School were replaced by Christa McAuliffe School on the Kimball School site, Conant School (and Rumford School, which closed a year earlier) were replaced by Abbot-Downing School at the Conant site, and Eastman and Dame schools were replaced by Mill Brook School, serving kindergarten through grade two, located next to Broken Ground Elementary School, serving grades three to five. Beaver Meadow School, the remaining elementary school, was unaffected by the changes.
Concord schools in the Merrimack Valley School District include Merrimack Valley High School and Merrimack Valley Middle School, which are adjacent to each other and to Rolfe Park in Penacook village, and Penacook Elementary School, just south of the village.
===Private and charter schools===
Concord has two parochial schools, Bishop Brady High School and Saint John Regional School.
Other area private schools include Concord Christian Academy, Parker Academy, Trinity Christian School, and Shaker Road School. Also in Concord is St. Paul's School, a boarding school located in the city's West End neighborhood.
===Post-secondary schools===
Concord is home to New Hampshire Technical Institute, the city's primary community college, and Granite State College, which offers online two-year and four-year degrees. The University of New Hampshire School of Law is located near downtown, and the Franklin Pierce University Doctorate of Physical Therapy program also has a location in the city. Concord Hospital recently announced plans to open a joint program with the New England College School of Nursing as part of their Bachelor of Nursing degree. Concord is also a major clinical site of Dartmouth College's Geisel School of Medicine, New Hampshire's only medical school.
|
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"Annie Kuster",
"Sustainable urbanism",
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"2016 New Hampshire gubernatorial election",
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"2014 United States Senate election in New Hampshire",
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"melon",
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"WJYY",
"city manager",
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"New Hampshire Executive Council"
] |
6,505 |
Chlorophyceae
|
The Chlorophyceae, also known as chlorophycean algae, are one of the classes of green algae, within the phylum Chlorophyta. They are a large assemblage of mostly freshwater and terrestrial organisms; many members are important primary producers in the ecosystems they inhabit. Their body plans are diverse and range from single flagellated or non-flagellated cells to colonies or filaments of cells. The class Chlorophyceae has been distinguished on the basis of ultrastructural morphology; molecular traits are also being used to classify taxa within the class. They are usually green due to the presence of chlorophyll a and b; they can also contain the pigment beta-carotene. Chloroplasts are diverse in morphology and include many forms, including, cup-shaped (e.g. Chlamydomonas), or axial, or parietal and reticulate (e.g. Oedogonium). Some algae may also store food in the form of oil droplets. The inner cell wall layer is made of cellulose and the outer layer of pectose.
===Ultrastructure===
Cells of Chlorophyceae usually have two or four flagella, but in some cases may have numerous flagella. The flagella emerge from the apex of the cell, and are connected to the nucleus via rhizoplasts.
A combination of ultrastructural features are characteristic of the Chlorophyceae. These include: closed mitosis, the telophase spindle collapsing before cytokinesis, and a system of microtubules called a phycoplast running parallel to the plane of cytokinesis.
In addition to normal asexual reproduction, some genera such as Chlamydomonas and Dunaliella can go through a temporary phase known as the "palmella stage", in which flagella are absent and the cells divide vegetatively within a common mucilaginous envelope. Algae enter the palmella stage in response to stressful conditions, such as changes in salinity or predation. Additionally, Haematococcus produces resistant stages with thick cell walls, termed akinetes.
Sexual reproduction shows considerable variation in the type and formation of sex cells; it may be isogamous (with two morphologically identical gamete types), anisogamous (with two morphologically distinct gamete types), and oogamous (with larger, nonmotile eggs and smaller motile sperm cells). Members of Chlorophyceae that undergo sexual reproduction have a zygotic life cycle, in which the zygotes are the only diploid stages. Zygotes may have thick and/or spiny cell walls; these are called hypnozygotes and they also function as resting stages. However, unlike higher plants they do not go through a multicellular alternation of generations.
Chlorococcales – Chlorococcum and Chlorococcaceae are placed in Chlamydomonadales by AlgaeBase
Microsporales – Microspora and Microsporaceae are placed in Sphaeropleales by AlgaeBase
Tetrasporales – Tetraspora and Tetrasporaceae are placed in Chlamydomonadales by AlgaeBase
===Phylogeny===
Current thinking of phylogenetic relationships are as follows:
|
[
"isogamous",
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"flagella",
"Dunaliellaceae",
"chlorophyll b",
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"Chaetopeltidales",
"Oedogonium",
"Chaetophorales",
"diploid",
"eukaryotic",
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"cell (biology)",
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"incertae sedis",
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"pyrenoid",
"ultrastructural"
] |
6,508 |
Cyril
|
Cyril (also Cyrillus or Cyryl) is a masculine given name. It is derived from the Greek name (Kýrillos), meaning 'lordly, masterful', which in turn derives from Greek (kýrios) 'lord'. There are various variant forms of the name Cyril such as Cyrill, Cyrille, Ciril, Kirill, Kiryl, Kirillos, Kyrylo, Kiril, Kiro, Kyril, Kyrill and Quirrel.
It may also refer to:
==Christian patriarchs or bishops==
Cyril of Jerusalem (386), theologian and bishop
Cyril of Alexandria (444), Patriarch of Alexandria
Cyril the Philosopher (826–869), co-invented the Slavic alphabet (Glagolitic) and translated the Bible into Old Church Slavonic; namesake of the Cyrillic alphabet
Pope Cyril II of Alexandria, reigned 1078–1092
Greek Patriarch Cyril II of Alexandria, reigned in the 12th century
Cyril of Turaw (1130–1182), Belarusian bishop and orthodox saint
Pope Cyril III of Alexandria, reigned 1235–1243
Cyril I of Serbia, reigned 1407–1419
Cyril, Metropolitan of Moscow (died 1572), Metropolitan of Moscow and all Rus' from 1568 to 1572
Cyril Lucaris (Patriarch Cyril I of Constantinople), reigned for six terms between 1612 and 1638
Cyril II of Constantinople, patriarch in 1633, 1635–1636, 1638–1639
Patriarch Cyril III of Constantinople, patriarch in 1652 and 1654
Cyril IV of Constantinople, patriarch 1711–1713
Cyril V Zaim, Melkite patriarch of Antioch died 1720
Cyril VI Tanas, Melkite patriarch of Antioch 1724–1760
Patriarch Cyril V of Constantinople, patriarch in 1748–1751, 1752–1757
Cyril II of Serbia, reigned 1759–1763
Cyril VII Siaj, Melkite patriarch of Antioch 1794–1796
Patriarch Cyril VI of Constantinople, patriarch in 1813–1818
Cyril, Metropolitan of Belgrade, Metropolitan of Belgrade during 1825–1827
Patriarch Cyril II of Jerusalem, reigned 1845–1875
Patriarch Cyril VII of Constantinople, patriarch in 1855–1860
Pope Cyril IV of Alexandria, reigned 1854–1861
Pope Cyril V of Alexandria, reigned 1874–1921
Cyril VIII Jaha, Melkite patriarch of Antioch 1902–1916
Cyril IX Moghabghab, Melkite patriarch of Antioch 1925–1946
Patriarch Cyril of Bulgaria, reigned 1953–1971
Pope Cyril VI of Alexandria, reigned 1959–1971
Patriarch Cyril I of Moscow, reigning from 2009
==Other individuals==
Cyrillus, 5th-century Greek jurist
Cyril Abiteboul (born 1977), French motor racing engineer and manager, formerly the managing director of Renault Sport F1 Team
Cyril Almeida, Pakistani journalist
Cyril Eugene Attygalle, Sri Lankan Sinhala politician
Cyril Benson, founder of British company Bensons for Beds
Cyril Bourlon de Rouvre (born 1945), French businessman and politician
Sir Cyril Burt (1883–1971), psychologist
Cyril Connolly (1903–1974), English literary critic and writer
Cyril Delevanti (1889–1975), British actor
Cyril Despres (born 1974), French motorcycle rider
Cyril De Zoysa (1896–1978), Sri Lankan businessman and Buddhist revivalist
Cyril Dissanayaka, Sri Lankan Sinhala senior police officer
Cyril Dodd (1844–1913), British politician
Cyril Domoraud (born 1971), Ivorian football player
Cyril Dunne (1941–2024), Irish Gaelic footballer
Cyril Fernando (1895–1974), Sri Lankan Sinhala clinician and researcher
Cyril Fletcher (1913–2005), English comedian, actor and businessman
Ciryl Gane (born 1990), French mixed martial artist, former interim UFC heavyweight champion
Cyril Gautier (born 1987), French racing cyclist
Cyril Goulden (1897–1981), Welsh/Canadian geneticist, statistician, and agronomist
Cyril Grayson (born 1993), American football player
Cyril Haran (1931–2014), Gaelic footballer and manager, priest, scholar and schoolteacher
Cyril Stanley Harrison (1915–1998), English cricketer
Cyril Leo Heraclius, Prince Toumanoff (born Toumanishvili) (1913–1997), Russian-born historian and genealogist who was a Professor Emeritus at Georgetown University
Cyril Herath (died 2011), Inspector-General of Sri Lanka Police from 1985 to 1988
Cyril Jordan (born 1948), American guitarist and founder of the Flamin' Groovies
Cyril Keeper (born 1943), Canadian politician
Cyril Knowles (1944–1991), English footballer
C. M. Kornbluth (1923–1958), American science fiction author
Cyril Lawrence (1920–2020), English footballer
Cyril Lewis (1909–1999), Welsh footballer
Sister M. Cyril Mooney (1936–2023), educational innovator in India
Cyril Nicholas (1898–1961), Sri Lankan Burgher army captain, civil servant, and forester
Cyril Ornadel (1924–2011), British conductor and composer
Elder Cyril Pavlov (1919–2017), Russian Orthodox Christian monk, mystic and wonder-worker
Cyril Pearl (1904–1987), Australian journalist
Cyril Perkins (1911–2013), English cricketer
Cyril C. Perera (1923–2016), Sri Lankan Sinhala author, translator of world literature into Sinhala
Cyril E. S. Perera (1892–1968), Sri Lankan Sinhala member of the Ceylon House of Representatives
Cyril Pinto Jayatilake Seneviratne (1918–1984), Sri Lankan Sinhala military officer and politician
Cyril Ponnamperuma (1923–1994), Sri Lankan Sinhala scientist in the fields of chemical evolution and the origin of life
Cyril Ramaphosa (born 1952), South African president, businessman, and trade unionist
Cyril Ranatunga, Sri Lankan Sinhala army general
Cyril Richardson (born 1990), American football player
Cyril Riley, known mononymously as Cyril, an Australian musician, best known for his version of "Stumblin' In"
Cyril Rioli (born 1989), Australian rules footballer
Cyril Smith (1928–2010), English Liberal politician
Cyril Stapleton (1914–1974), English musician and bandleader
Cyril Symes (born 1943), Canadian politician
Cyril Takayama (born 1973), American-Japanese magician
Cyril Wickramage (born 1932), Sri Lankan Sinhala actor, director, and vocalist
==Fictional characters==
Cyril "Blakey" Blake, the bus depot inspector from the 1970s British comedy TV series On the Buses
Cyril Fielding, character in E. M. Forster's novel A Passage to India
Cyril Figgis, character in the TV series Archer
Cyril Gray, character from the film Nanny McPhee and the Big Bang, played by Eros Vlahos
Cyril Kinnear, the menacing and urbane mastermind from the 1971 British crime film Get Carter
Cyril Orchard, the murder victim in the 1948 Nero Wolfe mystery And Be a Villain
Cyril Playfair, the reverend from the 1952 film The Quiet Man
Cyril Proudbottom, Mr. Toad's horse from the 1949 film The Adventures of Ichabod and Mr. Toad
Cyril O'Reily, character from television series Oz
Cyril Sneer, the villain aardvark of the 1980s cartoon series The Raccoons
Cyril Woodcock, from the film Phantom Thread, played by Lesley Manville
Cyril the Fogman, a character from the television series Thomas & Friends
Cyril, a character from Doctor Who
Cyril, a character from Fire Emblem: Three Houses
Cyril the Ice Dragon, from The Legend of Spyro
Cyril the Squirrel, from Maisy
Cyril, the main character in The Heart's Invisible Furies by John Boyne
Cyril, a giant squirrel kaiju from Rampage: Total Destruction
Cyril Bassington-Bassington, from "Jeeves and the Chump Cyril"
|
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"Fire Emblem: Three Houses",
"Cyril Smith",
"Patriarch Cyril II of Jerusalem",
"Cyril Dunne",
"C. E. Attygalle",
"Cyril IX Moghabghab",
"Cyril Domoraud",
"Cirillo",
"A Passage to India",
"Cyril the Philosopher",
"Cyril Ornadel",
"Cyril Perkins",
"Cyril Richardson",
"Maisy",
"Cyril VII Siaj",
"Cyril Bourlon de Rouvre",
"Patriarch Cyril VII of Constantinople",
"Cyril O'Reily",
"Cyril Fernando",
"Patriarch Cyril II of Alexandria",
"Cyril Nicholas",
"Patriarch Cyril III of Constantinople",
"Cyril Rioli",
"given name",
"The Heart's Invisible Furies",
"Jeeves and the Chump Cyril",
"Cyril Lucaris",
"The Quiet Man",
"Greek language",
"Kiro (name)",
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"Cyril Almeida",
"House of Representatives (Ceylon)",
"Kiryl",
"Cyril of Jerusalem",
"Cyril Lawrence",
"Cyril VI of Constantinople",
"Bensons for Beds",
"Nanny McPhee and the Big Bang",
"Cyril IV of Constantinople",
"Cyril Abiteboul",
"Cyril Haran",
"C. P. J. Seneviratne",
"Cyril Gautier",
"Pope Cyril V of Alexandria",
"Cyril Ramaphosa",
"Cyril of Bulgaria",
"Rampage: Total Destruction",
"Cyril Dissanayake",
"Cyril Goulden",
"Cyryl",
"Cyril Jordan",
"Pope Cyril IV of Alexandria",
"Inspector General of Police (Sri Lanka)",
"Kyril",
"Doctor Who",
"Kyrillos",
"Cyril Symes",
"Flamin' Groovies",
"Cyril Harrison (cricketer)",
"Cyril Toumanoff",
"Cyril Lewis",
"C. M. Kornbluth",
"Cyril Burt",
"Cyril Keeper",
"Cyril Despres",
"Ciryl Gane",
"Male",
"Cyril VIII Jaha",
"Cyril Ponnamperuma",
"Cyril Delevanti",
"Cyril (DJ)",
"Pope Cyril VI of Alexandria",
"Archer (2009 TV series)",
"Get Carter",
"Cyril I of Serbia",
"Kyrylo",
"Cyril Takayama",
"Cyrillus",
"Pope Cyril III of Alexandria",
"Cyril Herath",
"Cyril VI Tanas",
"Cyril Pavlov",
"Cyril C. Perera",
"Cyril, Metropolitan of Belgrade",
"Cyrillus (crater)",
"Cyril Grayson",
"Cyril De Zoysa",
"kaiju",
"Cyril Wickramage",
"And Be a Villain",
"Cyril II of Constantinople",
"Patriarch Cyril V of Constantinople",
"Cyril Ranatunga",
"Phantom Thread",
"Cyril, Metropolitan of Moscow",
"S. M. Cyril",
"Cyril V Zaim",
"Cyril Dodd",
"John Boyne",
"List of people and animals from Thomas & Friends",
"kýrios",
"lord",
"Kirill",
"Cyril Knowles",
"Cyril Stapleton",
"The Raccoons",
"Patriarch Cyril I of Moscow",
"Kiril",
"Cyril Fletcher",
"Cyril Pearl",
"The Adventures of Ichabod and Mr. Toad",
"Cyril of Alexandria",
"On the Buses",
"Cyrille",
"Cyril E. S. Perera",
"Pope Cyril II of Alexandria",
"Cyril Connolly",
"Cyril of Turaw",
"The Legend of Spyro"
] |
6,511 |
Computational complexity
|
In computer science, the computational complexity or simply complexity of an algorithm is the amount of resources required to run it. Particular focus is given to computation time (generally measured by the number of needed elementary operations) and memory storage requirements. The complexity of a problem is the complexity of the best algorithms that allow solving the problem.
The study of the complexity of explicitly given algorithms is called analysis of algorithms, while the study of the complexity of problems is called computational complexity theory. Both areas are highly related, as the complexity of an algorithm is always an upper bound on the complexity of the problem solved by this algorithm. Moreover, for designing efficient algorithms, it is often fundamental to compare the complexity of a specific algorithm to the complexity of the problem to be solved. Also, in most cases, the only thing that is known about the complexity of a problem is that it is lower than the complexity of the most efficient known algorithms. Therefore, there is a large overlap between analysis of algorithms and complexity theory.
As the amount of resources required to run an algorithm generally varies with the size of the input, the complexity is typically expressed as a function , where is the size of the input and is either the worst-case complexity (the maximum of the amount of resources that are needed over all inputs of size ) or the average-case complexity (the average of the amount of resources over all inputs of size ). Time complexity is generally expressed as the number of required elementary operations on an input of size , where elementary operations are assumed to take a constant amount of time on a given computer and change only by a constant factor when run on a different computer. Space complexity is generally expressed as the amount of memory required by an algorithm on an input of size .
==Resources==
===Time===
The resource that is most commonly considered is time. When "complexity" is used without qualification, this generally means time complexity.
The usual units of time (seconds, minutes etc.) are not used in complexity theory because they are too dependent on the choice of a specific computer and on the evolution of technology. For instance, a computer today can execute an algorithm significantly faster than a computer from the 1960s; however, this is not an intrinsic feature of the algorithm but rather a consequence of technological advances in computer hardware. Complexity theory seeks to quantify the intrinsic time requirements of algorithms, that is, the basic time constraints an algorithm would place on any computer. This is achieved by counting the number of elementary operations that are executed during the computation. These operations are assumed to take constant time (that is, not affected by the size of the input) on a given machine, and are often called steps.
===Bit complexity===
Formally, the bit complexity refers to the number of operations on bits that are needed for running an algorithm. With most models of computation, it equals the time complexity up to a constant factor. On computers, the number of operations on machine words that are needed is also proportional to the bit complexity. So, the time complexity and the bit complexity are equivalent for realistic models of computation.
===Space===
Another important resource is the size of computer memory that is needed for running algorithms.
===Communication===
For the class of distributed algorithms that are commonly executed by multiple, interacting parties, the resource that is of most interest is the communication complexity. It is the necessary amount of communication between the executing parties.
===Others===
The number of arithmetic operations is another resource that is commonly used. In this case, one talks of arithmetic complexity. If one knows an upper bound on the size of the binary representation of the numbers that occur during a computation, the time complexity is generally the product of the arithmetic complexity by a constant factor.
For many algorithms the size of the integers that are used during a computation is not bounded, and it is not realistic to consider that arithmetic operations take a constant time. Therefore, the time complexity, generally called bit complexity in this context, may be much larger than the arithmetic complexity. For example, the arithmetic complexity of the computation of the determinant of a integer matrix is O(n^3) for the usual algorithms (Gaussian elimination). The bit complexity of the same algorithms is exponential in , because the size of the coefficients may grow exponentially during the computation. On the other hand, if these algorithms are coupled with multi-modular arithmetic, the bit complexity may be reduced to .
In sorting and searching, the resource that is generally considered is the number of entry comparisons. This is generally a good measure of the time complexity if data are suitably organized.
==Complexity as a function of input size==
It is impossible to count the number of steps of an algorithm on all possible inputs. As the complexity generally increases with the size of the input, the complexity is typically expressed as a function of the size (in bits) of the input, and therefore, the complexity is a function of . However, the complexity of an algorithm may vary dramatically for different inputs of the same size. Therefore, several complexity functions are commonly used.
The worst-case complexity is the maximum of the complexity over all inputs of size , and the average-case complexity is the average of the complexity over all inputs of size (this makes sense, as the number of possible inputs of a given size is finite). Generally, when "complexity" is used without being further specified, this is the worst-case time complexity that is considered.
==Asymptotic complexity==
It is generally difficult to compute precisely the worst-case and the average-case complexity. In addition, these exact values provide little practical application, as any change of computer or of model of computation would change the complexity somewhat. Moreover, the resource use is not critical for small values of , and this makes that, for small , the ease of implementation is generally more interesting than a low complexity.
For these reasons, one generally focuses on the behavior of the complexity for large , that is on its asymptotic behavior when tends to the infinity. Therefore, the complexity is generally expressed by using big O notation.
For example, the usual algorithm for integer multiplication has a complexity of O(n^2), this means that there is a constant c_u such that the multiplication of two integers of at most digits may be done in a time less than c_un^2. This bound is sharp in the sense that the worst-case complexity and the average-case complexity are \Omega(n^2), which means that there is a constant c_l such that these complexities are larger than c_ln^2. The radix does not appear in these complexity, as changing of radix changes only the constants c_u and c_l.
==Models of computation==
The evaluation of the complexity relies on the choice of a model of computation, which consists in defining the basic operations that are done in a unit of time. When the model of computation is not explicitly specified, it is generally implicitely assumed as being a multitape Turing machine, since several more realistic models of computation, such as random-access machines are asymptotically equivalent for most problems. It is only for very specific and difficult problems, such as integer multiplication in time O(n\log n), that the explicit definition of the model of computation is required for proofs.
===Deterministic models===
A deterministic model of computation is a model of computation such that the successive states of the machine and the operations to be performed are completely determined by the preceding state. Historically, the first deterministic models were recursive functions, lambda calculus, and Turing machines. The model of random-access machines (also called RAM-machines) is also widely used, as a closer counterpart to real computers.
When the model of computation is not specified, it is generally assumed to be a multitape Turing machine. For most algorithms, the time complexity is the same on multitape Turing machines as on RAM-machines, although some care may be needed in how data is stored in memory to get this equivalence.
===Non-deterministic computation===
In a non-deterministic model of computation, such as non-deterministic Turing machines, some choices may be done at some steps of the computation. In complexity theory, one considers all possible choices simultaneously, and the non-deterministic time complexity is the time needed, when the best choices are always done. In other words, one considers that the computation is done simultaneously on as many (identical) processors as needed, and the non-deterministic computation time is the time spent by the first processor that finishes the computation. This parallelism is partly amenable to quantum computing via superposed entangled states in running specific quantum algorithms, like e.g. Shor's factorization of yet only small integers (: 21 = 3 × 7).
Even when such a computation model is not realistic yet, it has theoretical importance, mostly related to the P = NP problem, which questions the identity of the complexity classes formed by taking "polynomial time" and "non-deterministic polynomial time" as least upper bounds. Simulating an NP-algorithm on a deterministic computer usually takes "exponential time". A problem is in the complexity class NP, if it may be solved in polynomial time on a non-deterministic machine. A problem is NP-complete if, roughly speaking, it is in NP and is not easier than any other NP problem. Many combinatorial problems, such as the Knapsack problem, the travelling salesman problem, and the Boolean satisfiability problem are NP-complete. For all these problems, the best known algorithm has exponential complexity. If any one of these problems could be solved in polynomial time on a deterministic machine, then all NP problems could also be solved in polynomial time, and one would have P = NP. it is generally conjectured that with the practical implication that the worst cases of NP problems are intrinsically difficult to solve, i.e., take longer than any reasonable time span (decades!) for interesting lengths of input.
===Parallel and distributed computation===
Parallel and distributed computing consist of splitting computation on several processors, which work simultaneously. The difference between the different model lies mainly in the way of transmitting information between processors. Typically, in parallel computing the data transmission between processors is very fast, while, in distributed computing, the data transmission is done through a network and is therefore much slower.
