id
int64 39
7.86M
| section
stringlengths 0
4.51M
| length
int64 0
50.1k
| title
stringlengths 1
182
| chunk_id
int64 0
68
|
|---|---|---|---|---|
1,857 |
## Strategic voting {#strategic_voting}
### Strategy examples {#strategy_examples}
In the example election described here, assume that the voters in each faction share the following von Neumann--Morgenstern utilities, fitted to the interval between 0 and 100. The utilities are consistent with the rankings given earlier and reflect a strong preference each faction has for choosing its city, compared to weaker preferences for other factors such as the distance to the other cities.
Fraction of voters (living close to) Candidates
-------------------------------------- ------------ -------------
Memphis Nashville Chattanooga
Memphis (42%) 100 15
Nashville (26%) 0 100
Chattanooga (15%) 0 15
Knoxville (17%) 0 15
: Voter utilities for each candidate city
Using these utilities, voters choose their optimal strategic votes based on what they think the various pivot probabilities are for pairwise ties. In each of the scenarios summarized below, all voters share a common set of pivot probabilities.
Strategy scenario Winner Runner-up Candidate vote totals
------------------------------- --------------- ------------- -----------------------
Memphis Nashville Chattanooga Knoxville
Zero-info Memphis Chattanooga 42
Memphis leading Chattanooga Three-way tie 42
Chattanooga leading Knoxville Chattanooga Nashville 42
Chattanooga leading Nashville Nashville Memphis 42
Nashville leading Memphis Nashville Memphis 42
: Approval Voting results for scenarios using optimal strategic voting
In the first scenario, voters all choose their votes based on the assumption that all pairwise ties are equally likely. As a result, they vote for any candidate with an above-average utility. Most voters vote for only their first choice. Only the Knoxville faction also votes for its second choice, Chattanooga. As a result, the winner is Memphis, the Condorcet loser, with Chattanooga coming in second place. In this scenario, the winner has minority approval (more voters disapproved than approved) and all the others had even less support, reflecting the position that no choice gave an above-average utility to a majority of voters.
In the second scenario, all of the voters expect that Memphis is the likely winner, that Chattanooga is the likely runner-up, and that the pivot probability for a Memphis-Chattanooga tie is much larger than the pivot probabilities of any other pair-wise ties. As a result, each voter votes for any candidate they prefer more than the leading candidate, and also vote for the leading candidate if they prefer that candidate more than the expected runner-up. Each remaining scenario follows a similar pattern of expectations and voting strategies.
In the second scenario, there is a three-way tie for first place. This happens because the expected winner, Memphis, was the Condorcet loser and was also ranked last by any voter that did not rank it first.
Only in the last scenario does the actual winner and runner-up match the expected winner and runner-up. As a result, this can be considered a stable strategic voting scenario. In the language of game theory, this is an \"equilibrium.\" In this scenario, the winner is also the Condorcet winner.
| 474 |
Approval voting
| 6 |
1,857 |
## Strategic voting {#strategic_voting}
### Dichotomous cutoff {#dichotomous_cutoff}
Modeling voters with a \'dichotomous cutoff\' assumes a voter has an immovable approval cutoff, while having meaningful cardinal preferences. This means that rather than voting for their top 3 candidates, or all candidates above the average approval, they instead vote for all candidates above a certain approval \'cutoff\' that they have decided. This cutoff does not change, regardless of which and how many candidates are running, so when all available alternatives are either above or below the cutoff, the voter votes for all or none of the candidates, despite preferring some over others. This could be imagined to reflect a case where many voters become disenfranchised and apathetic if they see no candidates they approve of. In a case such as this, many voters may have an internal cutoff, and would not simply vote for their top 3, or the above average candidates.
For example, in this scenario, voters are voting for candidates with approval above 50% (bold signifies that the voters voted for the candidate):
Proportion of electorate Approval of Candidate A Approval of Candidate B Approval of Candidate C Approval of Candidate D Average approval
-------------------------- ------------------------- ------------------------- ------------------------- ------------------------- ------------------
25% **90%** **60%** 40% 10% *50%*
35% 10% **90%** **60%** 40% *50%*
30% 40% 10% **90%** **60%** *50%*
10% **60%** 40% 10% **90%** *50%*
C wins with 65% of the voters\' approval, beating B with 60%, D with 40% and A with 35%
If voters\' threshold for receiving a vote is that the candidate has an above average approval, or they vote for their two most approved of candidates, this is not a dichotomous cutoff, as this can change if candidates drop out. On the other hand, if voters\' threshold for receiving a vote is fixed (say 50%), this is a dichotomous cutoff, and satisfies IIA as shown below:
Proportion of electorate Approval of Candidate A Approval of Candidate B Approval of Candidate C Approval of Candidate D Average approval
-------------------------- ------------------------- ------------------------- ------------------------- ------------------------- ------------------
25% -- **60%** **40%** 10% *37%*
35% -- **90%** 60% 40% *63%*
30% -- 10% **90%** **60%** *53%*
10% -- 40% 10% **90%** *47%*
: A drops out, candidates voting for above average approval
B now wins with 60%, beating C with 55% and D with 40%
Proportion of electorate Approval of Candidate A Approval of Candidate B Approval of Candidate C Approval of Candidate D Average approval
-------------------------- ------------------------- ------------------------- ------------------------- ------------------------- ------------------
25% -- **60%** 40% 10% *37%*
35% -- **90%** **60%** 40% *63%*
30% -- 10% **90%** **60%** *53%*
10% -- 40% 10% **90%** *47%*
: A drops out, candidates voting for approval \> 50%
With dichotomous cutoff, C still wins.
Proportion of electorate Approval of Candidate A Approval of Candidate B Approval of Candidate C Approval of Candidate D Average approval
-------------------------- ------------------------- ------------------------- ------------------------- ------------------------- ------------------
25% **90%** **60%** 40% -- *63%*
35% 10% **90%** **60%** -- *53%*
30% **40%** 10% **90%** -- *47%*
10% **60%** **40%** 10% -- *37%*
: D drops out, candidates voting for top 2 candidates
B now wins with 70%, beating C and A with 65%
Proportion of electorate Approval of Candidate A Approval of Candidate B Approval of Candidate C Approval of Candidate D Average approval
-------------------------- ------------------------- ------------------------- ------------------------- ------------------------- ------------------
25% **90%** **60%** 40% -- *63%*
35% 10% **90%** **60%** -- *53%*
30% 40% 10% **90%** -- *47%*
10% **60%** 40% 10% -- *37%*
: D drops out, candidates voting for approval \> 50%
With dichotomous cutoff, C still wins.
| 590 |
Approval voting
| 7 |
1,857 |
## Compliance with voting system criteria {#compliance_with_voting_system_criteria}
Most of the mathematical criteria by which voting systems are compared were formulated for voters with ordinal preferences. In this case, approval voting requires voters to make an additional decision of where to put their approval cutoff (see examples above). Depending on how this decision is made, approval satisfies different sets of criteria
| 60 |
Approval voting
| 8 |
1,866 |
***Alarums and Excursions**\'\' (***A&E**\'\') was an amateur press association (APA) started in June 1975 by Lee Gold; the final issue, #593, was published in April 2025. It was one of the first publications to focus solely on role-playing games.
## History
In 1964, Bruce Pelz of the Los Angeles Science Fiction Society (LASFS) began a weekly amateur press association named *APA-L*. In 1974, with the publication of *Dungeons & Dragons* by TSR, Inc., articles and comments about the new roleplaying game began to fill the pages of *APA-L*, a development to which Pelz objected. Lee Gold took note of this and started a new APA, *Alarums and Excursions* (the title taken from an Elizabethan drama stage direction that moved soldiers across a stage), to focus entirely on roleplaying games, attracting such material away from *APA-L*. The first issue appeared in June 1975.
In addition to removing roleplaying games discussion out of *APA-L*, the initial aim of the publication was to prevent roleplaying games from becoming so divergent that people from different cities could not participate in games together.
The June 2017 issue of *Alarums and Excursions* was number 500, with a color cover drawn by Lee Moyer and printed by Rob Heinsoo.
## Contents
Each issue is a collection of contributions from different authors, often featuring game design discussions, rules variants, write-ups of game sessions, reviews, and comments on others contributions.
Although game reports and social reactions are common parts of many *A&E* contributions, it has also, over the years, become a testing ground for new ideas on the development of the RPG as a genre and an art form. The idea that role-playing games *are* an art form took strong root in this zine, and left a lasting impression on many of the RPG professionals who contributed. The 1992 role-playing game *Over the Edge* was inspired by discussions in *A&E*.
Among the contributors over the years were: `{{div col|colwidth=12em}}`{=mediawiki}
- Terry K. Amthor
- Wilf K. Backhaus
- Scott Bennie
- Greg Costikyan
- Doc Cross
- John M. Ford
- E. Gary Gygax
- Andrew Gelman
- David A. Hargrave
- Rob Heinsoo
- John Eric Holmes
- Wes Ives
- Robin Laws
- Nicole Lindroos
- Samuel Edward Konkin III
- Stephen R. Marsh
- Phil McGregor
- Dave Nalle
- Mark Rein·Hagen
- Ken Rolston
- John T. Sapienza Jr.
- Lawrence M. Schoen
- Edward E. Simbalist
- Jonathan Tweet
- Erick Wujcik
- John Nephew
- Spike Y Jones
## Reception
In the February 1976 issue of *Strategic Review* (Issue 6), Gary Gygax complimented the new APA, calling it \"an excellent source of ideas, inspirations and fun.\" Although Gygax felt some of the contributors were \"woefully lacking in background\", and the quality of printing varied dramatically from issue to issue, he concluded, \"For all of its faults, it is far and away the best *D&D* \'zine, and well worth reading. See for yourself why it rates a Major Triumph.\"
In the June 1981 edition of *Dragon* (Issue #50), Dave Nalle reviewed *Alarums and Excursions* after its 63rd issue (November 1980), and although he found the writing style \"a bit stuffy\", with a \"tendency for the writers to pat each other on the back\", he still called it \"the top APA publication\... This is a very well run APA and features many of the leading thinkers in fantasy gaming
| 564 |
Alarums and Excursions
| 0 |
1,870 |
**Amalric** or **Amalaric** (also Americ, Almerich, Emeric, Emerick and other variations) is a personal name derived from the tribal name *Amal* (referring to the Gothic Amali) and *ric* (Gothic *reiks*) meaning \"ruler, prince\".
Equivalents in different languages include:
- French: Amaury (surname/given name), Amalric (surname), Amaurich (surname), Maury (surname)
- German: Amalrich, Emmerich
- Italian: Amerigo, Arrigo
- Hungarian: Imre
- Latin: Amalricus, Americus, Almericus, Emericus
- Greek: Έμέρικοσ (Emérikos)
- Polish: Amalaryk, Amalryk, Emeryk
- Dutch: Emmerik, Amerik, Hamelink, Hamelryck
- Portuguese: Amáuri, Américo
- Spanish: Amauri, Américo
- Serbo-Croatian: Emerik/Емерик
- Arabic: عَمُورِي (ʻAmūrī)
## Given name {#given_name}
- Amalaric (502--531), King of the Visigoths from 526 to 531
- Malaric (fl. 585), King of the Suevi
- Amaury, Count of Valenciennes (fl.953-973)
- Amalric of Nesle (fl. 1151--1180), Patriarch of Jerusalem from 1158 to 1180
- Amalric I of Jerusalem (1136--1174), King of Jerusalem from 1162 to 1174
- Amalric II of Jerusalem (fl. 1155--1205), King of Jerusalem from 1197 to 1205
- Amalric of Bena (f. 1200--1204), French theologian
- Arnaud Amalric (fl. 1196--1225), seventeenth abbot of Citeaux
- Amaury de Montfort (disambiguation), several individuals including:
- Amaury de Montfort (died 1241) (1195--1241), crusader
- Amalric, Lord of Tyre (c. 1272 -- 1310), Governor of Cyprus from 1306 to 1310
- Amerigo Vespucci (1451--1512), Italian merchant, explorer, and navigator from the Republic of Florence, from whose name the term \"America\" is derived
| 236 |
Amalric
| 0 |
1,872 |
**Aimery of Lusignan** (*Aimericus*, *Αμωρί*, *Amorí*; before 1155`{{snd}}`{=mediawiki}1 April 1205), erroneously referred to as **Amalric** (*Amaury*) in earlier scholarship, reigned as the first king of Cyprus from 1196 to his death in 1205. He also reigned as the king of Jerusalem as the husband and co-ruler of Queen Isabella I from 1197 to his death. He was a younger son of Hugh VIII of Lusignan, a nobleman in Poitou. After participating in a rebellion against Henry II of England in 1168, he went to the Holy Land and settled in the Kingdom of Jerusalem.
Aimery\'s marriage to Eschiva of Ibelin (whose father was an influential nobleman) strengthened his position in the kingdom. His younger brother, Guy, married Sibylla, the sister and heir presumptive of Baldwin IV of Jerusalem. Baldwin made Aimery the constable of Jerusalem around 1180. He was one of the commanders of the Christian army in the Battle of Hattin, which ended with a decisive defeat at the hands of the army of Saladin, the Ayyubid sultan of Egypt and Syria, on 4 July 1187.
Aimery supported Guy even after he lost his claim to the Kingdom of Jerusalem according to most barons of the realm, because of the death of Sibylla and their two daughters. The new king of Jerusalem, Henry II of Champagne, arrested Aimery for a short period. After his release, he retired to Jaffa which was the fief of his elder brother, Geoffrey of Lusignan, who had left the Holy Land.
After Guy died in May 1194, his vassals in Cyprus elected Aimery as their lord. He accepted the suzerainty of Holy Roman Emperor Henry VI. With the emperor\'s authorization, Aimery was crowned king of Cyprus in September 1197. The widowed Aimery soon married Henry of Champagne\'s widow, Isabella I of Jerusalem. Aimery and Isabella were crowned king and queen of Jerusalem in January 1198. He signed a truce with Al-Adil I, the Ayyubid sultan of Egypt, which secured the Christian possession of the coastline from Acre to Antioch. His rule was a period of peace and stability in both of his realms.
| 349 |
Aimery of Cyprus
| 0 |
1,872 |
## Early life {#early_life}
Aimery was born before 1155. He was the fifth son of Hugh VIII of Lusignan and his wife, Burgundia of Rancon. His family had been noted for generations of crusaders in their native Poitou. His great-grandfather, Hugh VI of Lusignan, died in the Battle of Ramla in 1102; Aimery\'s grandfather, Hugh VII of Lusignan, took part in the Second Crusade. Aimery\'s father also came to the Holy Land and died in a Muslim prison in the 1160s. Earlier scholarship erroneously referred to him as Amalric (or Amaury, its French form), but evidence from documentaries shows he was actually called *Aimericus*, which is a distinct name (although it was sometimes confused with *Amalricus* already in the Middle Ages). Runciman and other modern historians erroneously refer to him as Amalric II of Jerusalem, because they confused his name with that of Amalric \"I\" of Jerusalem.
Aimery joined a rebellion against Henry II of England (who also ruled Poitou) in 1168, according to Robert of Torigni\'s chronicle, but Henry crushed the rebellion. Aimery left for the Holy Land and settled in the Kingdom of Jerusalem. He was captured in a battle and held in captivity in Damascus. A popular tradition (which was first recorded by the 13th-century Philip of Novara and John of Ibelin) held, the King of Jerusalem, Amalric, ransomed him personally.
Ernoul (whose reliability is questioned) claimed Aimery was a lover of Amalric of Jerusalem\'s former wife, Agnes of Courtenay. Aimery married Eschiva of Ibelin, a daughter of Baldwin of Ibelin, who was one of the most powerful noblemen in the Kingdom of Jerusalem. Amalric of Jerusalem, who died on 11 July 1174, was succeeded by his thirteen-year-old son by Agnes of Courtenay, Baldwin IV who suffered from leprosy. Aimery became a member of the royal court with his father-in-law\'s support.
Aimery\'s youngest brother, Guy, married Baldwin IV\'s widowed sister, Sibylla, in April 1180. Ernoul wrote, it was Aimery who had spoken of his brother to her and her mother, Agnes of Courtenay, describing him as a handsome and charming young man. Aimery, continued Ernoul, hurried back to Poitou and persuaded Guy to come to the kingdom, although Sibylla had promised herself to Aimery\'s father-in-law. Another source, William of Tyre, did not mention that Aimery had played any role in the marriage of his brother and the King\'s sister. Consequently, many elements of Ernoul\'s report (especially Aimery\'s alleged journey to Poitou) were most probably invented.
| 408 |
Aimery of Cyprus
| 1 |
1,872 |
## Constable of Jerusalem {#constable_of_jerusalem}
Aimery was first mentioned as Constable of Jerusalem on 24 February 1182. According to Steven Runciman and Malcolm Barber, he had already been granted the office shortly after his predecessor, Humphrey II of Toron, died in April 1179. Historian Bernard Hamilton writes that Aimery\'s appointment was the consequence of the growing influence of his brother and he was appointed only around 1181.
Saladin, the Ayyubid sultan of Egypt and Syria, launched a campaign against the Kingdom of Jerusalem on 29 September 1183. Aimery defeated the sultan\'s troops in a minor skirmish with the support of his father-in-law and his brother, Balian of Ibelin. After the victory, the crusaders\' main army could advance as far as a spring near Saladin\'s camp, forcing him to retreat nine days later. During the campaign, it turned out that most barons of the realm were unwilling to cooperate with Aimery\'s brother, Guy, who was the designated heir to Baldwin IV. The ailing king dismissed Guy and made his five-year-old nephew (Guy\'s stepson), Baldwin V, his co-ruler on 20 November 1183.
In early 1185, Baldwin IV decreed that the Pope, the Holy Roman Emperor and the Kings of France and England were to be approached to choose between his sister, Sybilla, and their half-sister, Isabella, if Baldwin V died before reaching the age of majority. The leper king died in April or May 1185, his nephew in late summer of 1186. Ignoring Baldwin IV\'s decree, Sybilla was proclaimed queen by her supporters and she crowned her husband, Guy, king. Aimery was not listed among those who were present at the ceremony, but he obviously supported his brother and sister-in-law, according to Hamilton.
As Constable, Aimery organised the army of the Kingdom of Jerusalem into units before the Battle of Hattin, which ended with the decisive victory of Saladin on 4 July 1187. Along with most commanders of the Christian army, Aimery was captured in the battlefield. During the siege of Ascalon, Saladin promised the defenders that he would set free ten persons whom they named if they surrendered. Aimery and Guy were among those whom the defenders named before surrendering on 4 September, but Saladin postponed their release until the spring of 1188.
Most barons of the realm thought that Guy lost his claim to the Kingdom of Jerusalem when Sybilla and their two daughters died in late 1190, but Aimery remained loyal to his brother. Guy\'s opponents supported Conrad of Montferrat who married Sybilla\'s half-sister Isabella in late November. An assembly of the noblemen of the realm unanimously declared Conrad the lawful king on 16 April 1192. Although Conrad was murdered twelve days later, his widow soon married Henry II of Champagne, who was elected King of Jerusalem. To compensate Guy for the loss of Jerusalem, Richard I of England authorized him to purchase the island of Cyprus (that Richard had conquered in May 1191) from the Knights Templar. He was also to pay 40,000 bezants to Richard who donated the right to collect the sum from Guy to Henry. Guy settled in Cyprus in early May.
Aimery remained in the Kingdom of Jerusalem, which was reduced to a narrow strip of land along the coast of the Mediterranean Sea from Jaffa to Tyre. King Henry ordered the expulsion of the merchants from Pisa from Acre in May, because he accused them of plotting with Guy of Lusignan. After Aimery intervened on behalf of the merchants, Henry had him arrested. Aimery was only released at the demand of the grand masters of the Templars and the Hospitallers. He retired to Jaffa, which King Richard had granted to Aimery\'s eldest brother, Geoffrey of Lusignan.
| 613 |
Aimery of Cyprus
| 2 |
1,872 |
## Reign
### Lord of Cyprus {#lord_of_cyprus}
Guy died in May 1194, and bequeathed Cyprus to his elder brother, Geoffrey. However Geoffrey had already returned to Poitou, thus Guy\'s vassals elected Aimery their new lord. Henry of Champagne demanded the right to be consulted about the succession in Cyprus, but the Cypriote noblemen ignored him. Around the same time, Henry replaced Aimery with John of Ibelin as constable of Jerusalem.
Aimery realized that the treasury of Cyprus was almost empty because his brother had granted most landed property on the island to his supporters, according to Ernoul. He summoned his vassals to an assembly. After emphasizing that each of them owned more land than he had, he persuaded them one by one \"either by force, or by friendship, or by agreement\" to surrender some of their rents and lands.
Aimery dispatched an embassy to Pope Celestine III, asking him to set up Roman Catholic dioceses in Cyprus. He also sent his representative, Rainier of Gibelet, to the Holy Roman Emperor, Henry VI, proposing that he would acknowledge the emperor\'s suzerainty, if the emperor sent a royal crown to him. Aimery primarily wanted to secure the emperor\'s assistance against a potential Byzantine invasion of Cyprus, but he also wanted to strengthen his own legitimacy as king. Rainier of Gibelet swore loyalty to Henry VI on behalf of Aimery in Gelnhausen in October 1196. The emperor who had decided to lead a crusade to the Holy Land promised that he would personally crown Aimery king. He dispatched the archbishops of Brindisi and Trani to take a golden sceptre to Aimery as a symbol of his right to rule Cyprus.
### King of Cyprus {#king_of_cyprus}
Henry VI\'s two envoys landed in Cyprus in April or May 1196. Aimery may have adopted the title of king around that time, because Pope Celestine styled him as king already in a letter in December 1196. In the same month, the Pope set up a Roman Catholic archdiocese in Nicosia with three suffragan bishops in Famagusta, Limassol and Paphos. The Greek Orthodox bishops were not expelled, but their property and income were seized by the new Catholic prelates.
Henry VI\'s chancellor, Conrad, Bishop of Hildesheim, crowned Aimery king in Nicosia in September 1197. Aimery did homage to the chancellor. The noblemen who owned fiefs in both Cyprus and the Kingdom of Jerusalem wanted to bring about a reconciliation between Aimery and Henry of Champagne. One of them, Baldwin of Beisan, Constable of Cyprus, persuaded King Henry to visit Cyprus in early 1197. The two kings made peace, agreeing that Aimery\'s three sons were to marry Henry\'s three daughters. Henry also renounced the debt that Aimery still owed to him for Cyprus and allowed Aimery to garrison his troops at Jaffa. Aimery sent Reynald Barlais to take possession of Jaffa. Aimery again used the title of Constable of Jerusalem in November 1197, which suggests that he had also recovered that office as a consequence of his treaty with Henry.
| 501 |
Aimery of Cyprus
| 3 |
1,872 |
## Reign
### King of two realms {#king_of_two_realms}
Henry of Champagne fell from the window in his palace and died in Acre on 10 September 1197. The aristocratic-yet-impoverished Raoul of Saint Omer was one of the possible candidates to succeed him, but the grand masters of the military orders opposed him vehemently. A few days later, Al-Adil I, the Ayyubid sultan of Egypt, occupied Jaffa.
Conrad of Wittelsbach, the archbishop of Mainz, who arrived to Acre on 20 September, was the first to propose that the crown should be offered to Aimery. Since Aimery\'s first wife had died, he could marry the widowed queen of Jerusalem, Isabella I. Although Aymar, the patriarch of Jerusalem, stated that the marriage would be uncanonical, Joscius, archbishop of Tyre, started negotiations with Aimery who accepted the offer. The patriarch also withdrew his objections and crowned Aimery and Isabella in Tyre in January 1198.
The Cypriot Army fought for the Kingdom of Jerusalem during Aimery\'s rule, but otherwise, he administered his two realms separately. Even before his coronation, Aimery united his forces with the German crusaders who were under the command of Duke Henry I of Brabant to launch a campaign against the Ayyubid troops. They forced Al-Adil to withdraw and captured Beirut on 21 October. He laid siege to Toron, but he had to lift the siege on 2 February, because the German crusaders decided to return to the Holy Roman Empire after learning that Emperor Henry VI had died.
Aimery was riding at Tyre when four German knights attacked him in March 1198. His retainers rescued him and captured the four knights. Aimery accused Raoul of Saint Omer of hiring the assailants and sentenced him to banishment without a trial by his peers. At Raoul\'s demand, the case was submitted to the High Court of Jerusalem which held that Aimery had unlawfully banished Raoul. Nevertheless, Raoul voluntarily left the kingdom and settled in Tripoli, because he knew that he had lost Aimery\'s goodwill.
Aimery signed a truce with Al-Adil on 1 July 1198, securing the possession of the coast from Acre as far as to Antioch for the crusaders for five years and eight months. The Byzantine emperor, Alexios III Angelos, did not abandon the idea of recovering Cyprus. He promised that he would help a new crusade if Pope Innocent III excommunicated Aimery to enable a Byzantine invasion in 1201, but Innocent refused him, stating that the Byzantines had lost their right to Cyprus when Richard I conquered the island in 1191.
Aimery kept the peace with the Muslims, even when Reynald II of Dampierre, who arrived at the head of 300 French crusaders, demanded that he launch a campaign against the Muslims in early 1202. After Aimery reminded him that more than 300 soldiers were needed to wage war against the Ayyubids, Reynald left the Kingdom of Jerusalem for the Principality of Antioch. An Egyptian emir seized a fortress near Sidon and made plundering raids against the neighbouring territory. As Al-Adil failed to force the emir to respect the truce, Aimery\'s fleet seized 20 Egyptian ships and he invaded Al-Adil\'s realm. In retaliation, Al-Adil\'s son, Al-Mu\'azzam Isa plundered the region of Acre. In May 1204, Aimery\'s fleet sacked a small town in the Nile Delta in Egypt. The envoys of Aimery and Al-Adil signed a new truce for six years in September 1204. Al-Adil ceded Jaffa and Ramleh to the Kingdom of Jerusalem and simplified the Christian pilgrims\' visits to Jerusalem and Nazareth.