The time needed for a computation on processors is at least the quotient by of the time needed by a single processor. In fact this theoretically optimal bound can never be reached, because some subtasks cannot be parallelized, and some processors may have to wait a result from another processor.
The main complexity problem is thus to design algorithms such that the product of the computation time by the number of processors is as close as possible to the time needed for the same computation on a single processor.
===Quantum computing===
A quantum computer is a computer whose model of computation is based on quantum mechanics. The Church–Turing thesis applies to quantum computers; that is, every problem that can be solved by a quantum computer can also be solved by a Turing machine. However, some problems may theoretically be solved with a much lower time complexity using a quantum computer rather than a classical computer. This is, for the moment, purely theoretical, as no one knows how to build an efficient quantum computer.
Quantum complexity theory has been developed to study the complexity classes of problems solved using quantum computers. It is used in post-quantum cryptography, which consists of designing cryptographic protocols that are resistant to attacks by quantum computers.
==Problem complexity (lower bounds)==
The complexity of a problem is the infimum of the complexities of the algorithms that may solve the problem, including unknown algorithms. Thus the complexity of a problem is not greater than the complexity of any algorithm that solves the problems.
It follows that every complexity of an algorithm, that is expressed with big O notation, is also an upper bound on the complexity of the corresponding problem.
On the other hand, it is generally hard to obtain nontrivial lower bounds for problem complexity, and there are few methods for obtaining such lower bounds.
For solving most problems, it is required to read all input data, which, normally, needs a time proportional to the size of the data. Thus, such problems have a complexity that is at least linear, that is, using big omega notation, a complexity \Omega(n).
The solution of some problems, typically in computer algebra and computational algebraic geometry, may be very large. In such a case, the complexity is lower bounded by the maximal size of the output, since the output must be written. For example, a system of polynomial equations of degree in indeterminates may have up to d^n complex solutions, if the number of solutions is finite (this is Bézout's theorem). As these solutions must be written down, the complexity of this problem is \Omega(d^n). For this problem, an algorithm of complexity d^{O(n)} is known, which may thus be considered as asymptotically quasi-optimal.
A nonlinear lower bound of \Omega(n\log n) is known for the number of comparisons needed for a sorting algorithm. Thus the best sorting algorithms are optimal, as their complexity is O(n\log n). This lower bound results from the fact that there are ways of ordering objects. As each comparison splits in two parts this set of orders, the number of of comparisons that are needed for distinguishing all orders must verify 2^N>n!, which implies N =\Omega(n\log n), by Stirling's formula.
A standard method for getting lower bounds of complexity consists of reducing a problem to another problem. More precisely, suppose that one may encode a problem of size into a subproblem of size of a problem , and that the complexity of is \Omega(g(n)). Without loss of generality, one may suppose that the function increases with and has an inverse function . Then the complexity of the problem is \Omega(g(h(n))). This is the method that is used to prove that, if P ≠ NP (an unsolved conjecture), the complexity of every NP-complete problem is \Omega(n^k), for every positive integer .
==Use in algorithm design==
Evaluating the complexity of an algorithm is an important part of algorithm design, as this gives useful information on the performance that may be expected.
It is a common misconception that the evaluation of the complexity of algorithms will become less important as a result of Moore's law, which posits the exponential growth of the power of modern computers. This is wrong because this power increase allows working with large input data (big data). For example, when one wants to sort alphabetically a list of a few hundreds of entries, such as the bibliography of a book, any algorithm should work well in less than a second. On the other hand, for a list of a million of entries (the phone numbers of a large town, for example), the elementary algorithms that require O(n^2) comparisons would have to do a trillion of comparisons, which would need around three hours at the speed of 10 million of comparisons per second. On the other hand, the quicksort and merge sort require only n\log_2 n comparisons (as average-case complexity for the former, as worst-case complexity for the latter). For , this gives approximately 30,000,000 comparisons, which would only take 3 seconds at 10 million comparisons per second.
Thus the evaluation of the complexity may allow eliminating many inefficient algorithms before any implementation. This may also be used for tuning complex algorithms without testing all variants. By determining the most costly steps of a complex algorithm, the study of complexity allows also focusing on these steps the effort for improving the efficiency of an implementation.
|
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] |
6,512 |
Coercion
|
Coercion involves compelling a party to act in an involuntary manner through the use of threats, including threats to use force against that party. It involves a set of forceful actions which violate the free will of an individual in order to induce a desired response. These actions may include extortion, blackmail, or even torture and sexual assault. Common-law systems codify the act of violating a law while under coercion as a duress crime.
Coercion used as leverage may force victims to act in a way contrary to their own interests. Coercion can involve not only the infliction of bodily harm, but also psychological abuse (the latter intended to enhance the perceived credibility of the threat). The threat of further harm may also lead to the acquiescence of the person being coerced. The concepts of coercion and persuasion are similar, but various factors distinguish the two. These include the intent, the willingness to cause harm, the result of the interaction, and the options available to the coerced party.
Political authors such as John Rawls, Thomas Nagel, and Ronald Dworkin contend whether governments are inherently coercive. In 1919, Max Weber (1864–1920), building on the view of Ihering (1818–1892), defined a state as "a human community that (successfully) claims a monopoly on the legitimate use of physical force". Morris argues that the state can operate through incentives rather than coercion. a practice which raises ethical concerns. Such practices has also been shown to cause moral distress among healthcare staff, especially when staff attitudes toward coercive measures are negative. To minimize the need for coercion in psychiatric care, various models such as Safewards and Six Core Strategies have been implemented with promising results.
==Overview==
The purpose of coercion is to substitute one's aims with weaker ones that the aggressor wants the victim to have. For this reason, many social philosophers have considered coercion as the polar opposite to freedom. Various forms of coercion are distinguished: first on the basis of the kind of injury threatened, second according to its aims and scope, and finally according to its effects, from which its legal, social, and ethical implications mostly depend.
===Physical===
Physical coercion is the most commonly considered form of coercion, where the content of the conditional threat is the use of force against a victim, their relatives or property. An often used example is "putting a gun to someone's head" (at gunpoint) or putting a "knife under the throat" (at knifepoint or cut-throat) to compel action under the threat that non-compliance may result in the attacker harming or even killing the victim. These are so common that they are also used as metaphors for other forms of coercion.
Armed forces in many countries use firing squads to maintain discipline and intimidate the masses, or opposition, into submission or silent compliance. However, there also are nonphysical forms of coercion, where the threatened injury does not immediately imply the use of force. Byman and Waxman (2000) define coercion as "the use of threatened force, including the limited use of actual force to back up the threat, to induce an adversary to behave differently than it otherwise would." Coercion does not in many cases amount to destruction of property or life since compliance is the goal.
====Pain compliance====
|
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] |
6,513 |
Client–server model
|
The client–server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate over a computer network on separate hardware, but both client and server may be on the same device. A server host runs one or more server programs, which share their resources with clients. A client usually does not share its computing resources, but it requests content or service from a server and may share its own content as part of the request. Clients, therefore, initiate communication sessions with servers, which await incoming requests.
Examples of computer applications that use the client–server model are email, network printing, and the World Wide Web.
==Client and server role==
The server component provides a function or service to one or many clients, which initiate requests for such services.
Servers are classified by the services they provide. For example, a web server serves web pages and a file server serves computer files. A shared resource may be any of the server computer's software and electronic components, from programs and data to processors and storage devices. The sharing of resources of a server constitutes a service.
Whether a computer is a client, a server, or both, is determined by the nature of the application that requires the service functions. For example, a single computer can run a web server and file server software at the same time to serve different data to clients making different kinds of requests. The client software can also communicate with server software within the same computer. Communication between servers, such as to synchronize data, is sometimes called inter-server or server-to-server communication.
==Client and server communication==
Generally, a service is an abstraction of computer resources and a client does not have to be concerned with how the server performs while fulfilling the request and delivering the response. The client only has to understand the response based on the relevant application protocol, i.e. the content and the formatting of the data for the requested service.
Clients and servers exchange messages in a request–response messaging pattern. The client sends a request, and the server returns a response. This exchange of messages is an example of inter-process communication. To communicate, the computers must have a common language, and they must follow rules so that both the client and the server know what to expect. The language and rules of communication are defined in a communications protocol. All protocols operate in the application layer. The application layer protocol defines the basic patterns of the dialogue. To formalize the data exchange even further, the server may implement an application programming interface (API). The API is an abstraction layer for accessing a service. By restricting communication to a specific content format, it facilitates parsing. By abstracting access, it facilitates cross-platform data exchange.
A server may receive requests from many distinct clients in a short period. A computer can only perform a limited number of tasks at any moment, and relies on a scheduling system to prioritize incoming requests from clients to accommodate them. To prevent abuse and maximize availability, the server software may limit the availability to clients. Denial of service attacks are designed to exploit a server's obligation to process requests by overloading it with excessive request rates.
Encryption should be applied if sensitive information is to be communicated between the client and the server.
==Example==
When a bank customer accesses online banking services with a web browser (the client), the client initiates a request to the bank's web server. The customer's login credentials are compared against a database, and the webserver accesses that database server as a client. An application server interprets the returned data by applying the bank's business logic and provides the output to the webserver. Finally, the webserver returns the result to the client web browser for display.
In each step of this sequence of client–server message exchanges, a computer processes a request and returns data. This is the request-response messaging pattern. When all the requests are met, the sequence is complete.
This example illustrates a design pattern applicable to the client–server model: separation of concerns.
==Server-side==
Server-side refers to programs and operations that run on the server. This is in contrast to client-side programs and operations which run on the client.
=== General concepts ===
"Server-side software" refers to a computer application, such as a web server, that runs on remote server hardware, reachable from a user's local computer, smartphone, or other device. Operations may be performed server-side because they require access to information or functionality that is not available on the client, or because performing such operations on the client side would be slow, unreliable, or insecure.
Client and server programs may be commonly available ones such as free or commercial web servers and web browsers, communicating with each other using standardized protocols. Or, programmers may write their own server, client, and communications protocol which can only be used with one another.
Server-side operations include both those that are carried out in response to client requests, and non-client-oriented operations such as maintenance tasks.
=== Computer security ===
In a computer security context, server-side vulnerabilities or attacks refer to those that occur on a server computer system, rather than on the client side, or in between the two. For example, an attacker might exploit an SQL injection vulnerability in a web application in order to maliciously change or gain unauthorized access to data in the server's database. Alternatively, an attacker might break into a server system using vulnerabilities in the underlying operating system and then be able to access database and other files in the same manner as authorized administrators of the server.
=== Examples ===
In the case of distributed computing projects such as SETI@home and the Great Internet Mersenne Prime Search, while the bulk of the operations occur on the client side, the servers are responsible for coordinating the clients, sending them data to analyze, receiving and storing results, providing reporting functionality to project administrators, etc. In the case of an Internet-dependent user application like Google Earth, while querying and display of map data takes place on the client side, the server is responsible for permanent storage of map data, resolving user queries into map data to be returned to the client, etc.
Web applications and services can be implemented in almost any language, as long as they can return data to standards-based web browsers (possibly via intermediary programs) in formats which they can use.
==Client side==
Client-side refers to operations that are performed by the client in a computer network.
=== General concepts ===
Typically, a client is a computer application, such as a web browser, that runs on a user's local computer, smartphone, or other device, and connects to a server as necessary. Operations may be performed client-side because they require access to information or functionality that is available on the client but not on the server, because the user needs to observe the operations or provide input, or because the server lacks the processing power to perform the operations in a timely manner for all of the clients it serves. Additionally, if operations can be performed by the client, without sending data over the network, they may take less time, use less bandwidth, and incur a lesser security risk.
When the server serves data in a commonly used manner, for example according to standard protocols such as HTTP or FTP, users may have their choice of a number of client programs (e.g. most modern web browsers can request and receive data using both HTTP and FTP). In the case of more specialized applications, programmers may write their own server, client, and communications protocol which can only be used with one another.
Programs that run on a user's local computer without ever sending or receiving data over a network are not considered clients, and so the operations of such programs would not be termed client-side operations.
=== Computer security ===
In a computer security context, client-side vulnerabilities or attacks refer to those that occur on the client / user's computer system, rather than on the server side, or in between the two. As an example, if a server contained an encrypted file or message which could only be decrypted using a key housed on the user's computer system, a client-side attack would normally be an attacker's only opportunity to gain access to the decrypted contents. For instance, the attacker might cause malware to be installed on the client system, allowing the attacker to view the user's screen, record the user's keystrokes, and steal copies of the user's encryption keys, etc. Alternatively, an attacker might employ cross-site scripting vulnerabilities to execute malicious code on the client's system without needing to install any permanently resident malware. and RFC 4. This usage was continued at Xerox PARC in the mid-1970s.
One context in which researchers used these terms was in the design of a computer network programming language called Decode-Encode Language (DEL). By 1992, the word server had entered into general parlance.
==Centralized computing==
The client-server model does not dictate that server-hosts must have more resources than client-hosts. Rather, it enables any general-purpose computer to extend its capabilities by using the shared resources of other hosts. Centralized computing, however, specifically allocates a large number of resources to a small number of computers. The more computation is offloaded from client-hosts to the central computers, the simpler the client-hosts can be. It relies heavily on network resources (servers and infrastructure) for computation and storage. A diskless node loads even its operating system from the network, and a computer terminal has no operating system at all; it is only an input/output interface to the server. In contrast, a rich client, such as a personal computer, has many resources and does not rely on a server for essential functions.
As microcomputers decreased in price and increased in power from the 1980s to the late 1990s, many organizations transitioned computation from centralized servers, such as mainframes and minicomputers, to rich clients. This afforded greater, more individualized dominion over computer resources, but complicated information technology management. During the 2000s, web applications matured enough to rival application software developed for a specific microarchitecture. This maturation, more affordable mass storage, and the advent of service-oriented architecture were among the factors that gave rise to the cloud computing trend of the 2010s.
==Comparison with peer-to-peer architecture==
In addition to the client-server model, distributed computing applications often use the peer-to-peer (P2P) application architecture.
In the client-server model, the server is often designed to operate as a centralized system that serves many clients. The computing power, memory and storage requirements of a server must be scaled appropriately to the expected workload. Load-balancing and failover systems are often employed to scale the server beyond a single physical machine.
Load balancing is defined as the methodical and efficient distribution of network or application traffic across multiple servers in a server farm. Each load balancer sits between client devices and backend servers, receiving and then distributing incoming requests to any available server capable of fulfilling them.
In a peer-to-peer network, two or more computers (peers) pool their resources and communicate in a decentralized system. Peers are coequal, or equipotent nodes in a non-hierarchical network. Unlike clients in a client-server or client-queue-client network, peers communicate with each other directly. In peer-to-peer networking, an algorithm in the peer-to-peer communications protocol balances load, and even peers with modest resources can help to share the load. If a node becomes unavailable, its shared resources remain available as long as other peers offer it. Ideally, a peer does not need to achieve high availability because other, redundant peers make up for any resource downtime; as the availability and load capacity of peers change, the protocol reroutes requests.
Both client-server and master-slave are regarded as sub-categories of distributed peer-to-peer systems.
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6,514 |
County Dublin
|
County Dublin ( or ) is a county in Ireland, and holds its capital city, Dublin. It is located on the island's east coast, within the province of Leinster. Until 1994, County Dublin (excluding the city) was a single local government area; in that year, the county council was divided into three new administrative counties: Dún Laoghaire–Rathdown, Fingal and South Dublin. The three administrative counties together with Dublin City proper form a NUTS III statistical region of Ireland (coded IE061). County Dublin remains a single administrative unit for the purposes of the courts (including the Dublin County Sheriff, but excluding the bailiwick of the Dublin City Sheriff) and Dublin County combined with Dublin City forms the Judicial County of Dublin, including Dublin Circuit Court, the Dublin County Registrar and the Dublin Metropolitan District Court. Dublin also sees law enforcement (the Garda Dublin metropolitan division) and fire services (Dublin Fire Brigade) administered county-wide.
Dublin is Ireland's most populous county, with a population of 1,458,154 – approximately 28% of the Republic of Ireland's total population. Dublin city is the capital and largest city of the Republic of Ireland, as well as the largest city on the island of Ireland. Roughly 9 out of every 10 people in County Dublin lives within Dublin city and its suburbs. Several sizeable towns that are considered separate from the city, such as Rush, Donabate and Balbriggan, are located in the far north of the county. Swords, while separated from the city by a green belt around Dublin Airport, is considered a suburban commuter town and an emerging small city.
The third smallest county by land area, Dublin is bordered by Meath to the west and north, Kildare to the west, Wicklow to the south and the Irish Sea to the east. The southern part of the county is dominated by the Dublin Mountains, which rise to around and contain numerous valleys, reservoirs and forests. The county's east coast is punctuated by several bays and inlets, including Rogerstown Estuary, Broadmeadow Estuary, Baldoyle Bay and most prominently, Dublin Bay. The northern section of the county, today known as Fingal, varies enormously in character, from densely populated suburban towns of the city's commuter belt to flat, fertile plains, which are some of the country's largest horticultural and agricultural hubs.
Dublin is the oldest county in Ireland, and was the first part of the island to be shired following the Norman invasion in the late 1100s. While it is no longer a local government area, Dublin retains a strong identity, and continues to be referred to as both a region and county interchangeably, including at government body level.
==Etymology==
County Dublin is named after the city of Dublin, which is an anglicisation of its Old Norse name . The city was founded in the 9th century AD by Viking settlers who established the Kingdom of Dublin. The Viking settlement was preceded by a Christian ecclesiastical site known as , from which took its name. derives from the Middle Irish word (literally "Blackpool"), from "black, dark" and "pool", referring to a dark tidal pool. This tidal pool was located where the River Poddle entered the Liffey, to the rear of Dublin Castle.
The hinterland of Dublin in the Norse period was named .
In addition to , a Gaelic settlement known as ('ford of hurdles') was located further up the Liffey, near present-day Father Mathew Bridge. means 'town of the hurdled ford', with referring to a fording point along the river. As with , an early Christian monastery was also located at , on the site that is currently occupied by the Whitefriar Street Carmelite Church.
Dublin was the first county in Ireland to be shired after the Norman Conquest in the late 12th century. The Normans captured the Kingdom of Dublin from its Norse-Gael rulers and the name was used as the basis for the county's official Anglo-Norman (and later English) name. However, in Modern Irish the region was named after the Gaelic settlement of or simply . As a result, Dublin is one of four counties in Ireland with a different name origin for both Irish and English – the others being Wexford, Waterford, and Wicklow, whose English names are also derived from Old Norse.
==History==
The earliest recorded inhabitants of present-day Dublin settled along the mouth of the River Liffey. The remains of five wooden fish traps were discovered near Spencer Dock in 2007. These traps were designed to catch incoming fish at high tide and could be retrieved at low tide. Thin-bladed stone axes were used to craft the traps and radiocarbon dating places them in the Late Mesolithic period (–5,700 BCE).
The Vikings invaded the region in the mid-9th century AD and founded what would become the city of Dublin. Over time they mixed with the natives of the area, becoming Norse–Gaels. The Vikings raided across Ireland, Britain, France and Spain during this period and under their rule Dublin developed into the largest slave market in Western Europe. While the Vikings were formidable at sea, the superiority of Irish land forces soon became apparent, and the kingdom's Norse rulers were first exiled from the region as early as 902. Dublin was captured by the High King of Ireland, Máel Sechnaill II, in 980, who freed the kingdom's Gaelic slaves. Dublin was again defeated by Máel Sechnaill in 988 and forced to accept Brehon law and pay taxes to the High King. Successive defeats at the hands of Brian Boru in 999 and, most famously, at the Battle of Clontarf in 1014, relegated Dublin to the status of lesser kingdom.
In 1170, the ousted King of Leinster, Diarmait Mac Murchada, and his Norman allies agreed to capture Dublin at a war council in Waterford. They evaded the intercepting army of High King Ruaidrí Ua Conchobair by marching through the Wicklow Mountains, arriving outside the walls of Dublin in late September. The King of Dublin, Ascall mac Ragnaill, met with Mac Murchada for negotiations; however, while talks were ongoing, the Normans, led by de Cogan and FitzGerald, stormed Dublin and overwhelmed its defenders, forcing mac Ragnaill to flee to the Northern Isles. Separate attempts to retake Dublin were launched by both Ua Conchobair and mac Ragnaill in 1171, both of which were unsuccessful.
The authority over Ireland established by the Anglo-Norman King Henry II was gradually lost during the Gaelic resurgence from the 13th century onwards. English power diminished so significantly that by the early 16th century English laws and customs were restricted to a small area around Dublin known as "The Pale". The Earl of Kildare's failed rebellion in 1535 reignited Tudor interest in Ireland, and Henry VIII proclaimed the Kingdom of Ireland in 1542, with Dublin as its capital. Over the next 60 years the Tudor conquest spread to every corner of the island, which was fully subdued by 1603.
Despite harsh penal laws and unfavourable trade restrictions imposed upon Ireland, Dublin flourished in the 18th century. The Georgian buildings which still define much of Dublin's architectural landscape to this day were mostly built over a 50-year period spanning from about 1750 to 1800. Bodies such as the Wide Streets Commission completely reshaped the city, demolishing most of medieval Dublin in the process. During the Enlightenment, the penal laws were gradually repealed and members of the Protestant Ascendancy began to regard themselves as citizens of a distinct Irish nation. The Irish Patriot Party, led by Henry Grattan, agitated for greater autonomy from Great Britain, which was achieved under the Constitution of 1782. These freedoms proved short-lived, as the Irish Parliament was abolished under the Acts of Union 1800 and Ireland was incorporated into the United Kingdom. Dublin lost its political status as a capital and went into a marked decline throughout the 19th century, leading to widespread demands to repeal the union.
Although at one time the second city of the British Empire, by the late 1800s Dublin was one of the poorest cities in Europe. The city had the worst housing conditions of anywhere in the United Kingdom, and overcrowding, disease and malnourishment were rife within central Dublin. In 1901, The Irish Times reported that the disease and mortality rates in Calcutta during the 1897 bubonic plague outbreak compared "favourably with those of Dublin at the present moment". Most of the upper and middle class residents of Dublin had moved to wealthier suburbs, and the grand Georgian homes of the 1700s were converted en masse into tenement slums. In 1911, over 20,000 families in Dublin were living in one-room tenements which they rented from wealthy landlords. Henrietta Street was particularly infamous for the density of its tenements, with 845 people living on the street in 1911, including 19 families – totalling 109 people – living in just one house.
After decades of political unrest, Ireland appeared to be on the brink of civil war as a result of the Home Rule Crisis. Despite being the centre of Irish unionism outside of Ulster, Dublin was overwhelmingly in favour of Home Rule. Unionist parties had performed poorly in the county since the 1870s, leading contemporary historian W. E. H. Lecky to conclude that "Ulster unionism is the only form of Irish unionism that is likely to count as a serious political force". Unlike their counterparts in the north, "southern unionists" were a clear minority in the rest of Ireland, and as such were much more willing to co-operate with the Irish Parliamentary Party (IPP) to avoid partition. Following the Anglo-Irish Treaty, Belfast unionist Dawson Bates decried the "effusive professions of loyalty and confidence in the Provisional Government" that was displayed by former unionists in the new Irish Free State.