After eating an excess of white mullet, Aimery fell seriously ill. He died after a short illness on 1 April 1205. His six-year-old son, Hugh I, succeeded him in Cyprus; and Queen Isabella ruled the Kingdom of Jerusalem until her own death four days later.
| 627 |
Aimery of Cyprus
| 4 |
1,872 |
## Legacy
Historian Mary Nickerson Hardwicke described Aimery as a \"self-assured, politically astute, sometimes hard, seldom sentimentally indulgent\" ruler. His rule was a period of peace and consolidation. He initiated the revision of the laws of the Kingdom of Jerusalem to specify royal prerogatives. The lawyers of the Kingdom of Jerusalem held him in high esteem. One of them, John of Ibelin, emphasized that Aimery had governed both Cyprus and Jerusalem \"well and wisely\" until his death.
## Family
Aimery\'s first wife, Eschiva of Ibelin, was the elder daughter of Baldwin of Ibelin, lord of Mirabel and Ramleh, and Richelda of Beisan. They had five children:
- Bourgogne, who married (1) Raymond VI of Toulouse in 1193 (div 1196 with no issue); (2) Walter of Montbéliard in 1204. Walter was the regent of Cyprus for her younger brother, Hugh I, from 1205 to 1210.
- Helvis, who married Raymond-Roupen, the prince of Antioch from 1216 to 1219.
- Guy, who died young
- John, who died young
- Hugh I, who married Alice of Champagne
Aimery\'s second wife, Isabella I of Jerusalem, was the only daughter of Amalric I of Jerusalem and Maria Komnene. They had three children:
- Sybilla, who was the second wife of Leo I, king of Armenia.
- Melisende, who married Bohemond IV of Antioch.
- Amalric, who died during childhood, 2 February 1205
| 228 |
Aimery of Cyprus
| 5 |
1,873 |
**Anthemius of Tralles** (*Ἀνθέμιος ὁ Τραλλιανός*, Medieval Greek: `{{IPA|el|anˈθemios o traliaˈnos|}}`{=mediawiki}, *Anthémios o Trallianós*; `{{c.|lk=no|474}}`{=mediawiki} -- 533 `{{abbr|x|sometime between}}`{=mediawiki} 558)`{{r|Boyer}}`{=mediawiki} was a Byzantine Greek from Tralles who worked as a geometer and architect in Constantinople, the capital of the Byzantine Empire. With Isidore of Miletus, he designed the Hagia Sophia for Justinian I. `{{anchor|History|Biography}}`{=mediawiki}
## Life
Anthemius was one of the five sons of Stephanus of Tralles, a physician. His brothers were Dioscorus, Alexander, Olympius, and Metrodorus. Dioscorus followed his father\'s profession in Tralles; Alexander did so in Rome and became one of the most celebrated medical men of his time; Olympius became a noted lawyer; and Metrodorus worked as a grammarian in Constantinople.
Anthemius was said to have annoyed his neighbor Zeno in two ways: first, by engineering a miniature earthquake by sending steam through leather tubes he had fixed among the joists and flooring of Zeno\'s parlor while he was entertaining friends and, second, by simulating thunder and lightning and flashing intolerable light into Zeno\'s eyes from a slightly hollowed mirror. In addition to his familiarity with steam, some dubious authorities credited Anthemius with a knowledge of gunpowder or other explosive compound.
## Mathematics
Anthemius was a capable mathematician. In the course of his treatise *On Burning Mirrors*, he intended to facilitate the construction of surfaces to reflect light to a single point, he described the string construction of the ellipse`{{r|Boyer}}`{=mediawiki} and assumed a property of ellipses not found in Apollonius of Perga\'s *Conics*: the equality of the angles subtended at a focus by two tangents drawn from a point. His work also includes the first practical use of the directrix: having given the focus and a double ordinate, he used the focus and directrix to obtain any number of points on a parabola. This work was later known to Arab mathematicians such as Alhazen.
Eutocius of Ascalon\'s commentary on Apollonius\'s *Conics* was dedicated to Anthemius.`{{r|Boyer}}`{=mediawiki}
## Architecture
As an architect, Anthemius is best known for his work designing the Hagia Sophia. He was commissioned with Isidore of Miletus by Justinian I shortly after the earlier church on the site burned down in 532 but died early on in the project. He is also said to have repaired the flood defenses at Daras
| 373 |
Anthemius of Tralles
| 0 |
1,874 |
**Absalon** (c. 1128`{{snd}}`{=mediawiki}21 March 1201) was a Danish statesman and prelate of the Catholic Church who served as the bishop of Roskilde from 1158 to 1192 and archbishop of Lund from 1178 until his death. He was the foremost politician and church father of Denmark in the second half of the 12th century, and was the closest advisor of King Valdemar I of Denmark. He was a key figure in the Danish policies of territorial expansion in the Baltic Sea, Europeanization in close relationship with the Holy See, and reform in the relation between the Church and the public. He combined the ideals of Gregorian Reform with loyal support of a strong monarchical power.
Absalon was born into the powerful *Hvide* clan, and owned great land possessions. He endowed several church institutions, most prominently his family\'s Sorø Abbey. He was granted lands by the crown, and built the first fortification of the city that evolved into modern-day Copenhagen. His titles were passed on to his nephews Anders Sunesen and Peder Sunesen. He died in 1201, and was interred at Sorø Abbey.
## Early life {#early_life}
Absalon was born around 1128 near Sorø, Zealand.`{{fact|date=January 2021}}`{=mediawiki} Due to his name being unusual in Denmark, it is speculated that he was baptized on the Danish \"Absalon\" name day, 30 October. He was the son of Asser Rig, a magnate of the *Hvide* clan from Fjenneslev on Zealand, and Inger Eriksdotter. He was also a kinsman of Archbishop Eskil of Lund. He grew up at the castle of his father, and was brought up alongside his older brother Esbern Snare and the young prince Valdemar, who later became King Valdemar I of Denmark. During the civil war following the death of Eric III of Denmark in 1146, Absalon travelled abroad to study theology in Paris, while Esbern fought for Valdemar\'s ascension to the throne. In Paris, he was influenced by the Gregorian Reform ideals of churchly independence from monarchical rule. He also befriended the canon William of Æbelholt at the Abbey of St Genevieve, whom he later made abbot of Eskilsø Abbey.
Absalon first appears in Saxo Grammaticus\'s contemporary chronicle *Gesta Danorum* at the end of the civil war, in the brokering of the peace agreement between Sweyn III and Valdemar at St. Alban\'s Priory in Odense. He was a guest at the subsequent Roskilde banquet given in 1157 by Sweyn for his rivals Canute V and Valdemar. Both Absalon and Valdemar narrowly escaped assassination by Sweyn on this occasion, and escaped to Jutland, whither Sweyn followed them. Absalon probably did not take part in the following battle of Grathe Heath in 1157, where Sweyn was defeated and slain. This led to Valdemar ascending to the Danish throne. On Good Friday 1158, bishop `{{interlanguage link|Asser of Roskilde|qid=Q12302360}}`{=mediawiki} died, and Absalon was eventually elected bishop of Roskilde on Zealand with the help of Valdemar, as the king\'s reward for *Hvide* family support.
| 487 |
Absalon
| 0 |
1,874 |
## Bishop and advisor {#bishop_and_advisor}
Absalon was a close counsellor of Valdemar, and chief promoter of the Danish crusades against the Wends. During the Danish civil war, Denmark had been open to coastal raids by the Wends. It was Absalon\'s intention to clear the Baltic Sea of the Wendish pirates who inhabited its southern littoral zone, which was later called Pomerania. The pirates had raided the Danish coasts during the civil war of Sweyn III, Canute V, and Valdemar, to the point where at the accession of Valdemar one-third of Denmark lay wasted and depopulated. Absalon formed a guardian fleet, built coastal defenses, and led several campaigns against the Wends. He even advocated forgiving the earlier enemies of Valdemar, which helped stabilize Denmark internally.
### Wendish campaigns {#wendish_campaigns}
The first expedition against the Wends conducted by Absalon in person, set out in 1160. These expeditions were successful, but brought no lasting victories. What started out as mere retribution, eventually evolved into full-fledged campaigns of expansion with religious motives. In 1164 began twenty years of crusades against the Wends, sometimes with the help of German duke Henry the Lion, sometimes in opposition to him.
In 1168 the chief Wendish fortress at Arkona in Rügen, containing the sanctuary of their god Svantevit, was conquered. The Wends agreed to accept Danish suzerainty and the Christian religion at the same time. From Arkona, Absalon proceeded by sea to Charenza, in the midst of Rügen, the political capital of the Wends and an all but impregnable stronghold. But the unexpected fall of Arkona had terrified the garrison, which surrendered unconditionally at the first appearance of the Danish ships. Absalon, with only Bishop Sweyn of Aarhus and twelve \"housecarls\", thereupon disembarked, passed between a double row of Wendish warriors, 6000 strong, along the narrow path winding among the morasses, to the gates of the fortress, and, proceeding to the temple of the seven-headed god Rugievit, caused the idol to be hewn down, dragged forth and burnt. The whole population of Garz was then baptized, and Absalon laid the foundations of twelve churches in the isle of Rügen. Rügen was then subjected to Absalon\'s Bishopric of Roskilde. The destruction of this chief sally-port of the Wendish pirates enabled Absalon to considerably reduce the Danish fleet. But he continued to keep a watchful eye over the Baltic, and in 1170 destroyed another pirate stronghold, farther eastward, at Dziwnów on the isle of Wolin. Absalon\'s last military exploit came in 1184, off Stralsund at Whitsun, when he soundly defeated a Pomeranian fleet that had attacked Denmark\'s vassal, Jaromar of Rügen.
| 431 |
Absalon
| 1 |
1,874 |
## Bishop and advisor {#bishop_and_advisor}
### Policies
Absalon\'s main political goal was to free Denmark from entanglements with the Holy Roman Empire. Absalon reformed the Danish church organisation to closer match Holy See praxis, and worked to keep Denmark a close ally of the Holy See. However, during the schism between Pope Alexander III and Antipope Victor IV, Absalon stayed loyal to Valdemar even as he joined the Holy Roman Emperor Frederick Barbarossa in supporting Victor IV. This caused a split within the Danish church, as it possibly forced Eskil of Lund into exile around 1161, despite Abaslon\'s attempts to keep the Danish church united. It was contrary to Absalon\'s advice and warnings that Valdemar I rendered fealty to the emperor Frederick Barbarossa at Dole in 1162. When Valdemar returned to Denmark, he was convinced to strengthen the Danevirke fortifications at the German border, with the support of Absalon.
Absalon built churches and monasteries, supporting international religious orders like the Cistercians and Augustinians, founding schools and doing his utmost to promote civilization and enlightenment. In 1162, Absalon transformed the Sorø Abbey of his family from Benedictine to Cistercian, granting it lands from his personal holdings. In 1167, Absalon was granted the land around the city of Havn (English: \"Harbour\"), and built there a castle for coastal defense against the Wends. Havn quickly expanded into one of Scandinavia\'s most important centers of trade, and eventually evolved into modern-day Copenhagen. It was also Absalon who held the first Danish Synod at Lund in 1167. He was interested in history and culture, and commissioned Saxo Grammaticus to write *Gesta Danorum*, a comprehensive chronicle of the history of the Danes. In 1171, Absalon issued the \"Zealand church law\" (*Sjællandske Kirkelov*), which reduced the number of Canonical Law offenses for which the church could fine the public, while instituting the tithe payment system. Violation of the law was specified as subject to a secular legal process.
## Archbishop of Lund {#archbishop_of_lund}
Archbishop Eskil returned from exile in 1167. Eskil agreed on canonizing Valdemar\'s father Knud Lavard in 1170, with Absalon assisting him at the feast. When Eskil stepped down as Archbishop of Lund in 1177, he chose Absalon as his successor. Absalon initially resisted the new position, as he did not want to lose his power position on Zealand, but complied with Papal orders to do so in 1178. By a unique Papal dispensation, Absalon was allowed to simultaneously maintain his post as Bishop of Roskilde. As the Archbishop of Lund, Absalon utilized ombudsmen from Zealand, demanded unfree labour from the peasantry, and instituted tithes. He was a harsh and effective ruler, who cleared all Orthodox Christian liturgical remnants in favour of Papal standards. A rebellion in the Scanian peasantry forced him to flee to Zealand in 1180, but he returned and subdued the Scanians with the help of Valdemar.
Valdemar died in 1182 and was succeeded by his son, Canute VI, whom Absalon also served as counsellor. Under Canute VI, Absalon was the chief policymaker in Danish politics. Absalon kept his hostile attitude to the Holy Roman Empire. On the accession of Canute VI in 1182, an imperial ambassador arrived at Roskilde to get the new king to swear fealty to Frederick Barbarossa, but Absalon resolutely withstood him.
| 544 |
Absalon
| 2 |
1,874 |
## Death
When Absalon retired from military service in 1184 at the age of fifty-seven, he resigned the command of fleets and armies to younger men, like Duke Valdemar, the later king Valdemar II. He instead confined himself to the administration of the Danish empire. In 1192, Absalon made his nephew Peder Sunesen his successor as Bishop of Roskilde, while his other nephew Anders Sunesen was named the chancellor of Canute VI. Absalon died at Sorø Abbey on 21 March 1201, 73 years old, with his last will granting his personal holdings to the Abbey, apart from Fjenneslev which went to Esbern Snarre. He had already given Copenhagen to the Bishopric of Roskilde. Absalon was interred at Sorø Abbey, and was succeeded as Archbishop of Lund by Anders Sunesen.
## Legacy
Saxo Grammaticus\' *Gesta Danorum* was not finished until after the death of Absalon, but Absalon was one of the chief heroic figures of the chronicle, which was to be the main source of knowledge about early Danish history. Absalon left a legacy as the foremost politician and churchfather of Denmark in the 12th century. Absalon was equally great as churchman, statesman, and warrior. His policy of expansion was to give Denmark the dominion of the Baltic for three generations. That he enjoyed warfare there can be no doubt; yet he was not like the ordinary fighting bishops of the Middle Ages, whose sole indication of their religious role was to avoid the *shedding of blood* by using a mace in battle instead of a sword. Absalon never neglected his ecclesiastical duties.
In the 2000s, \"Absalon\" was adopted as the name for a class of Royal Danish Navy vessels, and the lead vessel of the class. HDMS Absalon (L16) and *Esbern Snare* (L17) were launched and commissioned by Denmark in 2004 and 2005
| 303 |
Absalon
| 3 |
1,875 |
{{ Infobox Christian leader \| type = bishop \| name = Adhemar of Le Puy \| image = Adhémar de Monteil à Antioche.jpeg \| caption = A mitred Adhémar de Monteil carrying the Holy Lance in one of the battles of the First Crusade \| title = Bishop of Le Puy-en-Velay \| church = Catholic Church \| see = Diocese of Le Puy-en-Velay \| term = 1082--1098 \| predecessor = Stephan de Polignac \| successor = Pons de Tournon \| birth_date = 1055 \| birth_place = Valentinois, Kingdom of France \| death_date = 1 August 1098 (aged 43) \| death_place = Principality of Antioch }}
**Adhemar** (also known as **Adémar**, **Aimar**, or **Aelarz**) **de Monteil** (died 1 August 1098) was one of the principal figures of the First Crusade and was bishop of Puy-en-Velay from before 1087. He was the chosen representative of Pope Urban II for the expedition to the Holy Land. Remembered for his martial prowess, he led knights and men into battle and fought beside them, particularly at the Battle of Dorylaeum and Siege of Antioch. Adhemar is said to have carried the Holy Lance in the Crusaders' desperate breakout at Antioch on 28 June 1098, in which superior Islamic forces under the atabeg Kerbogha were routed, securing the city for the Crusaders. He died in 1098 due to illness.
## Life
Born around 1045 into the family of the Counts of Valentinois and elected Bishop of Le Puy around 1080, he was an advocate of the Gregorian Reform. Among his supporters were the future Pope Urban II and Raymond of Saint-Gilles, Count of Toulouse and the richest, most powerful nobleman in France. He was also said to have gone on pilgrimage to Jerusalem around 1086. He was the brother of William Hugh of Monteil, who was also a Crusader in the First Crusade. Adhemar most likely met Pope Urban II, when he visited Puy in August 1095.
At the Council of Clermont in 1095, Adhemar showed great zeal for the crusade (there is evidence that Urban II had conferred with Adhemar before the council). Adhemar was named apostolic legate and appointed to lead the crusade by Pope Urban II on 27 November 1095. In part, Adhemar was selected to lead because he had already undertaken a pilgrimage to Jerusalem in 1086 and 1087. Following the announcement of the Crusade Adhemar spent the next year raising money and recruiting men. Departing on 15 August 1096, he accompanied Raymond of Toulouse and his army to the east. Whilst Raymond and the other leaders often quarrelled with each other over the leadership of the crusade, Adhemar was always recognized as the spiritual leader of the crusade and was widely respected by the majority of the Crusaders.
During the leg of the trip from Durazzo to Constantinople, in the Valley of Pelagonia, Adhemar was set upon by a group of Pecheneg mercenaries, when he had wandered too far from the majority of the Crusader forces. The Pechenegs beat and robbed Adhemar, but began to fight among themselves over his belongings; Adhemar was saved by Crusader forces who had noticed the disturbance. Once the army had reached Thessalonica, Adhemar decided to stay there for some time, due to sickness, whilst the Crusader forces moved onward. Adhemar eventually was able to rejoin the Crusaders.
Adhemar negotiated with Alexius I Comnenus at Constantinople, reestablished some discipline among the crusaders at Nicaea, fought a crucial role at the Battle of Dorylaeum and was largely responsible for sustaining morale during the siege of Antioch through various religious rites including fasting and special observances of holy days. One such time he did this, was after an earthquake during the siege of Antioch, he had the Crusaders fast for three days and had the priests and clergy perform mass and prayers. Adhemar also ordered the Crusaders to shave and wear a cross in an attempt to stop Crusaders from attacking one another by accident. After the capture of the city in June 1098 and the subsequent siege led by Kerbogha, Adhemar organized a procession through the streets and had the gates locked so that the Crusaders, many of whom had begun to panic, would be unable to leave the city. He was extremely skeptical of Peter Bartholomew\'s discovery in Antioch of the Holy Lance, especially because he knew such a relic already existed in Constantinople; however, he was willing to let the Crusader army believe it was real if it raised their morale. Adhemar was protected by a band of Crusaders led by Henry of Esch to preserve the (albeit suspect) relic. In June 1098 Adhemar fell prey to sickness and in the following months his condition would deteriorate.
When Kerbogha was defeated, Adhemar organized a council in an attempt to settle the leadership disputes, but died on 1 August 1098, probably of typhus. Adhemar was buried in Antioch within the Basilica of St Peter. The disputes among the higher nobles went unsolved and the march to Jerusalem was delayed for months. However, the lower-class soldiers continued to think of Adhemar as a leader. Following his death, Adhemar reportedly appeared in several visions of various Crusaders. One of the first was reported by Peter Bartholomew who stated that Adhemar appeared to him stating that, due to his skepticism of the Holy Lance, he had spent a few days in hell and was only rescued because a candle had been burned in his memory, he had given a gift to the Shrine where the Holy Lance was kept, and due to the prayers of Bohemond. At the siege of Jerusalem, Peter Desiderius claimed that to have received a vision from Adhemar himself. Peter also claimed that, in this vision, Adhemar had instructed him to have the Crusaders fast and lead a procession around the Walls of Jerusalem. This was done and Jerusalem was taken by the Crusaders in 1099. Later, Stephen of Valence also claimed to have had visions featuring Adhemar in which Adhemar spoke to Stephen of several relics. Adhemar told Stephen great reverence should be given to the cross Adhemar had taken with him on the crusade. He also told Stephen how the Holy Lance should be treated and told Stephen to give Stephen\'s ring to Count Raymond. He told Stephen that, through this ring, Count Raymond would be able to call upon the power of Mary
| 1,061 |
Adhemar of Le Puy
| 0 |
1,879 |
**Alfonso Jordan**, also spelled **Alfons Jordan** or **Alphonse Jourdain** (1103--1148), was the Count of Tripoli (1105--09), Count of Rouergue (1109--48) and Count of Toulouse, Margrave of Provence and Duke of Narbonne (1112--48).
## Life
Alfonso was the son of Raymond IV of Toulouse by his third wife, Elvira of Castile. He was born in the castle of Mont Pèlerin in Tripoli while his father was on the First Crusade. He was given the name \"Jourdain\" after being baptised in the Jordan River. Alfonso\'s father died when he was two years old and he remained under the guardianship of his cousin, William Jordan, Count of Cerdagne, until he was five. He was then taken to Europe, where his half-brother Bertrand had given him the county of Rouergue. Upon Bertrand\'s death in 1112, Alfonso succeeded to the county of Toulouse and marquisate of Provence.
In 1114, Duke William IX of Aquitaine, who claimed Toulouse by right of his wife Philippa, daughter of Count William IV, invaded the county and conquered it. Alfonso recovered a part in 1119, but he was not in full control until 1123. When at last successful, he was excommunicated by Pope Callixtus II for having damaged the abbey of Saint-Gilles and assaulting the monks.
Alfonso next had to fight for his rights in Provence against Count Raymond Berengar III of Barcelona. Not until September 1125 did their war end in \"peace and concord\" (*pax et concordia*). At this stage, Alfonso was master of the regions lying between the Pyrenees and the Alps, the Auvergne and the sea. His ascendancy was, according to one commentator, an unmixed good to the country, for during a period of fourteen years art and industry flourished.
In March 1126, Alfonso was at the court of King Alfonso VII of León when he acceded to the throne. According to the *Chronica Adefonsi imperatoris*, Alfonso and Suero Vermúdez took the city of León from opposition magnates and handed it over to Alfonso VII. Among those who may have accompanied Alfonso on one of his many extended stays in Spain was the troubadour Marcabru.
By 1132, Alfonso was embroiled in a succession war over the county of Melgueil against Count Berengar Raymond of Provence. This brief conflict was resolved with Alfonso\'s defeat and Berengar marrying Beatrice, heiress of Melgueil.
Alfonso seized the viscounty of Narbonne in 1134, and ruled it during the minority of Viscountess Ermengarde, only restoring it to her in 1143. In 1141 King Louis VII of France pressed the claim of his wife, Eleanor of Aquitaine, granddaughter of Philippa, even besieging Toulouse, but without result. That same year Alfonso Jordan was again in Spain, making a pilgrimage to Saint James of Compostela, when he proposed a peace between the king of León and García Ramírez of Navarre, which became the basis for subsequent negotiations.
In 1144, Alfonso again incurred the displeasure of the church by siding with the citizens of Montpellier against their lord. In 1145, Bernard of Clairvaux addressed a letter to him full of concern about a heretic named Henry in the diocese of Toulouse. Bernard even went there to preach against the heresy, an early expression of Catharism. A second time he was excommunicated; but in 1146 he took the cross (i.e., vowed to go on crusade) at a meeting in Vézelay called by Louis VII. In August 1147, he embarked for the near east on the Second Crusade. He lingered on the way in Italy and probably in Constantinople, where he may have met Emperor Manuel I.
Alfonso finally arrived at Acre in 1148. He died at Caesarea, which was followed by accusations of poisoning, levelled against either Eleanor of Aquitaine or Melisende of Jerusalem, who may have wanted to eliminate him as a rival to her brother-in-law Count Raymond II of Tripoli.
Alfonso and Faydiva d\'Uzès had:
1. Raymond, who succeeded him
2. Alfonso II
3.
4. Faydiva (died 1154), married to Count Humbert III of Savoy
5. Agnes (died 1187)
6. Laurentia, who married Count Bernard III of Comminges
He also had an illegitimate son, Bertrand
| 679 |
Alfonso Jordan
| 0 |
1,880 |
**Ambroise**, sometimes **Ambroise of Normandy**, (flourished c. 1190) was a Norman poet and chronicler of the Third Crusade, author of a work called **L\'Estoire de la guerre sainte**, which describes in rhyming Old French verse the adventures of *Richard Cœur de Lion\]\]* as a crusader.
## Life
The credit for detecting its value belongs to Gaston Paris, although his edition (1897) was partially anticipated by the editors of the **\[\[Monumenta Germaniae Historica\]\]**, who published some selections in the twenty-seventh volume of their Scriptores (1885). Ambroise followed Richard I as a noncombatant, and not improbably as a court-minstrel. He speaks as an eyewitness of the king\'s doings at Messina, in Cyprus, at the siege of Acre, and in the abortive campaign which followed the capture of that city.
## Commentary on his work {#commentary_on_his_work}
Ambroise is surprisingly accurate in his chronology; though he did not complete his work before 1195, it is evidently founded upon notes which he had taken in the course of his pilgrimage. He shows no greater political insight than we should expect from his position; but relates what he had seen and heard with a naïve vivacity which compels attention. He is by no means an impartial source: he is prejudiced against the Saracens, against the French, and against all the rivals or enemies of his master, including the *Polein* party which supported Conrad of Montferrat against Guy of Lusignan. He is rather to be treated as a biographer than as a historian of the Crusade in its broader aspects. Nonetheless, he is an interesting primary source for the events of the years 1190--1192 in the Kingdom of Jerusalem.
Books 2--6 of the *Itinerarium Regis Ricardi*, a Latin prose narrative of the same events apparently compiled by Richard, a canon of Holy Trinity, London, are closely related to Ambroise\'s poem. They were formerly sometimes regarded as the first-hand narrative on which Ambroise based his work, but that can no longer be maintained.
### History of the poem {#history_of_the_poem}
The poem is known to us only through one Vatican manuscript, and long escaped the notice of historians.
## Published edition {#published_edition}
- Ambroise, *L´Estoire de la guerre sainte*. Paris, 1897: <http://gallica.bnf.fr/ark:/12148/bpt6k6517331f.r>
- Ambroise, *Itinerarium regis Ricardi*. London, 1920: <https://archive.org/details/itinerariumregis00richuoft>
- Ambroise, *The History of the Holy War*, translated by Marianne Ailes, Boydell Press, 2003
| 386 |
Ambroise
| 0 |
1,887 |
**Alexius** is the Latinized form of the given name **Alexios** (*Αλέξιος*, polytonic *Ἀλέξιος*, \"defender\", cf. Alexander), especially common in the Byzantine Empire. The female form is **Alexia** (*Αλεξία*) and its variants such as Alessia (the masculine form of which is Alessio) in Italian.
The name belongs to the most ancient attested Greek names (a-re-ke-se-u in the Linear B tablets KN Df 1229 and MY Fu 718).
## Rulers
- Alexios I Komnenos (1048--1118), Byzantine emperor
- Alexios II Komnenos (1167--1183), Byzantine emperor
- Alexios III, Byzantine emperor
- Alexios IV, Byzantine emperor
- Alexios V Doukas, Byzantine emperor
- Alexios I of Trebizond, Emperor of Trebizond
- Alexios II of Trebizond, Emperor of Trebizond
- Alexios III of Trebizond, Emperor of Trebizond
- Alexios IV of Trebizond, Emperor of Trebizond
- Alexios V of Trebizond, Emperor of Trebizond
- Alexius Mikhailovich (1629--1676), Tsar of Russia
- Alexius Petrovich (1690--1718), Russian tsarevich
## Religious figures {#religious_figures}
- Alexius, Metropolitan of Moscow (1354--1378)
- Patriarch Alexius I of Constantinople (1025--1043)
- Alexius (c. 1425--1488), Russian archpriest who converted to Judaism
- Patriarch Alexius I of Moscow and All Russia (r. 1945--1970)
- Patriarch Alexius II of Moscow and All Russia (r
| 199 |
Alexius
| 0 |
1,894 |
The **Africa Alphabet** (also **International African Alphabet** or **IAI alphabet**) is a set of letters designed as the basis for Latin alphabets for the languages of Africa. It was initially developed in 1928 by the International Institute of African Languages and Cultures from a combination of the English alphabet and the International Phonetic Alphabet (IPA). Development was assisted by native speakers of African languages and led by Diedrich Hermann Westermann, who served as director of the organization from 1926 to 1939. The aim of the International Institute of African Languages and Cultures, later renamed the International African Institute (IAI), was to enable people to write for practical and scientific purposes in all African languages without the need of diacritics.
The Africa Alphabet influenced the development of orthographies of many African languages, serving \"as the basis for the transcription\" of about 60 by one count. Discussion of how to harmonize these with other systems led to several largely abortive proposals such as the African Reference Alphabet and the World Orthography.
## Overview
The Africa Alphabet was built from the consonant letters of the English alphabet and the vowel letters, and any additional consonants, of the IPA. Capital forms of IPA letters were invented as necessary. Thus J and Y are pronounced `{{IPAblink|d͡ʒ}}`{=mediawiki} and `{{IPAblink|j}}`{=mediawiki} as in English, while Ɔ, Ɛ and Ŋ are pronounced `{{IPAblink|ɔ}}`{=mediawiki}, `{{IPAblink|ɛ}}`{=mediawiki} and `{{IPAblink|ŋ}}`{=mediawiki} as in the IPA
| 231 |
Africa Alphabet
| 0 |
1,896 |
***Acquire*** is a board game published by 3M in 1964 that involves multi-player mergers and acquisitions. It was one of the most popular games in the 3M Bookshelf games series published in the 1960s, and the only one still published in the United States.
## Description
*Acquire* is a board game for 2--6 players in which players attempt to earn the most money by developing and merging hotel chains. When a chain in which a player owns stock is acquired by a larger chain, players earn money based on the size of the acquired chain. At the end of the game, all players liquidate their stock in order to determine which player has the most money. It is played with play money, stock certificates, and tiles representing hotels that are arranged on the board. The components of the game have varied over the years. In particular, the tiles have been made from wood, plastic, and cardboard in various editions of the game.
### Set up {#set_up}
Before play begins, the players must decide whether the numbers of players\' shares will be public or private information. Keeping this information private can greatly extend the game since players will be less certain of their status, and therefore less willing to end the game.
Each player receives play cash and a small random set of playing tiles and becomes the founder of a nascent hotel chain by drawing and placing a tile representing a hotel on the board. Tiles are ordered, and correspond to spaces on the board. Position of the starting tiles determines order of play.
### Gameplay
Play consists of placing a tile on the board and optionally buying stock. The placed tile may found a new hotel chain, grow an existing one or merge two or more chains. Chains are sets of edge-wise adjacent tiles. Founders receive a share of stock in new chains. A chain can become \"safe\", immune to acquisition, by attaining a specified size. Following placement of a tile, the player may then buy a limited number of shares of stock in existing chains. Shares have a market value determined by the size and stature of the hotel chain. At the end of his or her turn, the player receives a new tile to replace the one played.
When mergers occur, the smaller chain becomes defunct, and its tiles are then part of the acquiring chain. The two largest shareholders in the acquired chain receive cash bonuses; players may sell their shares in the defunct chain, trade them in for shares of the acquiring chain, or keep them. Mergers between 3 or more chains are handled in order from larger to smaller.
### Ending the game {#ending_the_game}
A player during their turn may declare the game at an end if the largest chain exceeds a specified size (about 40% of the board), or all chains on the board are too large to be acquired. When the game ends, shareholder bonuses are paid to the two largest shareholders of each chain, and players cash out their shares at market price (shares in any defunct chains are worthless). The player with the most money wins.
## Publication history {#publication_history}
When Sid Sackson was a child, he played a Milton Bradley gambling-themed board game titled *Lotto*. When he became a game designer, Sackson reworked the game into a wargame he called *Lotto War*. In 1962, Sackson and Alex Randolph were commissioned by 3M to start a new games division. When Sackson submitted *Lotto War* to 3M the following year, he retitled the game *Vacation*. 3M suggested changing the name to *Acquire*, and Sackson agreed. The game was test marketed in several U.S. cities in 1963, and production began in 1964 as a part of the 3M Bookshelf games series.
In 1976, the 3M game division was sold to Avalon Hill and *Acquire* became part of their bookcase game series. Four years later, Avalon Hill published the computer game *Computer Acquire* for the PET, Apple II, and TRS-80.
In 1998, Avalon Hill became part of Hasbro. The new owners reissued a slightly revised version of *Acquire* in 2000, in which the hotel chains were replaced by fictitious corporations, though the actual gameplay was unchanged. Hasbro soon thereafter discontinued it. In the mid-2000s, the game was transferred to a Hasbro subsidiary, Wizards of the Coast (WotC). In 2008, WotC celebrated \"*50 years of Avalon Hill Games\"* with the release of a new edition of *Acquire*, although the game was not yet 50 years old. In 2016, the game was transferred back to the Hasbro games division and republished in 2016 under the Avalon label, with hotels chains reinstated.
| 776 |
Acquire
| 0 |
1,896 |
## Reception
In *The Playboy Winner\'s Guide to Board Games*, game designer Jon Freeman compared *Cartel* (*A Gamut of Games*) and *Acquire*, noting that both were \"better games which focus on the joining of companies into conglomerates.\" Freeman thought *Acquire* had an edge over *Cartel* \"in the quality of its components \[\...\] *Acquire*{{\'}}s higher price is unquestionably reflected in its packaging and presentation \[and deserves\] a place in your game library.\"
*Games Magazine* included *Acquire* in their \"Top 100 Games\" in four consecutive years:
- In 1980 the editors praised it as a \"classic game of getting in on the ground floor\" and \"proof that you need money to make money\", noting that \"a delicate sense of timing is important, but greed and a lust for power also help.\"
- In 1981, the editors noted that it \"combines the flavors of Monopoly and the stock market\" and cautioned that \"Since the object is to acquire cash, careful timing of investments (and raids on competitors\' chains!) is critical to winning\".
- In 1982, the editors commented that \"Among family games, this is one of the most strategic.\"
- In 1983, the editors commented \"Adding to chains increases their value, but you must anticipate mergers, which occur when someone plays the right connecting tile at the right time.\"
In the December 1993 edition of *Dragon* (Issue 200), Allen Varney advised readers to ignore the hotel theme: \"Supposedly a game of hotel acquisitions and mergers, this is actually a superb abstract game of strategy and capital.\" Varney called the game \"An early masterpiece from \[Sid\] Sackson, game historian and one of the great designers of our time.\"
### Awards
The game was short-listed for the first Spiel des Jahres board game awards in 1979.
*GAMES* magazine inducted *Acquire* into their buyers\' guide Hall of Fame. The magazine\'s stated criteria for the Hall of Fame encompasses \"games that have met or exceeded the highest standards of quality and play value and have been continuously in production for at least 10 years; i.e., classics.\"
*Acquire* was inducted into the Academy of Adventure Gaming Arts & Design\'s Hall of Fame, along with game designer Sid Sackson, in 2011. It is also one of the Mind Sports Olympiad games
| 372 |
Acquire
| 1 |
1,905 |
thumb\|right\|upright=1.3\|French royalist rebels preparing an ambush during the War in the Vendée (*The Ambush* by Évariste Carpentier, 1889) `{{wikt | ambush}}`{=mediawiki}
An **ambush** is a surprise attack carried out by people lying in wait in a concealed position. The concealed position itself or the concealed person(s) may also be called an \"`{{linktext|ambush}}`{=mediawiki}\". Ambushes as a basic fighting tactic of soldiers or of criminals have been used consistently throughout history, from ancient to modern warfare. The term \"ambush\" is also used in animal behavior studies, journalism, and marketing to describe methods of approach and strategy.
In the 20th century, a military ambush might involve thousands of soldiers on a large scale, such as at a choke point like a mountain pass. Conversely, it could involve a small irregular band or insurgent group attacking a regular armed-force patrol. Theoretically, a single well-armed, and concealed soldier could ambush other troops in a surprise attack.
In recent centuries, a military ambush can involve the exclusive or combined use of improvised explosive devices (IED). This allows attackers to hit enemy convoys or patrols while minimizing the risk of being exposed to return fire.
## History
The use of ambush tactics by early people dates as far back as two million years when anthropologists have recently suggested that ambush techniques were used to hunt large game.
One example from ancient times is the Battle of the Trebia River. Hannibal encamped within striking distance of the Romans with the Trebia River between them, and placed a strong force of cavalry and infantry in concealment, near the battle zone. He had noticed, says Polybius, a \"place between the two camps, flat indeed and treeless, but well adapted for an ambuscade, as it was traversed by a water-course with steep banks, densely overgrown with brambles and other thorny plants, and here he proposed to lay a stratagem to surprise the enemy\". When the Roman infantry became entangled in combat with his army, the hidden ambush force attacked the Roman infantry in the rear. The result was slaughter and defeat for the Romans. Nevertheless, the battle also displays the effects of good tactical discipline on the part of the ambushed force. Although most of the legions were lost, about 10,000 Romans cut their way through to safety, maintaining unit cohesion. This ability to maintain discipline and break out or maneuver away from a kill zone is a hallmark of good troops and training in any ambush situation.
Ambushes were widely used by the Lusitanians, in particular by their chieftain Viriathus. Their usual tactic, called *concursare*, involved repeatedly charging and retreating, forcing the enemy to eventually give them chase, to set up ambushes in difficult terrain where allied forces would be awaiting. In his first victory, he eluded the siege of Roman praetor Gaius Vetilius and attracted him to a narrow pass next to the Barbesuda river, where he destroyed his army and killed the praetor. Viriathus\'s ability to turn chases into ambushes would grant him victories over a number of Roman generals.
Another Lusitanian ambush was performed by Curius and Apuleius on Roman general Quintus Fabius Maximus Servilianus, who led a numerically superior army complete with war elephants and Numidian cavalry. The ambush allowed Curius and Apuleius to steal Servilianus\'s loot train. However, a tactic error in their retreat led to the Romans retaking the train and putting the Lusitanians to flight. Viriathus later defeated Servilianus with a surprise attack.`{{page needed|date=August 2019}}`{=mediawiki}
Germanic war chief Arminius sprung an ambush against the Romans at Battle of the Teutoburg Forest. This particular ambush was to affect the course of Western history. The Germanic forces demonstrated several principles needed for a successful ambush. They took cover in difficult forested terrain, allowing the warriors time and space to mass without detection. They had the element of surprise, and this was also aided by the defection of Arminius from Roman ranks prior to the battle. They sprang the attack when the Romans were most vulnerable; when they had left their fortified camp, and were on the march in a pounding rainstorm.
The Germans did not dawdle at the hour of decision but attacked quickly, using a massive series of short, rapid, vicious charges against the length of the whole Roman line, with charging units sometimes withdrawing to the forest to regroup while others took their place. The Germans also used blocking obstacles, erecting a trench and earthen wall to hinder Roman movement along the route of the killing zone. The result was a mass slaughter of the Romans and the destruction of three legions. The Germanic victory caused a limit on Roman expansion in the West. Ultimately, it established the Rhine as the boundary of the Roman Empire for the next four hundred years, until the decline of the Roman influence in the West. The Roman Empire made no further concerted attempts to conquer Germania beyond the Rhine.
There are many notable examples of ambushes during the Roman-Persian Wars. A year after their victory at Carrhae, the Parthians invaded Syria but were driven back after a Roman ambush near Antigonia. Roman Emperor Julian was mortally wounded in an ambush near Samarra in 363 during the retreat from his Persian campaign. A Byzantine invasion of Persian Armenia was repelled by a small force at Anglon who performed a meticulous ambush by using the rough terrain as a force multiplier and concealing in houses. Heraclius\' discovery of a planned ambush by Shahrbaraz in 622 was a decisive factor in his campaign.
### Arabia during Muhammad\'s era {#arabia_during_muhammads_era}
According to Muslim tradition, Islamic Prophet Muhammad used ambush tactics in his military campaigns. His first such use was during the Caravan raids. In the Kharrar caravan raid, Sa\'d ibn Abi Waqqas was ordered to lead a raid against the Quraysh. His group consisted of about twenty Muhajirs. This raid was about a month after the previous one. Sa\'d, with his soldiers, set up an ambush in the valley of Kharrar on the road to Mecca and waited to raid a Meccan caravan returning from Syria. However, the caravan had already passed and the Muslims returned to Medina without any loot.
Arab tribes during Muhammad\'s era also used ambush tactics. One example retold in Muslim tradition is said to have taken place during the First Raid on Banu Thalabah. The Banu Thalabah tribe were already aware of the impending attack; so they lay in wait for the Muslims. When Muhammad ibn Maslama arrived at the site, the Banu Thalabah with 100 men ambushed the Muslims while they were making preparation to sleep and, after a brief resistance, killed them all except for Muhammad ibn Maslama, who feigned death. A Muslim who happened to pass that way found him and assisted him to return to Medina. The raid was unsuccessful.
| 1,129 |
Ambush
| 0 |
1,905 |
## Procedure
In modern warfare, an ambush can be employed by ground troops up to platoon size against enemy targets, which may be other ground troops, or possibly vehicles. However, in some situations, especially when deep behind enemy lines, the actual attack will be carried out by a platoon. A company-sized unit will be deployed to support the attack group, setting up and maintaining a forward patrol harbour from which the attacking force will deploy, and to which they will retire after the attack.
### Planning
Ambushes are complex multiphase operations and are therefore usually planned in some detail. First, a suitable killing zone is identified. This is where the ambush will be laid, where enemy units are expected to pass, and gives reasonable cover for the deployment, execution, and extraction phases of the ambush patrol. A path along a wooded valley floor would be a typical example.
Ambush can be described geometrically as:
- **Linear**, when a number of firing units are equally distant from the linear kill zone. It can easily be controlled under all visibility conditions.
- **L-shaped**, when a short leg of firing units are placed to enfilade (fire the length of) the sides of the linear kill zone.
- **V-shaped**, when the firing units are distant from the kill zone where the enemy enters and the firing units lay down bands of intersecting and interlocking fire. This ambush is normally triggered only when the enemy is well into the kill zone. The intersecting bands of fire prevent any attempt of moving out of the kill zone.
### Viet Cong ambush techniques {#viet_cong_ambush_techniques}
#### Ambush criteria {#ambush_criteria}
The terrain for the ambush had to meet strict criteria:
- provide concealment to prevent detection from the ground or air
- enable ambush force to deploy, encircle and divide the enemy
- allow for heavy weapons emplacements to provide sustained fire
- enable the ambush force to set up observation posts for early detection of the enemy
- permit the secret movement of troops to the ambush position and the dispersal of troops during withdrawal
One important feature of the ambush was that the target units should \'pile up\' after being attacked, thus preventing them any easy means of withdrawal from the kill zone and hindering their use of heavy weapons and supporting fire. Terrain was usually selected which would facilitate this and slow down the enemy. Any terrain around the ambush site which was not favourable to the ambushing force, or which offered some protection to the target, was heavily mined and booby trapped or pre-registered for mortars.
#### Ambush units {#ambush_units}
The NVA/VC ambush formations consisted of:
- lead-blocking element
- main-assault element
- rear-blocking element
- observation posts
- command post
Other elements might also be included if the situation demanded, such as a sniper screen along a nearby avenue of approach to delay enemy reinforcements.
#### Command posts {#command_posts}
When deploying into an ambush site, the NVA first occupied several observation posts, placed to detect the enemy as early as possible and to report on the formation it was using, its strength and firepower, as well as to provide early warning to the unit commander. Usually, one main OP and numerous secondary OPs were established. Runners and radios were used to communicate between the OPs and the main command post. The OPs were located so that enemy movement into the ambush could be observed. They would remain in position throughout the ambush to report routes of reinforcement and withdrawal by the enemy, as well as his manoeuvre options. Frequently the OPs were reinforced to squad size and served as flank security. The command post was situated in a central location, frequently on terrain which afforded it a vantage point overlooking the ambush site.
#### Recon methods {#recon_methods}
Reconnaissance elements observing a potential ambush target on the move generally stayed 300--500 meters away. A \"leapfrogging\" recon technique can be used. Surveillance units were echeloned one behind the other. As the enemy drew close to the first, it fell back behind the last recon team, leaving an advance group in its place. This one in turn fell back as the enemy again closed the gap, and the cycle rotated. This method helped keep the enemy under continuous observation from a variety of vantage points, and allowed the recon groups to cover one another
| 727 |
Ambush
| 1 |
1,910 |
**Agarose gel electrophoresis** is a method of gel electrophoresis used in biochemistry, molecular biology, genetics, and clinical chemistry to separate a mixed population of macromolecules such as DNA or proteins in a matrix of agarose, one of the two main components of agar. The proteins may be separated by charge and/or size (isoelectric focusing agarose electrophoresis is essentially size independent), and the DNA and RNA fragments by length. Biomolecules are separated by applying an electric field to move the charged molecules through an agarose matrix, and the biomolecules are separated by size in the agarose gel matrix.
Agarose gel is easy to cast, has relatively fewer charged groups, and is particularly suitable for separating DNA of size range most often encountered in laboratories, which accounts for the popularity of its use. The separated DNA may be viewed with stain, most commonly under UV light, and the DNA fragments can be extracted from the gel with relative ease. Most agarose gels used are between 0.7--2% dissolved in a suitable electrophoresis buffer.
## Properties of agarose gel {#properties_of_agarose_gel}
Agarose gel is a three-dimensional matrix formed of helical agarose molecules in supercoiled bundles that are aggregated into three-dimensional structures with channels and pores through which biomolecules can pass. The 3-D structure is held together with hydrogen bonds and can therefore be disrupted by heating back to a liquid state. The melting temperature is different from the gelling temperature, depending on the sources, agarose gel has a gelling temperature of 35 -- and a melting temperature of 85 --. Low-melting and low-gelling agaroses made through chemical modifications are also available.
Agarose gel has large pore size and good gel strength, making it suitable as an anticonvection medium for the electrophoresis of DNA and large protein molecules. The pore size of a 1% gel has been estimated from 100 nm to 200--500 nm, and its gel strength allows gels as dilute as 0.15% to form a slab for gel electrophoresis. Low-concentration gels (0.1--0.2%) however are fragile and therefore hard to handle. Agarose gel has lower resolving power than polyacrylamide gel for DNA but has a greater range of separation, and is therefore used for DNA fragments of usually 50--20,000 bp in size. The limit of resolution for standard agarose gel electrophoresis is around 750 kb, but resolution of over 6 Mb is possible with pulsed field gel electrophoresis (PFGE). It can also be used to separate large proteins, and it is the preferred matrix for the gel electrophoresis of particles with effective radii larger than 5--10 nm. A 0.9% agarose gel has pores large enough for the entry of bacteriophage T4.
The agarose polymer contains charged groups, in particular pyruvate and sulfate. These negatively charged groups create a flow of water in the opposite direction to the movement of DNA in a process called electroendosmosis (EEO), and can therefore retard the movement of DNA and cause blurring of bands. Higher concentration gels would have higher electroendosmotic flow. Low EEO agarose is therefore generally preferred for use in agarose gel electrophoresis of nucleic acids, but high EEO agarose may be used for other purposes. The lower sulfate content of low EEO agarose, particularly low-melting point (LMP) agarose, is also beneficial in cases where the DNA extracted from gel is to be used for further manipulation as the presence of contaminating sulfates may affect some subsequent procedures, such as ligation and PCR. Zero EEO agaroses however are undesirable for some applications as they may be made by adding positively charged groups and such groups can affect subsequent enzyme reactions. Electroendosmosis is a reason agarose is used in preference to agar as the agaropectin component in agar contains a significant amount of negatively charged sulfate and carboxyl groups. The removal of agaropectin in agarose substantially reduces the EEO, as well as reducing the non-specific adsorption of biomolecules to the gel matrix. However, for some applications such as the electrophoresis of serum proteins, a high EEO may be desirable, and agaropectin may be added in the gel used.
| 669 |
Agarose gel electrophoresis
| 0 |
1,910 |
## Migration of nucleic acids in agarose gel {#migration_of_nucleic_acids_in_agarose_gel}
### Factors affecting migration of nucleic acid in gel {#factors_affecting_migration_of_nucleic_acid_in_gel}
A number of factors can affect the migration of nucleic acids: the dimension of the gel pores (gel concentration), size of DNA being electrophoresed, the voltage used, the ionic strength of the buffer, and the concentration of intercalating dye such as ethidium bromide if used during electrophoresis.
Smaller molecules travel faster than larger molecules in gel, and double-stranded DNA moves at a rate that is inversely proportional to the logarithm of the number of base pairs. This relationship however breaks down with very large DNA fragments, and separation of very large DNA fragments requires the use of pulsed field gel electrophoresis (PFGE), which applies alternating current from different directions and the large DNA fragments are separated as they reorient themselves with the changing field.
For standard agarose gel electrophoresis, larger molecules are resolved better using a low concentration gel while smaller molecules separate better at high concentration gel. Higher concentration gels, however, require longer run times (sometimes days).
The movement of the DNA may be affected by the conformation of the DNA molecule, for example, supercoiled DNA usually moves faster than relaxed DNA because it is tightly coiled and hence more compact. In a normal plasmid DNA preparation, multiple forms of DNA may be present. Gel electrophoresis of the plasmids would normally show the negatively supercoiled form as the main band, while nicked DNA (open circular form) and the relaxed closed circular form appears as minor bands. The rate at which the various forms move however can change using different electrophoresis conditions, and the mobility of larger circular DNA may be more strongly affected than linear DNA by the pore size of the gel.
Ethidium bromide which intercalates into circular DNA can change the charge, length, as well as the superhelicity of the DNA molecule, therefore its presence in gel during electrophoresis can affect its movement. For example, the positive charge of ethidium bromide can reduce the DNA movement by 15%. Agarose gel electrophoresis can be used to resolve circular DNA with different supercoiling topology.
DNA damage due to increased cross-linking will also reduce electrophoretic DNA migration in a dose-dependent way.
The rate of migration of the DNA is proportional to the voltage applied, i.e. the higher the voltage, the faster the DNA moves. The resolution of large DNA fragments however is lower at high voltage. The mobility of DNA may also change in an unsteady field -- in a field that is periodically reversed, the mobility of DNA of a particular size may drop significantly at a particular cycling frequency. This phenomenon can result in band inversion in field inversion gel electrophoresis (FIGE), whereby larger DNA fragments move faster than smaller ones.
### Migration anomalies {#migration_anomalies}
- \"Smiley\" gels - this edge effect is caused when the voltage applied is too high for the gel concentration used.
- Overloading of DNA - overloading of DNA slows down the migration of DNA fragments.
- Contamination - presence of impurities, such as salts or proteins can affect the movement of the DNA.