The question of Home Rule was put on hold due to the outbreak of the First World War but was never to be revisited as a series of missteps by the British government, such as executing the leaders of the 1916 Easter Rising and the Conscription Crisis of 1918, fuelled the Irish revolutionary period. The IPP were nearly wiped out by Sinn Féin in the 1918 general election and, following a brief war of independence, 26 of Ireland's 32 counties seceded from the United Kingdom in December 1922, with Dublin becoming the capital of the Irish Free State, and later the Republic of Ireland.
From the 1960s onwards, Dublin city greatly expanded due to urban renewal works and the construction of large suburbs such as Tallaght, Coolock and Ballymun, which resettled both the rural and urban poor of County Dublin in newer state-built accommodation. Dublin was the driving force behind Ireland's Celtic Tiger period, an era of rapid economic growth that started in the early 1990s. In stark contrast to the turn of the 20th century, Dublin entered the 21st century as one of Europe's richest cities, attracting immigrants and investment from all over the world.
==Geography and subdivisions==
Dublin is the third smallest of Ireland's 32 counties by area, and the largest in terms of population. It is the third-smallest of Leinster's 12 counties in size and the largest by population. Dublin shares a border with three counties – Meath to the north and west, Kildare to the west and Wicklow to the south. To the east, Dublin has an Irish Sea coastline which stretches for .
Dublin is a topographically varied region. The city centre is generally very low-lying, and many areas of coastal Dublin are at or near sea-level. In the south of the county, the topography rises steeply from sea-level at the coast to over in just a few kilometres. This natural barrier has resulted in densely populated coastal settlements in Dún Laoghaire–Rathdown and westward urban sprawl in South Dublin. In contrast, Fingal is generally rural in nature and much less densely populated than the rest of the county. Consequently, Fingal is significantly larger than the other three local authorities and covers about 49.5% of County Dublin's land area. Fingal is also perhaps the flattest region in Ireland, with the low-lying Naul Hills rising to a maximum height of just .
Dublin is bounded to the south by the Wicklow Mountains. Where the mountains extend into County Dublin, they are known locally as the Dublin Mountains (Sléibhte Bhaile Átha Cliath). Kippure, on the Dublin–Wicklow border, is the county's highest mountain, at above sea level. Crossed by the Dublin Mountains Way, they are a popular amenity area, with Two Rock, Three Rock, Tibradden, Ticknock, Montpelier Hill, and Glenasmole being among the most heavily foot-falled hiking destinations in Ireland. Forest cover extends to over within the county, nearly all of which is located in the Dublin Mountains. With just 6.5% of Dublin under forest, it is the 6th least forested county in Ireland.
Much of the county is drained by its three major rivers – the River Liffey, the River Tolka in north Dublin, and the River Dodder in south Dublin. The Liffey, at in length, is the 8th longest river in Ireland, and rises near Tonduff in County Wicklow, reaching the Irish Sea at the Dublin Docklands. The Liffey cuts through the centre of Dublin city, and the resultant Northside–Southside divide is an often used social, economic and linguistic distinction. Notable inlets include the central Dublin Bay, Rogerstown Estuary, the estuary of the Broadmeadow and Killiney Bay, under Killiney Hill. Headlands include Howth Head, Drumanagh and the Portraine Shore. In terms of biodiversity, these estuarine and coastal regions are home to a wealth ecologically important areas. County Dublin contains 11 EU-designated Special Areas of Conservation (SACs) and 11 Special Protection Areas (SPAs).
The bedrock geology of Dublin consists primarily of Lower Carboniferous limestone, which underlies about two thirds of the entire county, stretching from Skerries to Booterstown. During the Lower Carboniferous (ca. 340 Mya), the area was part of a warm tropical sea inhabited by an abundance of corals, crinoids and brachiopods. The oldest rocks in Dublin are the Cambrian shales located on Howth Head, which were laid down ca. 500 Mya. Disruption following the closure of the Iapetus Ocean approximately 400 Mya resulted in the formation of granite. This is now exposed at the surface from the Dublin Mountains to the coastal areas of Dún Laoghaire. 19th-century Lead extraction and smelting at the Ballycorus Leadmines caused widespread lead poisoning, and the area was once nicknamed "Death Valley".
===Climate===
Dublin is in a maritime temperate oceanic region according to Köppen climate classification. Its climate is characterised by cool winters, mild humid summers, and a lack of temperature extremes. Met Éireann have a number of weather stations in the county, with its two primary stations at Dublin Airport and Casement Aerodrome.
Annual temperatures typically fall within a narrow range. In Merrion Square, the coldest month is February, with an average minimum temperature of , and the warmest month is July, with an average maximum temperature of . Due to the urban heat island effect, Dublin city has the warmest summertime nights in Ireland. The average minimum temperature at Merrion Square in July is , similar to London and Berlin, and the lowest July temperature ever recorded at the station was on 3 July 1974. At Dublin Airport, the driest month is February with of rainfall, and the wettest month is November, with of rain on average.
As the prevailing wind direction in Ireland is from the south and west, the Wicklow Mountains create a rain shadow over much of the county. Dublin's sheltered location makes it the driest place in Ireland, receiving only about half the rainfall of the west coast. Ringsend in the south of Dublin city records the lowest rainfall in the country, with an average annual precipitation of . The wettest area of the county is the Glenasmole Valley, which receives of rainfall per year. As a temperate coastal county, snow is relatively uncommon in lowland areas; however, Dublin is particularly vulnerable to heavy snowfall on rare occasions where cold, dry easterly winds dominate during the winter.
During the late summer and early autumn, Dublin can experience Atlantic storms, which bring strong winds and torrential rain to Ireland. Dublin was the county worst-affected by Hurricane Charley in 1986. It caused severe flooding, especially along the River Dodder, and is reputed to be the worst flood event in Dublin's history. Rainfall records were shattered across the county. Kippure recorded of rain over a 24-hour period, the greatest daily rainfall total ever recorded in Ireland. The government allocated IR£6,449,000 (equivalent to US$20.5 million in 2020) to repair the damage wrought by Charley. The two reservoirs at Bohernabreena in the Dublin Mountains were upgraded in 2006 after a study into the impact of Hurricane Charley concluded that a slightly larger storm would have caused the reservoir dams to burst, which would have resulted in catastrophic damage and significant loss of life.
===Offshore islands===
In contrast with the Atlantic Coast, the east coast of Ireland has relatively few islands. County Dublin has one of the highest concentrations of islands on the Irish east coast. Colt Island, St. Patrick's Island, Shenick Island and numerous smaller islets are clustered off the coast of Skerries, and are collectively known as the "Skerries Islands Natural Heritage Area". Further out lies Rockabill, which is Dublin's most isolated island, at about offshore. Lambay Island, at , is the largest island off Ireland's east coast and the easternmost point of County Dublin. Lambay supports one of the largest seabird colonies in Ireland and, curiously, also supports a population of non-native Red-necked wallabies. To the south of Lambay lies a smaller island known as Ireland's Eye – the result of a mistranslation of the island's Irish name by invading Vikings.
Bull Island is a man-made island lying roughly parallel to the shoreline which began to form following the construction of the Bull Wall in 1825. The island is still growing and is currently long and wide. In 1981, North Bull Island (Oileán an Tairbh Thuaidh) was designated as a UNESCO biosphere.
===Subdivisions===
For statistical purposes at European level, the county as a whole forms the Dublin Region – a NUTS III entity – which is in turn part of the Eastern and Midland Region, a NUTS II entity. Each of the local authorities have representatives on the Eastern and Midland Regional Assembly.
====Baronies====
There are ten historic baronies in the county. While baronies continue to be officially defined units, they ceased to have any administrative function following the Local Government Act 1898, and any changes to county boundaries after the mid-19th century are not reflected in their extent. The last boundary change of a barony in Dublin was in 1842, when the barony of Balrothery was divided into Balrothery East and Balrothery West. The largest recorded barony in Dublin in 1872 was Uppercross, at , and the smallest barony was Dublin, at .
====Townlands====
Townlands are the smallest officially defined geographical divisions in Ireland. There are 1,090 townlands in Dublin, of which 88 are historic town boundaries. These town boundaries are registered as their own townlands and are much larger than rural townlands. The smallest rural townlands in Dublin are just 1 acre in size, most of which are offshore islands (Clare Rock Island, Lamb Island, Maiden Rock, Muglins, Thulla Island). The largest rural townland in Dublin is 2,797 acres (Caastlekelly). The average size of a townland in the county (excluding towns) is 205 acres.
====Towns and suburbs====
====Urban and rural districts====
Under the Local Government (Ireland) Act 1898, County Dublin was divided into urban districts of Blackrock, Clontarf, Dalkey, Drumcondra, Clonliffe and Glasnevin, Killiney and Ballybrack, Kingstown, New Kilmainham, Pembroke, and Rathmines and Rathgar, and the rural districts of Balrothery, Celbridge No. 2, North Dublin, Rathdown, and South Dublin.
Howth, formerly within the rural district of Dublin North, became an urban district in 1919. Kingstown was renamed Dún Laoghaire in 1920. The rural districts were abolished in 1930.
Balbriggan, in the rural district of Balrothery, had town commissioners under the Towns Improvement (Ireland) Act 1854. This became a town council in 2002. In common with all town councils, it was abolished in 2014.
The urban districts were gradually absorbed by the city of Dublin, except for four coastal districts of Blackrock, Dalkey, Dún Laoghaire, and Killiney and Ballybrack, which formed the borough of Dún Laoghaire in 1930.
====County boundaries====
====Counties and the city====
The city of Dublin had been administered separately since the 13th century. Under the Local Government (Ireland) Act 1898, the two areas were defined as the administrative county of Dublin and the county borough of Dublin, with the latter in the city area.
In 1985, County Dublin was divided into three electoral counties: Dublin–Belgard to the southwest (South Dublin from 1991), Dublin–Fingal to the north (Fingal from 1991), and Dún Laoghaire–Rathdown to the southeast.
On 1 January 1994, under the Local Government (Dublin) Act 1993, the County Dublin ceased to exist as a local government area, and was succeeded by the counties of Dún Laoghaire–Rathdown, Fingal and South Dublin, each coterminous (with minor boundary adjustments) with the area of the corresponding electoral county. In discussing the legislation, Avril Doyle TD said, "The Bill before us today effectively abolishes County Dublin, and as one born and bred in these parts of Ireland I find it rather strange that we in this House are abolishing County Dublin. I am not sure whether Dubliners realise that that is what we are about today, but in effect that is the case."
Although the Electoral Commission should, as far as practicable, avoid breaching county boundaries when recommending Dáil constituencies, this does not include the boundaries of a city or the boundary between the three counties in Dublin. There is also still a sheriff appointed for County Dublin.
The term "County Dublin" is still in common usage. Many organisations and sporting teams continue to organise on a County Dublin basis. The Placenames Branch of the Department of Tourism, Culture, Arts, Gaeltacht, Sport and Media maintains a Placenames Database that records all placenames, past and present. County Dublin is listed in the database along with the subdivisions of that county. It is also used as an address for areas within Dublin outside of the Dublin postal district system.
For a period in 2020 during the COVID-19 pandemic, to reduce person-to-person contact, government regulations restricted activity to "within the county in which the relevant residence is situated". Within the regulations, the local government areas of "Dún Laoghaire–Rathdown, Fingal, South Dublin and Dublin City" were deemed to be a single county (as were the city and the county of Cork, and the city and the county of Galway).
The latest Ordnance Survey Ireland "Discovery Series" (Third Edition 2005) 1:50,000 map of the Dublin Region, Sheet 50, shows the boundaries of the city and three surrounding counties of the region. Extremities of the Dublin Region, in the north and south of the region, appear in other sheets of the series, 43 and 56 respectively.
==Local government==
There are four local authorities whose remit collectively encompasses the geographic area of the county and city of Dublin. These are Dublin City Council, South Dublin County Council, Dún Laoghaire–Rathdown County Council and Fingal County Council.
Until 1 January 1994, the administrative county of Dublin was administered by Dublin County Council. From that date, its functions were succeeded by Dún Laoghaire–Rathdown County Council, Fingal County Council and South Dublin County Council, each with its county seat, respectively administering the new counties established on that date.
The city was previously designated a county borough and administered by Dublin Corporation. Under the Local Government Act 2001, the country was divided into local government areas of cities and counties, with the county borough of Dublin being designated a city for all purposes, now administered by Dublin City Council. Each local authority is responsible for certain local services such as sanitation, planning and development, libraries, the collection of motor taxation, local roads and social housing.
Dublin, comprising the four local government areas in the county, is a strategic planning area within the Eastern and Midland Regional Assembly (EMRA). It is a NUTS Level III region of Ireland. The region is one of eight regions of Ireland for Eurostat statistics at NUTS 3 level. Its NUTS code is IE061.
This area formerly came under the remit of the Dublin Regional Authority. This Authority was dissolved in 2014.
==Demographics==
===Population===
As of the 2022 census, the population of Dublin was 1,458,154, an 8.4% increase since the 2016 Census. The county's population first surpassed 1 million in 1981, and is projected to reach 1.8 million by 2036.
Dublin is Ireland's most populous county, a position it has held since the 1926 Census, when it overtook County Antrim. As of 2022, County Dublin has over twice the population of County Antrim and two and a half times the population of County Cork. Approximately 21% of Ireland's population lives within County Dublin (28% if only the Republic of Ireland is counted). Additionally, Dublin has more people than the combined populations of Ireland's 16 smallest counties.
With an area of just , Dublin is by far the most densely populated county in Ireland. The population density of the county is 1,582 people per square kilometre – over 7 times higher than Ireland's second most densely populated county, County Down in Northern Ireland.
During the Celtic Tiger period, a large number of Dublin natives (Dubliners) moved to the rapidly expanding commuter towns in the adjoining counties. As of 2022, approximately 27.2% (345,446) of Dubliners were living outside of County Dublin. People born within Dublin account for 28% of the population of Meath, 32% of Kildare, and 37% of Wicklow. There are 922,744 Dublin natives living within the county, accounting for 63.3% of the population. People born in other Irish counties living within Dublin account for roughly 11% of the population.
Between 2016 and 2022, international migration produced a net increase of 88,300 people. Dublin has the highest proportion of international residents of any county in Ireland, with around 25% of the county's population being born outside of the Republic of Ireland.
As of the 2022 census, 5.6 percent of the county's population was reported as younger than 5 years old, 25.7 percent were between 5 and 25, 55.3 percent were between 25 and 65, and 13.4 percent of the population was older than 65. Of this latter group, 48,865 people (3.4 percent) were over the age of 80, more than doubling since 2016. Across all age groups, there were slightly more females (51.06 percent) than males (48.94 percent).
In 2021, there were 16,596 births within the county, and the average age of a first time mother was 31.9.
===Migration===
Over a quarter (25.2 percent) of County Dublin's population was born outside of the Republic of Ireland. In 2022, Dublin City had the highest percentage of non-nationals in the county (27.3 percent), and South Dublin had the lowest (20.9 percent). Historically, the immigrant population of Dublin was mainly from the United Kingdom and other European Union member states. However, results from the 2022 census revealed that immigrants from non-EU/UK countries were the largest source of foreign-born residents for the first time, accounting for 12.9 percent of the county's population. Those from other European Union member states accounted for 8.3 percent of Dublin's population, and those from the United Kingdom a further 4.1 percent.
Prior to the 2000s, the UK was consistently the largest single source of non-nationals living in Dublin. After declining in the previous two census periods, the number of UK-born residents living in Dublin increased by 5.8 percent between 2016 and 2022. There was a large difference between the number of people living in Dublin who were born in the UK (58,586) and those who held sole-UK citizenship in the 2022 census (22,936). This discrepancy can arise for a variety of factors, such as people born in Northern Ireland claiming Irish citizenship rather than UK citizenship, Irish people born in the UK who now live in Dublin, British people who have become natural citizens, and foreign residents of Dublin who were born in the UK but are not UK citizens. Depending on an individual's responses in the census, all of these examples could result in the country of birth being registered by the CSO as the United Kingdom, but nationality being registered as Irish or a third country.
Following its accession to the EU, the Polish quickly became the fastest growing immigrant community in Dublin. Just 188 Poles applied for Irish work permits in 1999. By 2006 this number had grown to 93,787. After the 2008 Irish economic downturn, as many as 3,000 Poles left Ireland each month. Despite this, Poles remain one of Dublin's largest foreign-born groups. In contrast to more recent arrivals, a large percentage of Dublin's Polish citizens (30.9 percent) also hold Irish citizenship.
Outside of Europe, Indians and Brazilians are the predominant foreign-national groups. As of 2022, Indians were the fastest growing major immigrant group in Dublin, and they are now the county's second largest foreign-born group after the UK. Dublin's Indian community grew by 155.2 percent between 2016 and 2022. There were 29,582 Indian-born residents within Dublin as of 2022, up from 9,884 in the 2011 census. The influx of Indians is driven in part by multinational tech companies such as Microsoft, Google and Meta who have located their European headquarters within the county, in areas such as the Silicon Docks and Sandyford. In August 2020, the first dedicated Hindu temple in Ireland was built in Walkinstown.
The number of Brazilian citizens living in Dublin more than tripled between 2011 and 2022, from 4,641 to 16,441. This increase is mainly a result of Ireland's participation in the Brazilian government's Ciência sem Fronteiras programme, which sees thousands of Brazilian students come to study in Ireland each year, many of whom remain in the country afterwards.
Although not fully captured during the census period, Dublin also houses a significant number of Ukrainian refugees under the Temporary Protection Directive. As of October 2023, the number of Ukrainians living in emergency accommodation within the county is estimated to be around 14,000.
===Ethnicity===
According to the Central Statistics Office, in 2022 the population of County Dublin self-identified as:
80.4% White (68.0% White Irish, 12.0% Other White Background, 0.4% Irish Traveller)
5.8% Asian
3.0% Mixed background
2.2% Black
8.5% Not stated
In terms of total numbers, Dublin has the largest non-white population in Ireland, with an estimated 158,653 residents, accounting for 11.1% of the county's population. Over two-fifths (42.2 percent) of Ireland's black residents live within the county. In terms of percentage of population, Fingal has the highest percentage of both black (3.6 percent) and non-white (12.4 percent) residents of any local authority in Ireland. Conversely, Dún Laoghaire–Rathdown in the south of the county has one of Ireland's lowest percentages of black residents, with only 0.77% of the population identifying as black in 2022. Additionally, 43.3% of Ireland's multiracial population lives within County Dublin. Those who did not state their ethnicity more than doubled between 2016 and 2022, from 4.1% to 8.5%.
===Religion===
The largest religious denomination by both number of adherents and as a percentage of Dublin's population in 2022 was the Roman Catholic Church, at 57.4 percent. All other Christian denominations including Church of Ireland, Eastern Orthodox, Presbyterian and Methodist accounted for 8.1 percent of Dublin's population. Together, all denominations of Christianity accounted for 65.5 percent of the county's population. According to the 2022 census, Dún Laoghaire–Rathdown is the least religious local authority in Ireland, with 23.9 percent of the population declaring themselves non-religious, followed closely by Dublin city (22.6 percent). In the county as a whole, those unaffiliated with any religion represented 20.1 percent of the population, which is the largest percentage of non-religious people of any county in Ireland. A further 9.1 percent of the population did not state their religion, up from just 4.1 percent in 2016.
Of the non-Christian religions, Islam is the largest in terms of number of adherents, with Muslims accounting for 2.6% of the population. After Islam, the largest non-Christian religions in 2022 were Hinduism (1.4 percent) and Buddhism (0.27 percent). While relatively small in absolute terms, County Dublin contains over half of Ireland's Hindu (58.7 percent) residents, and just under half of its Eastern Orthodox (45.3 percent), Islamic (45.0 percent) and Buddhist (41.7 percent) residents.
Dublin and its hinterland has been a Christian diocese since 1028. For centuries, the Primacy of Ireland was disputed between Dublin, the social and political capital of Ireland, and Armagh, site of Saint Patrick's main church, which was founded in 445 AD. In 1353 the dispute was settled by Pope Innocent VI, who proclaimed that the Archbishop of Dublin was Primate of Ireland, while the Archbishop of Armagh was titled Primate of All Ireland. These two distinct titles were replicated in the Church of Ireland following the Reformation. Historically, County Dublin was the epicentre of Protestantism in Ireland outside of Ulster. Records from the 1891 census show that the county was 21.4 percent Protestant towards the end of the 19th century. By the 1911 census this had gradually declined to around 20% due to poor economic conditions, as Dublin Protestants moved to industrial Belfast. Following the War of Independence (1919–1921), Dublin's Protestant community went into a steady decline, falling to 8.5 percent of the population by 1936.
Between 2016 and 2022, the fastest growing religions in Dublin were Hinduism (148.9 percent), Eastern Orthodox (51.6 percent), and Islam (27.9 percent), while the most rapidly declining religions were Evangelicalism (−10.4 percent), Catholicism (−8.7 percent), Jehovah's Witnesses (−5.9 percent) and Buddhism (−5.4 percent).
===Metropolitan area===
====Dublin city====
The boundaries of Dublin City Council form the urban core of the city, often referred to as "Dublin city centre", an area of 117.8 square kilometres. This encompasses the central suburbs of the city, extending as far south as Terenure and Donnybrook; as far north as Ballymun and Donaghmede; and as far west as Ballyfermot. As of 2022, there were 592,713 people living within Dublin city centre. However, as the continuous built-up area extends beyond the city boundaries, the term "Dublin city and suburbs" is commonly employed when referring to the actual extent of Dublin.
====Dublin city and suburbs====
Dublin city and suburbs is a CSO-designated urban area which includes the densely populated contiguous built-up area which surrounds Dublin city centre. As of the 2022 census, Dublin city and suburbs encompassed 345 km2, expanding in size by 8.7 percent (or 27.5 km2) since the 2016 census. The population of Dublin city and suburbs grew from 1,173,179 in 2016 to 1,263,219 in 2022, an increase of 7.7 percent.
Following the 2022 census, Dublin city and suburbs was designated a cross-county settlement for the first time, as the CSO included the Kribensis Manor housing development within the contiguous built-up area of the city. The houses are located in County Meath, along the R149 road between Hilltown and the village of Clonee.
Approximately 87% of County Dublin's population lives within Dublin city and suburbs as of the 2022 census. The remainder of the county covers roughly two thirds of Dublin's land area, but is home to just 196,140 people.
====Dublin metropolitan area====
As the city proper does not extend beyond Dublin Airport, nearby towns such as Swords, Donabate, Portmarnock and Malahide are not considered part of the city, and are recorded by the CSO as separate settlements. However, under Ireland's National Planning Framework, these towns are considered part of the Dublin Metropolitan Area Strategic Plan (MASP). The MASP also includes towns outside of the county, such as Naas, Leixlip and Maynooth in County Kildare, Dunboyne in County Meath, and Bray, Kilmacanogue and Greystones in County Wicklow, but does not include Balbriggan, Lusk, Rush or Skerries, which are located in the far north of County Dublin.
====Greater Dublin Area====
The Greater Dublin Area (GDA) is a commonly used planning jurisdiction which extends to the wider network of commuter towns that are economically connected to Dublin city. The GDA consists of County Dublin and its three neighboring counties, Kildare, Meath and Wicklow.
With a population of 2.1 million and an area of 6,986 square kilometres, it contains 40% of the population of the State, and covers 9.9% of its land area.
===Urban areas===
Under CSO classification, an "urban area" is a town with a population greater than 1,500. Dublin is the most urbanised county in Ireland, with 98% of its residents residing in urban areas as of 2022. Of Dublin's three non-city local authorities, Fingal has the highest proportion of people living in rural areas (7.9%), while Dún Laoghaire–Rathdown has the lowest (1.19%). The western suburbs of Dublin city such as Tallaght and Blanchardstown have experienced rapid growth in recent decades, and both areas have a population roughly equivalent to Galway city.