### Mechanism of migration and separation {#mechanism_of_migration_and_separation}
The negative charge of its phosphate backbone moves the DNA towards the positively charged anode during electrophoresis. However, the migration of DNA molecules in solution, in the absence of a gel matrix, is independent of molecular weight during electrophoresis. The gel matrix is therefore responsible for the separation of DNA by size during electrophoresis, and a number of models exist to explain the mechanism of separation of biomolecules in gel matrix. A widely accepted one is the Ogston model which treats the polymer matrix as a sieve. A globular protein or a random coil DNA moves through the interconnected pores, and the movement of larger molecules is more likely to be impeded and slowed down by collisions with the gel matrix, and the molecules of different sizes can therefore be separated in this sieving process.
The Ogston model however breaks down for large molecules whereby the pores are significantly smaller than size of the molecule. For DNA molecules of size greater than 1 kb, a reptation model (or its variants) is most commonly used. This model assumes that the DNA can crawl in a \"snake-like\" fashion (hence \"reptation\") through the pores as an elongated molecule. A biased reptation model applies at higher electric field strength, whereby the leading end of the molecule become strongly biased in the forward direction and pulls the rest of the molecule along. Real-time fluorescence microscopy of stained molecules, however, showed more subtle dynamics during electrophoresis, with the DNA showing considerable elasticity as it alternately stretching in the direction of the applied field and then contracting into a ball, or becoming hooked into a U-shape when it gets caught on the polymer fibres.
| 804 |
Agarose gel electrophoresis
| 1 |
1,910 |
## General procedure {#general_procedure}
The details of an agarose gel electrophoresis experiment may vary depending on methods, but most follow a general procedure.
### Casting of gel {#casting_of_gel}
The gel is prepared by dissolving the agarose powder in an appropriate buffer, such as TAE or TBE, to be used in electrophoresis. The agarose is dispersed in the buffer before heating it to near-boiling point, but avoid boiling. The melted agarose is allowed to cool sufficiently before pouring the solution into a cast as the cast may warp or crack if the agarose solution is too hot. A comb is placed in the cast to create wells for loading sample, and the gel should be completely set before use.
The concentration of gel affects the resolution of DNA separation. The agarose gel is composed of microscopic pores through which the molecules travel, and there is an inverse relationship between the pore size of the agarose gel and the concentration -- pore size decreases as the density of agarose fibers increases. High gel concentration improves separation of smaller DNA molecules, while lowering gel concentration permits large DNA molecules to be separated. The process allows fragments ranging from 50 base pairs to several mega bases to be separated depending on the gel concentration used. The concentration is measured in weight of agarose over volume of buffer used (g/ml). For a standard agarose gel electrophoresis, a 0.8% gel gives good separation or resolution of large 5--10kb DNA fragments, while 2% gel gives good resolution for small 0.2--1kb fragments. 1% gels is often used for a standard electrophoresis. High percentage gels are often brittle and may not set evenly, while low percentage gels (0.1-0.2%) are fragile and not easy to handle. Low-melting-point (LMP) agarose gels are also more fragile than normal agarose gel. Low-melting point agarose may be used on its own or simultaneously with standard agarose for the separation and isolation of DNA. PFGE and FIGE are often done with high percentage agarose gels.
### Loading of samples {#loading_of_samples}
Once the gel has set, the comb is removed, leaving wells where DNA samples can be loaded. Loading buffer is mixed with the DNA sample before the mixture is loaded into the wells. The loading buffer contains a dense compound, which may be glycerol, sucrose, or Ficoll, that raises the density of the sample so that the DNA sample may sink to the bottom of the well. If the DNA sample contains residual ethanol after its preparation, it may float out of the well. The loading buffer also includes colored dyes such as xylene cyanol and bromophenol blue used to monitor the progress of the electrophoresis. The DNA samples are loaded using a pipette.
### Electrophoresis
Agarose gel electrophoresis is most commonly done horizontally in a subaquaeous mode whereby the slab gel is completely submerged in buffer during electrophoresis. It is also possible, but less common, to perform the electrophoresis vertically, as well as horizontally with the gel raised on agarose legs using an appropriate apparatus. The buffer used in the gel is the same as the running buffer in the electrophoresis tank, which is why electrophoresis in the subaquaeous mode is possible with agarose gel.
For optimal resolution of DNA greater than 2`{{Spaces}}`{=mediawiki}kb in size in standard gel electrophoresis, 5 to 8 V/cm is recommended (the distance in cm refers to the distance between electrodes, therefore this recommended voltage would be 5 to 8 multiplied by the distance between the electrodes in cm). Voltage may also be limited by the fact that it heats the gel and may cause the gel to melt if it is run at high voltage for a prolonged period, especially if the gel used is LMP agarose gel. Too high a voltage may also reduce resolution, as well as causing band streaking for large DNA molecules. Too low a voltage may lead to broadening of band for small DNA fragments due to dispersion and diffusion.
Since DNA is not visible in natural light, the progress of the electrophoresis is monitored using colored dyes. Xylene cyanol (light blue color) comigrates large DNA fragments, while Bromophenol blue (dark blue) comigrates with the smaller fragments. Less commonly used dyes include Cresol Red and Orange G which migrate ahead of bromophenol blue. A DNA marker is also run together for the estimation of the molecular weight of the DNA fragments. Note however that the size of a circular DNA like plasmids cannot be accurately gauged using standard markers unless it has been linearized by restriction digest, alternatively a supercoiled DNA marker may be used.
| 761 |
Agarose gel electrophoresis
| 2 |
1,910 |
## General procedure {#general_procedure}
### Staining and visualization {#staining_and_visualization}
DNA as well as RNA are normally visualized by staining with ethidium bromide, which intercalates into the major grooves of the DNA and fluoresces under UV light. The intercalation depends on the concentration of DNA and thus, a band with high intensity will indicate a higher amount of DNA compared to a band of less intensity. The ethidium bromide may be added to the agarose solution before it gels, or the DNA gel may be stained later after electrophoresis. Destaining of the gel is not necessary but may produce better images. Other methods of staining are available; examples are MIDORI Green, SYBR Green, GelRed, methylene blue, brilliant cresyl blue, Nile blue sulfate, and crystal violet. SYBR Green, GelRed and other similar commercial products are sold as safer alternatives to ethidium bromide as it has been shown to be mutagenic in Ames test, although the carcinogenicity of ethidium bromide has not actually been established. SYBR Green requires the use of a blue-light transilluminator. DNA stained with crystal violet can be viewed under natural light without the use of a UV transilluminator which is an advantage, however it may not produce a strong band.
When stained with ethidium bromide, the gel is viewed with an ultraviolet (UV) transilluminator. The UV light excites the electrons within the aromatic ring of ethidium bromide, and once they return to the ground state, light is released, making the DNA and ethidium bromide complex fluoresce. Standard transilluminators use wavelengths of 302/312-nm (UV-B), however exposure of DNA to UV radiation for as little as 45 seconds can produce damage to DNA and affect subsequent procedures, for example reducing the efficiency of transformation, *in vitro* transcription, and PCR. Exposure of DNA to UV radiation therefore should be limited. Using a higher wavelength of 365 nm (UV-A range) causes less damage to the DNA but also produces much weaker fluorescence with ethidium bromide. Where multiple wavelengths can be selected in the transilluminator, shorter wavelength can be used to capture images, while longer wavelength should be used if it is necessary to work on the gel for any extended period of time.
The transilluminator apparatus may also contain image capture devices, such as a digital or polaroid camera, that allow an image of the gel to be taken or printed.
For gel electrophoresis of protein, the bands may be visualised with Coomassie or silver stains.
| 403 |
Agarose gel electrophoresis
| 3 |
1,910 |
## General procedure {#general_procedure}
### Downstream procedures {#downstream_procedures}
The separated DNA bands are often used for further procedures, and a DNA band may be cut out of the gel as a slice, dissolved and purified. Contaminants however may affect some downstream procedures such as PCR, and low melting point agarose may be preferred in some cases as it contains fewer of the sulfates that can affect some enzymatic reactions. The gels may also be used for blotting techniques.
| 78 |
Agarose gel electrophoresis
| 4 |
1,910 |
## Buffers
In general, the ideal buffer should have good conductivity, produce less heat and have a long life. There are a number of buffers used for agarose electrophoresis; common ones for nucleic acids include tris/acetate/EDTA (TAE) and tris/borate/EDTA (TBE). The buffers used contain EDTA to inactivate many nucleases which require divalent cation for their function. The borate in TBE buffer can be problematic as borate can polymerize, and/or interact with cis diols such as those found in RNA. TAE has the lowest buffering capacity, but it provides the best resolution for larger DNA. This means a lower voltage and more time, but a better product.
Many other buffers have been proposed, e.g. lithium borate (LB), iso electric histidine, pK matched goods buffers, etc.; in most cases the purported rationale is lower current (less heat) and or matched ion mobilities, which leads to longer buffer life. Tris-phosphate buffer has high buffering capacity but cannot be used if DNA extracted is to be used in phosphate sensitive reaction. LB is relatively new and is ineffective in resolving fragments larger than 5 kbp; However, with its low conductivity, a much higher voltage could be used (up to 35 V/cm), which means a shorter analysis time for routine electrophoresis. As low as one base pair size difference could be resolved in 3% agarose gel with an extremely low conductivity medium (1 mM lithium borate).
Other buffering system may be used in specific applications, for example, barbituric acid-sodium barbiturate or tris-barbiturate buffers may be used for in agarose gel electrophoresis of proteins, for example in the detection of abnormal distribution of proteins.
| 268 |
Agarose gel electrophoresis
| 5 |
1,910 |
## Applications
- Estimation of the size of DNA molecules following digestion with restriction enzymes, e.g., in restriction mapping of cloned DNA.
- Estimation of the DNA concentration by comparing the intensity of the nucleic acid band with the corresponding band of the size marker.
- Analysis of products of a polymerase chain reaction (PCR), e.g., in molecular genetic diagnosis or genetic fingerprinting
- Separation of DNA fragments for extraction and purification.
- Separation of restricted genomic DNA prior to Southern transfer, or of RNA prior to Northern transfer.
- Separation of proteins, for example, screening of protein abnormalities in clinical chemistry.
Agarose gels are easily cast and handled compared to other matrices and nucleic acids are not chemically altered during electrophoresis. Samples are also easily recovered. After the experiment is finished, the resulting gel can be stored in a plastic bag in a refrigerator.
Electrophoresis is performed in buffer solutions to reduce pH changes due to the electric field, which is important because the charge of DNA and RNA depends on pH, but running for too long can exhaust the buffering capacity of the solution. Further, different preparations of genetic material may not migrate consistently with each other, for morphological or other reasons
| 204 |
Agarose gel electrophoresis
| 6 |
1,912 |
\| width2 = 180 \| alt2 =
\| pronounce = \| tradename = Principen, others \| Drugs.com = `{{drugs.com|monograph|ampicillin}}`{=mediawiki} \| MedlinePlus = a685002 \| DailyMedID = Ampicillin \| pregnancy_AU = A \| pregnancy_AU_comment = \| pregnancy_category = \| routes_of_administration = By mouth, intravenous, intramuscular \| class = Aminopenicillins \| ATC_prefix = J01 \| ATC_suffix = CA01 \| ATC_supplemental = `{{ATC|S01|AA19}}`{=mediawiki} `{{ATCvet|J51|CA01}}`{=mediawiki} `{{ATC|J01|CR50}}`{=mediawiki} `{{ATC|J01|CA51}}`{=mediawiki}
\| legal_AU = S4 \| legal_AU_comment = \| legal_BR = \| legal_BR_comment = \| legal_CA = Rx-only \| legal_CA_comment = \| legal_DE = \| legal_DE_comment = \| legal_NZ = \| legal_NZ_comment = \| legal_UK = POM \| legal_UK_comment = \| legal_US = Rx-only \| legal_US_comment = \| legal_UN = \| legal_UN_comment = \| legal_status =
\| bioavailability = 62% ±17% (parenteral)\
\< 30--55% (oral) \| protein_bound = 15 to 25% \| metabolism = 12 to 50% \| metabolites = Penicilloic acid \| onset = \| elimination_half-life = Approx. 1 hour \| duration_of_action = \| excretion = 75 to 85% kidney
\| CAS_number_Ref = `{{cascite|correct|??}}`{=mediawiki} \| CAS_number = 69-53-4 \| CAS_supplemental = \| PubChem = 6249 \| IUPHAR_ligand = \| DrugBank_Ref = `{{drugbankcite|correct|drugbank}}`{=mediawiki} \| DrugBank = DB00415 \| ChemSpiderID_Ref = `{{chemspidercite|correct|chemspider}}`{=mediawiki} \| ChemSpiderID = 6013 \| UNII_Ref = `{{fdacite|correct|FDA}}`{=mediawiki} \| UNII = 7C782967RD \| KEGG_Ref = `{{keggcite|correct|kegg}}`{=mediawiki} \| KEGG = D00204 \| KEGG2_Ref = `{{keggcite|correct|kegg}}`{=mediawiki} \| KEGG2 = C06574 \| ChEBI_Ref = `{{ebicite|correct|EBI}}`{=mediawiki} \| ChEBI = 28971 \| ChEMBL_Ref = `{{ebicite|correct|EBI}}`{=mediawiki} \| ChEMBL = 174 \| NIAID_ChemDB = \| PDB_ligand = AIC \| synonyms = AM/AMP
\| IUPAC_name = (2*S*,5*R*,6*R*)-6-(\[(2*R*)-2-Amino-2-phenylacetyl\]amino)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo\[3.2.0\]heptane-2-carboxylic acid \| C = 16 \| H = 19 \| N = 3 \| O = 4 \| S = 1 \| SMILES = CC1(C(N2C(S1)C(C2=O)NC(=O)C(C3=CC=CC=C3)N)C(=O)O)C \| StdInChI_Ref = `{{stdinchicite|correct|chemspider}}`{=mediawiki} \| StdInChI = 1S/C16H19N3O4S/c1-16(2)11(15(22)23)19-13(21)10(14(19)24-16)18-12(20)9(17)8-6-4-3-5-7-8/h3-7,9-11,14H,17H2,1-2H3,(H,18,20)(H,22,23)/t9-,10-,11+,14-/m1/s1 \| StdInChI_comment = \| StdInChIKey_Ref = `{{stdinchicite|correct|chemspider}}`{=mediawiki} \| StdInChIKey = AVKUERGKIZMTKX-NJBDSQKTSA-N \| density = \| density_notes = \| melting_point = \| melting_high = \| melting_notes = \| boiling_point = \| boiling_notes = \| solubility = \| sol_units = \| specific_rotation = }}
**Ampicillin** is an antibiotic belonging to the aminopenicillin class of the penicillin family. The drug is used to prevent and treat several bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously.
Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include *Clostridioides difficile* colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe.
Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization\'s List of Essential Medicines. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a generic medication.
| 485 |
Ampicillin
| 0 |
1,912 |
## Medical uses {#medical_uses}
### Diseases
- Bacterial meningitis; an aminoglycoside can be added to increase efficacy against gram-negative meningitis bacteria
- Endocarditis by enterococcal strains (off-label use); often given with an aminoglycoside
- Gastrointestinal infections caused by contaminated water or food (for example, by *Salmonella*)
- Genito-urinary tract infections
- Healthcare-associated infections that are related to infections from using urinary catheters and that are unresponsive to other medications
- Otitis media (middle ear infection)
- Prophylaxis (i.e. to prevent infection) in those who previously had rheumatic heart disease or are undergoing dental procedures, vaginal hysterectomies, or C-sections. It is also used in pregnant woman who are carriers of group B streptococci to prevent early-onset neonatal infections.
- Respiratory infections, including bronchitis, pharyngitis
- Sinusitis
- Sepsis
- Whooping cough, to prevent and treat secondary infections
Ampicillin used to also be used to treat gonorrhea, but there are now too many strains resistant to penicillins.
### Bacteria
Ampicillin is used to treat infections by many gram-positive and gram-negative bacteria. It was the first \"broad spectrum\" penicillin with activity against gram-positive bacteria, including *Streptococcus pneumoniae*, *Streptococcus pyogenes*, some isolates of *Staphylococcus aureus* (but not penicillin-resistant or methicillin-resistant strains), *Trueperella*, and some *Enterococcus*. It is one of the few antibiotics that works against multidrug resistant *Enterococcus faecalis* and *E. faecium*. Activity against gram-negative bacteria includes *Neisseria meningitidis*, some *Haemophilus influenzae*, and some of the Enterobacteriaceae (though most Enterobacteriaceae and *Pseudomonas* are resistant). Its spectrum of activity is enhanced by co-administration of sulbactam, a drug that inhibits beta lactamase, an enzyme produced by bacteria to inactivate ampicillin and related antibiotics. It is sometimes used in combination with other antibiotics that have different mechanisms of action, like vancomycin, linezolid, daptomycin, and tigecycline.
### Available forms {#available_forms}
Ampicillin can be administered by mouth, an intramuscular injection (shot) or by intravenous infusion. The oral form, available as capsules or oral suspensions, is not given as an initial treatment for severe infections, but rather as a follow-up to an IM or IV injection. For IV and IM injections, ampicillin is kept as a powder that must be reconstituted.
IV injections must be given slowly, as rapid IV injections can lead to convulsive seizures.
### Specific populations {#specific_populations}
Ampicillin is one of the most used drugs in pregnancy, and has been found to be generally harmless both by the Food and Drug Administration in the U.S. (which classified it as category B) and the Therapeutic Goods Administration in Australia (which classified it as category A). It is the drug of choice for treating *Listeria monocytogenes* in pregnant women, either alone or combined with an aminoglycoside. Pregnancy increases the clearance of ampicillin by up to 50%, and a higher dose is thus needed to reach therapeutic levels.
Ampicillin crosses the placenta and remains in the amniotic fluid at 50--100% of the concentration in maternal plasma; this can lead to high concentrations of ampicillin in the newborn.
While lactating mothers secrete some ampicillin into their breast milk, the amount is minimal.
In newborns, ampicillin has a longer half-life and lower plasma protein binding. The clearance by the kidneys is lower, as kidney function has not fully developed.
## Contraindications
Ampicillin is contraindicated in those with a hypersensitivity to penicillins, as they can cause fatal anaphylactic reactions. Hypersensitivity reactions can include frequent skin rashes and hives, exfoliative dermatitis, erythema multiforme, and a temporary decrease in both red and white blood cells.
Ampicillin is not recommended in people with concurrent mononucleosis, as over 40% of patients develop a skin rash.
| 588 |
Ampicillin
| 1 |
1,912 |
## Side effects {#side_effects}
Ampicillin is comparatively less toxic than other antibiotics, and side effects are more likely in those who are sensitive to penicillins and those with a history of asthma or allergies. In very rare cases, it causes severe side effects such as angioedema, anaphylaxis, and *C. difficile* infection (that can range from mild diarrhea to serious pseudomembranous colitis). Some develop black \"furry\" tongue. Serious adverse effects also include seizures and serum sickness. The most common side effects, experienced by about 10% of users are diarrhea and rash. Less common side effects can be nausea, vomiting, itching, and blood dyscrasias. The gastrointestinal effects, such as hairy tongue, nausea, vomiting, diarrhea, and colitis, are more common with the oral form of penicillin. Other conditions may develop up several weeks after treatment.
### Overdose
Ampicillin overdose can cause behavioral changes, confusion, blackouts, and convulsions, as well as neuromuscular hypersensitivity, electrolyte imbalance, and kidney failure.
## Interactions
Ampicillin reacts with probenecid and methotrexate to decrease renal excretion. Large doses of ampicillin can increase the risk of bleeding with concurrent use of warfarin and other oral anticoagulants, possibly by inhibiting platelet aggregation. Ampicillin has been said to make oral contraceptives less effective, but this has been disputed. It can be made less effective by other antibiotic, such as chloramphenicol, erythromycin, cephalosporins, and tetracyclines. For example, tetracyclines inhibit protein synthesis in bacteria, reducing the target against which ampicillin acts. If given at the same time as aminoglycosides, it can bind to it and inactivate it. When administered separately, aminoglycosides and ampicillin can potentiate each other instead.
Ampicillin causes skin rashes more often when given with allopurinol.
Both the live cholera vaccine and live typhoid vaccine can be made ineffective if given with ampicillin. Ampicillin is normally used to treat cholera and typhoid fever, lowering the immunological response that the body has to mount.
| 310 |
Ampicillin
| 2 |
1,912 |
## Pharmacology
### Mechanism of action {#mechanism_of_action}
Ampicillin is in the penicillin group of beta-lactam antibiotics and is part of the aminopenicillin family. It is roughly equivalent to amoxicillin in terms of activity. Ampicillin is able to penetrate gram-positive and some gram-negative bacteria. It differs from penicillin G, or benzylpenicillin, only by the presence of an amino group. This amino group, present on both ampicillin and amoxicillin, helps these antibiotics pass through the pores of the outer membrane of gram-negative bacteria, such as *Escherichia coli*, *Proteus mirabilis*, *Salmonella enterica*, and *Shigella*.
Ampicillin acts as an irreversible inhibitor of the enzyme transpeptidase, which is needed by bacteria to make the cell wall. It inhibits the third and final stage of bacterial cell wall synthesis in binary fission, which ultimately leads to cell lysis; therefore, ampicillin is usually bacteriolytic.
### Pharmacokinetics
Ampicillin is well-absorbed from the GI tract (though food reduces its absorption), and reaches peak concentrations in one to two hours. The bioavailability is around 62% for parenteral routes. Unlike other penicillins, which usually bind 60--90% to plasma proteins, ampicillin binds to only 15--20%.
Ampicillin is distributed through most tissues, though it is concentrated in the liver and kidneys. It can also be found in the cerebrospinal fluid when the meninges become inflamed (such as, for example, meningitis). Some ampicillin is metabolized by hydrolyzing the beta-lactam ring to penicilloic acid, though most of it is excreted unchanged. In the kidneys, it is filtered out mostly by tubular secretion; some also undergoes glomerular filtration, and the rest is excreted in the feces and bile.
Hetacillin and pivampicillin are ampicillin esters that have been developed to increase bioavailability.
## History
Ampicillin has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against gram-positive organisms such as staphylococci and streptococci. Ampicillin (originally branded as \"Penbritin\") also demonstrated activity against gram-negative organisms such as *H. influenzae*, coliforms, and *Proteus* spp.
## Society and culture {#society_and_culture}
### Economics
Ampicillin is relatively inexpensive. In the United States, it is available as a generic medication.
## Veterinary use {#veterinary_use}
In veterinary medicine, ampicillin is used in cats, dogs, and farm animals to treat:
- Anal gland infections
- Cutaneous infections, such as abscesses, cellulitis, and pustular dermatitis
- *E. coli* and *Salmonella* infections in cattle, sheep, and goats (oral form). Ampicillin use for this purpose had declined as bacterial resistance has increased.
- Mastitis in sows
- Mixed aerobic--anaerobic infections, such as from cat bites
- Multidrug-resistant *Enterococcus faecalis* and *E. faecium*
- Prophylactic use in poultry against *Salmonella* and sepsis from *E. coli* or *Staphylococcus aureus*
- Respiratory tract infections, including tonsilitis, bovine respiratory disease, shipping fever, bronchopneumonia, and calf and bovine pneumonia
- Urinary tract infections in dogs
Horses are generally not treated with oral ampicillin, as they have low bioavailability of beta-lactams.
The half-life in animals is around that same of that in humans (just over an hour). Oral absorption is less than 50% in cats and dogs, and less than 4% in horses
| 515 |
Ampicillin
| 3 |
1,915 |
In immunology, an **antigen** (**Ag**) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response.
Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungi, and bacteria.
Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are *antigen-specific*, meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react to bind more than one antigen. The reaction between an antigen and an antibody is called the antigen-antibody reaction.
Antigen can originate either from within the body (\"self-protein\" or \"self antigens\") or from the external environment (\"non-self\"). The immune system identifies and attacks \"non-self\" external antigens. Antibodies usually do not react with self-antigens due to negative selection of T cells in the thymus and B cells in the bone marrow. The diseases in which antibodies react with self antigens and damage the body\'s own cells are called autoimmune diseases.
Vaccines are examples of antigens in an immunogenic form, which are intentionally administered to a recipient to induce the memory function of the adaptive immune system towards antigens of the pathogen invading that recipient. The vaccine for seasonal influenza is a common example.
## Etymology
Paul Ehrlich coined the term *antibody* (*Antikörper*) in his side-chain theory at the end of the 19th century. In 1899, Ladislas Deutsch (László Detre) named the hypothetical substances halfway between bacterial constituents and antibodies \"antigenic or immunogenic substances\" (*substances immunogènes ou antigènes*). He originally believed those substances to be precursors of antibodies, just as a zymogen is a precursor of an enzyme. But, by 1903, he understood that an antigen induces the production of immune bodies (antibodies) and wrote that the word *antigen* is a contraction of antisomatogen (*Immunkörperbildner*). The *Oxford English Dictionary* indicates that the logical construction should be \"anti(body)-gen\". The term originally referred to a substance that acts as an antibody generator.
| 398 |
Antigen
| 0 |
1,915 |
## Terminology
- Epitope -- the distinct surface features of an, its *antigenic determinant*.\
Antigenic molecules, normally \"large\" biological polymers, usually present surface features that can act as points of interaction for specific antibodies. Any such feature constitutes an epitope. Most antigens have the potential to be bound by multiple antibodies, each of which is specific to one of the antigen\'s epitopes. Using the \"lock and key\" metaphor, the antigen can be seen as a string of keys (epitopes) each of which matches a different lock (antibody). Different antibody idiotypes, each have distinctly formed complementarity-determining regions.
- Allergen -- A substance capable of causing an allergic reaction. The (detrimental) reaction may result after exposure via ingestion, inhalation, injection, or contact with skin.
- Superantigen -- A class of antigens that cause non-specific activation of T-cells, resulting in polyclonal T-cell activation and massive cytokine release.
- Tolerogen -- A substance that invokes a specific immune non-responsiveness due to its molecular form. If its molecular form is changed, a tolerogen can become an immunogen.
- Immunoglobulin-binding protein -- Proteins such as protein A, protein G, and protein L that are capable of binding to antibodies at positions outside of the antigen-binding site. While antigens are the \"target\" of antibodies, immunoglobulin-binding proteins \"attack\" antibodies.
- T-dependent antigen -- Antigens that require the assistance of T cells to induce the formation of specific antibodies.
- T-independent antigen -- Antigens that stimulate B cells directly.
- Immunodominant antigens -- Antigens that dominate (over all others from a pathogen) in their ability to produce an immune response. T cell responses typically are directed against a relatively few immunodominant epitopes, although in some cases (e.g., infection with the malaria pathogen *Plasmodium spp.*) it is dispersed over a relatively large number of parasite antigens.
Antigen-presenting cells present antigens in the form of peptides on histocompatibility molecules. The T cells selectively recognize the antigens; depending on the antigen and the type of the histocompatibility molecule, different types of T cells will be activated. For T-cell receptor (TCR) recognition, the peptide must be processed into small fragments inside the cell and presented by a major histocompatibility complex (MHC). The antigen cannot elicit the immune response without the help of an immunologic adjuvant. Similarly, the adjuvant component of vaccines plays an essential role in the activation of the innate immune system.
An immunogen is an antigen substance (or adduct) that is able to trigger a humoral (innate) or cell-mediated immune response. It first initiates an innate immune response, which then causes the activation of the adaptive immune response. An antigen binds the highly variable immunoreceptor products (B-cell receptor or T-cell receptor) once these have been generated. Immunogens are those antigens, termed immunogenic, capable of inducing an immune response.
At the molecular level, an antigen can be characterized by its ability to bind to an antibody\'s paratopes. Different antibodies have the potential to discriminate among specific epitopes present on the antigen surface. A hapten is a small molecule that can only induce an immune response when attached to a larger carrier molecule, such as a protein. Antigens can be proteins, polysaccharides, lipids, nucleic acids or other biomolecules. This includes parts (coats, capsules, cell walls, flagella, fimbriae, and toxins) of bacteria, viruses, and other microorganisms. Non-microbial non-self antigens can include pollen, egg white, and proteins from transplanted tissues and organs or on the surface of transfused blood cells.
## Antigenic specificity {#antigenic_specificity}
Antigenic specificity is the ability of the host cells to recognize an antigen specifically as a unique molecular entity and distinguish it from another with exquisite precision. Antigen specificity is due primarily to the side-chain conformations of the antigen. It is measurable and need not be linear or of a rate-limited step or equation. Both T cells and B cells are cellular components of adaptive immunity
| 635 |
Antigen
| 1 |
1,941 |
The word **aeon** `{{IPAc-en|ˈ|iː|ɒ|n}}`{=mediawiki}, also spelled **eon** (in American and Australian English), originally meant \"life\", \"vital force\" or \"being\", \"generation\" or \"a period of time\", though it tended to be translated as \"age\" in the sense of \"ages\", \"forever\", \"timeless\" or \"for eternity\". It is a Latin transliteration from the ancient Greek word *ὁ αἰών* (**ho aion**), from the archaic *αἰϝών* (**aiwōn**) meaning \"century\". In Greek, it literally refers to the timespan of one hundred years. A cognate Latin word **aevum** (cf. *αἰϝών*) for \"age\" is present in words such as *eternal*, *longevity* and *mediaeval*.
Although the term aeon may be used in reference to a period of a billion years (especially in geology, cosmology and astronomy), its more common usage is for any long, indefinite period. Aeon can also refer to the four aeons on the geologic time scale that make up the Earth\'s history, the Hadean, Archean, Proterozoic, and the current aeon, Phanerozoic.
## Astronomy and cosmology {#astronomy_and_cosmology}
In astronomy, an aeon is defined as a billion years (10^9^ years, abbreviated AE).
Roger Penrose uses the word *aeon* to describe the period between successive and cyclic Big Bangs within the context of conformal cyclic cosmology.
## Philosophy and mysticism {#philosophy_and_mysticism}
In Buddhism, aeon may be used as a translation of the term kalpa or **mahakalpa** (Sanskrit: *italic=no*). A mahakalpa is often said to be 1,334,240,000 years, the life cycle of the world. Yet, these numbers are symbolic, not literal.
Christianity\'s idea of \"eternal life\" comes from the word for life, **zōḗ** (*italic=no*), and a form of **aión** (*italic=no*), which could mean life in the next aeon, the Kingdom of God, or Heaven, just as much as immortality, as in John 3:16.`{{lopsided|date=June 2022}}`{=mediawiki}
According to Christian universalism, the Greek New Testament scriptures use the word **aión** (*italic=no*) to mean a long period and the word **aiṓnion** (*αἰώνιον*) to mean \"during a long period\"; thus, there was a time before the aeons, and the aeonian period is finite. After each person\'s mortal life ends, they are judged worthy of aeonian life or aeonian punishment. That is, after the period of the aeons, all punishment will cease and death is overcome and then God becomes the all in each one (1Cor 15:28). This contrasts with the conventional Christian belief in eternal life and eternal punishment.
Occultists of the Thelema and Ordo Templi Orientis (English: \"Order of the Temple of the East\") traditions sometimes speak of a \"magical Aeon\" that may last for perhaps as little as 2,000 years.
### Gnosticism
In many Gnostic systems, the various emanations of God, who is also known by such names as the *One*, the *Monad*, *Aion teleos* (\"The Broadest Aeon\", Greek: *αἰών τέλεος*), *Bythos* (\"depth or profundity\", Greek: *βυθός*), *Proarkhe* (\"before the beginning\", Greek: *προαρχή*), **Arkhe** (\"the beginning\", Greek: *ἀρχή*), **Sophia** (\"wisdom\"), and **Christos** (\"the Anointed One\"), are called *Aeons*. In the different systems these emanations are differently named, classified, and described, but the emanation theory itself is common to all forms of Gnosticism.
In the Basilidian Gnosis they are called sonships (*υἱότητες* **huiotetes**; singular: *υἱότης* **huiotes**); according to Marcus, they are numbers and sounds; in Valentinianism they form male/female pairs called \"*syzygies*\" (Greek *συζυγίαι*, from *σύζυγοι* **syzygoi**)
| 533 |
Aeon
| 0 |
1,949 |
**Andreas Capellanus** (*Capellanus* meaning \"chaplain\"), also known as **Andrew the Chaplain** (`{{fl.|{{circa}} 1185}}`{=mediawiki}), and occasionally by a French translation of his name, **André le Chapelain**, was the 12th-century author of a treatise commonly known as *De amore* (\"About Love\"), and often known in English, somewhat misleadingly, as *The Art of Courtly Love*, though its realistic, somewhat cynical tone suggests that it is in some measure an antidote to courtly love. Little is known of Andreas Capellanus\'s life, but he is presumed to have been a courtier of Marie de Champagne, and probably of French origin.
## His work {#his_work}
*De Amore* was written at the request of Marie de Champagne, daughter of King Louis VII of France and of Eleanor of Aquitaine. In it, the author informs a young pupil, Walter, of the pitfalls of love. A dismissive allusion in the text to the \"wealth of Hungary\" has suggested the hypothesis that it was written after 1184, at the time when Bela III of Hungary had sent to the French court a statement of his income and had proposed marriage to Marie\'s half-sister Marguerite of France, but before 1186, when his proposal was accepted.
*De Amore* is made up of three books. The first book covers the etymology and definition of love and is written in the manner of an academic lecture. The second book consists of sample dialogues between members of different social classes; it outlines how the romantic process between the classes should work. This second work is largely considered to be an inferior to the first. Book three is made of stories from actual courts of love presided over by noble women.
John Jay Parry, the editor of one modern edition of *De Amore*, quotes critic Robert Bossuat as describing *De Amore* as \"one of those capital works which reflect the thought of a great epoch, which explains the secret of a civilization\". It may be viewed as didactic, mocking, or merely descriptive; in any event it preserves the attitudes and practices that were the foundation of a long and significant tradition in Western literature.
The social system of \"courtly love\", as gradually elaborated by the Provençal troubadours from the mid twelfth century, soon spread. One of the circles in which this poetry and its ethic were cultivated was the court of Eleanor of Aquitaine (herself the granddaughter of an early troubadour poet, William IX of Aquitaine). *De Amore* codifies the social and love life of Eleanor\'s court at Poitiers between 1170 and 1174, though it was evidently written at least ten years later and, apparently, at Troyes. It deals with several specific themes that were the subject of poetical debate among late twelfth century troubadours and trobairitz.
The meaning of *De Amore* has been debated over the centuries. In the years immediately following its release many people took Andreas\' opinions concerning Courtly Love seriously. In more recent times, however, scholars have come to view the priest\'s work as satirical. Many scholars now agree that Andreas was commenting on the materialistic, superficial nature of medieval nobles. Andreas seems to have been warning young Walter, his protégé, about love in the Middle Ages
| 525 |
Andreas Capellanus
| 0 |
1,967 |
**Apollo 12** (November 14--24, 1969) was the sixth crewed flight in the United States Apollo program and the second to land on the Moon. It was launched on November 14, 1969, by NASA from the Kennedy Space Center in Florida. Commander Charles \"Pete\" Conrad and Lunar Module Pilot Alan L. Bean completed just over one day and seven hours of lunar surface activity while Command Module Pilot Richard F. Gordon remained in lunar orbit.
Apollo 12 would have attempted the first lunar landing had Apollo 11 failed, but after the success of the earlier mission, Apollo 12 was postponed by two months, and other Apollo missions also put on a more relaxed schedule. More time was allotted for geologic training in preparation for Apollo 12 than for Apollo 11, Conrad and Bean making several geology field trips in preparation for their mission. Apollo 12\'s spacecraft and launch vehicle were almost identical to Apollo 11\'s. One addition was a set of hammocks, designed to provide Conrad and Bean with a more comfortable resting arrangement inside the Lunar Module during their stay on the Moon.
Shortly after being launched on a rainy day at Kennedy Space Center, Apollo 12 was twice struck by lightning, causing instrumentation problems but little damage. The crew found that switching to the auxiliary power supply resolved the data relay problem, which helped save the mission. The outward journey to the Moon otherwise saw few problems. On November 19, Conrad and Bean achieved a precise landing at their expected location within walking distance of the Surveyor 3 robotic probe, which had landed on April 20, 1967. In making a pinpoint landing, they showed that NASA could plan future missions in the expectation that astronauts could land close to sites of scientific interest. Conrad and Bean carried the Apollo Lunar Surface Experiments Package, a group of nuclear-powered scientific instruments, as well as the first color television camera taken by an Apollo mission to the lunar surface, but transmission was lost after Bean accidentally pointed the camera at the Sun and its sensor was burned out. On the second of two moonwalks, they visited Surveyor 3 and removed parts for return to Earth.
Lunar Module *Intrepid* lifted off from the Moon on November 20 and docked with the command module, which subsequently traveled back to Earth. The Apollo 12 mission ended on November 24 with a splashdown.
| 397 |
Apollo 12
| 0 |
1,967 |
## Crew and key Mission Control personnel {#crew_and_key_mission_control_personnel}
The commander of the all-Navy Apollo 12 crew was Charles \"Pete\" Conrad, who was 39 years old at the time of the mission. After receiving a bachelor\'s degree in aeronautical engineering from Princeton University in 1953, he became a naval aviator, and completed United States Naval Test Pilot School at Patuxent River Naval Air Station. He was selected in the second group of astronauts in 1962, and flew on Gemini 5 in 1965, and as command pilot of Gemini 11 in 1966. Command Module Pilot Richard \"Dick\" Gordon, 40 years old at the time of Apollo 12, also became a naval aviator in 1953, following graduation from the University of Washington with a degree in chemistry, and completed test pilot school at Patuxent River. Selected as a Group 3 astronaut in 1963, he flew with Conrad on Gemini 11.
The original Lunar Module pilot assigned to work with Conrad was Clifton C. Williams Jr., who was killed in October 1967 when the T-38 he was flying crashed near Tallahassee. When forming his crew, Conrad had wanted Alan L. Bean, a former student of his at the test pilot school, but had been told by Director of Flight Crew Operations Deke Slayton that Bean was unavailable due to an assignment to the Apollo Applications Program. After Williams\'s death, Conrad asked for Bean again, and this time Slayton yielded. Bean, 37 years old when the mission flew, had graduated from the University of Texas in 1955 with a degree in aeronautical engineering. Also a naval aviator, he was selected alongside Gordon in 1963, and first flew in space on Apollo 12. The three Apollo 12 crew members had backed up Apollo 9 earlier in 1969.
The Apollo 12 backup crew was David R. Scott as commander, Alfred M. Worden as Command Module pilot, and James B. Irwin as Lunar Module pilot. They became the crew of Apollo 15. For Apollo, a third crew of astronauts, known as the support crew, was designated in addition to the prime and backup crews used on projects Mercury and Gemini. Slayton created the support crews because James McDivitt, who would command Apollo 9, believed that, with preparation going on in facilities across the US, meetings that needed a member of the flight crew would be missed. Support crew members were to assist as directed by the mission commander. Usually low in seniority, they assembled the mission\'s rules, flight plan, and checklists, and kept them updated; For Apollo 12, they were Gerald P. Carr, Edward G. Gibson and Paul J. Weitz. Flight directors were Gerry Griffin, first shift, Pete Frank, second shift, Clifford E. Charlesworth, third shift, and Milton Windler, fourth shift. Flight directors during Apollo had a one-sentence job description, \"The flight director may take any actions necessary for crew safety and mission success.\" Capsule communicators (CAPCOMs) were Scott, Worden, Irwin, Carr, Gibson, Weitz and Don Lind.
| 489 |
Apollo 12
| 1 |
1,967 |
## Preparation
### Site selection {#site_selection}
The landing site selection process for Apollo 12 was greatly informed by the site selection for Apollo 11. There were rigid standards for the possible Apollo 11 landing sites, in which scientific interest was not a major factor: they had to be close to the lunar equator and not on the periphery of the portion of the lunar surface visible from Earth; they had to be relatively flat and without major obstructions along the path the Lunar Module (LM) would fly to reach them, their suitability confirmed by photographs from Lunar Orbiter probes. Also desirable was the presence of another suitable site further west in case the mission was delayed, and the Sun would have risen too high in the sky at the original site for desired lighting conditions. The need for three days to recycle if a launch had to be scrubbed meant that only three of the five suitable sites found were designated as potential landing sites for Apollo 11, of which the Apollo 11 landing site in the Sea of Tranquility was the easternmost. Since Apollo 12 was to attempt the first lunar landing if Apollo 11 failed, both sets of astronauts trained for the same sites.
With the success of Apollo 11, it was initially contemplated that Apollo 12 would land at the site next further west from the Sea of Tranquility, in Sinus Medii. However, NASA planning coordinator Jack Sevier and engineers at the Manned Spaceflight Center at Houston argued for a landing close enough to the crater in which the Surveyor 3 probe had landed in 1967 to allow the astronauts to cut parts from it for return to Earth. The site was otherwise suitable and had scientific interest. Given that Apollo 11 had landed several miles off-target, though, some NASA administrators feared Apollo 12 would land far enough away that the astronauts could not reach the probe, and the agency would be embarrassed. Nevertheless, the ability to perform pinpoint landings was essential if Apollo\'s exploration program was to be carried out, and on July 25, 1969, Apollo Program Manager Samuel Phillips designated what became known as Surveyor crater as the landing site, despite the unanimous opposition of members of two site selection boards.
To locate Surveyor 3, NASA invited Ewen Whitaker, who together with Gerard Kuiper worked on multiple Moon atlases. Whitaker had found the Surveyor 1 landing site with better precision than NASA. By studying images from Surveyor 3 and comparing them with photographs of thousands of similar craters under the microscope, he identified two rocks near Surveyor 3, that led to the identification of the probe\'s location.
| 442 |
Apollo 12
| 2 |
1,967 |
## Preparation
### Training and preparation {#training_and_preparation}
The Apollo 12 astronauts spent five hours in mission-specific training for every hour they expected to spend in flight on the mission, a total exceeding 1,000 hours per crew member. Conrad and Bean received more mission-specific training than Apollo 11\'s Neil Armstrong and Buzz Aldrin had. This was in addition to the 1,500 hours of training they received as backup crew members for Apollo 9. The Apollo 12 training included over 400 hours per crew member in simulators of the Command Module (CM) and of the LM. Some of the simulations were linked in real time to flight controllers in Mission Control. To practice landing on the Moon, Conrad flew the Lunar Landing Training Vehicle (LLTV), training in which continued to be authorized even though Armstrong had been forced to bail out of a similar vehicle in 1968, just before it crashed.
Soon after being assigned as Apollo 12 crew commander, Conrad met with NASA geologists and told them that the training for lunar surface activities would be conducted much as Apollo 11\'s, but there was to be no publicity or involvement by the media. Conrad felt he had been abused by the press during Gemini, and the sole Apollo 11 geology field trip had turned into a near-fiasco, with a large media contingent present, some getting in the way---the astronauts had trouble hearing each other due to a hovering press helicopter. After the return of Apollo 11 in July 1969, more time was allotted for geology, but the astronauts\' focus was on getting time in the simulators without being preempted by the Apollo 11 crew. On the six Apollo 12 geology field trips, the astronauts would practice as if on the Moon, collecting samples and documenting them with photographs, while communicating with a CAPCOM and geologists who were out of sight in a nearby tent. Afterwards, the astronauts\' performance in choosing samples and taking photographs would be critiqued. To the frustration of the astronauts, the scientists kept changing the photo documentation procedures; after the fourth or fifth such change, Conrad required that there be no more. After the return of Apollo 11, the Apollo 12 crew was able to view the lunar samples, and be briefed on them by scientists.
As Apollo 11 was targeted for an ellipse-shaped landing zone, rather than at a specific point, there was no planning for geology traverses, the designated tasks to be done at sites of the crew\'s choosing. For Apollo 12, before the mission, some of NASA\'s geology team met with the crew and Conrad suggested they lay out possible routes for him and Bean. The result was four traverses, based on four potential landing points for the LM. This was the start of geology traverse planning that on later missions became a considerable effort involving several organizations.
The stages of the lunar module, LM--6, were delivered to Kennedy Space Center (KSC) on March 24, 1969, and were mated to each other on April 28. Command module CM--108 and service module SM--108 were delivered to KSC on March 28, and were mated to each other on April 21. Following installation of gear and testing, the launch vehicle, with the spacecraft atop it, was rolled out to Launch Complex 39A on September 8, 1969. The training schedule was complete, as planned, by November 1, 1969; activities after that date were intended as refreshers. The crew members felt that the training, for the most part, was adequate preparation for the Moon mission.
| 585 |
Apollo 12
| 3 |
1,967 |
## Hardware
### Launch vehicle {#launch_vehicle}
There were no significant changes to the Saturn V launch vehicle used on Apollo 12, SA--507, from that used on Apollo 11. There were another 17 instrumentation measurements in the Apollo 12 launch vehicle, bringing the number to 1,365. The entire vehicle, including the spacecraft, weighed 6,487,742 lb at launch, an increase from Apollo 11\'s 6,477,875 lb. Of this figure, the spacecraft weighed 110,044 lb, up from 109,646 lb on Apollo 11.
#### Third stage trajectory {#third_stage_trajectory}
After LM separation, the third stage of the Saturn V, the S-IVB, was intended to fly into solar orbit. The S-IVB auxiliary propulsion system was fired, with the intent that the Moon\'s gravity would slingshot the stage into solar orbit. Due to an error, the S-IVB flew past the Moon at too high an altitude to achieve Earth escape velocity. It remained in a semi-stable Earth orbit until it finally escaped Earth orbit in 1971, but briefly returned to Earth orbit 31 years later. It was discovered by amateur astronomer Bill Yeung who gave it the temporary designation J002E3 before it was determined to be an artificial object. Again in solar orbit as of 2021, it may again be captured by Earth\'s gravity, but not at least until the 2040s. The S-IVBs used on later lunar missions were deliberately crashed into the Moon to create seismic events that would register on the seismometers left on the Moon and provide data about the Moon\'s structure.
### Spacecraft
The Apollo 12 spacecraft consisted of Command Module 108 and Service Module 108 (together Command and Service Modules 108, or CSM--108), Lunar Module 6 (LM--6), a Launch Escape System (LES), and Spacecraft-Lunar Module Adapter 15 (SLA--15). The LES contained three rocket motors to propel the CM to safety in the event of an abort shortly after launch, while the SLA housed the LM and provided a structural connection between the Saturn V and the LM. The SLA was identical to Apollo 11\'s, while the LES differed only in the installation of a more reliable motor igniter.
The CSM was given the call sign *Yankee Clipper*, while the LM had the call sign *Intrepid*. These sea-related names were selected by the all-Navy crew from several thousand proposed names submitted by employees of the prime contractors of the respective modules. George Glacken, a flight test engineer at North American Aviation, builder of the CSM, proposed *Yankee Clipper* as such ships had \"majestically sailed the high seas with pride and prestige for a new America\". *Intrepid* was from a suggestion by Robert Lambert, a planner at Grumman, builder of the LM, as evocative of \"this nation\'s resolute determination for continued exploration of space, stressing our astronauts\' fortitude and endurance of hardship\".
The differences between the CSM and LM of Apollo 11, and those of Apollo 12, were few and minor. A hydrogen separator was added to the CSM to stop the gas from entering the potable water tank---Apollo 11 had had one, though mounted on the water dispenser in the CM\'s cabin. Gaseous hydrogen in the water had given the Apollo 11 crew severe flatulence. Other changes included the strengthening of the recovery loop attached following splashdown, meaning that the swimmers recovering the CM would not have to attach an auxiliary loop. LM changes included a structural modification so that scientific experiment packages could be carried for deployment on the lunar surface. Two hammocks were added for greater comfort of the astronauts while resting on the Moon, and a color television camera substituted for the black and white one used on the lunar surface during Apollo 11.
| 603 |
Apollo 12
| 4 |
1,967 |
## Hardware
### ALSEP
The Apollo Lunar Surface Experiments Package (ALSEP) was a suite of scientific instruments designed to be emplaced on the lunar surface by the Apollo astronauts, and thereafter operate autonomously, sending data to Earth. Development of the ALSEP was part of NASA\'s response to some scientists who opposed the crewed lunar landing program (they felt that robotic craft could explore the Moon more cheaply) by demonstrating that some tasks, such as deployment of the ALSEP, required humans. In 1966, a contract to design and build the ALSEPs was awarded to the Bendix Corporation. Due to the limited time the Apollo 11 crew would have on the lunar surface, a smaller suite of experiments was flown, known as the Early Apollo Surface Experiment Package (EASEP). Apollo 12 was the first mission to carry an ALSEP; one would be flown on each of the subsequent lunar landing missions, though the components that were included would vary. Apollo 12\'s ALSEP was to be deployed at least 300 ft away from the LM to protect the instruments from the debris that would be generated when the ascent stage of the LM took off to return the astronauts to lunar orbit.
Apollo 12\'s ALSEP included a Lunar Surface Magnetometer (LSM), to measure the magnetic field at the Moon\'s surface, a Lunar Atmosphere Detector (LAD, also known as the Cold Cathode Gauge Experiment), intended to measure the density and temperature of the thin lunar atmosphere and how it varies, a Lunar Ionosphere Detector (LID, also known as the Suprathermal Ion Detector Experiment, or SIDE), intended to study the charged particles in the lunar atmosphere, and the Solar Wind Spectrometer, to measure the strength and direction of the solar wind at the Moon\'s surface---the free-standing Solar Wind Composition Experiment, to measure what makes up the solar wind, would be deployed and then brought back to Earth by the astronauts. A Dust Detector was used to measure the accumulation of lunar dust on the equipment. Apollo 12\'s Passive Seismic Experiment (PSE), a seismometer, would measure moonquakes and other movements in the Moon\'s crust, and would be calibrated by the nearby planned impact of the ascent stage of Apollo 12\'s LM, an object of known mass and velocity hitting the Moon at a known location, and projected to be equivalent to the explosive force of one ton of TNT.
The ALSEP experiments left on the Moon by Apollo 12 were connected to a Central Station, which contained a transmitter, receiver, timer, data processor, and equipment for power distribution and control of the experiments. The equipment was powered by SNAP-27, a radioisotope thermoelectric generator (RTG) developed by the Atomic Energy Commission. Containing plutonium, the RTG flown on Apollo 12 was the first use of atomic energy on a crewed NASA spacecraft---some NASA and military satellites had previously used similar systems. The plutonium core was brought from Earth in a cask attached to an LM landing leg, a container designed to survive re-entry in the event of an aborted mission, something NASA considered unlikely. The cask would survive re-entry on Apollo 13, sinking in the Tonga Trench of the Pacific Ocean, apparently without radioactive leakage.