==Transportation==
County Dublin has the oldest and most extensive transportation infrastructure in Ireland. The Dublin and Kingstown Railway, opened in December 1834, was Ireland's first railway line. The line, which ran from Westland Row to Dún Laoghaire, was originally intended to be used for cargo. However, it proved far more popular with passengers and became the world's first commuter railway line. The line has been upgraded multiple times throughout its history and is still in use to this day, making it the oldest commuter railway route in the world.
Public transport in Dublin was managed by the Dublin Transportation Office until 2009, when it was replaced by the National Transport Authority (NTA). The three pillars currently underpinning the public transport network of the Greater Dublin Area (GDA) are Dublin Suburban Rail, the Luas and the bus system. There are six commuter lines in Dublin, which are managed by Iarnród Éireann. Five of these lines serve as routes between Dublin and towns across the GDA and beyond. The sixth route, known as Dublin Area Rapid Transit (DART), is electrified and serves only Dublin and northern Wicklow. The newest addition to Dublin's public transport network is a tram system called the Luas. The service began with two disconnected lines in 2004, with three extensions opened in 2009, 2010 and 2011 before a cross-city link between the lines and further extension opened in 2017.
Historically, Dublin had an extensive tram system which commenced in 1871 and at its peak had over of active line. It was operated by the Dublin United Transport Company (DUTC) and was very advanced for its day, with near-full electrification from 1901. From the 1920s onwards, the DUTC began to acquire private bus operators and gradually closed some of its lines. Further declines in passenger numbers were driven in part by a belief at the time that trams were outdated and archaic. All tram lines terminated in 1949, except for the tram to Howth, which ran until 1959.
Dublin Bus is the county's largest bus operator, carrying 138 million passengers in 2019. For much of the city, particularly west Dublin, the bus is the only public transport option available, and there are numerous smaller private bus companies in operation across County Dublin. National bus operator Bus Éireann provides long-distance routes to towns and villages located outside of Dublin city and its immediate hinterland.
In November 2005, the government announced a €34 billion initiative called Transport 21 which included a substantial expansion to Dublin's transport network. The project was cancelled in May 2011 in the aftermath of the 2008 recession. Consequently, by 2017 Hugh Creegan, deputy chief of the NTA, stated that there had been a "chronic underinvestment in public transport for more than a decade". By 2019, Dublin was reportedly the 17th most congested city in the world, and had the 5th highest average commute time in the European Union. The Luas and rail network regularly experience significant overcrowding and delays during peak hours, and in 2019 Iarnród Éireann was widely ridiculed for asking commuters to "stagger morning journeys" to alleviate the problem.
The M50 is a orbital motorway around Dublin city, and is the busiest motorway in the country. It serves as the centre of both Dublin and Ireland's motorway network, and most of the national primary roads to other cities begin at the M50 and radiate outwards. The current route was built in various sections over the course of 27 years, from 1983 to 2010. All major roads in Ireland are managed by Transport Infrastructure Ireland (TII), which is headquartered in Parkgate Street, Dublin 8. As of 2019, there were over 550,000 cars registered in County Dublin, accounting for 25.3% of all cars registered in the State. Due to the county's small area and high degree of urbanisation, there is a preference for "D" registered used cars throughout Ireland, as they are considered to have undergone less wear and tear.
For international travel, around 1.7 million passengers travel by ferry through Dublin Port each year. A Dún Laoghaire to Holyhead ferry was formerly operated by Stena Line, but the route was closed in 2015. Dublin Airport is Ireland's largest airport, and 32.9 million passengers passed through it in 2019, making it Europe's 12th-busiest airport.
==Economy==
The Dublin Region, which is conterminous with County Dublin, has the largest and most highly developed economy in Ireland, accounting for over two-fifths of national Gross Domestic Product (GDP). The Central Statistics Office estimates that the GDP of the Dublin Region in 2020 was €157.2 billion ($187 billion / £141 billion at 2020 exchange rates). In nominal terms, Dublin's economy is larger than roughly 140 sovereign states. The county's GDP per capita is €107,808 ($117,688 / £92,620), one of the highest regional GDPs per capita in the EU. As of 2019, Dublin also had the highest Human Development Index in Ireland at 0.965, placing it among the most developed places in the world in terms of life expectancy, education and per capita income.
===Affluence===
In 2020, average disposable income per person in Dublin was €27,686, or 118% of the national average (€23,400), the highest of any county in Ireland. As Ireland's most populous county, Dublin has the highest total household income in the country, at an estimated €46.8 billion in 2017 – higher than the Border, Midlands, West and South-East regions combined. Dublin residents were the highest per capita tax contributors in the State, returning a total of €15.1 billion in taxes in 2017.
Many of Ireland's most prominent political, educational, cultural and media centres are concentrated south of the River Liffey in Dublin city. Further south, areas like Dún Laoghaire, Dalkey and Killiney have long been some of Dublin's most affluent areas, and Dún Laoghaire–Rathdown consistently has the highest average house prices in Ireland. This has resulted in a perceived socio-economic divide in Dublin, between the generally less affluent Northside and the wealthier Southside. In Dublin (both city and county), residents will commonly refer to themselves as a "Northsider" or a "Southsider", and the division is often caricatured in Irish comedy, media and literature, for example Ross O'Carroll-Kelly and Damo and Ivor. References to the divide have also become colloquialisms in their own right, such as "D4" (referring to the Dublin 4 postal district), which is a pejorative term for an upper middle class Irish person.
While the northside-southside divide remains prevalent in popular culture, economic indices such as the Pobal HP deprivation index have shown that the distinction does not reflect economic reality. Many of Dublin's most affluent areas (Clontarf, Raheny, Howth, Portmarnock, Malahide) are located in the north of the county, and many of its most deprived areas (Jobstown, Ballyogan, Ballybrack, Dolphin's Barn, Clondalkin) are located in the south of the county.
Utilising CSO data from the past three censuses, Pobal HP revealed that there was a much higher concentration of below average, disadvantaged and very disadvantaged areas in west Dublin. In 2012, Irish Times columnist Fintan O'Toole posited that the real economic divide in Dublin was not north–south, but east–west – between the older coastal areas of eastern Dublin and the newer sprawling suburbs of western Dublin – and that the perpetuation of the northside–southside "myth" was a convenient way to gloss over class division within the county. O'Toole argued that framing the city's wealth divide as a light-hearted north–south stereotype was easier than having to address the socio-economic impacts of deliberate government policy to remove working-class people from the city centre and settle them on the margins.
===Finance===
Dublin is both a European and Global financial hub, and around 200 of the world's leading financial services firms have operations within the county. In 2017 and 2018 respectively, Dublin was ranked 5th in Europe and 31st globally in the Global Financial Centres Index (GFCI). In the mid-1980s, parts of central Dublin had fallen into a state of dereliction and the Irish government pursued an urban regeneration programme. An 11-hectare special economic zone (SEZ) was set up in 1987, known as the International Financial Services Centre (IFSC). At the time of its establishment, the SEZ had the lowest corporate tax rate in the EU. The IFSC has since expanded into a 37.8-hectare site centred around the Dublin Docklands. As of 2020, over €1.8 trillion of funds are administered from Ireland.
There was renewed interest in Dublin's financial services sector in the wake of the UK's vote to withdraw from the European Union in 2016. Many firms, including Barclays and Bank of America, pre-emptively moved some of their operations from London to Dublin in anticipation of restricted EU market access. A survey conducted by Ernst & Young in 2021 found that Dublin was the most popular destination for firms in the UK considering relocating to the EU, ahead of Luxembourg and Frankfurt. It is estimated that Dublin's financial sector will grow by about 25% as a direct result of Brexit, and as many as 13,000 jobs could move from the UK to County Dublin in the years immediately after its withdrawal.
===Industry and energy===
The economy of Dublin benefits from substantial amounts of both indigenous and foreign investment. In 2018, the Financial Times ranked Dublin the most attractive large city in the world for Foreign Direct Investment, and the city has been consistently ranked by Forbes as one of the world's most business-friendly. The economy is centered on financial services, the pharmaceuticals and biotechnology industries, information technology, logistics and storage, professional services, agriculture and tourism. IDA Ireland, the state agency responsible for attracting foreign direct investment, was founded in Dublin in 1949.
Dublin has four power plants, all of which are concentrated in the docklands area of Dublin city. Three are natural-gas plants operated by the ESB, and the Poolbeg Incinerator is operated by Covanta Energy. The four plants have a combined capacity of 1.039 GW, roughly 12.5% of the island of Ireland's generation capacity as of 2019. The disused Poolbeg chimneys are the tallest structures in the county, and were granted protection by Dublin city council in 2014.
As a result of Dublin city's location within a sheltered bay at the mouth of a navigable river, shipping has been a key industry in the county since medieval times. By the 18th-century, Dublin was a bustling maritime city and large-scale engineering projects were undertaken to enhance the port's capacity, such as the Great South Wall, which was the largest sea wall in the world at the time of its construction in 1715. Dublin Port was originally located along the Liffey, but gradually moved towards the coast over the centuries as vessel size increased. It is today the largest and busiest port in Ireland. It handles 50% of the Republic of Ireland's trade, and receives 60% of all vessel arrivals.
Dublin Port occupies an area of in one of the most expensive places in the country, with an estimated price per acre of around €10 million. Since the 2000s, there have been calls to relocate Dublin Port out of the city and free up its land for residential and commercial development. This was first proposed by the Progressive Democrats at the height of the Celtic Tiger in 2006, who valued the land at between €25 and €30 billion, although nothing became of this proposal. During the housing crisis of the late 2010s the idea again began to attract supporters, among them economist David McWilliams. Currently, there are no official plans to move the port elsewhere, and the Dublin Port Company strongly opposes relocation.
Dublin hosts the headquarters of some of Ireland's largest multinational corporations, including 14 of the 20 companies which make up the ISEQ 20 index – those with the highest trading volume and market capitalisation of all Irish Stock Exchange listed companies. These are: AIB, Applegreen, Bank of Ireland, Cairn Homes, Continental Group, CRH, Dalata Hotel Group, Flutter Entertainment, Greencoat Renewables, Hibernia REIT, IRES, Origin Enterprises, Ryanair and Smurfit Kappa.
===Tourism===
County Dublin receives by far the most overseas tourists of any county in Ireland. This is primarily due to Dublin city's status as Ireland's largest city and its transportation hub. Dublin is also Ireland's most popular destination for domestic tourists. According to Fáilte Ireland, in 2017 Dublin received nearly 6 million overseas tourists, and just under 1.5 million domestic tourists. Most of Ireland's international flights transit through Dublin Airport, and the vast majority of passenger ferry arrivals dock at Dublin Port. In 2019, the port also facilitated 158 cruise ship arrivals. The tourism industry in the county is worth approximately €2.3 billion per year.
As of 2019, 4 of the top 10 fee-paying tourist attractions in Ireland are located within County Dublin, as well as 5 of the top 10 free attractions. The Guinness Storehouse at St. James's Gate is Ireland's most visited tourist attraction, receiving 1.7 million visitors in 2019, and over 20 million total visits since 2000. Additionally, Dublin also contains Ireland's 3rd (Dublin Zoo), 4th (Book of Kells) and 6th (St Patrick's Cathedral) most visited fee-paying attractions. The top free attractions in Dublin are the National Gallery of Ireland, the National Botanic Gardens, the National Museum of Ireland and the Irish Museum of Modern Art, all of which receive over half a million visitors per year.
===Agriculture===
Despite having the smallest farmed area of any county, Dublin is one of Ireland's major agricultural producers. Dublin is the largest producer of fruit and vegetables in Ireland, the third largest producer of oilseed rape and has the fifth largest fishing industry. Fingal alone produces 55% of Ireland's fresh produce, including soft fruits and berries, apples, lettuces, peppers, asparagus, potatoes, onions, and carrots. As of 2020, the Irish Farmers' Association estimates that the total value of Dublin's agricultural produce is €205 million. According to the CSO, fish landings in the county are worth a further €20 million.
Approximately 41% of the county's land area (38,576 ha) is farmed. Of this, is under tillage, the 9th highest in the country, and is dedicated to fruit & horticulture, the 4th highest. Rural County Dublin is considered a peri-urban region, where an urban environment transitions into a rural one. Due to the growth of Dublin city and its commuter towns in the north of the county, the region is considered to be under significant pressure from urban sprawl. Between 1991 and 2010, the amount of agricultural land within the county decreased by 22.9%. In 2015, the local authorities of Fingal, South Dublin and Dún Laoghaire–Rathdown developed a joint Dublin Rural Local Development Strategy aimed at enhancing the region's agricultural output, while also managing and minimising the impact of urbanisation on biodiversity and the identity and culture of rural Dublin.
The county has a small forestry industry that is based almost entirely in the upland areas of south County Dublin. According to the 2017 National Forestry Inventory, of the county was under forest, of which was private forestry. The majority of Dublin's forests are owned by the national forestry company, Coillte. In the absence of increased private planting, the county's commercial timber capacity is expected to decrease in the coming decades, as Coillte intends to convert much of their holdings in the Dublin Mountains into non-commercial mixed forests.
Dublin has 810 individual farms with an average size of , the largest average farm size of any county in Ireland. Roughly 9,400 people within the county are directly employed in either agriculture or the food and drink processing industry. Numerous Irish and multinational food and drink companies are either based in Dublin or have facilities within the county, including Mondelez, Coca-Cola, Mars, Diageo, Kellogg's, Danone, Ornua, Pernod Ricard and Glanbia. In 1954, Tayto Crisps were established in Coolock and developed into cultural phenomenon throughout much of the Republic of Ireland. Its operations and headquarters have since moved to neighbouring County Meath. Another popular crisp brand, Keogh's, are based in Oldtown, Fingal.
==Education==
In Ireland, spending on education is controlled by the government and the allocation of funds is decided each year in the annual budget. Local authorities retain limited responsibilities such as funding for school meals, service supports costs and the upkeep of libraries.
There are hundreds of primary and secondary schools within County Dublin, most of which are English-language schools. Several international schools are based in Dublin, such as St Kilian's German School and Lycée Français d'Irlande, which teach in foreign languages. There is also a large minority of students attending gaelscoileanna (Irish-language primary schools). There are 34 gaelscoileanna and 10 gaelcholáistí (Irish-language secondary schools) in the county, with a total of 12,950 students as of 2018. In terms of college acceptance rates, gaelcholáistí are consistently the best performing schools in Dublin, and among the best performing in Ireland.
Although the government pays for a large majority of school costs, including teachers' salaries, the Roman Catholic Church is the largest owner of schools in Dublin, and preference is given to Catholic students over non-Catholic students in oversubscribed areas. This has resulted in a growing movement towards non-denominational and co-educational schools in the county.
The majority of private secondary schools in Dublin are still single sex, and continue to have religious patronages with either congregations of the Catholic Church (Spiritans, Sisters of Loreto, Jesuits) or Protestant denominations (Church of Ireland, Presbyterian). Newer private schools which cater for the Leaving Cert cycle such as the Institute of Education and Ashfield College are generally non-denominational and co-educational. In 2018, Nord Anglia International School Dublin opened in Leopardstown, becoming the most expensive private school in Ireland.
As of 2023–24, four of Dublin's third level institutions are listed in the Top 500 of either the Times Higher Education Rankings or the QS World Rankings, placing them amongst the top 5% of all third level institutions in the world. TCD (81), UCD (171) and DCU (436) are within the Top 500 of the QS rankings; and TCD (161), RCSI (201–250), UCD (201–250) and DCU (451–500) and are within the Top 500 of the Times rankings. Newly amalgamated TUD also placed within the world's Top 1,000 universities in the QS rankings, and within the Top 500 for Engineering and Electronics.
County Dublin has four public universities, as well as numerous other colleges, institutes of technology and institutes of further education. Several of Dublin's largest third level institutions and their associated abbreviations are listed below:
Dublin Business School (DBS)
Dublin City University (DCU)
Dún Laoghaire Institute of Art, Design and Technology (IADT)
Griffith College Dublin (GCD)
National College of Ireland (NCI)
Royal College of Surgeons in Ireland (RCSI)
Technological University Dublin (TUD)
Trinity College Dublin (TCD)
University College Dublin (UCD)
==Politics==
===Elections===
For elections to Dáil Éireann, the area of the county is currently divided into eleven constituencies: Dublin Bay North, Dublin Bay South, Dublin Central, Dublin Fingal, Dublin Mid-West, Dublin North-West, Dublin Rathdown, Dublin South-Central, Dublin South-West, Dublin West, and Dún Laoghaire. Together they return 45 deputies (TDs) to the Dáil.
The first Irish Parliament convened in the small village of Castledermot, County Kildare on 18 June 1264. Representatives from seven constituencies were present, one of which was the constituency of Dublin City. Dublin was historically represented in the Irish House of Commons through the constituencies of Dublin City and County Dublin. Three smaller constituencies had been created by the 17th century: Swords; which was created sometime between 1560 and 1585, with Walter Fitzsimons and Thomas Taylor being its first recorded MPs; Newcastle in the west of the county, created in 1613; and Dublin University, which was a university constituency covering Trinity College, also created in 1613. While proceedings of the Irish Parliament were well-documented, many of the records from this time were lost during the shelling of the Four Courts in July 1922.
Following the Acts of Union 1800, Dublin was represented in Westminster through three constituencies from 1801 to 1885: Dublin City, County Dublin and the Dublin University. A series of local government and electoral reforms in the late 19th century radically alerted the county's political map, and by 1918 there were twelve constituencies within County Dublin.
Throughout the twentieth century the representation in Dublin expanded as the population grew. In the Electoral Act 1923, the first division of constituencies arranged by Irish legislation, geographical constituencies in Dublin were 23 of the 147 TDs in geographical constituencies; this contrasts with 45 of 160 at the most recent division.
Twenty-three Dáil Éireann constituencies have been created and abolished within the county since independence, the most recent being the constituencies of Dublin South, Dublin North, Dublin North-Central, Dublin North-East and Dublin South-East, which were abolished in 2016.
Of the fifteen people to have held the office of Taoiseach since 1922, more than half were either born or raised within County Dublin: W. T. Cosgrave, John A. Costello, Seán Lemass, Liam Cosgrave, Charles Haughey (born in County Mayo but raised in Dublin), Garret FitzGerald, Bertie Ahern and Leo Varadkar (Cosgrave held the office of President of the Executive Council; by convention, Taoisigh are numbered to include this position). Conversely, just one of Ireland's nine presidents have hailed from the county, namely Seán T. O'Kelly, who served as president from 1945 to 1959.
====European elections====
The four local government areas in County Dublin form the 4-seat constituency of Dublin in European Parliament elections.
===National government===
As the capital city, Dublin is the seat of the national parliament of Ireland, the Oireachtas. It is composed of the President of Ireland, Dáil Éireann as a house of representatives, and Seanad Éireann as an upper house. Both houses of the Oireachtas meet in Leinster House, a former ducal palace on Kildare Street. It has been the home of the Irish government since the creation of the Irish Free State. The First Dáil of the revolutionary Irish Republic met in the Round Room of the Mansion House, the present-day residence of the Lord Mayor of Dublin, in January 1919. The former Irish Parliament, which was abolished in 1801, was located at College Green; Parliament House now holds a branch of Bank of Ireland. Government Buildings, located on Merrion Street, houses the Department of the Taoiseach, the Council Chamber, the Department of Finance, and the Office of the Attorney General.
The president resides in Áras an Uachtaráin in Phoenix Park, a stately ranger's lodge built in 1757. The house was bought by the Crown in 1780 to be used as the summer residence of the Lord Lieutenant of Ireland, the British viceroy in the Kingdom of Ireland. Following independence, the lodge was earmarked as the potential home of the Governor-General, but this was highly controversial as it symbolised continued British rule over Ireland, so it was left empty for many years. President Douglas Hyde "temporarily" occupied the building in 1938, as Taoiseach Éamon de Valera intended to demolish it and build a more modest presidential bungalow on the site. Those plans were scrapped during The Emergency and the lodge became the president's permanent residence.
Much like Áras an Uachtaráin, many of the grand estate homes of the former aristocracy were re-purposed for State use in the 20th century. The Deerfield Residence, also in Phoenix Park, is the official residence of the United States Ambassador to Ireland, while Glencairn House in south Dublin is used as the British Ambassador's residence. Farmleigh House, one of the Guinness family residences, was acquired by the government in 1999 for use as the official Irish state guest house.
Many other prominent judicial and political organs are located within Dublin, including the Four Courts, which is the principal seat of the Supreme Court, the Court of Appeal, the High Court and the Dublin Circuit Court; and the Custom House, which houses the Department of Housing, Local Government and Heritage. Once the centuries-long seat of the British government's administration in Ireland, Dublin Castle is now only used for ceremonial purposes, such as policy launches, hosting of State visits, and the inauguration of the president.
===Social issues and ideology===
Dublin is among the most socially liberal places in Ireland, and popular sentiment on issues such as LGBT rights, abortion and divorce has often foreran the rest of the island. Referendums held on these issues have consistently received much stronger support within Dublin, particularly the south of the county, than the majority of the country. While over 66% of voters nationally voted in favour of the Eighth Amendment in 1983, 58% of voters in Dún Laoghaire and 55% in Dublin South voted against it. In 2018, over 75.5% of voters in County Dublin voted to repeal the amendment, compared with 66.4% nationally.
In 1987, Dublin Senator David Norris took the Irish government to the European Court of Human Rights (see Norris v. Ireland) over the criminalisation of homosexual acts. In 1988, the Court ruled that the law criminalising same sex activities was contrary to the European Convention on Human Rights, in particular Article 8 which protects the right to respect for private life. The law was held to infringe on the right of adults to engage in acts of their own choice. This led directly to the repeal of the law in 1993. Numerous LGBT events and venues are now located within the county. Dublin Pride is an annual pride parade held on the last Saturday of June and is Ireland's largest public LGBT event. In 2018, an estimated 60,000 people attended. During the 2015 vote to allow same-sex marriage, 71% of County Dublin voted in favour, compared with 62% nationally.
In general, the south-eastern coastal regions of the county such as Dún Laoghaire and Dublin Bay South are a stronghold for the liberal-conservative Fine Gael party. Since the late-2000s the Green Party has also developed a strong support base in these areas. The democratic socialist Sinn Féin party generally performs well in south-central and west Dublin, in areas like Tallaght and Crumlin. In recent elections Sinn Féin have increasingly taken votes in traditional Labour Party areas, whose support has been on the decline since 2016. As a result of the economic crisis, centre-right Fianna Fáil failed to gain a single seat in Dublin in the 2011 general election. This was a first for the long-time dominant party of Irish politics. The party regained a footing in 7 of the 11 Dublin constituencies in 2020, and were also the largest party in Dublin City, Fingal and South Dublin in the 2019 local elections.
==Sport==
===GAA===
Dublin is a dual county in Gaelic games, and it competes at a similar level in both hurling/camogie and Gaelic football. The Dublin county board is the governing body for Gaelic games within the county. The county's current GAA crest, adopted in 2004, represents Dublin's four constituent areas. The castle represents Dublin city, the raven represents Fingal, the Viking longboat represents Dún Laoghaire–Rathdown and the book of Saint Tamhlacht in the centre represents South Dublin.