The Apollo 12 ALSEP experiments were activated from Earth on November 19, 1969. The LAD returned only a small amount of useful data due to the failure of its power supply soon after activation. The LSM was deactivated on June 14, 1974, as was the other LSM deployed on the Moon, from Apollo 15. All powered ALSEP experiments that remained active were deactivated on September 30, 1977, principally because of budgetary constraints.
| 599 |
Apollo 12
| 5 |
1,967 |
## Mission highlights {#mission_highlights}
### Launch
With President Richard Nixon in attendance, the first time a current U.S. president had witnessed a crewed space launch, as well as Vice President Spiro Agnew, Apollo 12 launched as planned on November 14, 1969, from the Kennedy Space Center at 16:22:00 UTC (11:22 am EST, local time at the launch site). This was at the start of a launch window of three hours and four minutes to reach the Moon with optimal lighting conditions at the planned landing point. There were completely overcast rainy skies, and the vehicle encountered winds of 151.7 kn during ascent, the strongest of any Apollo mission. There was a NASA rule against launching into a cumulonimbus cloud; this had been waived and it was later determined that the launch vehicle never entered such a cloud. Had the mission been postponed, it could have been launched on November 16 with landing at a backup site where there would be no Surveyor, but since time pressure to achieve a lunar landing had been removed by Apollo 11\'s success, NASA might have waited until December for the next opportunity to go to the Surveyor crater.
Lightning struck the Saturn V 36.5 seconds after lift-off, triggered by the vehicle itself. The static discharge caused a voltage transient that knocked all three fuel cells offline, meaning the spacecraft was being powered entirely from its batteries, which could not supply enough current to meet demand. A second strike at 52 seconds knocked out the \"8-ball\" attitude indicator. The telemetry stream at Mission Control was garbled, but the Saturn V continued to fly normally; the strikes had not affected the Saturn V instrument unit guidance system, which functioned independently from the CSM. The astronauts unexpectedly had a board red with caution and warning lights, but could not tell exactly what was wrong.
The Electrical, Environmental and Consumables Manager (EECOM) in Mission Control, John Aaron, remembered the telemetry failure pattern from an earlier test when a power loss caused a malfunction in the CSM signal conditioning electronics (SCE), which converted raw signals from instrumentation to data that could be displayed on Mission Control\'s consoles, and knew how to fix it. Aaron made a call, \"Flight, EECOM. Try SCE to Aux\", to switch the SCE to a backup power supply. The switch was fairly obscure, and neither Flight Director Gerald Griffin, CAPCOM Gerald P. Carr, nor Conrad knew what it was; Bean, who as LMP was the spacecraft\'s engineer, knew where to find it and threw the switch, after which the telemetry came back online, revealing no significant malfunctions. Bean put the fuel cells back online, and the mission continued. Once in Earth parking orbit, the crew carefully checked out their spacecraft before re-igniting the S-IVB third stage for trans-lunar injection. The lightning strikes caused no serious permanent damage.
Initially, it was feared that the lightning strike could have damaged the explosive bolts that opened the Command Module\'s parachute compartment. The decision was made not to share this with the astronauts and to continue with the flight plan, since they would die if the parachutes failed to deploy, whether following an Earth-orbit abort or upon a return from the Moon, so nothing was to be gained by aborting. The parachutes deployed and functioned normally at the end of the mission.
### Outward journey {#outward_journey}
After systems checks in Earth orbit, performed with great care because of the lightning strikes, the trans-lunar injection burn, made with the S-IVB, took place at 02:47:22.80 into the mission, setting Apollo 12 on course for the Moon. An hour and twenty minutes later, the CSM separated from the S-IVB, after which Gordon performed the transposition, docking, and extraction maneuver to dock with the LM and separate the combined craft from the S-IVB, which was then sent on an attempt to reach solar orbit. The stage fired its engines to leave the vicinity of the spacecraft, a change from Apollo 11, where the SM\'s Service Propulsion System (SPS) engine was used to distance it from the S-IVB.
As there were concerns the LM might have been damaged by the lightning strikes, Conrad and Bean entered it on the first day of flight to check its status, earlier than planned. They found no issues. At 30:52.44.36, the only necessary midcourse correction during the translunar coast was made, placing the craft on a hybrid, non-free-return trajectory. Previous crewed missions to lunar orbit had taken a free-return trajectory, allowing an easy return to Earth if the craft\'s engines did not fire to enter lunar orbit. Apollo 12 was the first crewed spacecraft to take a hybrid free-return trajectory, that would require another burn to return to Earth, but one that could be executed by the LM\'s Descent Propulsion System (DPS) if the SPS failed. The use of a hybrid trajectory allowed more flexibility in mission planning. It for example allowed Apollo 12 to launch in daylight and reach the planned landing spot on schedule. Use of a hybrid trajectory meant that Apollo 12 took 8 hours longer to go from trans-lunar injection to lunar orbit.
| 849 |
Apollo 12
| 6 |
1,967 |
## Mission highlights {#mission_highlights}
### Lunar orbit and Moon landing {#lunar_orbit_and_moon_landing}
Apollo 12 entered a lunar orbit of 170.2 by with an SPS burn of 352.25 seconds at mission time 83:25:26.36. On the first lunar orbit, there was a television transmission that resulted in good-quality video of the lunar surface. On the third lunar orbit, there was another burn to circularize the craft\'s orbit to 66.1 by, and on the next revolution, preparations began for the lunar landing. The CSM and LM undocked at 107:54:02.3; a half hour later there was a burn by the CSM to separate them. The 14.4 second burn by some of the CSM\'s thrusters meant that the two craft would be 2.2 nmi apart when the LM began the burn to move to a lower orbit in preparation for landing on the Moon.
The LM\'s Descent Propulsion System began a 29-second burn at 109:23:39.9 to move the craft to the lower orbit, from which the 717-second powered descent to the lunar surface began at 110:20:38.1. Conrad had trained to expect a pattern of craters known as \"the Snowman\" to be visible when the craft underwent \"pitchover\", with the Surveyor crater in its center, but had feared he would see nothing recognizable. He was astonished to see the Snowman right where it should be, meaning they were directly on course. He took over manual control, planning to land the LM, as he had in simulations, in an area near the Surveyor crater that had been dubbed \"Pete\'s Parking Lot\", but found it rougher than expected. He had to maneuver, and landed the LM at 110:32:36.2 (06:54:36 UTC on November 19, 1969), just 535 ft from the Surveyor probe. This achieved one objective of the mission, to perform a precision landing near the Surveyor craft.
The lunar coordinates of the landing site were 3.01239° S latitude, 23.42157° W longitude. The landing caused high velocity sandblasting of the Surveyor probe. It was later determined that the sandblasting removed more dust than it delivered onto the Surveyor, because the probe was covered by a thin layer that gave it a tan hue as observed by the astronauts, and every portion of the surface exposed to the direct sandblasting was lightened back toward the original white color through the removal of lunar dust.
| 383 |
Apollo 12
| 7 |
1,967 |
## Mission highlights {#mission_highlights}
### Lunar surface activities {#lunar_surface_activities}
When Conrad, the shortest man of the initial groups of astronauts, stepped onto the lunar surface his first words were \"Whoopie! Man, that may have been a small one for Neil, but that\'s a long one for me.\" This was not an off-the-cuff remark: Conrad had made a `{{USD|500}}`{=mediawiki} bet with reporter Oriana Fallaci he would say these words, after she had queried whether NASA had instructed Neil Armstrong what to say as he stepped onto the Moon. Conrad later said he was never able to collect the money.
thumb\|left\|upright=1.36\|Bean prepares to step onto the lunar surface.
To improve the quality of television pictures from the Moon, a color camera was carried on Apollo 12 (unlike the monochrome camera on Apollo 11). When Bean carried the camera to the place near the LM where it was to be set up, he inadvertently pointed it directly into the Sun, destroying the Secondary Electron Conduction (SEC) tube. Television coverage of this mission was thus terminated almost immediately.
After raising a U.S. flag on the Moon, Conrad and Bean devoted much of the remainder of the first EVA to deploying the Apollo Lunar Surface Experiments Package (ALSEP). There were minor difficulties with the deployment. Bean had trouble extracting the RTG\'s plutonium fuel element from its protective cask, and the astronauts had to resort to the use of a hammer to hit the cask and dislodge the fuel element. Some of the ALSEP packages proved hard to deploy, though the astronauts were successful in all cases. With the PSE able to detect their footprints as they headed back to the LM, the astronauts secured a core tube full of lunar material, and collected other samples. The first EVA lasted 3 hours, 56 minutes and 3 seconds.
Four possible geologic traverses had been planned, the variable being where the LM might set down. Conrad had landed it between two of these potential landing points, and during the first EVA and the rest break that followed, scientists in Houston combined two of the traverses into one that Conrad and Bean could follow from their landing point. The resultant traverse resembled a rough circle, and when the astronauts emerged from the LM some 13 hours after ending the first EVA, the first stop was Head crater, some 100 yard from the LM. There, Bean noticed that Conrad\'s footprints showed lighter material underneath, indicating the presence of ejecta from Copernicus crater, 230 mi to the north, something that scientists examining overhead photographs of the site had hoped to find. After the mission, samples from Head allowed geologists to date the impact that formed Copernicus---according to initial dating, some 810,000,000 years ago.
thumb\|upright=1.3\|right\|Conrad with the U.S. flag
The astronauts proceeded to Bench crater and Sharp crater and past Halo crater before arriving at Surveyor crater, where the Surveyor 3 probe had landed. Fearing treacherous footing or that the probe might topple on them, they approached Surveyor cautiously, descending into the shallow crater some distance away and then following a contour to reach the craft, but found the footing solid and the probe stable. They collected several pieces of Surveyor, including the television camera, as well as taking rocks that had been studied by television. Conrad and Bean had procured an automatic timer for their Hasselblad cameras, and had brought it with them without telling Mission Control, hoping to take a selfie of the two of them with the probe, but when the time came to use it, could not locate it among the lunar samples they had already placed in their Hand Tool Carrier. Before returning to the LM\'s vicinity, Conrad and Bean went to Block crater, within Surveyor crater. The second EVA lasted 3 hours, 49 minutes, 15 seconds, during which they traveled 4300 ft. During the EVAs, Conrad and Bean went as far as 1350 ft from the LM, and collected 73.75 lb of samples.
### Lunar orbit solo activities {#lunar_orbit_solo_activities}
After the LM\'s departure, Gordon had little to say as Mission Control focused on the lunar landing. Once that was accomplished, Gordon sent his congratulations and, on the next orbit, was able to spot both the LM and the Surveyor on the ground and convey their locations to Houston. During the first EVA, Gordon prepared for a plane change maneuver, a burn to alter the CSM\'s orbit to compensate for the rotation of the Moon, though at times he had difficulty communicating with Houston since Conrad and Bean were using the same communications circuit. Once the two moonwalkers had returned to the LM, Gordon executed the burn, which ensured he would be in the proper position to rendezvous with the LM when it launched from the Moon.
While alone in orbit, Gordon performed the Lunar Multispectral Photography Experiment, using four Hasselblad cameras arranged in a ring and aimed through one of the CM\'s windows. With each camera having a different color filter, simultaneous photos would be taken by each, showing the appearance of lunar features at different points on the spectrum. Analysis of the images might reveal colors not visible to the naked eye or detectable with ordinary color film, and information could be obtained about the composition of sites that would not soon be visited by humans. Among the sites studied were contemplated landing points for future Apollo missions.
### Return
LM *Intrepid* lifted off from the Moon at mission time 143:03:47.78, or 14:25:47 UTC on November 20, 1969; after several maneuvers, CSM and LM docked three and a half hours later. At 147:59:31.6, the LM ascent stage was jettisoned, and shortly thereafter the CSM maneuvered away. Under control from Earth, the LM\'s remaining propellant was depleted in a burn that caused it to impact the Moon 39 nmi from the Apollo 12 landing point. The seismometer the astronauts had left on the lunar surface registered the resulting vibrations for more than an hour.
The crew stayed another day in lunar orbit taking photographs of the surface, including of candidate sites for future Apollo landings. A second plane change maneuver was made at 159:04:45.47, lasting 19.25 seconds.
The trans-Earth injection burn, to send the CSM *Yankee Clipper* towards home, was conducted at 172:27:16.81 and lasted 130.32 seconds. Two short midcourse correction burns were made en route. A final television broadcast was made, the astronauts answering questions submitted by the media. There was ample time for rest on the way back to Earth. One event was the photography of a solar eclipse that occurred when the Earth came between the spacecraft and the Sun; Bean described it as the most spectacular sight of the mission.
| 1,108 |
Apollo 12
| 8 |
1,967 |
## Mission highlights {#mission_highlights}
### Splashdown
*Yankee Clipper* returned to Earth on November 24, 1969, splashing down in the South Pacific Ocean southeast of Samoa at 244:36:25 (20:58:24 UTC, 10:58:24 am HST, local time at the landing site). The landing was hard, resulting in a camera becoming dislodged and striking Bean in the forehead. After recovery by `{{USS|Hornet|CV-12|6}}`{=mediawiki}, they entered the Mobile Quarantine Facility (MQF), while lunar samples and Surveyor parts were sent ahead by air to the Lunar Receiving Laboratory (LRL) in Houston. Once the *Hornet* docked in Hawaii, the MQF was offloaded and flown to Ellington Air Force Base near Houston on November 29, from where it was taken to the LRL, where the astronauts remained until released from quarantine on December 10.
## Mission insignia {#mission_insignia}
frameless\|left\|upright=0.8
The Apollo 12 mission patch shows the crew\'s naval background; all three astronauts at the time of the mission were U.S. Navy commanders. It features a clipper ship arriving at the Moon, representing the CM *Yankee Clipper*. The ship trails fire, and flies the flag of the United States. The mission name APOLLO XII and the crew names are on a wide gold border, with a small blue trim. Blue and gold are traditional U.S. Navy colors. The patch has four stars on it -- one each for the three astronauts who flew the mission and one for Clifton Williams, the original LMP on Conrad\'s crew who was killed in 1967 and would have flown the mission. The star was placed there at the suggestion of his replacement, Bean.
The insignia was designed by the crew with the aid of several employees of NASA contractors. The Apollo 12 landing area on the Moon is within the portion of the lunar surface shown on the insignia, based on a photograph of a globe of the Moon, taken by engineers. The clipper ship was based on photographs of such a ship obtained by Bean.
| 322 |
Apollo 12
| 9 |
1,967 |
## Aftermath and spacecraft location {#aftermath_and_spacecraft_location}
thumb\|upright=1.3\|right\|Apollo 12 CM *Yankee Clipper* on display at the Virginia Air and Space Center in Hampton, Virginia
After the mission, Conrad urged his crewmates to join him in the Skylab program, seeing in it the best chance of flying in space again. Bean did so---Conrad commanded Skylab 2, the first crewed mission to the space station, while Bean commanded Skylab 3. Gordon, though, still hoped to walk on the Moon and remained with the Apollo program, serving as backup commander of Apollo 15. He was the likely commander of Apollo 18, but that mission was canceled and he did not fly in space again.
The Apollo 12 command module *Yankee Clipper*, was displayed at the Paris Air Show and was then placed at NASA\'s Langley Research Center in Hampton, Virginia; ownership was transferred to the Smithsonian in July 1971. It is on display at the Virginia Air and Space Center in Hampton.
Mission Control had remotely fired the service module\'s thrusters after jettison, hoping to have it skip off the atmosphere and enter a high-apogee orbit, but the lack of tracking data confirming this caused it to conclude it most likely burned up in the atmosphere at the time of CM re-entry. The S-IVB is in a solar orbit that is sometimes affected by the Earth.
The ascent stage of LM *Intrepid* impacted the Moon November 20, 1969, at 22:17:17.7 UT (5:17 pm EST)`{{spaces}}`{=mediawiki}3.94 S 21.20 W type:event_globe:moon name=Apollo 12 Intrepid lunar module impact. In 2009, the Lunar Reconnaissance Orbiter (LRO) photographed the Apollo 12 landing site, where the descent stage, ALSEP, Surveyor 3 spacecraft, and astronaut footpaths remain. In 2011, the LRO returned to the landing site at a lower altitude to take higher resolution photographs
| 293 |
Apollo 12
| 10 |
1,969 |
**Apollo 15** (July 26`{{snd}}`{=mediawiki}August 7, 1971) was the ninth crewed mission in the Apollo program and the fourth Moon landing. It was the first J mission, with a longer stay on the Moon and a greater focus on science than earlier landings. Apollo 15 saw the first use of the Lunar Roving Vehicle.
The mission began on July 26 and ended on August 7, with the lunar surface exploration taking place between July 30 and August 2. Commander David Scott and Lunar Module Pilot James Irwin landed near Hadley Rille and explored the local area using the rover, allowing them to travel further from the Lunar Module than had been possible on previous missions. They spent 18`{{frac|1|2}}`{=mediawiki} hours on the Moon\'s surface on four extravehicular activities (EVA), and collected 77 kg of surface material.
At the same time, Command Module Pilot Alfred Worden orbited the Moon, operating the sensors in the scientific instrument module (SIM) bay of the service module. This suite of instruments collected data on the Moon and its environment using a panoramic camera, a gamma-ray spectrometer, a mapping camera, a laser altimeter, a mass spectrometer, and a lunar subsatellite deployed at the end of the moonwalks. The Lunar Module returned safely to the command module and, at the end of Apollo 15\'s 74th lunar orbit, the engine was fired for the journey home. During the return trip, Worden performed the first spacewalk in deep space. The Apollo 15 mission splashed down safely on August 7 despite the partial opening of one of its three parachutes.
The mission accomplished its goals and also saw the collection of the Genesis Rock, thought to be part of the Moon\'s early crust, and Scott\'s use of a hammer and a feather to validate Galileo\'s theory that when there is no air resistance, objects fall at the same rate due to gravity regardless of their mass. The mission received negative publicity the following year when it emerged that the crew had carried unauthorized postal covers to the lunar surface, some of which were sold by a West German stamp dealer. The members of the crew were reprimanded for poor judgment, and did not fly in space again.
## Background
In 1962, NASA contracted for the construction of fifteen Saturn V rockets to achieve the Apollo program\'s goal of a crewed landing on the Moon by 1970; at the time no one knew how many missions this would require. In 1969 Apollo 11 succeeded in landing on the Moon with the sixth Saturn V, so nine rockets remained available for a hoped-for total of ten landings. These plans included a heavier, extended version of the Apollo spacecraft to be used in the last five missions (Apollo 16 through 20). The revamped Lunar Module would be capable of up to a 75-hour stay, and would carry a Lunar Roving Vehicle to the Moon\'s surface. The service module would house a package of orbital experiments to gather data on the Moon. In the original plan Apollo 15 was to be the last of the non-extended missions to land in Censorinus crater. But in anticipation of budget cuts, NASA cancelled three landing missions by September 1970. Apollo 15 became the first of three extended missions, known as J missions, and the landing site was moved to Hadley Rille, originally planned for Apollo 19.
| 557 |
Apollo 15
| 0 |
1,969 |
## Crew and key Mission Control personnel {#crew_and_key_mission_control_personnel}
### Crew
Scott was born in 1932 in San Antonio, Texas, and, after spending his freshman year at the University of Michigan on a swimming scholarship, transferred to the United States Military Academy, from which he graduated in 1954. Serving in the Air Force, Scott had received two advanced degrees from MIT in 1962 before being selected as one of the third group of astronauts the following year. He flew in Gemini 8 in 1966 alongside Neil Armstrong and as command module pilot of Apollo 9 in 1969. Worden was born in 1932 in Jackson, Michigan, and like his commander, had attended West Point (class of 1955) and served in the Air Force. Worden earned two master\'s degrees in engineering from Michigan in 1963. Irwin had been born in 1930 in Pittsburgh, and had attended the United States Naval Academy, graduating in 1951 and serving in the Air Force, receiving a master\'s degree from Michigan in 1957. Both Worden and Irwin were selected in the fifth group of astronauts (1966), and Apollo 15 would be their only spaceflight. All three future astronauts had attended Michigan, and two had taken degrees from there; it had been the first university to offer an aeronautical engineering program.
The backup crew was Richard F. Gordon Jr. as commander, Vance D. Brand as command module pilot and Harrison H. Schmitt as Lunar Module pilot. By the usual rotation of crews, the three would most likely have flown Apollo 18, which was canceled. Brand flew later on the Apollo--Soyuz Test Project and on STS-5, the first operational Space Shuttle mission. With NASA under intense pressure to send a professional scientist to the Moon, Schmitt, a geologist, was selected as LMP of Apollo 17 instead of Joe Engle. Apollo 15\'s support crew consisted of astronauts Joseph P. Allen, Robert A. Parker and Karl G. Henize. All three were scientist-astronauts, selected in 1967, as the prime crew felt they needed more assistance with the science than with the piloting. None of the support crew would fly during the Apollo program, waiting until the Space Shuttle program to go into space.
### Mission Control {#mission_control}
The flight directors for Apollo 15 were as follows:
- Gerry Griffin, Gold team
- Milton Windler, Maroon team
- Glynn Lunney, Black team
- Gene Kranz, White team
During a mission the capsule communicators (CAPCOMs), always fellow astronauts, were the only people who normally would speak to the crew. For Apollo 15, the CAPCOMs were Allen, Brand, C. Gordon Fullerton, Gordon, Henize, Edgar D. Mitchell, Parker, Schmitt and Alan B. Shepard.
| 436 |
Apollo 15
| 1 |
1,969 |
## Planning and training {#planning_and_training}
Schmitt and other scientist-astronauts advocated for a greater place for science on the early Apollo missions. They were often met with disinterest from other astronauts, or found science displaced by higher priorities. Schmitt realized that what was needed was an expert teacher who could fire the astronauts\' enthusiasm, and contacted Caltech geologist Lee Silver, whom Schmitt introduced to Apollo 13\'s commander, Jim Lovell, and to its Lunar Module pilot, Fred Haise, then in training for their mission. Lovell and Haise were willing to go on a field expedition with Silver, and geology became a significant part of their training. Geologist Farouk El-Baz trained the prime crew\'s command module pilot, Ken Mattingly to inform his planned observations from lunar orbit. The crew\'s newly acquired skills mostly went unused, due to the explosion that damaged the Apollo 13 spacecraft, and caused an abort of the mission. Apollo 14\'s CMP, Stuart Roosa, was enthusiastic about geology, but the mission commander, Shepard, less so.
Already familiar with the spacecraft as the backup crew for Apollo 12, Scott, Worden and Irwin could devote more of their training time as prime crew for Apollo 15 to geology and sampling techniques. Scott was determined that his crew bring back the maximum amount of scientific data possible, and met with Silver in April 1970 to begin planning the geological training. Schmitt\'s assignment as Apollo 15\'s backup LMP made him an insider, and allowed him to spark competition between the prime and backup crews. The cancellation of two Apollo missions in September 1970 transformed Apollo 15 into a J mission, with a longer stay on the lunar surface, and the first Lunar Roving Vehicle (LRV). This change was welcomed by Scott, who according to David West Reynolds in his account of the Apollo program, was \"something more than a hotshot pilot. Scott had the spirit of a true explorer\", one determined to get the most from the J mission. The additional need for communications, including from planned experiments and the rover, required the near-rebuilding of the Honeysuckle Creek Tracking Station in Australia.
Geology field trips took place about once a month throughout the crew\'s 20 months of training. At first, Silver would take the commanders and LMPs from the prime and backup crews to geological sites in Arizona and New Mexico as if for a normal field geology lesson, but closer to launch, these trips became more realistic. Crews began to wear mock-ups of the backpacks they would carry while hiking near the Rio Grande Gorge, and communicate using walkie-talkies to a CAPCOM in a tent. The CAPCOM was accompanied by a geologist unfamiliar with the area who would rely on the astronauts\' descriptions to interpret the findings, and familiarized the crew members with describing landscapes to people who could not see them. Considering himself a serious amateur, Scott came to enjoy field geology.
The decision to land at Hadley came in September 1970. The Site Selection Committee had narrowed the field down to two sites---Hadley Rille, a deep channel on the edge of Mare Imbrium close to the Apennine mountains or the crater Marius, near which were a group of low, possibly volcanic, domes. Although not ultimately his decision, the commander of a mission always held great sway. To David Scott the choice was clear, as Hadley \"had more variety. There is a certain intangible quality which drives the spirit of exploration and I felt that Hadley had it. Besides it looked beautiful and usually when things look good they are good.\" The selection of Hadley was made although NASA lacked high resolution images of the landing site; none had been made as the site was considered too rough to risk one of the earlier Apollo missions. The proximity of the Apennine mountains to the Hadley site required a landing approach trajectory of 26 degrees, far steeper than the 15 degrees in earlier Apollo landings.
The expanded mission meant that Worden spent much of his time at North American Rockwell\'s facilities at Downey, California, where the command and service module (CSM) was being built. He undertook a different kind of geology training. Working with El-Baz, he studied maps and photographs of the craters he would pass over while orbiting alone in the CSM. As El-Baz listened and gave feedback, Worden learned how to describe lunar features in a way that would be useful to the scientists who would listen to his transmissions back on Earth. Worden found El-Baz to be an enjoyable and inspiring teacher. Worden usually accompanied his crewmates on their geology field trips, though he was often in an airplane overhead, describing features of the landscape as the plane simulated the speed at which the lunar landscape would pass below the CSM.
The demands of the training strained both Worden\'s and Irwin\'s marriages; each sought Scott\'s advice, fearing a divorce might endanger their places on the mission as not projecting the image NASA wanted for the astronauts. Scott consulted Director of Flight Crew Operations Deke Slayton, their boss, who stated what was important was that the astronauts do their jobs. Although the Irwins overcame their marital difficulties, the Wordens divorced before the mission.
| 862 |
Apollo 15
| 2 |
1,969 |
## Hardware
### Spacecraft
Apollo 15 used command and service module CSM-112, which was given the call sign *Endeavour*, named after HMS *Endeavour*, and Lunar Module LM-10, call sign *Falcon*, named after the United States Air Force Academy mascot. Scott explained the choice of the name *Endeavour* on the grounds that its captain, James Cook, had commanded the first purely scientific sea voyage, and Apollo 15 was the first lunar landing mission on which there was a heavy emphasis on science. Apollo 15 took with it a small piece of wood from Cook\'s ship, while *Falcon* carried two falcon feathers to the Moon in recognition of the crew\'s service in the Air Force. Also part of the spacecraft were a Launch Escape System and a Spacecraft-Lunar Module Adapter, numbered SLA-19.
Technicians at the Kennedy Space Center had some problems with the instruments in the service module\'s scientific instrument module (SIM) bay. Some instruments were late in arriving, and principal investigators or representatives of NASA contractors sought further testing or to make small changes. Mechanical problems came from the fact the instruments were designed to operate in space, but had to be tested on the surface of the Earth. As such, things like the 7.5 m (24 ft) booms for the mass and gamma ray spectrometers could be tested only using equipment that tried to mimic the space environment, and, in space, the mass spectrometer boom several times did not fully retract.
On the Lunar Module, the fuel and oxidizer tanks were enlarged on both the descent and ascent stages, and the engine bell on the descent stage was extended. Batteries and solar cells were added for increased electrical power. In all this increased the weight of the Lunar Module to 36000 lb, 4000 lb heavier than previous models.
If Apollo 15 had flown as an H mission, it would have been with CSM-111 and LM-9. That CSM was used by the Apollo--Soyuz Test Project in 1975, but the lunar module went unused and is now at the Kennedy Space Center Visitor Complex. *Endeavour* is on display at the National Museum of the United States Air Force at Wright-Patterson Air Force Base in Dayton, Ohio, following its transfer of ownership from NASA to the Smithsonian in December 1974.
### Launch vehicle {#launch_vehicle}
The Saturn V that launched Apollo 15 was designated SA-510, the tenth flight-ready model of the rocket. As the payload of the rocket was greater, changes were made to the rocket and to its launch trajectory. It was launched in a more southerly direction (80--100 degrees azimuth) than previous missions, and the Earth parking orbit was lowered to 166 km. These two changes meant 1100 lb more could be launched. The propellant reserves were reduced and the number of retrorockets on the S-IC first stage (used to separate the spent first stage from the S-II second stage) reduced from eight to four. The four outboard engines of the S-IC would be burned longer and the center engine would also burn longer. Changes were also made to the S-II to dampen pogo oscillations.
Once all major systems were installed in the Saturn V, it was moved from the Vehicle Assembly Building to the launch site, Launch Complex 39A. During late June and early July 1971, the rocket and Launch Umbilical Tower (LUT) were struck by lightning at least four times. There was no damage to the vehicle, and only minor damage to ground support equipment.
### Space suits {#space_suits}
The Apollo 15 astronauts wore redesigned space suits. On all previous Apollo flights, including the non-lunar flights, the commander and lunar module pilot had worn suits with the life support, liquid cooling, and communications connections in two parallel rows of three. On Apollo 15, the new suits, dubbed the \"A7LB\", had the connectors situated in triangular pairs. This new arrangement, along with the relocation of the entry zipper (which went in an up-down motion on the old suits), to run diagonally from the right shoulder to the left hip, aided in suiting and unsuiting in the cramped confines of the spacecraft. It also allowed for a new waist joint, letting the astronauts bend completely over, and sit on the rover. Upgraded backpacks allowed for longer-duration moonwalks. As in all missions from and after Apollo 13, the commander\'s suit bore a red stripe on the helmet, arms and legs.
Worden wore a suit similar to those worn by the Apollo 14 astronauts, but modified to interface with Apollo 15\'s equipment. Gear needed only for lunar surface EVAs, such as the liquid cooling garment, was not included with Worden\'s suit, as the only EVA he was expected to do was one to retrieve film cartridges from the SIM bay on the flight home.
| 790 |
Apollo 15
| 3 |
1,969 |
## Hardware
### Lunar Roving Vehicle {#lunar_roving_vehicle}
thumb\|upright=1.49\|right\|alt=Astronaut works on the Moon at the lunar rover\|Irwin with the Lunar Roving Vehicle on the Moon. Mons Hadley is in the background. *Main article: Lunar Roving Vehicle*
A vehicle that could operate on the surface of the Moon had been considered by NASA since the early 1960s. An early version was called MOLAB, which had a closed cabin and would have massed about 6000 lb; some scaled-down prototypes were tested in Arizona. As it became clear NASA would not soon establish a lunar base, such a large vehicle seemed unnecessary. Still, a rover would enhance the J missions, which were to concentrate on science, though its mass was limited to about 500 lb and it was not then clear that so light a vehicle could be useful. NASA did not decide to proceed with a rover until May 1969, as Apollo 10, the dress rehearsal for the Moon landing, made its way home from lunar orbit. Boeing received the contract for three rovers on a cost-plus basis; overruns (especially in the navigation system) meant the three vehicles eventually cost a total of \$40 million. These cost overruns gained considerable media attention at a time of greater public weariness with the space program, when NASA\'s budget was being cut.
The Lunar Roving Vehicle could be folded into a space 5 ft by 20 in (1.5 m by 0.5 m). Unloaded, it weighed 460 lb (209 kg) and when carrying two astronauts and their equipment, 1500 lb (700 kg). Each wheel was independently driven by a `{{frac|1|4}}`{=mediawiki} horsepower (200 W) electric motor. Although it could be driven by either astronaut, the commander always drove. Travelling at speeds up to 6 to 8 mph (10 to 12 km/h), astronauts for the first time could travel far afield from their lander and still have enough time to do some scientific experiments. The Apollo 15 rover bore a plaque, reading: \"Man\'s First Wheels on the Moon, Delivered by Falcon, July 30, 1971\". During pre-launch testing, the LRV was given additional bracing, lest it collapse if someone sat on it under Earth conditions.
| 355 |
Apollo 15
| 4 |
1,969 |
## Hardware
### Particles and Fields Subsatellite {#particles_and_fields_subsatellite}
The Apollo 15 Particles and Fields Subsatellite (PFS-1) was a small satellite released into lunar orbit from the SIM bay just before the mission left orbit to return to Earth. Its main objectives were to study the plasma, particle, and magnetic field environment of the Moon and map the lunar gravity field. Specifically, it measured plasma and energetic particle intensities and vector magnetic fields, and facilitated tracking of the satellite velocity to high precision. A basic requirement was that the satellite acquire fields and particle data everywhere on the orbit around the Moon. As well as measuring magnetic fields, the satellite contained sensors to study the Moon\'s mass concentrations, or mascons. The satellite orbited the Moon and returned data from August 4, 1971, until January 1973, when, following multiple failures of the subsatellite\'s electronics, ground support was terminated. It is believed to have crashed into the Moon sometime thereafter.
| 157 |
Apollo 15
| 5 |
1,969 |
## Mission highlights {#mission_highlights}
### Launch and outbound trip {#launch_and_outbound_trip}
*Main article: Journey of Apollo 15 to the Moon*
Apollo 15 was launched on July 26, 1971, at 9:34 am EDT from the Kennedy Space Center at Merritt Island, Florida. The time of launch was at the very start of the two-hour, 37-minute launch window, which would allow Apollo 15 to arrive at the Moon with the proper lighting conditions at Hadley Rille; had the mission been postponed beyond another window on July 27, it could not have been rescheduled until late August. The astronauts had been awakened five and a quarter hours before launch by Slayton, and after breakfast and suiting up, had been taken to Pad 39A, launch site of all seven attempts at crewed lunar landing, and entered the spacecraft about three hours before launch. There were no unplanned delays in the countdown.
At 000:11:36 into the mission, the S-IVB engine shut down, leaving Apollo 15 in its planned parking orbit in low Earth orbit. The mission remained there for 2 hours and 40 minutes, allowing the crew (and Houston, via telemetry) to check the spacecraft\'s systems. At 002:50.02.6 into the mission, the S-IVB was restarted for trans-lunar injection (TLI), placing the craft on a path to the Moon. Before TLI, the craft had completed 1.5 orbits around the Earth.
The command and service module (CSM) and the Lunar Module remained attached to the nearly-exhausted S-IVB booster. Once trans-lunar injection had been achieved, placing the spacecraft on a trajectory towards the Moon, explosive cords separated the CSM from the booster as Worden operated the CSM\'s thrusters to push it away. Worden then maneuvered the CSM to dock with the LM (mounted on the end of the S-IVB), and the combined craft was then separated from the S-IVB by explosives. After Apollo 15 separated from the booster, the S-IVB maneuvered away, and, as planned, impacted the Moon about an hour after the crewed spacecraft entered lunar orbit, though due to an error the impact was 146 km away from the intended target. The booster\'s impact was detected by the seismometers left on the Moon by Apollo 12 and Apollo 14, providing useful scientific data.
There was a malfunctioning light on the craft\'s service propulsion system (SPS); after considerable troubleshooting, the astronauts did a test burn of the system that also served as a midcourse correction. This occurred about 028:40:00 into the mission. Fearing that the light meant the SPS might unexpectedly fire, the astronauts avoided using the control bank with the faulty light, bringing it online only for major burns, and controlling it manually. After the mission returned, the malfunction proved to be caused by a tiny bit of wire trapped within the switch.
After purging and renewing the LM\'s atmosphere to eliminate any contamination, the astronauts entered the LM about 34 hours into the mission, needing to check the condition of its equipment and move in items that would be required on the Moon. Much of this work was televised back to Earth, the camera operated by Worden. The crew discovered a broken outer cover on the Range/Range Rate tapemeter. This was a concern not only because an important piece of equipment, providing information on distance and rate of approach, might not work properly, but because bits of the glass cover were floating around *Falcon*{{\'s}} interior. The tapemeter was supposed to be in a helium atmosphere, but due to the breakage, it was in the LM\'s oxygen atmosphere. Testing on the ground verified the tapemeter would still work properly, and the crew removed most of the glass using a vacuum cleaner and adhesive tape.
As yet, there had been only minor problems, but at about 61:15:00 mission time (the evening of July 28 in Houston), Scott discovered a leak in the water system while preparing to chlorinate the water supply. The crew could not tell where it was coming from, and the issue had the potential to become serious. The experts in Houston found a solution, which was successfully implemented by the crew. The water was mopped up with towels, which were then put out to dry in the tunnel between the command module (CM) and Lunar Module---Scott stated it looked like someone\'s laundry.
At 073:31:14 into the mission, a second midcourse correction, with less than a second of burn, was made. Although there were four opportunities to make midcourse corrections following TLI, only two were needed. Apollo 15 approached the Moon on July 29, and the lunar orbit insertion (LOI) burn had to be made using the SPS, on the far side of the Moon, out of radio contact with Earth. If no burn occurred, Apollo 15 would emerge from the lunar shadow and come back in radio contact faster than expected; the continued lack of communication allowed Mission Control to conclude that the burn had taken place. When contact resumed, Scott did not immediately give the particulars of the burn, but spoke admiringly of the beauty of the Moon, causing Alan Shepard, the Apollo 14 commander, who was awaiting a television interview, to grumble, \"To hell with that shit, give us details of the burn.\" The 398.36-second burn took place at 078:31:46.7 into the mission at an altitude of 86.7 nmi above the Moon, and placed Apollo 15 in an elliptical lunar orbit of 170.1 by.
| 891 |
Apollo 15
| 6 |
1,969 |
## Mission highlights {#mission_highlights}
### Lunar orbit and landing {#lunar_orbit_and_landing}
thumb\|upright=1.2\|alt=Control panel of lunar lander\|The interior of *Falcon* thumb\|upright=1.2\|The Apollo 15 command and service module in lunar orbit, photographed from *Falcon* On Apollo 11 and 12, the Lunar Module decoupled from the CSM and was piloted to a much lower orbit from which the lunar landing attempt commenced; to save fuel in an increasingly heavy lander, beginning with Apollo 14, the SPS in the service module made that burn, known as descent orbit insertion (DOI), with the lunar module still attached to the CSM. The initial orbit Apollo 15 was in had its apocynthion, or high point, over the landing site at Hadley; a burn at the opposite point in the orbit was performed, with the result that Hadley would now be under the craft\'s pericynthion, or low point. The DOI burn was performed at 082:39:49.09 and took 24.53 seconds; the result was an orbit with apocynthion of 58.5 nmi and pericynthion of 9.6 nmi. Overnight between July 29 and 30, as the crew rested, it became apparent to Mission Control that mass concentrations in the Moon were making Apollo 15\'s orbit increasingly elliptical---pericynthion was 7.6 nmi by the time the crew was awakened on July 30. This, and uncertainty as to the exact altitude of the landing site, made it desirable that the orbit be modified, or trimmed. Using the craft\'s RCS thrusters, this took place at 095:56:44.70, lasting 30.40 seconds, and raised the pericynthion to 8.8 nmi and the apocynthion to 60.2 nmi.
As well as preparing the Lunar Module for its descent, the crew continued observations of the Moon (including of the landing site at Hadley) and provided television footage of the surface. Then, Scott and Irwin entered the Lunar Module in preparation for the landing attempt. Undocking was planned for 100:13:56, over the far side of the Moon, but nothing happened when separation was attempted. After analyzing the problem, the crew and Houston decided the probe instrumentation umbilical was likely loose or disconnected; Worden went into the tunnel connecting the command and lunar modules and determined this was so, seating it more firmly. With the problem resolved, *Falcon* separated from *Endeavour* at 100:39:16.2, about 25 minutes late, at an altitude of 5.8 nmi. Worden in *Endeavour* executed a SPS burn at 101:38:58.98 to send *Endeavour* to an orbit of 65.2 nmi by 54.8 nmi in preparation for his scientific work.
Aboard *Falcon*, Scott and Irwin prepared for powered descent initiation (PDI), the burn that was to place them on the lunar surface, and, after Mission Control gave them permission, they initiated PDI at 104:30:09.4 at an altitude of 5.8 nmi, slightly higher than planned. During the first part of the descent, *Falcon* was aligned so the astronauts were on their backs and thus could not see the lunar surface below them, but after the craft made a pitchover maneuver, they were upright and could see the surface in front of them. Scott, who as commander performed the landing, was confronted with a landscape that did not at first seem to resemble what he had seen during simulations. Part of this was due to an error in the landing path of some 3000 ft, of which CAPCOM Ed Mitchell informed the crew prior to pitchover; part because the craters Scott had relied on in the simulator were difficult to make out under lunar conditions, and he initially could not see Hadley Rille. He concluded that they were likely to overshoot the planned landing site, and, once he could see the rille, started maneuvering the vehicle to move the computer\'s landing target back towards the planned spot, and looked for a relatively smooth place to land.
thumb\|upright=1.2\|alt=Film showing the lunar surface as the lander descends to it\|Apollo 15 landing on the Moon at Hadley, seen from the perspective of the Lunar Module Pilot. Starts at about 5000 feet. Below about 60 ft, Scott could see nothing of the surface because of the quantities of lunar dust being displaced by *Falcon*{{\'s}} exhaust. *Falcon* had a larger engine bell than previous LMs, in part to accommodate a heavier load, and the importance of shutting down the engine at initial contact rather than risk \"blowback\", the exhaust reflecting off the lunar surface and going back into the engine (possibly causing an explosion) had been impressed on the astronauts by mission planners. Thus, when Irwin called \"Contact\", indicating that one of the probes on the landing leg extensions had touched the surface, Scott immediately shut off the engine, letting the lander fall the remaining distance to the surface. Already moving downward at about .5 ft per second, *Falcon* dropped from a height of 1.6 ft. Scott\'s speed resulted in what was likely the hardest lunar landing of any of the crewed missions, at about 6.8 ft per second, causing a startled Irwin to yell \"Bam!\" Scott had landed *Falcon* on the rim of a small crater he could not see, and the lander settled back at an angle of 6.9 degrees and to the left of 8.6 degrees. Irwin described it in his autobiography as the hardest landing he had ever been in, and he feared that the craft would keep tipping over, forcing an immediate abort.
*Falcon* landed at 104:42:29.3 (22:16:29 GMT on July 30), with approximately 103 seconds of fuel remaining, about 1800 ft from the planned landing site. After Irwin\'s exclamation, Scott reported, \"Okay, Houston. The *Falcon* is on the Plain at Hadley.\" Once within the planned landing zone, the increased mobility provided by the Lunar Roving Vehicle made unnecessary any further maneuvering.
| 934 |
Apollo 15
| 7 |
1,969 |
## Mission highlights {#mission_highlights}
### Lunar surface {#lunar_surface}
#### Stand-up EVA and first EVA {#stand_up_eva_and_first_eva}
With *Falcon* due to remain on the lunar surface for almost three days, Scott deemed it important to maintain the circadian rhythm they were used to, and as they had landed in the late afternoon, Houston time, the two astronauts were to sleep before going onto the surface. But the time schedule allowed Scott to open the lander\'s top hatch (usually used for docking) and spend a half hour looking at their surroundings, describing them, and taking photographs. Lee Silver had taught him the importance of going to a high place to survey a new field site, and the top hatch served that purpose. Deke Slayton and other managers were initially opposed due to the oxygen that would be lost, but Scott got his way. During the only stand-up extravehicular activity (EVA) ever performed through the LM\'s top hatch on the lunar surface, Scott was able to make plans for the following day\'s EVA. He offered Irwin a chance to look out as well, but this would have required rearranging the umbilicals connecting Irwin to *Falcon*{{\'s}} life support system, and he declined. After repressurizing the spacecraft, Scott and Irwin removed their space suits for sleep, becoming the first astronauts to doff their suits while on the Moon.
Throughout the sleep period Mission Control in Houston monitored a slow but steady oxygen loss. Scott and Irwin eventually were awakened an hour early, and the source of the problem was found to be an open valve on the urine transfer device. In post-mission debriefing, Scott recommended that future crews be woken at once under similar circumstances. After the problem was solved, the crew began preparation for the first Moon walk.
After donning their suits and depressurizing the cabin, Scott and Irwin began their first full EVA, becoming the seventh and eighth humans, respectively, to walk on the Moon. They began deploying the lunar rover, stored folded up in a compartment of *Falcon*{{\'s}} descent stage, but this proved troublesome due to the slant of the lander. The experts in Houston suggested lifting the front end of the rover as the astronauts pulled it out, and this worked. Scott began a system checkout. One of the batteries gave a zero voltage reading, but this was only an instrumentation problem. A greater concern was that the front wheel steering would not work. However, the rear wheel steering was sufficient to maneuver the vehicle. Completing his checkout, Scott said \"Okay. Out of detent; we\'re moving\", maneuvering the rover away from *Falcon* in mid-sentence. These were the first words uttered by a human while driving a vehicle on the Moon. The rover carried a television camera, controlled remotely from Houston by NASA\'s Ed Fendell. The resolution was not high compared to the still photographs that would be taken, but the camera allowed the geologists on Earth to indirectly participate in Scott and Irwin\'s activities.
The rille was not visible from the landing site, but as Scott and Irwin drove over the rolling terrain, it came into view. They were able to see Elbow crater, and they began to drive in that direction. Reaching Elbow, a known location, allowed Mission Control to backtrack and get closer to pinpointing the location of the lander. The astronauts took samples there, and then drove to another crater on the flank of Mons Hadley Delta, where they took more. After concluding this stop, they returned to the lander to drop off their samples and prepare to set up the Apollo Lunar Surface Experiments Package (ALSEP), the scientific instruments that would remain when they left. Scott had difficulty drilling the holes required for the heat flow experiment, and the work was not completed when they had to return to the lander. The first EVA lasted 6 hours and 32 minutes.
#### Second and third EVAs {#second_and_third_evas}
The rover\'s front steering, inoperative during the first EVA, worked during the second and third ones. The target of the second EVA, on August 1, was the slope of Mons Hadley Delta, where the pair sampled boulders and craters along the Apennine Front. They spent an hour at Spur crater, during which the astronauts collected a sample dubbed the Genesis Rock. This rock, an anorthosite, is believed to be part of the early lunar crust---the hope of finding such a specimen had been one reason the Hadley area had been chosen. Once back at the landing site, Scott continued to try to drill holes for experiments at the ALSEP site, with which he had struggled the day before. After conducting soil-mechanics experiments and raising the U.S. flag, Scott and Irwin returned to the LM. EVA 2 lasted 7 hours and 12 minutes.
Although Scott had eventually been successful at drilling the holes, he and Irwin had been unable to retrieve a core sample, and this was an early order of business during EVA 3, their third and final moonwalk. Time that could have been devoted to geology ticked away as Scott and Irwin attempted to pull it out. Once it had been retrieved, more time passed as they attempted to break the core into pieces for transport to Earth. Hampered by an incorrectly mounted vise on the rover, they eventually gave up on this---the core would be transported home with one segment longer than planned. Scott wondered if the core was worth the amount of time and effort invested, and the CAPCOM, Joe Allen, assured him it was. The core proved one of the most important items brought back from the Moon, revealing much about its history, but the expended time meant the planned visit to a group of hills known as the North Complex had to be scrubbed. Instead, the crew again ventured to the edge of Hadley Rille, this time to the northwest of the immediate landing site.
Once the astronauts were beside the LM, Scott used a kit provided by the Postal Service to cancel a first day cover of two stamps being issued on August 2, the current date. Scott then performed an experiment in view of the television camera, using a falcon feather and hammer to demonstrate Galileo\'s theory that all objects in a given gravity field fall at the same rate, regardless of mass, in the absence of aerodynamic drag. He dropped the hammer and feather at the same time; because of the negligible lunar atmosphere, there was no drag on the feather, which hit the ground at the same time as the hammer. This was Joe Allen\'s idea (he also served as CAPCOM during it) and was part of an effort to find a memorable popular science experiment to do on the Moon along the lines of Shepard\'s hitting of golf balls. The feather was most likely from a female gyrfalcon (a type of falcon), a mascot at the United States Air Force Academy.
Scott then drove the rover to a position away from the LM, where the television camera could be used to observe the lunar liftoff. Near the rover, he left a small aluminum statuette called *Fallen Astronaut*, along with a plaque bearing the names of 14 known American astronauts and Soviet cosmonauts who had died in the furtherance of space exploration. The memorial was left while the television camera was turned away; he told Mission Control he was doing some cleanup activities around the rover. Scott disclosed the memorial in a post-flight news conference. He also placed a Bible on the control panel of the rover before leaving it for the last time to enter the LM.
The EVA lasted 4 hours, 49 minutes and 50 seconds. In total, the two astronauts spent 18`{{frac|1|2}}`{=mediawiki} hours outside the LM and collected approximately 77 kg of lunar samples.
| 1,294 |
Apollo 15
| 8 |
1,969 |
## Mission highlights {#mission_highlights}
### Command module activities {#command_module_activities}
After the departure of *Falcon*, Worden in *Endeavour* executed a burn to take the CSM to a higher orbit. While *Falcon* was on the Moon, the mission effectively split, Worden and the CSM being assigned their own CAPCOM and flight support team.
thumb\|upright=1.3\|left\|alt=A spacecraft seen with the Moon in background\|*Endeavour*, with the SIM bay exposed, as seen from the Lunar Module *Falcon* Worden got busy with the tasks that were to occupy him for much of the time he spent in space alone: photography and operating the instruments in the SIM bay. The door to the SIM bay had been explosively jettisoned during the translunar coast. Filling previously unused space in the service module, the SIM bay contained a gamma-ray spectrometer, mounted on the end of a boom, an X-ray spectrometer and a laser altimeter, which failed part way through the mission. Two cameras, a stellar camera and a metric camera, together comprised the mapping camera, which was complemented by a panoramic camera, derived from spy technology. The altimeter and cameras permitted the exact time and location from which pictures were taken to be determined. Also present were an alpha particle spectrometer, which could be used to detect evidence of lunar volcanism, and a mass spectrometer, also on a boom in the hope it would be unaffected by contamination from the ship. The boom would prove troublesome, as Worden would not always be able to get it to retract.
*Endeavour* was slated to pass over the landing site at the moment of planned landing, but Worden could not see *Falcon* and did not spot it until a subsequent orbit. He also exercised to avoid muscle atrophy, and Houston kept him up to date on Scott and Irwin\'s activities on the lunar surface. The panoramic camera did not operate perfectly, but provided enough images that no special adjustment was made. Worden took many photographs through the command module\'s windows, often with shots taken at regular intervals. His task was complicated by the lack of a working mission timer in the Lower Equipment Bay of the command module, as its circuit breaker had popped en route to the Moon. Worden\'s observations and photographs would inform the decision to send Apollo 17 to Taurus-Littrow to search for evidence of volcanic activity. There was a communications blackout when the CSM passed over the far side of the Moon from Earth; Worden greeted each resumption of contact with the words, \"Hello, Earth. Greetings from *Endeavour*\", expressed in different languages. Worden and El-Baz had come up with the idea, and the geology instructor had aided the astronaut in accumulating translations.
Results from the SIM bay experiments would include the conclusion, from data gathered by the X-ray spectrometer, that there was greater fluorescent X-ray flux than anticipated, and that the lunar highlands were richer in aluminum than were the mares. *Endeavour* was in a more inclined orbit than previous crewed missions, and Worden saw features that were not known previously, supplementing photographs with thorough descriptions.