In Gaelic football, the Dublin county team competes annually in Division 1 of the National Football League and the provincial Leinster Senior Football Championship. Dublin is the dominant force of Leinster football, with 62 Leinster Senior Championship wins. Nationally, the county is second only to Kerry for All-Ireland Senior Football Championship titles. The two counties are fierce rivals, and a meeting between them is considered the biggest game in Gaelic football. Dublin has won the All-Ireland on 31 occasions, including a record 6 in a row from 2015 to 2020.
In hurling, the Dublin hurling team currently compete in Division 1B of the National Hurling League and in the Leinster Senior Hurling Championship. Dublin is the second most successful hurling county in Leinster after Kilkenny, albeit a distant second, with 24 Leinster hurling titles. The county has seen less success in the All-Ireland Senior Hurling Championship, ranking joint-fifth alongside Wexford. Dublin has been in 21 All-Ireland hurling finals, winning just 6, the most recent of which was in 1938.
Within the county, Gaelic football and hurling clubs compete in the Dublin Senior Football Championship and the Dublin Senior Hurling Championship, which were both established in 1887. St Vincents based in Marino and Faughs based in Templeogue are by far the most successful clubs in Dublin their respective sports. Four Dublin football teams have won the All-Ireland Senior Club Football Championship; St Vincents, Kilmacud Crokes, UCD and Ballyboden St Enda's. Despite their historic dominance in Dublin, Faughs have never won an All-Ireland Senior Club Hurling Championship. Since the early 2010s, Dalkey's Cuala have been the county's main hurling force, and the club won back-to-back All-Ireland's in 2017 and 2018.
===Soccer===
Association football (soccer) is one of the most popular sports within the county. While Gaelic games are the most watched sport in Dublin, association football is the most widely played, and there are over 200 amateur football clubs in County Dublin. Dalymount Park in Phibsborough is known as the "home of Irish football", as it is both the country's oldest stadium and the former home ground for the national team from 1904 until 1990. The Republic of Ireland national football team is currently based in the 52,000 seater Aviva Stadium, which was built on the site of the old Lansdowne Road stadium in 2010. The Aviva Stadium has hosted the final of the UEFA Europa League twice, in 2011 and 2024. Five League of Ireland football clubs are based within County Dublin; Bohemians F.C., Shamrock Rovers, St Patrick's Athletic, University College Dublin and Shelbourne.
Shamrock Rovers, formerly of Milltown but now based in Tallaght, are the most successful club in the country, with 21 League of Ireland titles. They were also the first Irish side to reach the group stages of a European competition when they qualified for the 2011–12 UEFA Europa League group stage. The Dublin University Football Club, founded in 1854, are technically the world's oldest extant football club. However, the club currently only plays rugby union. Bohemians are Ireland's third oldest club currently playing football, after Belfast's Cliftonville F.C. and Athlone Town A.F.C. The Bohemians–Shamrock Rovers rivalry not only involves Dublin's two biggest clubs, but it is also a Northside-Southside rivalry, making it the most intense derby match in the county.
===Other sports===
Rugby Union is the county's third most popular sport, after Gaelic games and football. Leinster Rugby play their competitive home games in the RDS Arena & the Aviva Stadium. Donnybrook Stadium hosts Leinster's friendlies and A games, as well as the Ireland A and Women's teams, Leinster Schools and Youths and the home club games of All Ireland League sides Old Wesley and Bective Rangers. County Dublin is home to 13 of the senior rugby union clubs in Ireland, including 5 of the 10 sides in the top division 1A.
Other popular sports in the county include: cricket, hockey, golf, tennis, athletics and equestrian activities. Dublin has two ODI cricket grounds in Castle Avenue and Malahide Cricket Club Ground, and the Phoenix Cricket Club, founded in 1830, is the oldest in Ireland. As with many other sporting organisations in the county, the Fitzwilliam Lawn Tennis Club is one of the world's oldest. It hosted the now-discontinued Irish Open from 1879 until 1983. Field hockey, particularly women's field hockey, is becoming increasingly popular within the county. The Ireland women's national field hockey team made it to the 2018 World Cup final, and many of the players on that team were from Dublin clubs, such as UCD, Old Alex, Loreto, Monkstown, Muckross and Railway Union.
The Dublin Horse Show takes place at the RDS, which hosted the Show Jumping World Championships in 1982, and the county has a horse racing track at Leopardstown which hosts the Irish Champion Stakes every September. Dublin houses the national stadium for both boxing (National Stadium) and basketball (National Basketball Arena), and the city hosted the 2003 Special Olympics. Although a small county in size, Dublin contains one third of Leinster's 168 golf courses, and three-time major winner Pádraig Harrington is from Rathfarnham.
==Media==
Local radio stations include 98FM, FM104, Dublin City FM, Q102, SPIN 1038, Sunshine 106.8, Raidió Na Life and Radio Nova.
Local newspapers include The Echo, and the Liffey Champion.
Most of the area can receive the five main UK television channels as well as the main Irish channels, along with Sky TV and Virgin Media Ireland cable television.
==Places of interest==
3Arena
Abbey Theatre
Aviva Stadium
Blanchardstown Centre
Bord Gáis Energy Theatre
Broadmeadow Estuary
Bull Island
Chester Beatty Library
Christ Church Cathedral
Clondalkin Round Tower
College Green
Convention Centre Dublin
Croke Park (stadium)
The Custom House
Dalkey Island
Douglas Hyde Gallery
Drimnagh Castle
Drumanagh Head
Dublin Castle
Dublin Zoo
Dundrum Town Centre
EPIC – The Irish Emigration Museum
The Forty Foot
Four Courts
Gaiety Theatre
Gate Theatre
The General Post Office (GPO)
George's Street Arcade
Glasnevin Cemetery
Glenasmole Valley
Grafton Street
Grand Canal Dock
Guinness Storehouse
Henry Street
Howth Castle
Howth Head
Hugh Lane Gallery
Irish Museum of Modern Art
Irish National War Memorial Gardens
James Joyce Centre
Jameson Distillery
Killiney Hill
Kilmainham Gaol
Kilmashogue Wedge Tomb
Kippure
Lambay Island
Leinster House
Leopardstown Racecourse
Liberty Hall
The Little Museum of Dublin
Malahide Castle
Marlay Park
Martello Towers
Merrion Square
Montpelier Hill
Mount Jerome Cemetery
Museum of Literature Ireland
National Botanic Gardens
National Concert Hall
National Gallery of Ireland
National Library of Ireland
National Museum of Ireland
National Wax Museum
Natural History Museum
Olympia Theatre
Phoenix Park
Poolbeg Lighthouse
Portrane Beach
Rathfarnham Castle
Richmond Barracks
Royal Hibernian Academy
Rush Beach (North & South)
Seapoint
Skerries Natural Heritage Area
Spire of Dublin
St Macuilin's Church, Lusk
St Anne's Park
Saint Enda's Park and the Pearse Museum
St Mary's Pro-Cathedral
St Patrick's Cathedral
St Stephen's Green
St Michan's Church
Temple Bar
Three Rock
Tibradden
Ticknock Forest
Trinity College Dublin, including the Old Library
Two Rock
Velvet Strand
|
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] |
6,516 |
Cosmological argument
|
In the philosophy of religion, a cosmological argument is an argument for the existence of God based upon observational and factual statements concerning the universe (or some general category of its natural contents) typically in the context of causation, change, contingency or finitude. In referring to reason and observation alone for its premises, and precluding revelation, this category of argument falls within the domain of natural theology. A cosmological argument can also sometimes be referred to as an argument from universal causation, an argument from first cause, the causal argument or the prime mover argument.
The concept of causation is a principal underpinning idea in all cosmological arguments, particularly in affirming the necessity for a First Cause. The latter is typically determined in philosophical analysis to be God, as identified within classical conceptions of theism.
The origins of the argument date back to at least Aristotle, developed subsequently within the scholarly traditions of Neoplatonism and early Christianity, and later under medieval Islamic scholasticism through the 9th to 12th centuries. It would eventually be re-introduced to Christian theology in the 13th century by Thomas Aquinas. In the 18th century, it would become associated with the principle of sufficient reason formulated by Gottfried Leibniz and Samuel Clarke, itself an exposition of the Parmenidean causal principle that "nothing comes from nothing".
Contemporary defenders of cosmological arguments include William Lane Craig, Robert Koons, John Lennox, Stephen Meyer, and Alexander Pruss.
== History ==
=== Classical philosophy ===
Plato (c. 427–347 BC) and Aristotle (c. 384–322 BC) both posited first cause arguments, though each had certain notable caveats. In The Laws (Book X), Plato posited that all movement in the world and the Cosmos was "imparted motion". This required a "self-originated motion" to set it in motion and to maintain it. In Timaeus, Plato posited a "demiurge" of supreme wisdom and intelligence as the creator of the Cosmos.
Aristotle argued against the idea of a first cause, often confused with the idea of a "prime mover" or "unmoved mover" ( or primus motor) in his Physics and Metaphysics. Aristotle argued in favor of the idea of several unmoved movers, one powering each celestial sphere, which he believed lived beyond the sphere of the fixed stars, and explained why motion in the universe (which he believed was eternal) had continued for an infinite period of time. Aristotle argued the atomist's assertion of a non-eternal universe would require a first uncaused cause – in his terminology, an efficient first cause – an idea he considered a nonsensical flaw in the reasoning of the atomists.
Like Plato, Aristotle believed in an eternal cosmos with no beginning and no end (which in turn follows Parmenides' famous statement that "nothing comes from nothing"). In what he called "first philosophy" or metaphysics, Aristotle did intend a theological correspondence between the prime mover and a deity; functionally, however, he provided an explanation for the apparent motion of the "fixed stars" (now understood as the daily rotation of the Earth). According to his theses, immaterial unmoved movers are eternal unchangeable beings that constantly think about thinking, but being immaterial, they are incapable of interacting with the cosmos and have no knowledge of what transpires therein. From an "aspiration or desire", the celestial spheres, imitate that purely intellectual activity as best they can, by uniform circular motion. The unmoved movers inspiring the planetary spheres are no different in kind from the prime mover, they merely suffer a dependency of relation to the prime mover. Correspondingly, the motions of the planets are subordinate to the motion inspired by the prime mover in the sphere of fixed stars. Aristotle's natural theology admitted no creation or capriciousness from the immortal pantheon, but maintained a defense against dangerous charges of impiety.
=== Late antiquity to the Islamic Golden Age ===
Plotinus, a third-century Platonist, taught that the One transcendent absolute caused the universe to exist simply as a consequence of its existence (creatio ex deo). His disciple Proclus stated, "The One is God". In the 6th century, Syriac Christian neo-Platonist John Philoponus (c. 490 – c. 570) examined the contradiction between Greek pagan adherences to the concept of a past-eternal world and Aristotelian rejection of the existence of actual infinities. Thereupon, he formulated arguments in defense of temporal finitism, which underpinned his arguments for the existence of God. Philosopher Steven M. Duncan notes that Philoponus's ideas eventually received their fullest articulation "at the hands of Muslim and Jewish exponents of kalam", or medieval Islamic scholasticism.
In the 11th century, Islamic philosopher Avicenna (c. 980 – 1037) inquired into the question of being, in which he distinguished between essence (māhiyya) and existence (wuǧūd). He argued that the fact of existence could not be inferred from or accounted for by the essence of existing things, and that form and matter by themselves could not originate and interact with the movement of the universe or the progressive actualization of existing things. Thus, he reasoned that existence must be due to an agent cause that necessitates, imparts, gives, or adds existence to an essence. To do so, the cause must coexist with its effect and be an existing thing.
=== Medieval Christian theology ===
Thomas Aquinas (c. 1225 – 1274) adapted and enhanced the argument he found in his reading of Aristotle, Avicenna (the Proof of the Truthful) and Maimonides to formulate one of the most influential versions of the cosmological argument. His conception of the first cause was the idea that the universe must be caused by something that is itself uncaused, which he claimed is 'that which we call God': In the context of the cosmological argument the term 'regress' usually refers to causal regress, in which the series is a chain of cause and effect, with each element in the series arising from causal activity of the prior member. Some variants of the argument may also refer to temporal regress, wherein the elements are past events (discrete units of time) arranged in a temporal sequence. The cosmological argument is a type of positive infinite regress argument given that it defends a proposition (in this case, the existence of a first cause) by arguing that its negation would lead to a vicious regress. An infinite regress may be vicious due to various reasons:
Explanatory failure: A failure of explanatory goals resulting in an infinite regress of explanations. This may arise in the case of logical fallacies such as begging the question or from an attempt to investigate causes concerning origins or fundamental principles.
=== Accidental and essential ordering of causes ===
Aquinas refers to the distinction found in Aristotle's Physics (8.5) that a series of causes may either be accidental or essential, though the designation of this terminology would follow later under John Duns Scotus at the turn of the 14th century.
Based upon this distinction Frederick Copleston (1907–1994) characterises two types of causation: Causes in fieri, which cause an effect's becoming, or coming into existence, and causes in esse, which causally sustain an effect, in being, once it exists.
Two specific properties of an essentially ordered series have significance in the context of the cosmological argument:
"Each member of the series of causes possesses being solely by virtue of the actual present operation of a superior cause ... Life is dependent inter alia on a certain atmospheric pressure, this again on the continual operation of physical forces, whose being and operation depends on the position of the earth in the solar system, which itself must endure relatively unchanged, a state of being which can only be continuously produced by a definite—if unknown—constitution of the material universe. This constitution, however, cannot be its own cause ... We are thus irresistibly led to posit a first efficient cause which, while itself uncaused, shall impart causality to a whole series."
== Versions of the argument ==
=== Aquinas's argument from contingency ===
In the scholastic era, Aquinas formulated the "argument from contingency", following Aristotle, in claiming that there must be something to explain the existence of the universe. Since the universe could, under different circumstances, conceivably not exist (i.e. it is contingent) its existence must have a cause. This cause cannot be embodied in another contingent thing, but something that exists by necessity (i.e. that must exist in order for anything else to exist). he states: "... and this we understand to be God."
"Why is there something rather than nothing? The sufficient reason ... is found in a substance which ... is a necessary being bearing the reason for its existence within itself."
Alexander Pruss formulates the argument as follows:
Every contingent fact has an explanation.
There is a contingent fact that includes all other contingent facts.
Therefore, there is an explanation of this fact.
This explanation must involve a necessary being.
This necessary being is God.
Premise 1 expresses the principle of sufficient reason. In premise 2, Leibniz proposes the existence of a logical conjunction of all contingent facts, referred to in later literature as the Big Conjunctive Contingent Fact (BCCF), representing the sum total of contingent reality. Premise 3 applies the principle of sufficient reason to the BCCF, given that it too, as a contingency, has a sufficient explanation. It follows, in statement 4, that the explanation of the BCCF must be necessary, not contingent, given that the BCCF incorporates all contingent facts. Statement 5 proposes that the necessary being explaining the totality of contingent facts is God.
Philosophers Joshua Rasmussen and T. Ryan Byerly have argued in defence of the inference from statement 4 to statement 5.
===Duns Scotus's metaphysical argument===
At the turn of the 14th century, medieval Christian theologian John Duns Scotus (1265/66–1308) formulated a metaphysical argument for the existence of God inspired by Aquinas's argument of the unmoved mover. Like other philosophers and theologians, Scotus believed that his statement for God's existence could be considered distinct to that of Aquinas. The form of the argument can be summarised as follows:
An effect cannot be produced by itself.
An effect cannot be produced by nothing.
A circle of causes is impossible.
Therefore, an effect must be produced by something else.
An accidentally ordered causal series cannot exist without an essentially ordered series.
Each member in an accidentally ordered series (except a possible first) exists via causal activity of a prior member.
That causal activity is exercised by virtue of a certain form.
Therefore, that form is required by each member to effect causation.
The form itself is not a member of the series.
Therefore [c,d], accidentally ordered causes cannot exist without higher-order (essentially ordered) causes.
An essentially ordered causal series cannot regress to infinity.
Therefore [4,5,6], there exists a first agent.
Scotus affirms, in premise 5, that an accidentally ordered series of causes is impossible without higher-order laws and processes that govern the basic principles of accidental causation, which he characterises as essentially ordered causes.
Premise 6 continues, in accordance with Aquinas's discourses on the Second Way and Third Way, that an essentially ordered series of causes cannot be an infinite regress. On this, Scotus posits that, if it is merely possible that a first agent exists, then it is necessarily true that a first agent exists, given that the non-existence of a first agent entails the impossibility of its own existence (by virtue of being a first cause in the chain).
With the formulation of this argument, Scotus establishes the first component of his 'triple primacy': The characterisation of a being that is first in efficient causality, final causality and pre-eminence, or maximal excellence, which he ascribes to God. developed within the proceedings of medieval Islamic scholasticism through the 9th to 12th centuries, eventually returning to Christian theological scholarship in the 13th century.
These ideas were revitalised for modern discourse by philosopher and theologian William Lane Craig through publications such as The Kalām Cosmological Argument (1979) and the Blackwell Companion to Natural Theology (2009). The form of the argument popularised by Craig is expressed in two parts, as an initial deductive syllogism followed by further philosophical analysis.
If the universe has a cause, then an uncaused, personal Creator of the universe exists who sans (without) the universe is beginningless, changeless, immaterial, timeless, spaceless and enormously powerful.
Therefore, an uncaused, personal Creator of the universe exists, who sans the universe is beginningless, changeless, immaterial, timeless, spaceless and enormously powerful.
For scientific evidence of the finitude of the past, Craig refers to the Borde-Guth-Vilenkin theorem, which posits a past boundary to cosmic inflation, and the general consensus on the standard model of cosmology, which refers to the origin of the universe in the Big Bang.
For philosophical evidence, he cites Hilbert's paradox of the grand hotel and Bertrand Russell's tale of Tristram Shandy to prove (respectively) the impossibility of actual infinites existing in reality and of forming an actual infinite by successive addition. He concludes that past events, in comprising a series of events that are instantiated in reality and formed by successive addition, cannot extend to an infinite past.
Craig remarks upon the theological implications that follow from the conclusion of the argument:
"... our whole universe was caused to exist by something beyond it and greater than it. For it is no secret that one of the most important conceptions of what theists mean by 'God' is Creator of heaven and earth."
== Criticism and discourse ==
=== "What caused the first cause?" ===
Objections to the cosmological argument may question why a first cause is unique in that it does not require any causes. Critics contend that the concept of a first cause qualifies as special pleading, or that arguing for the first cause's exemption raises the question of why there should be a first cause at all. Defenders maintain that this question is addressed by various formulations of the cosmological argument, emphasizing that none of its major iterations rests on the premise that everything requires a cause.
Andrew Loke refers to the Kalam cosmological argument, in which the causal premise ("whatever begins to exist has a cause") stipulates that only things which begin to exist require a cause. William Lane Craig asserts that—even if one posits a plurality of causes for the existence of the universe—a first uncaused cause is necessary, otherwise an infinite regress of causes would arise, which he argues is impossible.
Various arguments have been presented to demonstrate the metaphysical impossibility of an actually infinite regress occurring in the real world, referring to thought experiments such as Hilbert's Hotel, the tale of Tristram Shandy, and variations.
=== "Does the universe need a cause?" ===
Craig maintains that the causal principle is predicated in the metaphysical intuition that nothing comes from nothing. If such intuitions are false, he argues it would be inexplicable why anything and everything does not randomly come into existence without a cause.
Whereas J. L. Mackie argues that cause and effect cannot be extrapolated to the origins of the universe based upon our inductive experiences and intellectual preferences, Craig proposes that causal laws are unrestricted metaphysical truths that are "not contingent upon the properties, causal powers, and dispositions of the natural kinds of substances which happen to exist".
=== Identifying the first cause ===
Secular philosophers such as Michael Martin argue that a cosmological argument may establish the existence of a first cause, but falls short of identifying that cause as personal, or as God as defined within classical or other specific conceptions of theism. In Scotus's Ordinatio, his metaphysical argument is the first component of the 'triple primacy' through which he characterises the first cause as a being with the attributes of maximal excellence. J. Richard Gott and James E. Gunn assert that the question of "What was there before the Universe?" makes no sense and that the concept of before becomes meaningless when considering a timeless state. They add that questioning what occurred before the Big Bang is akin to questioning what is north of the North Pole. He affirms that the history of 20th century cosmology belies the proposition that researchers have no strong intuition to pursue a causal explanation of the origin of time and the universe. Feser also notes that versions of the cosmological argument presented by classical philosophers do not require a commitment to the Big Bang, or even to a cosmic origin.
=== The Hume-Edwards principle ===
William L. Rowe characterises the Hume-Edwards principle, referring to arguments presented by David Hume, and later Paul Edwards, in their criticisms of the cosmological argument:
The principle stipulates that a causal series—even one that regresses to infinity—requires no explanatory causes beyond those that are members within that series. If every member of a series has a causal explanation within the sequence, the series in itself is explanatorily complete.
=== Causal loop arguments ===
Some objections to the cosmological argument refer to the possibility of loops in the structure of cause and effect that would avoid the need for a first cause. Gott and Li refer to the curvature of spacetime and closed timelike curves as possible mechanisms by which the universe may bring about its own existence. Richard Hanley contends that causal loops are neither logically nor physically impossible, remarking: "[In timed systems] the only possibly objectionable feature that all causal loops share is that coincidence is required to explain them."
Andrew Loke argues that there is insufficient evidence to postulate a causal loop of the type that would avoid a first cause. He proposes that such a mechanism would suffer from the problem of vicious circularity, rendering it metaphysically impossible.
|
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] |
6,517 |
Clutch
|
A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the work.
In a motor vehicle, the clutch acts as a mechanical linkage between the engine and transmission. By disengaging the clutch, the engine speed (RPM) is no longer determined by the speed of the driven wheels.
Another example of clutch usage is in electric drills. The clutch's input shaft is driven by a motor and the output shaft is connected to the drill bit (via several intermediate components). The clutch allows the drill bit to either spin at the same speed as the motor (clutch engaged), spin at a lower speed than the motor (clutch slipping) or remain stationary while the motor is spinning (clutch disengaged).
== Types ==
=== Dry clutch===
A dry clutch uses dry friction to transfer power from the input shaft to the output shaft, for example a friction disk presses against a car engine's flywheel by a spring mechanism. The wheels of the vehicle only rotate when the flywheel is in contact with the friction disk. To stop the transfer of power, the friction disk is moved away from the flywheel by means of a lever mechanism. The majority of automotive clutches on manual transmissions are dry clutches. Slippage of a friction clutch (where the clutch is partially engaged but the shafts are rotating at different speeds) is sometimes required, such as when a motor vehicle accelerates from a standstill; however the slippage should be minimised to avoid increased wear rates.
In a pull-type clutch, pressing the pedal pulls the release bearing to disengage the clutch. In a push-type clutch, pressing the pedal pushes the release bearing to disengage the clutch.
A multi-plate clutch consists of several friction plates arranged concentrically. In some cases, it is used instead of a larger diameter clutch. Drag racing cars use multi-plate clutches to control the rate of power transfer to the wheels as the vehicle accelerates from a standing start.
Some clutch disks include springs designed to change the natural frequency of the clutch disc, in order to reduce NVH within the vehicle. Also, some clutches for manual transmission cars use a clutch delay valve to avoid abrupt engagements of the clutch.
=== Wet clutch ===
In a wet clutch, the friction material sits in an oil bath (or has flow-through oil) which cools and lubricates the clutch. This can provide smoother engagement and a longer lifespan of the clutch, however wet clutches can have a lower efficiency due to some energy being transferred to the oil. Since the surfaces of a wet clutch can be slippery (as with a motorcycle clutch bathed in engine oil), stacking multiple clutch discs can compensate for the lower coefficient of friction and so eliminate slippage under power when fully engaged.
Wet clutches often use a composite paper material.
=== Centrifugal clutch ===
A centrifugal clutch automatically engages as the speed of the input shaft increases and disengages as the input shaft speed decreases. Applications include small motorcycles, motor scooters, chainsaws, and some older automobiles.
=== Cone clutch ===
A cone clutch is similar to dry friction plate clutch, except the friction material is applied to the outside of a conical shaped object. This conical shape allows wedging action to occur during engagement. A common application for cone clutches is the synchronizer ring in a manual transmission.
=== Dog clutch ===
A dog clutch is a non-slip design of clutch which is used in non-synchronous transmissions.
=== Single-revolution clutch ===
The single-revolution clutch was developed in the 19th century to power machinery such as shears or presses where a single pull of the operating lever or (later) press of a button would trip the mechanism, engaging the clutch between the power source and the machine's crankshaft for exactly one revolution before disengaging the clutch. When the clutch is disengaged, the driven member is stationary. Early designs were typically dog clutches with a cam on the driven member used to disengage the dogs at the appropriate point.
Greatly simplified single-revolution clutches were developed in the 20th century, requiring much smaller operating forces and in some variations, allowing for a fixed fraction of a revolution per operation. Fast action friction clutches replaced dog clutches in some applications, eliminating the problem of impact loading on the dogs every time the clutch engaged.
In addition to their use in heavy manufacturing equipment, single-revolution clutches were applied to numerous small machines. In tabulating machines, for example, pressing the operate key would trip a single revolution clutch to process the most recently entered number. In typesetting machines, pressing any key selected a particular character and also engaged a single rotation clutch to cycle the mechanism to typeset that character. Similarly, in teleprinters, the receipt of each character tripped a single-revolution clutch to operate one cycle of the print mechanism.
In 1928, Frederick G. Creed developed a single-turn wrap spring clutch that was particularly well suited to the repetitive start-stop action required in teleprinters. In 1942, two employees of Pitney Bowes Postage Meter Company developed an improved single turn spring clutch. In these clutches, a coil spring is wrapped around the driven shaft and held in an expanded configuration by the trip lever. When tripped, the spring rapidly contracts around the power shaft engaging the clutch. At the end of one revolution, if the trip lever has been reset, it catches the end of the spring (or a pawl attached to it), and the angular momentum of the driven member releases the tension on the spring. These clutches have long operating lives—many have performed tens and perhaps hundreds of millions of cycles without the need of maintenance other than occasional lubrication.
Cascaded-pawl single-revolution clutches superseded wrap-spring single-revolution clutches in page printers, such as teleprinters, including the Teletype Model 28 and its successors, using the same design principles. IBM Selectric typewriters also used them. These are typically disc-shaped assemblies mounted on the driven shaft. Inside the hollow disc-shaped drive drum are two or three freely floating pawls arranged so that when the clutch is tripped, the pawls spring outward much like the shoes in a drum brake. When engaged, the load torque on each pawl transfers to the others to keep them engaged. These clutches do not slip once locked up, and they engage very quickly, on the order of milliseconds. A trip projection extends out from the assembly. If the trip lever engaged this projection, the clutch was disengaged. When the trip lever releases this projection, internal springs and friction engage the clutch. The clutch then rotates one or more turns, stopping when the trip lever again engages the trip projection.
=== Other designs ===
Kickback clutch-brakes: Found in some types of synchronous-motor-driven electric clocks built before the 1940s, to prevent the clock from running backwards. The clutch consisted of a wrap-spring clutch-brake that was coupled to the rotor by one or two stages of reduction gearing. The clutch-brake locked up when rotated backwards, but also had some spring action. The inertia of the rotor going backwards engaged the clutch and wound the spring. As it unwound, it restarted the motor in the correct direction.
Belt clutch: used on agricultural equipment, lawnmowers, tillers, and snow blowers. Engine power is transmitted via a set of belts that are slack when the engine is idling, but an idler pulley can tighten the belts to increase friction between the belts and the pulleys.
BMA clutch: Invented by Waldo J Kelleigh in 1949, used for transmitting torque between two shafts consisting of a fixed driving member secured to one of said shafts, and a movable driving member, having a contacting surface with a plurality of indentations.
Electromagnetic clutch: typically engaged by an electromagnet that is an integral part of the clutch assembly. Another type, the magnetic particle clutch, contains magnetically influenced particles in a chamber between driving and driven members—application of direct current makes the particles clump together and adhere to the operating surfaces. Engagement and slippage are notably smooth.
Wrap-spring clutch: has a helical spring, typically wound with square-cross-section wire. These were developed in the late 19th and early 20th-century. In simple form the spring is fastened at one end to the driven member; its other end is unattached. The spring fits closely around a cylindrical driving member. If the driving member rotates in the direction that would unwind the spring expands minutely and slips although with some drag. Because of this, spring clutches must typically be lubricated with light oil. Rotating the driving member the other way makes the spring wrap itself tightly around the driving surface and the clutch locks up very quickly. The torque required to make a spring clutch slip grows exponentially with the number of turns in the spring, obeying the capstan equation.
== Usage in automobiles ==
=== Manual transmissions===
Most cars and trucks with a manual transmission use a dry clutch, which is operated by the driver using the left-most pedal. The motion of the pedal is transferred to the clutch using mechanical linkage, hydraulics (master and slave cylinders) or a cable. The clutch is only disengaged at times when the driver is pressing on the clutch pedal, therefore the default state is for the transmission to be connected to the engine. A "neutral" gear position is provided, so that the clutch pedal can be released with the vehicle remaining stationary.
The clutch is required for standing starts and in vehicles whose transmissions lack synchronising means to assist in matching the speeds of the engine and transmission during gear changes to avoid gear “crashing,” which can cause serious damage to gear teeth.
The clutch is usually mounted directly to the face of the engine's flywheel, as this already provides a convenient large-diameter steel disk that can act as one driving plate of the clutch. Some racing clutches use small multi-plate disk packs that are not part of the flywheel. Both clutch and flywheel are enclosed in a conical bellhousing for the gearbox. The friction material used for the clutch disk varies, with a common material being an organic compound resin with a copper wire facing or a ceramic material.
=== Automatic transmissions ===
In an automatic transmission, the role of the clutch is performed by a torque converter. However, the transmission itself often includes internal clutches, such as a lock-up clutch to prevent slippage of the torque converter, in order to reduce the energy loss through the transmission and therefore improve fuel economy.
=== Fans and compressors ===
Older belt-driven engine cooling fans often use a heat-activated clutch, in the form of a bimetallic strip. When the temperature is low, the spring winds and closes the valve, which lets the fan spin at about 20% to 30% of the crankshaft speed. As the temperature of the spring rises, it unwinds and opens the valve, allowing fluid past the valve, making the fan spin at about 60% to 90% of crankshaft speed.
A vehicle's air-conditioning compressor often uses magnetic clutches to engage the compressor as required.
== Usage in motorcycles ==
Motorcycles typically employ a wet clutch with the clutch riding in the same oil as the transmission. These clutches are usually made up of a stack of alternating friction plates and steel plates. The friction plates have lugs on their outer diameters that lock them into a basket that is turned by the crankshaft. The steel plates have lugs on their inner diameters that lock them to the transmission input shaft. A set of coil springs or a diaphragm spring plate force the plates together when the clutch is engaged.
On motorcycles the clutch is operated by a hand lever on the left handlebar. No pressure on the lever means that the clutch plates are engaged (driving), while pulling the lever back towards the rider disengages the clutch plates through cable or hydraulic actuation, allowing the rider to shift gears or coast. Racing motorcycles often use slipper clutches to eliminate the effects of engine braking, which, being applied only to the rear wheel, can cause instability.
|
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"motor scooter",
"dog clutch",
"Synchromesh",
"Torque limiter",
"angular momentum",
"noise, vibration, and harshness"
] |
6,520 |
Cow tipping
|
Cow tipping is the purported activity of sneaking up on any unsuspecting or sleeping upright cow and pushing it over for entertainment. The practice of cow tipping is generally considered an urban legend and stories of such feats viewed as tall tales. The concept of cow tipping apparently developed in the 1970s, though tales of animals that cannot rise if they fall has historical antecedents dating to the Roman Empire.
Cows routinely lie down and can easily regain their footing unless sick or injured. Scientific studies have been conducted to determine if cow tipping is theoretically possible, with varying conclusions. All agree that cows are large animals that are difficult to surprise and will generally resist attempts to be tipped. Estimates suggest a force of between is needed, and that at least four and possibly as many as fourteen people would be required to achieve this. In real-life situations where cattle have to be laid on the ground, or "cast", such as for branding, hoof care or veterinary treatment, either rope restraints are required or specialized mechanical equipment is used that confines the cow and then tips it over. On rare occasions, cattle can lie down or fall down in proximity to a ditch or hill that restricts their normal ability to rise without help. Cow tipping has many references in popular culture and is also used as a figure of speech.
== Scientific study ==
Some versions of the urban legend suggest that because cows sleep standing up, it is possible to approach them and push them over without the animals reacting. They lie down to sleep deeply.
A 2005 study led by Margo Lillie, a zoologist at the University of British Columbia, and her student Tracy Boechler, concluded that tipping a cow would require a force of nearly and is therefore impossible to accomplish by a single person. Her calculations found that it would require more than four people to apply enough force to push over a cow, Lillie and Boechler's analysis found that if a cow did not move, the principles of static physics suggest that two people might be able to tip a cow if its centre of mass were pushed over its hooves before the cow could react. However, cows are not rigid or unresponsive, and the faster humans have to move, the less force they can exert. Thus Lillie and Boechler concluded that it is unlikely that cows can actually be tipped over in this way. Vogel suggests that someone applying force at the requisite height to topple a cow might generate a maximum push of no more than 300 newtons. By this calculation, at least 10 people would be needed to tip over a non-reacting cow. However, this combined force requirement, he says, might not be the greatest impediment to such a prank. Standing cows are not asleep and, like other animals, have ever-vigilant reflexes. "If the cow does no more than modestly widen its stance without an overall shift of its center of gravity", he says, "about 4,000 newtons or 14 pushers would be needed—quite a challenge to deploy without angering the cow."
== Historical origins ==
The belief that certain animals cannot rise if pushed over has historical antecedents. Julius Caesar recorded a belief that a European elk had no knee joints and could not get up if it fell. Pliny said the same about the hind legs of an animal he called the achlis, which Pliny's 19th-century translators Bostock and Riley said was merely another name for the elk. They noted that Pliny's belief about the jointless back legs of the achlis (elk) was false. A drawing by the historian Matthew Paris for his Chronica Majora can be seen in his bestiary at Parker Library of Corpus Christi College, Cambridge.
Journalist Jake Steelhammer believes the American urban myth of cow tipping originated in the 1970s. It "stampeded into the '80s", he says, "when movies like Tommy Boy and Heathers featured cow tipping expeditions." Stories about cow tipping tend to be second-hand, he says, told by someone who does not claim to have tipped a cow but who knows someone else who says they did.
A calf table or calf cradle, also called a "tipping table" or a "throw down", is a relatively modern invention designed to be used on calves that are being branded. A calf is run into a chute, confined, and then tipped by the equipment onto its side for easier branding and castration.
Hydraulic tilt tables for adult cattle have existed since the 1970s and are designed to lift and tip cattle onto their sides to enable veterinary care, particularly of the animals' genitalia, and for hoof maintenance. One design, developed at the Western College of Veterinary Medicine in Saskatoon, Saskatchewan, included "cow comfort" as a unique aspect of care using this type of apparatus.
=== Involuntary recumbency ===
Cows may inadvertently tip themselves. Due to their bulk and relatively short legs, cattle cannot roll over. Those that lie down and roll to their sides with their feet pointing uphill may become stuck and unable to rise without assistance, with potentially fatal results. In such cases, two humans can roll or flip a cow onto its other side, so that its feet are aimed downhill, thus allowing it to rise on its own. In one documented case of "real-life cow tipping", a pregnant cow rolled into a gully in New Hampshire and became trapped in an inverted state until rescued by volunteer fire fighters. The owner of the cow commented that he had seen this happen "once or twice" before.
Trauma or illness may also result in a cow unable to rise to its feet. Such animals are sometimes called "downers." Sometimes this occurs as a result of muscle and nerve damage from calving or a disease such as mastitis. Downer cows are encouraged to get to their feet and have a much greater chance of recovery if they do. If unable to rise, some have survived—with medical care—as long as 14 days and were ultimately able to get back on their feet. Appropriate medical treatment for a downer cow to prevent further injury includes rolling from one side to the other every three hours, careful and frequent feeding of small amounts of fodder, and access to clean water.
=== Death ===
Dead animals may appear to have been tipped over, but this is actually the process of rigor mortis, which stiffens the muscles of the carcass, beginning six to eight hours after death and lasting for one to two days. It is particularly noticeable in the limbs, which stick out straight. Post-mortem bloat also occurs because of gas formation inside the body. The process may result in cattle carcasses that wind up on their back with all four feet in the air.
== In popular culture ==
Assorted individuals have claimed to have performed cow tipping, often while under the influence of alcohol. These claims, to date, cannot be reliably verified,
Pranksters have sometimes pushed over artificial cows. Along Chicago's Michigan Avenue in 1999, two "apparently drunk" men felled six fiberglass cows that were part of a Cows on Parade public art exhibit. Four other vandals removed a "Wow cow" sculpture from its lifeguard chair at Oak Street Beach and abandoned it in a pedestrian underpass. A year later, New York City anchored its CowParade art cows, including "A Streetcow Named Desire", to concrete bases "to prevent the udder disrespect of cow-tippers and thieves."
Cow tipping has been featured in films from the 1980s and later, such as Heathers (1988), Tommy Boy (1995), Barnyard (2006), and I Love You, Beth Cooper (2009). It was also used in the title of a 1992 documentary film by Randy Redroad, Cow Tipping—The Militant Indian Waiter.
Variants of cow tipping have also been seen in popular media such as the film Cars (2006), which features a vehicular variant called tractor-tipping, and the video game Fallout: New Vegas, which allows the character to sneak up on and tip over a Brahmin, the game's two-headed cow-like animal. The board game Battle Cattle is based on the practice, with heavily armed cows having "Tipping Defense Numbers."
In the Little Willies song "Lou Reed" from their 2006 self-titled debut album, Norah Jones sings about a fictional event during which musician Lou Reed tips cows in Texas. In another medium, The Big Bang Theory, a television show, uses cow tipping lore as an element to establish the nature of a rural character, Penny.
The term cow tipping is sometimes used as a figure of speech for pushing over something big. In A Giant Cow-Tipping by Savages, author John Weir Close uses the term to describe contemporary mergers and acquisitions. "Tipping sacred cows" has been used as a deliberate mixed metaphor in titles of books on Christian ministry and business management.
|
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] |
6,526 |
Cassandra
|
Cassandra or Kassandra (; , , sometimes referred to as Alexandra; ) in Greek mythology was a Trojan priestess dedicated to the god Apollo and fated by him to utter true prophecies but never to be believed. In modern usage her name is employed as a rhetorical device to indicate a person whose accurate prophecies, generally of impending disaster, are not believed.
Cassandra was a daughter of King Priam and Queen Hecuba of Troy. Her elder brother was Hector, the hero of the Greek-Trojan War. The older and most common versions of the myth state that she was admired by the god Apollo, who sought to win her love by means of the gift of seeing the future. According to Aeschylus, she promised him her favours, but after receiving the gift, she went back on her word. As the enraged Apollo could not revoke a divine power, he added to it the curse that nobody would believe her prophecies. In other sources, such as Hyginus and Pseudo-Apollodorus, Cassandra broke no promise to Apollo, but rather the power of foresight was given to her as an enticement to enter into a romantic engagement, the curse being added only when it failed to produce the result desired by the god.
Later versions on the contrary describe her falling asleep in a temple, where snakes licked (or whispered into) her ears which enabled her to hear the future.
==Etymology==
Hjalmar Frisk (Griechisches Etymologisches Wörterbuch, Heidelberg, 1960–1970) notes "unexplained etymology", citing "various hypotheses" found in Wilhelm Schulze, Edgar Howard Sturtevant, J. Davreux, and R. S. P. Beekes cites García Ramón's derivation of the name from the Proto-Indo-European root *(s)kend- "raise". The Online Etymology Dictionary states "though the second element looks like a fem. form of Greek andros "of man, male human being." Watkins suggests PIE *(s)kand- "to shine" as source of second element. The name also has been connected to kekasmai "to surpass, excel."
== Description ==
Cassandra was described by the chronicler Malalas in his account of the Chronography as "shortish, round-faced, white, mannish figure, good nose, good eyes, dark pupils, blondish, curly, good neck, bulky breasts, small feet, calm, noble, priestly, an accurate prophet foreseeing everything, practicing hard, virgin". Meanwhile, in the account of Dares the Phrygian, she was illustrated as ". . .of moderate stature, round-mouthed, and auburn-haired. Her eyes flashed. She knew the future."
==Biography==
Cassandra was one of the many children born to the king and queen of Troy, Priam and Hecuba. She is the fraternal twin sister of Helenus, as well as the sister to Hector and Paris. One of the oldest and most common versions of her myth states that Cassandra was admired for her beauty and intelligence by the god Apollo, who sought to win her with the gift to see the future. According to Aeschylus, Cassandra promised Apollo favors, but, after receiving the gift, went back on her word and refused Apollo. Since the enraged Apollo could not revoke a divine power, he added a curse that nobody would believe Cassandra's prophecies.
==Mythology==
Cassandra appears in texts written by Homer, Virgil, Aeschylus and Euripides. Each author depicts her prophetic powers differently.
In Homer's work, Cassandra is mentioned a total of four times "as a virgin daughter of Priam, as bewailing Hector's death, as chosen by Agamemnon as his slave mistress after the sack of Troy, and is killed by Clytemnestra over Agamemnon's corpse after Clytemnestra murders him on his return home."
In Virgil's work, Cassandra appears in book two of his epic poem titled Aeneid, with her powers of prophecy restored. In Book 2 of the Aeneid, unlike Homer, Virgil presents Cassandra as having fallen into a mantic state and her prophecies reflect it.
Likewise Seneca the Younger, in his play Agamemnon, has her prophesy why Agamemnon deserves his recorded death:Quid me vocatis sospitem solam e meis, umbrae meorum? te sequor, tota pater Troia sepulte; frater, auxilium Phrygum terrorque Danaum, non ego antiquum decus video aut calentes ratibus ambustis manus, sed lacera membra et saucios vinclo gravi illos lacertos. te sequor… (Ag. 741–747)
Why do you call me, the lone survivor of my family, My shades? I follow you, father buried with all of Troy; Brother, bulwark of Trojans, terrorizer of Greeks, I do not see your beauty of old or hands warmed by burnt ships, But your lacerated limbs and those famous shoulders savaged By heavy chains. I follow you..."
===Gift of prophecy===
Cassandra was given the gift of prophecy, but was also cursed by the god Apollo so that her true prophecies would not be believed. Many versions of the myth relate that she incurred the god's wrath by refusing him sexual favours after promising herself to him in exchange for the power of prophecy. In Aeschylus' Agamemnon, she bemoans her relationship with Apollo:
Apollo, Apollo!
God of all ways, but only Death's to me,
Once and again, O thou, Destroyer named,
Thou hast destroyed me, thou, my love of old!
And she acknowledges her fault:
I consented [marriage] to Loxias [Apollo] but broke my word. ... Ever since that fault I could persuade no one of anything.
Latin author Hyginus in Fabulae says:
Louise Bogan, an American poet, writes that another way Cassandra, as well as her twin brother Helenus, had earned their prophetic powers: "she and her brother Helenus were left overnight in the temple of the Thymbraean Apollo. No reason has been advanced for this night in the temple; perhaps it was a ritual routinely performed by everyone. When their parents looked in on them the next morning, the children were entwined with serpents, which flicked their tongues into the children's ears. This enabled Cassandra and Helenus to divine the future." It would not be until Cassandra is much older that Apollo appears in the same temple and tried to seduce Cassandra, who rejects his advances, and curses her by making her prophecies not be believed.
Her cursed gift from Apollo became an endless pain and frustration to her. She was seen as a liar and a madwoman by her family and by the Trojan people. Because of this, her father, Priam, had locked her away in a chamber and guarded her like the madwoman she was believed to be.
===Cassandra and the Fall of Troy===
====Before the fall of Troy====
Before the fall of Troy took place, Cassandra foresaw that if Paris went to Sparta and brought Helen back as his wife, the arrival of Helen would spark the downfall and destruction of Troy during the Trojan War. Despite the prophecy and ignoring Cassandra's warning, Paris still went to Sparta and returned with Helen. While the people of Troy rejoiced, Cassandra, angry with Helen's arrival, furiously snatched away Helen's golden veil and tore at her hair.
====During the fall of Troy====
Coroebus and Othronus came to the aid of Troy during the Trojan War out of love for Cassandra and in exchange for her hand in marriage, but both were killed. According to one account, Priam offered Cassandra to Telephus's son Eurypylus, in order to induce Eurypylus to fight on the side of the Trojans. Cassandra was also the first to see the body of her brother Hector being brought back to the city.In The Fall of Troy, told by Quintus Smyrnaeus, Cassandra attempted to warn the Trojan people that Greek warriors were hiding in the Trojan Horse while they were celebrating their victory over the Greeks with feasting. Disbelieving Cassandra, the Trojans resorted to calling her names and hurling insults at her. Attempting to prove herself right, Cassandra took an axe in one hand and a burning torch in the other, and ran towards the Trojan Horse, intent on destroying the Greeks herself, but the Trojans stopped her. The Greeks hiding inside the Horse were relieved, but alarmed by how clearly she had divined their plan.
At the fall of Troy, Cassandra sought shelter in the temple of Athena. There she embraced the wooden statue of Athena in supplication for her protection, but was abducted and brutally raped by Ajax the Lesser. Cassandra clung so tightly to the statue of the goddess that Ajax knocked it from its stand as he dragged her away. The actions of Ajax were a sacrilege because Cassandra was a supplicant at the sanctuary under the protection of the goddess Athena, and Ajax further defiled the temple by raping Cassandra.
In Apollodorus chapter 6, section 6, Ajax's death comes at the hands of both Athena and Poseidon: "Athena threw a thunderbolt at the ship of Ajax; and when the ship went to pieces he made his way safe to a rock, and declared that he was saved in spite of the intention of Athena. But Poseidon smote the rock with his trident and split it, and Ajax fell into the sea and perished; and his body, being washed up, was buried by Thetis in Myconos".
In some versions, Cassandra intentionally left a chest behind in Troy, with a curse on whichever Greek opened it first. Inside the chest was an image of Dionysus, made by Hephaestus and presented to the Trojans by Zeus. It was given to the Greek leader Eurypylus as a part of his share of the victory spoils of Troy. When he opened the chest and saw the image of the god, he went mad.
The final resting place of Cassandra is either in Amyclae or Mycenae. Statues of Cassandra exist both in Amyclae and across the Peloponnese peninsula from Mycenae to Leuctra. In Mycenae, German business man and pioneer archeologist Heinrich Schliemann discovered in Grave Circle A the graves of Cassandra and Agamemnon and telegraphed back to King George I of Greece:With great joy I announce to Your Majesty that I have discovered the tombs which the tradition proclaimed by Pausanias indicates to be the graves of Agamemnon, Cassandra, Eurymedon and their companions, all slain at a banquet by Clytemnestra and her lover Aegisthos.However, it was later discovered that the graves predated the Trojan War by at least 300 years.
==Agamemnon by Aeschylus==
The play Agamemnon from Aeschylus's trilogy Oresteia depicts the king treading the scarlet cloth laid down for him, and walking offstage to his death. She has been onstage, silent and ignored. Her madness that is unleashed now is not the physical torment of other characters in Greek tragedy, such as in Euripides' Heracles or Sophocles' Ajax.
According to author Seth Schein, two further familiar descriptions of her madness are that of Heracles in The Women of Trachis or Io in Prometheus Bound. witnessing past and future events. Schein says, "She evokes the same awe, horror and pity as do schizophrenics". on the powerful contrasts between declaimed and sung dialogue in this scene. The frightened and respectful chorus are unable to comprehend her. She goes to her inevitable offstage murder by Clytemnestra with full knowledge of what is to befall her.
|
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] |
6,530 |
Couplet
|
In poetry, a couplet ( ) or distich ( ) is a pair of successive lines that rhyme and have the same metre. A couplet may be formal (closed) or run-on (open). In a formal (closed) couplet, each of the two lines is end-stopped, implying that there is a grammatical pause at the end of a line of verse. In a run-on (open) couplet, the meaning of the first line continues to the second.
==Background==
The word "couplet" comes from the French word meaning "two pieces of iron riveted or hinged together". The term "couplet" was first used to describe successive lines of verse in Sir P. Sidney's Arcadia in 1590: "In singing some short coplets, whereto the one halfe beginning, the other halfe should answere."
While couplets traditionally rhyme, not all do. Poems may use white space to mark out couplets if they do not rhyme. Couplets in iambic pentameter are called heroic couplets. John Dryden in the 17th century and Alexander Pope in the 18th century were both well known for their writing in heroic couplets. The Poetic epigram is also in the couplet form. Couplets can also appear as part of more complex rhyme schemes, such as sonnets.
Rhyming couplets are one of the simplest rhyme schemes in poetry. Because the rhyme comes so quickly, it tends to call attention to itself. Good rhyming couplets tend to "explode" as both the rhyme and the idea come to a quick close in two lines. Here are some examples of rhyming couplets where the sense as well as the sound "rhymes":
True wit is nature to advantage dress'd;
What oft was thought, but ne'er so well express'd.
— Alexander Pope
Whether or not we find what we are seeking
Is idle, biologically speaking.
— Edna St. Vincent Millay (at the end of a sonnet)
On the other hand, because rhyming couplets have such a predictable rhyme scheme, they can feel artificial and plodding. Here is a Pope parody of the predictable rhymes of his era:
Where-e'er you find "the cooling western breeze,"
In the next line, it "whispers through the trees;"
If crystal streams "with pleasing murmurs creep,"
The reader's threatened (not in vain) with "sleep."
==In English poetry==
Regular rhyme was not originally a feature of English poetry: Old English verse came in metrically paired units somewhat analogous to couplets, but constructed according to alliterative verse principles. The rhyming couplet entered English verse in the early Middle English period through the imitation of medieval Latin and Old French models. The earliest surviving examples are a metrical paraphrase of the Lord's Prayer in short-line couplets, and the Poema Morale in septenary (or "heptameter") couplets, both dating from the twelfth century.
Rhyming couplets were often used in Middle English and early modern English poetry. Chaucer's Canterbury Tales, for instance, is predominantly written in rhyming couplets, and Chaucer also incorporated a concluding couplet into his rhyme royal stanza. Similarly, Shakespearean sonnets often employ rhyming couplets at the end to emphasize the theme. Take one of Shakespeare's most famous sonnets, Sonnet 18, for example (the rhyming couplet is shown in italics):
Shall I compare thee to a summer's day?
Thou art more lovely and more temperate:
Rough winds do shake the darling buds of May,
And summer's lease hath all too short a date:
Sometimes too hot the eye of heaven shines,
And often is his gold complexion dimm'd;
And every fair from fair sometime declines,
By chance or nature's changing course untrimm'd;
But thy eternal summer shall not fade
Nor lose possession of that fair thou owest;
Nor shall Death brag thou wander'st in his shade,
When in eternal lines to time thou growest:
So long as men can breathe or eyes can see,
So long lives this and this gives life to thee.
In the late seventeenth century and early eighteenth-century English rhyming couplets achieved the zenith of their prestige in English verse, in the popularity of heroic couplets. The heroic couplet was used by famous poets for ambitious translations of revered Classical texts, for instance, in John Dryden's translation of the Aeneid and in Alexander Pope's translation of the Iliad.
Though poets still sometimes write in couplets, the form fell somewhat from favour in English in the twentieth century; contemporary poets writing in English sometimes prefer unrhymed couplets, distinguished by layout rather than by matching sounds.
==In Chinese poetry==
Couplets called duilian may be seen on doorways in Chinese communities worldwide. Duilian displayed as part of the Chinese New Year festival, on the first morning of the New Year, are called chunlian (春聯; 春联). These are usually purchased at a market a few days before and glued to the doorframe. The text of the couplets is often traditional and contains hopes for prosperity. Other chunlian reflect more recent concerns. For example, the CCTV New Year's Gala usually promotes couplets reflecting current political themes in mainland China.
Some duilian may consist of two lines of four characters each. Duilian are read from top to bottom where the first line starts from the right.
==In Tamil poetry==
Tamil literature contains some of the notable examples of ancient couplet poetry. The Tamil language has a rich and refined grammar for couplet poetry, and distichs in Tamil poetry follow the venpa metre. One of the most notable examples of Tamil couplet poetry is the ancient Tamil moral text of the Tirukkural, which contains a total of 1330 couplets written in the kural venpa metre from which the title of the work was derived centuries later. Each Kural couplet is made of exactly 7 words—4 in the first line and 3 in the second. The first word may rhyme with the fourth or the fifth word. Below is an example of a couplet:
. (Tirukkural, verse 205)
Transliteration: Ilan endru theeyavai seyyarkka seyyin
Ilanaagum matrum peyartthu
Translation: Make not thy poverty a plea for ill;
Thine evil deeds will make thee poorer still. (Pope, 1886)
Kabir (also known as Kabirdas) is thought to be one of the greatest composers of Hindustani couplets.
==Distich==
The American poet J. V. Cunningham was noted for many distichs included in the various forms of epigrams included in his poetry collections, as exampled here:
Deep summer, and time passes. Sorrow wastesTo a new sorrow. While Time heals time hastes
|
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6,532 |
Charlotte Brontë
|
Charlotte Nicholls (; 21 April 1816 – 31 March 1855), commonly known as Charlotte Brontë (, commonly ), was an English novelist and poet, the eldest of the three Brontë sisters who survived into adulthood and whose novels became classics of English literature. She is best known for her novel Jane Eyre, which she published under the male pseudonym Currer Bell. Jane Eyre went on to become a success in publication, and is widely held in high regard in the gothic fiction genre of literature.
Brontë enrolled in school at Roe Head, Mirfield, in January 1831, aged 14 years. She left the year after to teach her sisters, Emily and Anne, at home, then returned to Roe Head in 1835 as a teacher. In 1839, she undertook the role of governess for the Sidgwick family, but left after a few months. The three sisters attempted to open a school in Haworth but failed to attract pupils. Instead, they turned to writing; they each first published in 1846 under the pseudonyms of Currer, Ellis, and Acton Bell. Although her first novel, The Professor, was rejected by publishers, her second novel, Jane Eyre, was published in 1847. The sisters admitted to their Bell pseudonyms in 1848, and by the following year were celebrated in London literary circles.
Brontë was the last to die of all her siblings. She became pregnant shortly after her wedding in June 1854 but died on 31 March 1855, almost certainly from hyperemesis gravidarum, a complication of pregnancy which causes excessive nausea and vomiting.
==Early years and education==
Charlotte Brontë was born on 21 April 1816 in Market Street, Thornton (in a house now known as the Brontë Birthplace), west of Bradford in the West Riding of Yorkshire, the third of the six children of Maria (née Branwell) and Patrick Brontë (formerly surnamed Brunty), an Irish Anglican clergyman. In 1820 her family moved a few miles to the village of Haworth, on the edge of the moors, where her father had been appointed perpetual curate of St Michael and All Angels Church. Maria died of cancer on 15 September 1821, leaving five daughters, Maria, Elizabeth, Charlotte, Emily and Anne, and a son, Branwell, to be taken care of by her sister, Elizabeth Branwell.
In August 1824, Patrick sent Charlotte, Emily, Maria, and Elizabeth to the Clergy Daughters' School at Cowan Bridge in Lancashire. Charlotte maintained that the school's poor conditions permanently affected her health and physical development, and hastened the deaths of Maria (born 1814) and Elizabeth (born 1815), who both died of tuberculosis in May (Maria) and June (Elizabeth) 1825. After the deaths of his older daughters, Patrick removed Charlotte and Emily from the school. Charlotte used the school as the basis for Lowood School in Jane Eyre, which is similarly affected by tuberculosis that is exacerbated by the poor conditions.
At home in Haworth Parsonage, Brontë acted as "the motherly friend and guardian of her younger sisters". Brontë wrote her first known poem at the age of 13 in 1829, and was to go on to write more than 200 poems in the course of her life. Many of her poems were "published" in their homemade magazine Branwell's Blackwood's Magazine, and concerned the fictional world of Glass Town. She and her surviving siblings – Branwell, Emily and Anne – created this shared world, and began chronicling the lives and struggles of the inhabitants of their imaginary kingdom in 1827. Charlotte, in private letters, called Glass Town "her 'world below', a private escape where she could act out her desires and multiple identities". Charlotte's "predilection for romantic settings, passionate relationships, and high society is at odds with Branwell's obsession with battles and politics and her young sisters' homely North Country realism, none the less at this stage there is still a sense of the writings as a family enterprise".
However, from 1831 onwards, Emily and Anne 'seceded' from the Glass Town Confederacy to create a 'spin-off' called Gondal, which included many of their poems. After 1831, Charlotte and Branwell concentrated on an evolution of the Glass Town Confederacy called Angria. Christine Alexander, a Brontë juvenilia historian, wrote "both Charlotte and Branwell ensured the consistency of their imaginary world. When Branwell exuberantly kills off important characters in his manuscripts, Charlotte comes to the rescue and, in effect, resurrects them for the next stories [...]; and when Branwell becomes bored with his inventions, such as the Glass Town magazine he edits, Charlotte takes over his initiative and keeps the publication going for several more years". The sagas the siblings created were episodic and elaborate, and they exist in incomplete manuscripts, some of which have been published as juvenilia. They provided them with an obsessive interest during childhood and early adolescence, which prepared them for literary vocations in adulthood.
Between 1831 and 1832, Brontë continued her education at a boarding school twenty miles away in Mirfield, Roe Head (now part of Hollybank Special School), where she met her lifelong friends and correspondents Ellen Nussey and Mary Taylor. In 1833 she wrote a novella, The Green Dwarf, using the name Wellesley. Around about 1833, her stories shifted from tales of the supernatural to more realistic stories. She returned to Roe Head as a teacher from 1835 to 1838. Unhappy and lonely as a teacher at Roe Head, Brontë took out her sorrows in poetry, writing a series of melancholic poems. In "We wove a Web in Childhood" written in December 1835, Brontë drew a sharp contrast between her miserable life as a teacher and the vivid imaginary worlds she and her siblings had created. In another poem "Morning was its freshness still" written at the same time, Brontë wrote "Tis bitter sometimes to recall/Illusions once deemed fair". Many of her poems concerned the imaginary world of Angria, often concerning Byronic heroes, and in December 1836 she wrote to the Poet Laureate Robert Southey asking him for encouragement of her career as a poet. Southey replied, famously, that "Literature cannot be the business of a woman's life, and it ought not to be. The more she is engaged in her proper duties, the less leisure will she have for it even as an accomplishment and a recreation." This advice she respected but did not heed.
In 1839 Brontë took up the first of many positions as governess to families in Yorkshire, a career she pursued until 1841. In particular, from May to July 1839 she was employed by the Sidgwick family at their summer residence, Stone Gappe, in Lothersdale, where one of her charges was John Benson Sidgwick (1835–1927), an unruly child who on one occasion threw the Bible at Charlotte, an incident that may have been the inspiration for a part of the opening chapter of Jane Eyre in which John Reed throws a book at the young Jane. Brontë did not enjoy her work as a governess, noting her employers treated her almost as a slave, constantly humiliating her. She was of slight build and was less than tall.
==Brussels and Haworth==
In 1842 Charlotte and Emily travelled to Brussels to enrol at the boarding school run by Constantin Heger (1809–1896) and his wife Claire Zoé Parent Heger (1804–1887). During her time in Brussels, Brontë, who favoured the Protestant ideal of an individual in direct contact with God, objected to the stern Catholicism of Madame Heger, which she considered a tyrannical religion that enforced conformity and submission to the Pope. In return for board and tuition Charlotte taught English and Emily taught music. Their time at the school was cut short when their aunt Elizabeth Branwell, who had joined the family in Haworth to look after the children after their mother's death, died of internal obstruction in October 1842. Charlotte returned alone to Brussels in January 1843 to take up a teaching post at the school. Her second stay was not happy: she was homesick and deeply attached to Constantin Heger. She returned to Haworth in January 1844 and used the time spent in Brussels as the inspiration for some of the events in The Professor and Villette.
After returning to Haworth, Charlotte and her sisters made headway with opening their own boarding school in the family home. It was advertised as "The Misses Brontë's Establishment for the Board and Education of a limited number of Young Ladies" and inquiries were made to prospective pupils and sources of funding. But none were attracted and in October 1844, the project was abandoned.
==First publication==
In May 1846, Charlotte, Emily, and Anne self-financed the publication of a joint collection of poems under their assumed names Currer, Ellis and Acton Bell. The pseudonyms veiled the sisters' sex while preserving their initials; thus Charlotte was Currer Bell. "Bell" was the middle name of Haworth's curate, Arthur Bell Nicholls whom Charlotte later married, and "Currer" was the surname of Frances Mary Richardson Currer who had funded their school (and maybe their father). Of the decision to use noms de plume, Charlotte wrote:
Although only two copies of the collection of poems were sold, the sisters continued writing for publication and began their first novels, continuing to use their noms de plume when sending manuscripts to potential publishers.
==The Professor and Jane Eyre==
Brontë's first manuscript, 'The Professor', did not secure a publisher, although she was heartened by an encouraging response from Smith, Elder & Co. of Cornhill, who expressed an interest in any longer works Currer Bell might wish to send. Brontë responded by finishing and sending a second manuscript in August 1847. Six weeks later, Jane Eyre was published. It tells the story of a plain governess, Jane, who, after difficulties in her early life, falls in love with her employer, Mr Rochester. They marry, but only after Rochester's insane first wife, of whom Jane initially has no knowledge, dies in a dramatic house fire. The book's style was innovative, combining Romanticism, naturalism with gothic melodrama, and broke new ground in being written from an intensely evoked first-person female perspective. Brontë believed art was most convincing when based on personal experience; in Jane Eyre she transformed the experience into a novel with universal appeal.
Jane Eyre had immediate commercial success and initially received favourable reviews. G. H. Lewes wrote that it was "an utterance from the depths of a struggling, suffering, much-enduring spirit", and declared that it consisted of "suspiria de profundis!" (sighs from the depths). Speculation about the identity and gender of the mysterious Currer Bell heightened with the publication of Wuthering Heights by Ellis Bell (Emily) and Agnes Grey by Acton Bell (Anne). Accompanying the speculation was a change in the critical reaction to Brontë's work, as accusations were made that the writing was "coarse", a judgement more readily made once it was suspected that Currer Bell was a woman. However, sales of Jane Eyre continued to be strong and may even have increased as a result of the novel developing a reputation as an "improper" book. A talented amateur artist, Brontë personally did the drawings for the second edition of Jane Eyre and in the summer of 1834 two of her paintings were shown at an exhibition by the Royal Northern Society for the Encouragement of the Fine Arts in Leeds.
==Shirley and bereavements==
In 1848 Brontë began work on the manuscript of her second novel, Shirley. It was only partially completed when the Brontë family suffered the deaths of three of its members within eight months. In September 1848 Branwell died of chronic bronchitis and marasmus, exacerbated by heavy drinking, although Brontë believed that his death was due to tuberculosis. Branwell may have had a laudanum addiction. Emily became seriously ill shortly after his funeral and died of pulmonary tuberculosis in December 1848. Anne died of the same disease in May 1849. Brontë was unable to write at this time.
After Anne's death Brontë resumed writing as a way of dealing with her grief, and Shirley, which deals with themes of industrial unrest and the role of women in society, was published in October 1849. Unlike Jane Eyre, which is written in the first person, Shirley is written in the third person and lacks the emotional immediacy of her first novel, and reviewers found it less shocking. Brontë, as her late sister's heir, suppressed the republication of Anne's second novel, The Tenant of Wildfell Hall, an action which had a deleterious effect on Anne's popularity as a novelist and has remained controversial among the sisters' biographers ever since.
==In society==
In view of the success of her novels, particularly Jane Eyre, Brontë was persuaded by her publisher to make occasional visits to London, where she revealed her true identity and began to move in more exalted social circles, becoming friends with Elizabeth Gaskell and Harriet Martineau whose sister Rachel had taught Gaskell's daughters. Brontë sent an early copy of Shirley to Martineau whose home at Ambleside she visited. The two friends shared an interest in racial relations and the abolitionist movement; recurrent themes in their writings. Brontë was also acquainted with William Makepeace Thackeray and G. H. Lewes. She never left Haworth for more than a few weeks at a time, as she did not want to leave her ageing father. Thackeray's daughter, writer Anne Isabella Thackeray Ritchie, recalled a visit to her father by Brontë:
Brontë's friendship with Elizabeth Gaskell, while not particularly close, was significant in that Gaskell wrote the first biography of Brontë after her death in 1855.
==Villette==
Brontë's third novel, the last published in her lifetime, was Villette, which appeared in 1853. Its main themes include isolation, how such a condition can be borne, and the internal conflict brought about by social repression of individual desire. Its main character, Lucy Snowe, travels abroad to teach in a boarding school in the fictional town of Villette, where she encounters a culture and religion different from her own and falls in love with a man (Paul Emanuel) whom she cannot marry. Her experiences result in a breakdown but eventually, she achieves independence and fulfilment through running her own school. A substantial amount of the novel's dialogue is in the French language. Villette marked Brontë's return to writing from a first-person perspective (that of Lucy Snowe), the technique she had used in Jane Eyre. Another similarity to Jane Eyre lies in the use of aspects of her own life as inspiration for fictional events, in particular her reworking of the time she spent at the pensionnat in Brussels. Villette was acknowledged by critics of the day as a potent and sophisticated piece of writing although it was criticised for "coarseness" and for not being suitably "feminine" in its portrayal of Lucy's desires.
==Marriage==
Before the publication of Villette, Brontë received an expected proposal of marriage from Irishman Arthur Bell Nicholls, her father's curate, who had long been in love with her. She initially refused him and her father objected to the union at least partly because of Nicholls's poor financial status. Elizabeth Gaskell, who believed that marriage provided "clear and defined duties" that were beneficial for a woman, encouraged Brontë to consider the positive aspects of such a union and tried to use her contacts to engineer an improvement in Nicholls's finances. According to James Pope-Hennessy in The Flight of Youth, it was the generosity of Richard Monckton Milnes that made the marriage possible. Brontë, meanwhile, was increasingly attracted to Nicholls and by January 1854, she had accepted his proposal. They gained the approval of her father by April and married on 29 June. Her father Patrick had intended to give Charlotte away, but at the last minute decided he could not, and Charlotte had to make her way to the church without him.
Because her father did not attend it was Miss Wooler (Charlotte's former teacher at Roe Head School, and life-long friend), as "friend", who "gave away" Charlotte (Gaskell: Vol II, Chap XIII).
The married couple took their honeymoon in Banagher, County Offaly, Ireland. By all accounts, her marriage was a success and Brontë found herself very happy in a way that was new to her.
==Death==
Brontë became pregnant soon after her wedding, but her health declined rapidly and, according to Gaskell, she was attacked by "sensations of perpetual nausea and ever-recurring faintness". She died, with her unborn child, on 31 March 1855, three weeks before her 39th birthday. Her death certificate gives the cause of death as phthisis, but biographers including Claire Harman and others suggest that she died from dehydration and malnourishment due to vomiting caused by severe morning sickness or hyperemesis gravidarum. Brontë was buried in the family vault in the Church of St Michael and All Angels at Haworth.
The Professor, the first novel Brontë had written, was published posthumously in 1857. The fragment of a new novel she had been writing in her last years has been twice completed by recent authors, the more famous version being Emma Brown: A Novel from the Unfinished Manuscript by Charlotte Brontë by Clare Boylan in 2003. Most of her writings about the imaginary country Angria have also been published since her death. In 2018, The New York Times published a belated obituary for her.
==Religion==
The daughter of an Irish Anglican clergyman, Brontë was herself an Anglican. In a letter to her publisher, she claims to "love the Church of England. Her Ministers indeed, I do not regard as infallible personages, I have seen too much of them for that – but to the Establishment, with all her faults – the profane Athanasian Creed excluded – I am sincerely attached."
In a letter to Ellen Nussey she wrote:
{{blockquote|If I could always live with you, and daily read the bible with you, if your lips and mine could at the same time, drink the same draught from the same pure fountain of Mercy – I hope, I trust, I might one day become better, far better, than my evil wandering thoughts, my corrupt heart, cold to the spirit, and warm to the flesh will now permit me to be. It has been argued that Gaskell's approach transferred the focus of attention away from the 'difficult' novels, not just Brontë's, but all the sisters', and began a process of sanctification of their private lives.
==Nussey letters==
Brontë held lifelong correspondence with her former schoolmate Ellen Nussey. 350 of the some 500 letters sent by Brontë to Nussey survive, whereas all of Nussey's letters to Brontë were burned at Nicholls's request. The surviving letters provide most of the information known on Charlotte Brontë's life and are the backbone of her biographies.
Brontë's letters to Nussey seem to have romantic undertones:
Some scholars believe it is possible, given their passionate friendship, that Charlotte Brontë was in a romantic or sexual relationship with Ellen Nussey.
==Heger letters==
On 29 July 1913 The Times of London printed four letters Brontë had written to Constantin Heger after leaving Brussels in 1844. Written in French except for one postscript in English, the letters broke the prevailing image of Brontë as an angelic martyr to Christian and female duties that had been constructed by many biographers, beginning with Gaskell. The letters, which formed part of a larger and somewhat one-sided correspondence in which Heger frequently appears not to have replied, reveal that she had been in love with a married man, although they are complex and have been interpreted in numerous ways, including as an example of literary self-dramatisation and an expression of gratitude from a former pupil.
In 1980 a commemorative plaque was unveiled at the Centre for Fine Arts, Brussels, on the site of the Madam Heger's school, in honour of Charlotte and Emily.
==Legacy==
Kazuo Ishiguro, when asked to name his favourite novelist, answered "Charlotte Brontë's recently edged out Dostoevsky...I owe my career, and a lot else besides, to Jane Eyre and Villette."
==Publications==
===Juvenilia===
The Young Men's Magazine, Volumes 1–3 (August 1830)
A Book of Ryhmes (1829)
The Spell
The Secret
''Lily Hart
Albion and Marina
Tales of Angria (written 1838–1839 – a collection of childhood and young adult writings including five short novels)
Mina Laury It shows the influence of Walter Scott, and Brontë's modifications to her earlier gothic style have led Christine Alexander to comment that, in the work, "it is clear that Brontë was becoming tired of the gothic mode per se''".
"At the end of 1839, Brontë said goodbye to her fantasy world in a manuscript called Farewell to Angria. More and more, she was finding that she preferred to escape to her imagined worlds over remaining in reality – and she feared that she was going mad. So she said goodbye to her characters, scenes and subjects. [...] She wrote of the pain she felt at wrenching herself from her 'friends' and venturing into lands unknown". the actual author was Constance Savery.
Emma Brown, by Clare Boylan, published 2003
===Poetry===
Selected Poems of the Brontës, Everyman Poetry (1997)
==Media portrayals==
In the 1946 Curtis Bernhardt film Devotion, a fictionalized biography of the Brontë sisters, Olivia de Havilland plays Charlotte.
A November 15, 1953 episode of the Loretta Young Show, "The Bronte Story", features Loretta Young as Charlotte.
The 2018 comic Die features a fictionalised version of Charlotte within the Brontes' fictional kingdom of Angria.
In the 2022 Frances O'Connor film Emily, about Emily Brontë, Alexandra Dowling plays Charlotte.
|
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6,533 |
Charles Williams (British writer)
|
Charles Walter Stansby Williams (20 September 1886 – 15 May 1945) was an English poet, novelist, playwright, theologian and literary critic. Most of his life was spent in London, where he was born, but in 1939 he moved to Oxford with the university press for which he worked until his death.
== Early life and education ==
Charles Williams was born in London in 1886, the only son of (Richard) Walter Stansby Williams (1848–1929) and Mary (née Wall). His father Walter was a journalist and foreign business correspondent for an importing firm, writing in French and German, who was a 'regular and valued' contributor of verse, stories and articles to many popular magazines. His mother Mary, the sister of the ecclesiologist and historian J. Charles Wall, of Islington. He had one sister, Edith, born in 1889. The Williams family lived in 'shabby-genteel' circumstances, owing to Walter's increasing blindness and the decline of the firm by which he was employed, in Holloway.
Educated at St Albans School, Williams was awarded a scholarship to University College London, but he left in 1904 without attempting to gain a degree due to an inability to pay tuition fees.
Williams began work in 1904 in a Methodist bookroom. He was employed by the Oxford University Press (OUP) as a proofreading assistant in 1908 and quickly climbed to the position of editor. He continued to work at the OUP in various positions of increasing responsibility until his death in 1945. One of his greatest editorial achievements was the publication of the first major English-language edition of the works of Søren Kierkegaard. His work was part of the literature event in the art competition at the 1924 Summer Olympics.
Although chiefly remembered as a novelist, Williams also published poetry, works of literary criticism, theology, drama, history, biography, and a voluminous number of book reviews. Some of his best-known novels are War in Heaven (1930), Descent into Hell (1937), and All Hallows' Eve (1945). T. S. Eliot, who wrote an introduction for the last of these, described Williams's novels as "supernatural thrillers" because they explore the sacramental intersection of the physical with the spiritual while also examining the ways in which power, even spiritual power, can corrupt as well as sanctify.
All of Williams's fantasies, unlike those of J. R. R. Tolkien and most of those of C. S. Lewis, are set in the contemporary world. Williams has been described by Colin Manlove as one of the three main writers of "Christian fantasy" in the twentieth century (the other two being C. S. Lewis and T. F. Powys). Some writers of fantasy novels with contemporary settings, notably Tim Powers, cite Williams as their inspiration.
W. H. Auden, one of Williams's greatest admirers, reportedly re-read Williams's extraordinary and highly unconventional history of the church, The Descent of the Dove (1939), every year. Williams's study of Dante entitled The Figure of Beatrice (1944) was very highly regarded at its time of publication and continues to be consulted by Dante scholars today. His work inspired Dorothy L. Sayers to undertake her translation of The Divine Comedy. Williams, however, regarded his most important work to be his extremely dense and complex Arthurian poetry, of which two books were published, Taliessin through Logres (1938) and The Region of the Summer Stars (1944), and more remained unfinished at his death. Some of Williams's essays were collected and published posthumously in Image of the City and Other Essays (1958), edited by Anne Ridler.
Williams gathered many followers and disciples during his lifetime. He was, for a period, a member of the Salvator Mundi Temple of the Fellowship of the Rosy Cross. He met fellow Anglican Evelyn Underhill in 1937 and later wrote the introduction to her published Letters in 1943.
When World War II broke out in 1939, Oxford University Press moved its offices from London to Oxford. Williams was reluctant to leave his beloved city, and his wife Florence refused to go. From the nearly 700 letters he wrote to his wife during the war years, a generous selection has been published — "primarily… love letters," the editor calls them.
The move to Oxford did allow him to participate regularly in Lewis's literary society, the Inklings. In this setting Williams read (and improved) his final published novel, All Hallows' Eve. He heard J. R. R. Tolkien read aloud to the group some of his early drafts of The Lord of the Rings. In addition to meeting in Lewis's rooms at Oxford, they regularly met at The Eagle and Child pub in Oxford. During this time Williams gave lectures at Oxford on John Milton, William Wordsworth, and other authors, and received an honorary M.A. degree.
Williams is buried in Holywell Cemetery in Oxford. His headstone bears the word "poet" followed by the words "Under the Mercy", a phrase often used by Williams himself.
==Personal life==
In 1917 Williams married his first sweetheart, Florence Conway, following a long courtship during which he presented her with a sonnet sequence that would later become his first published book of poetry, The Silver Stair. Their son Michael was born in 1922.
Williams was an unswerving and devoted member of the Church of England, reputedly with a tolerance of the scepticism of others and a firm belief in the necessity of a "doubting Thomas" in any apostolic body.
Although Williams attracted the attention and admiration of some of the most notable writers of his day, including T. S. Eliot and W. H. Auden, his greatest admirer was probably C. S. Lewis, whose novel That Hideous Strength (1945) has been regarded as partially inspired by his acquaintance with both the man and his novels and poems. Williams came to know Lewis after reading Lewis's then-recently published study The Allegory of Love; he was so impressed he jotted down a letter of congratulation and dropped it in the mail. Coincidentally, Lewis had just finished reading Williams's novel The Place of the Lion and had written a similar note of congratulation. The letters crossed in the mail and led to an enduring and fruitful friendship.
Lewis wrote the Preface to Essays presented to Charles Williams, originally intended as a festschrift for Williams, but published after his death. Essays were contributed by Lewis, Sayers, Tolkien, Owen Barfield, Gervase Mathew and Warren Lewis.
== Theology ==
Williams developed the concept of co-inherence and gave rare consideration to the theology of romantic love. Falling in love for Williams was a form of mystical envisioning in which one saw the beloved as he or she was seen through the eyes of God. Co-inherence was a term used in Patristic theology to describe the relationship between the human and divine natures of Jesus Christ and the relationship between the persons of the blessed Trinity. Williams extended the term to include the ideal relationship between the individual parts of God's creation, including human beings. It is our mutual indwelling: Christ in us and we in Christ, interdependent. It is also the web of interrelationships, social and economic and ecological, by which the social fabric and the natural world function. But especially for Williams, co-inherence is a way of talking about the Body of Christ and the communion of saints. He proposed founding an order, to be called the Companions of the Co-inherence, who would practice substitution and exchange, living in love-in-God, truly bearing one another's burdens, being willing to sacrifice and to forgive, living from and for one another in Christ. According to Gunnar Urang, co-inherence is the focus of all Williams's novels.
==Works==
=== Fiction ===
1930: War in Heaven (London: Victor Gollancz) – The Holy Grail surfaces in an obscure country parish and becomes variously a sacramental object to protect or a vessel of power to exploit.
1930: Many Dimensions (London: Victor Gollancz) – An evil antiquarian illegally purchases the fabled Stone of Suleiman (Williams uses this Muslim form rather than the more familiar King Solomon) from its Islamic guardian and returns to England to discover not only that the Stone can multiply itself infinitely without diminishing the original, but that it also allows its possessor to transcend the barriers of space and time.
"Et in Sempiternum Pereant," a short story first published in The London Mercury, December 1935, in which Lord Arglay (protagonist in Many Dimensions) has his life put at risk encountering a ghost on the path to damnation. Later included in The Oxford Book of English Ghost Stories (London: Oxford University Press, 1986)
1931: The Place of the Lion (London: Mundanus) – Platonic archetypes begin to appear around an English country town, wreaking havoc and drawing to the surface the spiritual strengths and flaws of individual characters.
1932: The Greater Trumps (London: Victor Gollancz) – The original Tarot deck is used to unlock enormous metaphysical powers by allowing the possessors to see across space and time, create matter, and raise powerful natural storms.
1933: Shadows of Ecstasy (London: Victor Gollancz) – A humanistic adept has discovered that by focusing his energies inward he can extend his life almost indefinitely. He undertakes an experiment using African lore to die and resurrect his own body thereby assuring his immortality. His followers begin a revolutionary movement to supplant European civilisation. The first of Williams's novels to be written, though not the first published. – Generally thought to be Williams's best novel, Descent deals with various forms of selfishness, and how the cycle of sin brings about the necessity for redemptive acts. In it, an academic becomes so far removed from the world that he fetishises a woman to the extent that his perversion takes the form of a succubus. Other characters include a doppelgänger, the ghost of a suicidal Victorian labourer, and a playwright modelled in some ways on the author. Illustrates Williams's belief in the replacement of sin and substitutional love.
1945: All Hallows' Eve (London: Faber & Faber) – Follows the fortunes of two women after death and their interactions with those they knew before, contrasting the results of action based either on selfishness or an accepting love.
1970–72: The Noises That Weren't There. Unfinished. First three chapters published in Mythlore 6 (Autumn 1970), 7 (Winter 1971) and 8 (Winter 1972).
===Plays===
c. 1912: The Chapel of the Thorn (edited by Sørina Higgins; Berkeley: Apocryphile Press, 2014)
1930: A Myth of Shakespeare (London: Oxford University Press)
1930: A Myth of Francis Bacon (Published in the Charles Williams Society Newsletter, 11, 12, and 14)
1929–31: Three Plays (London: Oxford University Press)
The Rite of the Passion (1929)
The Chaste Wanton (1930)
The Witch (1931)
1963: Collected Plays by Charles Williams (edited by John Heath-Stubbs; London: Oxford University Press)
Thomas Cranmer of Canterbury (1936). Canterbury Festival play, following T. S. Eliot's Murder in the Cathedral in the preceding (inaugural) year.
Seed of Adam (1937)
Judgement at Chelmsford (1939)
The Death of Good Fortune (1939)
The House by the Stable (1939)
Terror of Light (1940)
Grab and Grace (1941)
The Three Temptations (1942)
House of the Octopus (1945)
2000: The Masques of Amen House (edited by David Bratman. Mythopoeic Press).
The Masque of the Manuscript (1927)
The Masque of Perusal (1929)
The Masque of the Termination of Copyright (1930)
===Poetry===
1912: The Silver Stair (London: Herbert and Daniel)
1917: Poems of Conformity (London: Oxford University Press)
1920: Divorce (London: Oxford University Press)
1924: Windows of Night (London: Oxford University Press)
1930: Heroes and Kings (London: Sylvan Press)
1954: Taliessin through Logres (1938) and The Region of the Summer Stars (1944) (London: Oxford University Press)
1991: Charles Williams, ed. David Llewellyn Dodds (Woodbridge and Cambridge, UK: Boydell & Brewer: Arthurian Poets series). Part II, Uncollected and unpublished poems (pp. 149–281).
===Theology===
1938: He Came Down from Heaven (London: Heinemann).
1939: The Descent of the Dove: A Short History of the Holy Spirit in the Church (London: Longmans, Green)
1941: Witchcraft (London: Faber & Faber)
1942: The Forgiveness of Sins (London: G. Bles)
1958: The Image of the City and Other Essays (edited by Anne Ridler; London: Oxford University Press). Parts II through V
1990: Outlines of Romantic Theology (Grand Rapids, Mich.: Eerdmans)
===Literary criticism===
1930: Poetry at Present (Oxford: Clarendon Press).
1932: The English Poetic Mind (Oxford: Clarendon Press).
1933: Reason and Beauty in the Poetic Mind (Oxford: Clarendon Press)
1940: Introduction to Milton (based on a lecture at Oxford University), in The English Poems of John Milton (Oxford University Press)
1941: Religion and Love in Dante: The Theology of Romantic Love (Dacre Press, Westminster).
1943: The Figure of Beatrice (London: Faber & Faber)
1948: The Figure of Arthur (unfinished), in Arthurian Torso, ed. C. S. Lewis (London: Oxford University Press)
1958: The Image of the City and Other Essays (edited by Anne Ridler; London: Oxford University Press). Parts I and VI
2003: The Detective Fiction Reviews of Charles Williams (edited by Jared C. Lobdell; McFarland)
2017: The Celian Moment and Other Essays (edited by Stephen Barber; Oxford: The Greystones Press)
===Biography===
1933: Bacon (London: Arthur Barker)
1933: A Short Life of Shakespeare (Oxford: Clarendon Press). Abridgment of the 2-volume work by Sir Edmund Chambers
1934: James I (London: Arthur Barker)
1935: Rochester (London: Arthur Barker)
1936: Queen Elizabeth (London: Duckworth)
1937: Henry VII (London: Arthur Barker)
1937: Stories of Great Names (London: Oxford University Press). Alexander, Julius Caesar, Charlemagne, Joan of Arc, Shakespeare, Voltaire, John Wesley
1946: Flecker of Dean Close (London: Canterbury Press)
===Other works===
1931: Introduction, Poems of Gerard Manley Hopkins (Ed. Robert Bridges; 2nd ed.; London: Oxford University Press; )
1936: The Story of the Aeneid (London: Oxford University Press; )
1939: The Passion of Christ (Oxford University Press, New York, London )
1940: Introduction, Søren Kierkegaard's The Present Age (trans. Dru and Lowrie; Oxford University Press; )
1943: Introduction, The Letters of Evelyn Underhill (Longmans, Green and Co.)
1958: The New Christian Year (Oxford University Press )
1989: Letters to Lalage: The Letters of Charles Williams to Lois Lang-Sims (Kent State University Press)
2002: To Michal from Serge: Letters from Charles Williams to His Wife, Florence, 1939–1945 (edited by Roma King Jr.; Kent State University Press)
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6,535 |
Celery
|
Celery (Apium graveolens Dulce Group or Apium graveolens var. dulce) is a cultivated plant belonging to the species Apium graveolens in the family Apiaceae that has been used as a vegetable since ancient times.
The original wild species has been selectively bred over centuries into three primary cultivar groups: stalk celery (Dulce Group), consumed for its fibrous edible stalks; leaf celery (Secalinum Group), grown for its aromatic leaves; and celeriac (Rapaceum Group), cultivated for its large, edible hypocotyl. Celery is characterized by its long, ribbed stalks, pinnate leaves, and small white flowers arranged in umbels.
Celery is composed primarily of water (95%) but contains large amounts of vitamin K and negligible fat. The vegetable is commonly consumed raw in salads, cooked in soups and stews, or juiced. Celery seeds, which have a strong, aromatic flavor, are used as a spice or processed into celery salt. Celery is among a small group of foods that may provoke allergic reactions.
Historically, celery has held medicinal, culinary, and symbolic significance. Literary evidence shows evidence of celery cultivation in Ancient Greece, while ancient Egyptians incorporated it into funeral garlands. Celery remains eaten around the world.
==Description==
Celery leaves are pinnate to bipinnate with rhombic leaflets long and broad. The flowers are creamy-white, in diameter, and are produced in dense compound umbels. The seeds are broad ovoid to globose, long and wide. Modern cultivars have been selected for either solid petioles, leaf stalks, or a large hypocotyl.
=== Chemistry ===
The main chemicals responsible for the aroma and taste of celery are butylphthalide and sedanolide.
==Etymology==
First attested and printed in English as "sellery" by John Evelyn in 1664, the modern English word "celery" derives from the French céleri, in turn from Italian seleri, the plural of selero, which comes from Late Latin selinon, the latinisation of the , "celery". The earliest-attested form of the word is the Mycenaean Greek se-ri-no, written in Linear B syllabic script.
==Taxonomy==
The species Apium graveolens was described by Carl Linnaeus in Volume One of his Species Plantarum in 1753. Cultivated celery has been called Apium graveolens var. dulce or Apium graveolens Dulce Group.
Celery was first grown as a winter and early spring vegetable. It was considered a cleansing tonic to counter the deficiencies of a winter diet based on salted meats without fresh vegetables.
In North America, commercial production of celery is dominated by the cultivar called 'Pascal' celery. Gardeners can grow a range of cultivars, many of which differ from the wild species, mainly in having stouter leaf stems. They are ranged under two classes, white and red. The stalks grow in tight, straight, parallel bunches, and are typically marketed fresh that way. They are sold without roots and only a small amount of green leaf remaining.
The stalks can be eaten raw, or as an ingredient in salads, or as a flavouring in soups, stews, and pot roasts.
=== Harvesting and storage ===
Harvesting occurs when the average size of celery in a field is marketable; due to extremely uniform crop growth, fields are harvested only once. The petioles and leaves are removed and harvested; celery is packed by size and quality (determined by colour, shape, straightness and thickness of petiole, stalk and midrib length and absence of disease, cracks, splits, insect damage and rot). During commercial harvesting, celery is packaged into cartons which contain between 36 and 48 stalks and weigh up to . Under optimal conditions, celery can be stored for up to seven weeks from . Inner stalks may continue growing if kept at temperatures above . Shelf life can be extended by packaging celery in anti-fogging, micro-perforated shrink wrap. Freshly cut petioles of celery are prone to decay, which can be prevented or reduced through the use of sharp blades during processing, gentle handling, and proper sanitation.
Celery stalk may be preserved through pickling by first removing the leaves, then boiling the stalks in water before finally adding vinegar, salt, and vegetable oil.
==== Sulfites ====
In the past, restaurants used to store celery in a container of water with powdered vegetable preservative, but it was found that the sulfites in the preservative caused allergic reactions in some people. In 1986, the U.S. Food and Drug Administration banned the use of sulfites on fruits and vegetables intended to be eaten raw.
== Allergic reactions ==
Celery is among a small group of foods that may provoke allergic reactions; for people with celery allergy, exposure can cause potentially fatal anaphylactic shock. Cases of allergic reaction to ingestion of celery root have also been reported in pollen-sensitive individuals resulting in gastrointestinal disorders and other symptoms, although in most cases, celery sensitivity is not considered clinically significant. In the European Union and the United Kingdom, foods that contain or may contain celery, even in trace amounts, must be clearly marked.
The Apium graveolens plant has an OPALS allergy scale rating of 4 out of 10, indicating moderate potential to cause allergic reactions, exacerbated by over-use of the same plant throughout a garden. Celery has caused skin rashes and cross-reactions with carrots and ragweed. It is used in the Iranian stew khoresh karafs.
====Leaves====
Celery leaves are frequently used in cooking to add a mild spicy flavour to foods, similar to, but milder than black pepper. Celery leaves are suitable dried and sprinkled on baked, fried or roasted fish or meats, or as part of a blend of fresh seasonings suitable for use in soups and stews. They may also be eaten raw, mixed into a salad or as a garnish.
====Seeds====
In temperate countries, celery is also grown for its seeds. Actually very small fruit, these "seeds" yield a valuable essential oil that is used in the perfume industry. The oil contains the chemical compound apiole. Celery seeds can be used as flavouring or spice, either as whole seeds or ground.
====Celery salt====
Celery seeds can be ground and mixed with salt to produce celery salt. Celery salt can be made from an extract of the roots or by using dried leaves. Celery salt is used as a seasoning, in cocktails (commonly to enhance the flavour of Bloody Mary cocktails), on the Chicago-style hot dog, and in Old Bay Seasoning. Similarly, combinations of celery powder and salt are used to flavour and preserve cured pork and other processed meats as an alternative to industrial curing salt. The naturally occurring nitrates in celery work synergistically with the added salt to cure food.
====Celery juice====
In 2019, a trend of drinking celery juice was reported in the United States, based on "detoxification" claims posted on a blog. The claims have no scientific basis, but the trend caused a sizable spike in celery prices.
==In culture==
Daniel Zohary and Maria Hopf note that celery leaves and inflorescences were part of the garlands found in the tomb of pharaoh Tutankhamun (died 1323 BCE), and celery mericarps dated to the seventh century BCE were recovered in the Heraion of Samos. However, they note A. graveolens grows wild in these areas, it is hard to decide whether these remains represent wild or cultivated forms." Only by classical antiquity is it thought that celery was cultivated.
M. Fragiska mentions an archeological find of celery dating to the 9th century BCE, at Kastanas; however, the literary evidence for ancient Greece is far more abundant. In Homer's Iliad, the horses of the Myrmidons graze on wild celery that grows in the marshes of Troy, and in Odyssey, there is mention of the meadows of violet and wild celery surrounding Calypso's Cave.
In the Capitulary of Charlemagne, compiled c. 800, apium appears, as does olisatum, or alexanders, among medicinal herbs and vegetables the Frankish emperor desired to see grown. At some later point in medieval Europe, celery displaced alexanders.
The name "celery" retraces the plant's route of successive adoption in European cooking, as the English "celery" (1664) is derived from the French céleri coming from the Lombard term, seleri, from the Latin selinon, borrowed from Greek.
Celery's late arrival in the English kitchen is an end-product of the long tradition of seed selection needed to reduce the sap's bitterness and increase its sugars. By 1699, John Evelyn could recommend it in his Acetaria. A Discourse of Sallets: "Sellery, apium Italicum, (and of the Petroseline Family) was formerly a stranger with us (nor very long since in Italy) is a hot and more generous sort of Macedonian Persley or Smallage... and for its high and grateful Taste is ever plac'd in the middle of the Grand Sallet, at our Great Men's tables, and Praetors feasts, as the Grace of the whole Board".
Celery makes a minor appearance in colonial American gardens; its culinary limitations are reflected in the observation by the author of A Treatise on Gardening, by a Citizen of Virginia that it is "one of the species of parsley". Its first extended treatment in print was in Bernard M'Mahon's American Gardener's Calendar (1806).
After the mid-19th century, continued selections for refined crisp texture and taste brought celery to American tables, where it was served in celery vases to be salted and eaten raw. Celery was so popular in the United States during the 19th and early 20th centuries that the New York Public Library's historical menu archive shows that it was the third-most-popular dish in New York City menus during that time, behind only coffee and tea. In those days, celery cost more than caviar, as it was difficult to cultivate. There were also many varieties of celery back then that are no longer around because they are difficult to grow and do not ship well.
A chthonian symbol among the ancient Greeks, celery was said to have sprouted from the blood of Kadmilos, father of the Cabeiri, chthonian divinities celebrated in Samothrace, Lemnos, and Thebes. The spicy odor and dark leaf colour encouraged this association with the cult of death. In classical Greece, celery leaves were used as garlands for the dead, and the wreaths of the winners at the Isthmian Games were first made of celery before being replaced by crowns made of pine. According to Pliny the Elder, in Achaea, the garland worn by the winners of the sacred Nemean Games was also made of celery. The Ancient Greek colony of Selinous (, Selinous), on Sicily, was named after wild parsley that grew abundantly there; Selinountian coins depicted a parsley leaf as the symbol of the city.
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