By the time Scott and Irwin were ready to take off from the lunar surface and return to *Endeavour*, the CSM\'s orbit had drifted due to the rotation of the Moon, and a plane change burn was required to ensure that the CSM\'s orbit would be in the same plane as that of the LM once it took off from the Moon. Worden accomplished the 18-second burn with the SPS.
| 577 |
Apollo 15
| 9 |
1,969 |
## Mission highlights {#mission_highlights}
### Return to Earth {#return_to_earth}
thumb \|alt=Video showing the lunar lander taking off\|The liftoff from the Moon as seen by the TV camera on the lunar rover *Main article: Return of Apollo 15 to Earth*
*Falcon* lifted off the Moon at 17:11:22 GMT on August 2 after 66 hours and 55 minutes on the lunar surface. Docking with the CSM took place just under two hours later. After the astronauts transferred samples and other items from the LM to the CSM, the LM was sealed off, jettisoned, and intentionally crashed into the lunar surface, an impact registered by the seismometers left by Apollo 12, 14 and 15. The jettison proved difficult because of problems getting airtight seals, requiring a delay in discarding the LM. After the jettison, Slayton came on the loop to recommend the astronauts take sleeping pills, or at least that Scott and Irwin do so. Scott as mission commander refused to allow it, feeling there was no need. During the EVAs, the doctors had noticed irregularities in both Scott\'s and Irwin\'s heartbeats, but the crew were not informed during the flight. Irwin had heart problems after retiring as an astronaut and died in 1991 of a heart attack; Scott felt that he as commander should have been informed of the biomedical readings. NASA doctors at the time theorized the heart readings were due to potassium deficiency, due to their hard work on the surface and inadequate resupply through liquids.
The crew spent the next two days working on orbital science experiments, including more observations of the Moon from orbit and releasing the subsatellite. *Endeavour* departed lunar orbit with another burn of the SPS engine of 2 minutes 21 seconds at 21:22:45 GMT on August 4. The next day, during the return to Earth, Worden performed a 39-minute EVA to retrieve film cassettes from the service module\'s scientific instrument module (SIM) bay, with assistance from Irwin who remained at the command module\'s hatch. At approximately 171,000 nautical miles (197,000 mi; 317,000 km) from Earth, it was the first \"deep space\" EVA in history, performed at great distance from any planetary body. As of `{{year}}`{=mediawiki}, it remains one of only three such EVAs, all performed during Apollo\'s J missions under similar circumstances. Later that day, the crew set a record for the longest Apollo flight to that point.
On approach to Earth on August 7, the service module was jettisoned, and the command module reentered the Earth\'s atmosphere. Although one of the three parachutes on the CM failed after deploying, likely due to damage as the spacecraft vented fuel, only two were required for a safe landing (one extra for redundancy). Upon landing in the North Pacific Ocean, the CM and crew were recovered and taken aboard the recovery ship, `{{USS|Okinawa|LPH-3|6}}`{=mediawiki}, after a mission lasting 12 days, 7 hours, 11 minutes and 53 seconds.
| 479 |
Apollo 15
| 10 |
1,969 |
## Assessment
The mission objectives for Apollo 15 were to \"perform selenological inspection, survey, and sampling of materials and surface features in a pre-selected area of the Hadley--Apennine region. Emplace and activate surface experiments. Evaluate the capability of the Apollo equipment to provide extended lunar surface stay time, increased extravehicular operations, and surface mobility. \[and\] Conduct inflight experiments and photographic tasks from lunar orbit.\" It achieved all those objectives. The mission also completed a long list of other tasks, including experiments. One of the photographic objectives, to obtain images of the gegenschein from lunar orbit, was not completed, as the camera was not pointed at the proper spot in the sky. According to the conclusions in the *Apollo 15 Mission Report*, the journey \"was the fourth lunar landing and resulted in the collection of a wealth of scientific information. The Apollo system, in addition to providing a means of transportation, excelled as an operational scientific facility.\"
Apollo 15 saw an increase in public interest in the Apollo program, in part due to fascination with the LRV, as well as the attractiveness of the Hadley Rille site and the increased television coverage. According to David Woods in the *Apollo Lunar Flight Journal*, `{{blockquote|
Though subsequent missions travelled further on the Moon, brought back more samples and put the lessons of Apollo 15 into practice, this feat of unalloyed exploration still stands out as a great moment of human achievement. It is remembered still for its combination of competent enthusiasm, magnificent machinery, finely honed science and the grandeur of a very special site in the cosmos beside a meandering rille and graceful, massive mountains – Hadley Base.<ref group=ALFJ name=summary />
}}`{=mediawiki}
| 279 |
Apollo 15
| 11 |
1,969 |
## Controversies
Further information: Apollo 15 postal covers incident
Despite the successful mission, the careers of the crew were tarnished by a deal they had made before the flight to carry postal covers to the Moon in exchange for about \$7,000 each, which they planned to set aside for their children. Walter Eiermann, who had many professional and social contacts with NASA employees and the astronaut corps, served as intermediary between the astronauts and a West German stamp dealer, Hermann Sieger, and Scott carried about 400 covers onto the spacecraft; they were subsequently transferred into *Falcon* and remained inside the lander during the astronauts\' activities on the surface of the Moon. After the return to Earth, 100 of the covers were given to Eiermann, who passed them on to Sieger, receiving a commission. No permission had been received from Slayton to carry the covers, as required.
The 100 covers were put on sale to Sieger\'s customers in late 1971 at a price of about \$1,500 each. After receiving the agreed payments, the astronauts returned them, and accepted no compensation. In April 1972, Slayton learned that unauthorized covers had been carried, and removed the three as the backup crew for Apollo 17. The matter became public in June 1972 and the three astronauts were reprimanded for poor judgment; none ever flew in space again. During the investigation, the astronauts had surrendered those covers still in their possession; after Worden filed suit, they were returned in 1983, something *Slate* magazine deemed an exoneration.
Another controversy arose later, this time surrounding the *Fallen Astronaut* statuette that Scott had left on the Moon. Before the mission, Scott had made a verbal agreement with Belgian artist Paul Van Hoeydonck to sculpt the statuette. Scott\'s intent, in keeping with NASA\'s strict policy against commercial exploitation of the US government\'s space program, was for a simple memorial with a minimum of publicity, keeping the artist anonymous, no commercial replicas being made except for a single copy for public exhibit at the National Air and Space Museum commissioned after the sculpture\'s public disclosure during the post-flight press conference. Van Hoeydonck claims to have had a different understanding of the agreement, by which he would have received recognition as the creator of a tribute to human space exploration, with rights to sell replicas to the public. Under pressure from NASA, Van Hoeydonck canceled a plan to publicly sell 950 signed copies.
In 2021, Scott published a document entitled \"Memorandum for the Record\", in which he stated that the figurine left on the Moon was designed and fabricated by NASA personnel. While testifying before a Senate committee in 1972, he had stated that the figurine had been made and provided by Van Hoeydonck at Scott\'s request.
During those congressional hearings into the postal covers and Fallen Astronaut matters, two Bulova timepieces taken on the mission by Scott were also matters of controversy. Before the mission, Scott had been introduced to Bulova\'s representative, General James McCormack by Apollo 8 commander Frank Borman. Bulova had been seeking to have its timepieces taken on Apollo missions, but after evaluation, NASA had selected Omega watches instead. Scott brought the Bulova timepieces on the mission, without disclosing them to Slayton. During Scott\'s second EVA, the crystal on his NASA standard issue Omega Speedmaster watch popped off, and, during the third EVA, he used a Bulova watch. The Bulova Chronograph Model #88510/01 that Scott wore on the lunar surface was a prototype, given to him by the Bulova Company, and it is the only privately owned watch to have been worn while walking on the lunar surface. There are images of him wearing this watch, when he saluted the American flag on the Moon, with the Hadley Delta expanse in the background. In 2015, the watch sold for \$1.625 million, which makes it one of the most expensive astronaut-owned artifact ever sold at auction and one of the most expensive watches sold at auction.
## Mission insignia {#mission_insignia}
The Apollo 15 mission patch carries Air Force motifs, a nod to the crew\'s service there, just as the Apollo 12 all-Navy crew\'s patch had featured a sailing ship. The circular patch features stylized red, white and blue birds flying over Hadley Rille. Immediately behind the birds, a line of craters forms the Roman numeral XV. The Roman numerals were hidden in emphasized outlines of some craters after NASA insisted that the mission number be displayed in Arabic numerals. The artwork is circled in red, with a white band giving the mission and crew names and a blue border. Scott contacted fashion designer Emilio Pucci to design the patch, who came up with the basic idea of the three-bird motif on a square patch.
The crew changed the shape to round and the colors from blues and greens to a patriotic red, white and blue. Worden stated that each bird also represented an astronaut, white being his own color (and as Command Module Pilot, uppermost), Scott being the blue bird and Irwin the red. The colors matched Chevrolet Corvettes leased by the astronauts at KSC; a Florida car dealer had, since the time of Project Mercury, been leasing Chevrolets to astronauts for \$1 and later selling them to the public. The astronauts were photographed with the cars and the training LRV for the June 11, 1971, edition of *Life* magazine.
| 892 |
Apollo 15
| 12 |
1,969 |
## Visibility from space {#visibility_from_space}
The halo area of the Apollo 15 landing site, created by the LM\'s exhaust plume, was observed by a camera aboard the Japanese lunar orbiter SELENE and confirmed by comparative analysis of photographs in May 2008. This corresponds well to photographs taken from the Apollo 15 command module showing a change in surface reflectivity due to the plume, and was the first visible trace of crewed landings on the Moon seen from space since the close of the Apollo program.
## Gallery
### Still images {#still_images}
<File:Apollo> 15 rollout from VAB.jpg\|alt=A rocket on a launchpad\|The Apollo 15 launch vehicle during rollout <File:Jim> Irwin (left) Al Worden, and Dave Scott pose in front of the VAB during the Saturn V roll-out.jpg\|alt=Three men stand in front of a rocket\|The astronauts pose before the VAB as the Saturn V is rolled out <File:Al> Worden, Dave Scott, Deke Slayton, and Jack Schmitt dig into the pre-launch breakfast.jpg\|alt=Several men at a sit-down breakfast\|Worden, Scott, Slayton and Schmitt eat the pre-launch breakfast <File:Falcon> lunar module on the Moon.jpg\|alt=A lunar landscape with a lander in the background\|*Falcon* on the Moon. Note the slant of the vehicle <File:Apollo> 15 Station 2 Rille, Lunar Rover, Scott.jpg\|alt=Lunar landscape with man leaning over rover\|Scott does geology work near Hadley Rille <File:Apollo> 15 Dave Scott at St. 9a.jpg\|alt=A man in a spacesuit leans over a large rock\|Scott examines a boulder during the third EVA <File:A15.s74> 41836.jpg\|alt=A control room; visible on a large screen are two astronauts walking on the Moon\|Mission Control in Houston during the third Apollo 15 EVA, August 2, 1971. CAPCOM Joe Allen is to left (pointing) with Dick Gordon next to him. <File:S71-41759.jpg%7Calt=Several> rows of consoles. A large screen showed a lunar lander\|Mission Control in Houston as *Falcon* takes off from the Moon <File:Worden> podczas EVA S71-43202.jpg\|alt=A man in a spacesuit floating beside a spacecraft\|Alfred Worden in space suit retrieving film cartridges during the transearth coast <File:S71-42825.jpg%7Calt=Three> men in flight suits disembark a helicopter\|The astronauts disembark their helicopter aboard the *Okinawa* <File:Moon> AS15-M-2778.jpg\|alt=The Moon\|The Moon as seen from the departing Apollo 15 spacecraft <File:Stafford> Air & Space Museum, Weatherford, OK, US (60).jpg\|alt=A plaque to be left on the lander\|Backup of the plaque left on *Falcon*{{\'s}} descent stage <File:Apollo> 15 Command Module at the National Museum of the United States Air Force.jpg\|alt=A spaceship on display\|Command Module *Endeavour* on display at the National Museum of the United States Air Force in Dayton, Ohio <File:Apollo> 15 Space Suit David Scott.jpg\|The spacesuit David Scott wore during the Apollo 15 mission is on display at the National Air and Space Museum, Washington, D.C.
### Multimedia
<File:Apollo> 15 CSM moving away from LM.ogv \|alt=Film of a spacecraft in space\|*Endeavour* filmed from *Falcon* after undocking <File:Apollo> 15 Lunar Roving Vehicle deployment.webm\|alt=The lunar rover is set up\|Deployment of the lunar rover on the Moon <File:Apollo> 15 liftoff from inside LM.ogv\|alt=A spacecraft takes off from the Moon\|Liftoff from the Moon, seen through the LMP\'s window as Scott and Irwin play a prerecorded instrumental version of the song \"The U.S. Air Force\", commonly known as \"Wild Blue Yonder\". <File:Apollo> 15 splashdown
| 517 |
Apollo 15
| 13 |
1,974 | 0 |
April 17
| 0 |
|
2,003 |
The **argument from morality** is an argument for the existence of God. Arguments from morality tend to be based on moral normativity or moral order. Arguments from moral normativity observe some aspect of morality and argue that God is the best or only explanation for this, concluding that God must exist. Arguments from moral order are based on the asserted need for moral order to exist in the universe. They claim that, for this moral order to exist, God must exist to support it. The argument from morality is noteworthy in that one cannot evaluate the soundness of the argument without attending to almost every important philosophical issue in meta-ethics.
German philosopher Immanuel Kant devised an argument from morality based on practical reason. Kant argued that the goal of humanity is to achieve perfect happiness and virtue (the *summum bonum*) and believed that an afterlife must be assumed to exist in order for this to be possible, and that God must be assumed to exist to provide this. Rather than aiming to prove the existence of God, however, Kant was simply attempting to demonstrate that all moral thought requires the assumption that God exists, and therefore that we are entitled to make such an assumption only as a regulative principle rather than a constitutive principle (meaning that such a principle can guide our actions, but it does not provide knowledge). In his book *Mere Christianity*, C. S. Lewis argued that \"conscience reveals to us a moral law whose source cannot be found in the natural world, thus pointing to a supernatural Lawgiver.\" Lewis argued that accepting the validity of human reason as a given must include accepting the validity of practical reason, which could not be valid without reference to a higher cosmic moral order which could not exist without a God to create and/or establish it. A related argument is from conscience; John Henry Newman argued that the conscience supports the claim that objective moral truths exist because it drives people to act morally even when it is not in their own interest. Newman argued that, because the conscience suggests the existence of objective moral truths, God must exist to give authority to these truths.
Contemporary defenders of the argument from morality are Graham Ward, Alister McGrath and William Lane Craig.
| 382 |
Argument from morality
| 0 |
2,003 |
## General form {#general_form}
All variations of the argument from morality begin with an observation about moral thought or experiences and conclude with the existence of God. Some of these arguments propose moral facts which they claim evident through human experience, arguing that God is the best explanation for these. Other versions describe some end which humans should strive to attain that is only possible if God exists.
Many arguments from morality are based on moral normativity, which suggests that objective moral truths exist and require God\'s existence to give them authority. Often, they consider that morality seems to be binding -- obligations are seen to convey more than just a preference, but imply that the obligation will stand, regardless of other factors or interests. For morality to be binding, God must exist. In its most general form, the argument from moral normativity is:
1. A human experience of morality is observed.
2. God is the best or only explanation for this moral experience.
3. Therefore, God exists.`{{Failed verification|date=April 2020}}`{=mediawiki}
Some arguments from moral order suggest that morality is based on rationality and that this can only be the case if there is a moral order in the universe. The arguments propose that only the existence of God as orthodoxly conceived could support the existence of moral order in the universe, so God must exist. Alternative arguments from moral order have proposed that we have an obligation to attain the perfect good of both happiness and moral virtue. They attest that whatever we are obliged to do must be possible, and achieving the perfect good of both happiness and moral virtue is only possible if a natural moral order exists. A natural moral order requires the existence of God as orthodoxly conceived, so God must exist.
| 296 |
Argument from morality
| 1 |
2,003 |
## Variations
### Practical reason {#practical_reason}
In his *Critique of Pure Reason*, German philosopher Immanuel Kant stated that no successful argument for God\'s existence arises from reason alone. In his *Critique of Practical Reason* he went on to argue that, despite the failure of these arguments, morality requires that God\'s existence is assumed, owing to practical reason. Rather than proving the existence of God, Kant was attempting to demonstrate that all moral thought requires the assumption that God exists. Kant argued that humans are obliged to bring about the *summum bonum*: the two central aims of moral virtue and happiness, where happiness arises out of virtue. As ought implies can, Kant argued, it must be possible for the *summum bonum* to be achieved. He accepted that it is not within the power of humans to bring the *summum bonum* about, because we cannot ensure that virtue always leads to happiness, so there must be a higher power who has the power to create an afterlife where virtue can be rewarded by happiness.
Philosopher G. H. R. Parkinson notes a common objection to Kant\'s argument: that what ought to be done does not necessarily entail that it is possible. He also argues that alternative conceptions of morality exist which do not rely on the assumptions that Kant makes -- he cites utilitarianism as an example which does not require the *summum bonum*. Nicholas Everitt argues that much moral guidance is unattainable, such as the Biblical command to be Christ-like. He proposes that Kant\'s first two premises only entail that we must try to achieve the perfect good, not that it is actually attainable.
### Argument from objective moral truths {#argument_from_objective_moral_truths}
Both theists and non-theists have accepted that the existence of objective moral truths might entail the existence of God. Atheist philosopher J. L. Mackie accepted that, if objective moral truths existed, they would warrant a supernatural explanation. Scottish philosopher W. R. Sorley presented the following argument:
1. If morality is objective and absolute, God must exist.
2. Morality is objective and absolute.
3. Therefore, God must exist.
Many critics have challenged the second premise of this argument, by offering a biological and sociological account of the development of human morality which suggests that it is neither objective nor absolute. This account, supported by biologist E. O. Wilson and philosopher Michael Ruse, proposes that the human experience of morality is a by-product of natural selection, a theory philosopher Mark D. Linville calls evolutionary naturalism. According to the theory, the human experience of moral obligations was the result of evolutionary pressures, which attached a sense of morality to human psychology because it was useful for moral development; this entails that moral values do not exist independently of the human mind. Morality might be better understood as an evolutionary imperative in order to propagate genes and ultimately reproduce. No human society today advocates immorality, such as theft or murder, because it would undoubtedly lead to the end of that particular society and any chance for future survival of offspring. Scottish empiricist David Hume made a similar argument, that belief in objective moral truths is unwarranted and to discuss them is meaningless.
Because evolutionary naturalism proposes an empirical account of morality, it does not require morality to exist objectively; Linville considers the view that this will lead to moral scepticism or antirealism. C. S. Lewis argued that, if evolutionary naturalism is accepted, human morality cannot be described as absolute and objective because moral statements cannot be right or wrong. Despite this, Lewis argued, those who accept evolutionary naturalism still act as if objective moral truths exist, leading Lewis to reject naturalism as incoherent. As an alternative ethical theory, Lewis offered a form of divine command theory which equated God with goodness and treated goodness as an essential part of reality, thus asserting God\'s existence.
J. C. A. Gaskin challenges the first premise of the argument from moral objectivity, arguing that it must be shown why absolute and objective morality entails that morality is commanded by God, rather than simply a human invention. It could be the consent of humanity that gives it moral force, for example. American philosopher Michael Martin argues that it is not necessarily true that objective moral truths must entail the existence of God, suggesting that there could be alternative explanations: he argues that naturalism may be an acceptable explanation and, even if a supernatural explanation is necessary, it does not have to be God (polytheism is a viable alternative). Martin also argues that a non-objective account of ethics might be acceptable and challenges the view that a subjective account of morality would lead to moral anarchy.
William Lane Craig has argued for this form of the moral argument.
### Argument for conscience {#argument_for_conscience}
Related to the argument from morality is the argument from conscience, associated with eighteenth-century bishop Joseph Butler and nineteenth-century cardinal John Henry Newman. Newman proposed that the conscience, as well as giving moral guidance, provides evidence of objective moral truths which must be supported by the divine. He argued that emotivism is an inadequate explanation of the human experience of morality because people avoid acting immorally, even when it might be in their interests. Newman proposed that, to explain the conscience, God must exist.
British philosopher John Locke argued that moral rules cannot be established from conscience because the differences in people\'s consciences would lead to contradictions. Locke also noted that the conscience is influenced by \"education, company, and customs of the country\", a criticism mounted by J. L. Mackie, who argued that the conscience should be seen as an \"introjection\" of other people into an agent\'s mind. Michael Martin challenges the argument from conscience with a naturalistic account of conscience, arguing that naturalism provides an adequate explanation for the conscience without the need for God\'s existence. He uses the example of the internalization by humans of social pressures, which leads to the fear of going against these norms. Even if a supernatural cause is required, he argues, it could be something other than God; this would mean that the phenomenon of the conscience is no more supportive of monotheism than polytheism.
C. S. Lewis argues for the existence of God in a similar way in his book *Mere Christianity*, but he does not directly refer to it as the argument from morality
| 1,055 |
Argument from morality
| 2 |
2,009 |
**Hugo Alvar Henrik Aalto** (`{{IPA|fi|ˈhuːɡo ˈɑlʋɑr ˈhenrik ˈɑːlto|lang}}`{=mediawiki}; 3 February 1898 -- 11 May 1976) was a Finnish architect and designer. His work includes architecture, furniture, textiles and glassware, as well as sculptures and paintings. He never regarded himself as an artist, seeing painting and sculpture as \"branches of the tree whose trunk is architecture.\" Aalto\'s early career ran in parallel with the rapid economic growth and industrialization of Finland during the first half of the 20th century. Many of his clients were industrialists, among them the Ahlström-Gullichsen family, who became his patrons. The span of his career, from the 1920s to the 1970s, is reflected in the styles of his work, ranging from Nordic Classicism of the early work, to a rational International Style Modernism during the 1930s to a more organic modernist style from the 1940s onwards.
His architectural work, throughout his entire career, is characterized by a concern for design as Gesamtkunstwerk---a *total work of art* in which he, together with his first wife Aino Aalto, would design not only the building but the interior surfaces, furniture, lamps, and glassware as well. His furniture designs are considered Scandinavian Modern, an aesthetic reflected in their elegant simplification and concern for materials, especially wood, but also in Aalto\'s technical innovations, which led him to receiving patents for various manufacturing processes, such as those used to produce bent wood. As a designer he is celebrated as a forerunner of midcentury modernism in design; his invention of bent plywood furniture had a profound impact on the aesthetics of Charles and Ray Eames and George Nelson. The Alvar Aalto Museum, designed by Aalto himself, is located in what is regarded as his home city, Jyväskylä.
The entry for him on the Museum of Modern Art website notes his \"remarkable synthesis of romantic and pragmatic ideas,\" adding
> His work reflects a deep desire to humanize architecture through an unorthodox handling of form and materials that was both rational and intuitive. Influenced by the so-called International Style modernism (or functionalism, as it was called in Finland) and his acquaintance with leading modernists in Europe, including Swedish architect Erik Gunnar Asplund and many of the artists and architects associated with the Bauhaus, Aalto created designs that had a profound impact on the trajectory of modernism before and after World War II.
| 387 |
Alvar Aalto
| 0 |
2,009 |
## Biography
### Life
Hugo Alvar Henrik Aalto was born in Kuortane, Finland. His father, Johan Henrik Aalto, was a Finnish-speaking land-surveyor and his mother, Selma Matilda \"Selly\" (née Hackstedt) was a Swedish-speaking postmistress. When Aalto was 5 years old, the family moved to Alajärvi, and from there to Jyväskylä in Central Finland.
He studied at the Jyväskylä Lyceum school, where he completed his basic education in 1916, and took drawing lessons from local artist Jonas Heiska. In 1916, he then enrolled to study architecture at the Helsinki University of Technology. His studies were interrupted by the Finnish Civil War, in which he fought. He fought on the side of the *White Army* and fought at the Battle of Länkipohja and the Battle of Tampere.
He built his first piece of architecture while a student; a house for his parents at Alajärvi. Later, he continued his education, graduating in 1921. In the summer of 1922 he began military service, finishing at Hamina reserve officer training school, and was promoted to reserve second lieutenant in June 1923.
In 1920, while a student, Aalto made his first trip abroad, travelling via Stockholm to Gothenburg, where he briefly found work with architect Arvid Bjerke. In 1922, he accomplished his first independent piece at the Industrial Exposition in Tampere. In 1923, he returned to Jyväskylä, where he opened an architectural office under the name \'Alvar Aalto, Architect and Monumental Artist\'. At that time he wrote articles for the Jyväskylä newspaper *Sisä-Suomi* under the pseudonym Remus. During this time, he designed a number of small single-family houses in Jyväskylä, and the office\'s workload steadily increased.
On 6 October 1924, Aalto married architect Aino Marsio. Their honeymoon in Italy was Aalto\'s first trip there, though Aino had previously made a study trip there. The latter trip together sealed an intellectual bond with the culture of the Mediterranean region that remained important to Aalto for life.
On their return they continued with several local projects, notably the Jyväskylä Worker\'s Club, which incorporated a number of motifs which they had studied during their trip, most notably the decorations of the Festival hall modelled on the Rucellai Sepulchre in Florence by Leon Battista Alberti. After winning the architecture competition for the Southwest Finland Agricultural Cooperative building in 1927, the Aaltos moved their office to Turku. They had made contact with the city\'s most progressive architect, Erik Bryggman before moving. They began collaborating with him, most notably on the Turku Fair of 1928--29. Aalto\'s biographer, Göran Schildt, claimed that Bryggman was the only architect with whom Aalto cooperated as an equal. With an increasing quantity of work in the Finnish capital, the Aaltos\' office moved again in 1933 to Helsinki.
The Aaltos designed and built a joint house-office (1935--36) for themselves in Munkkiniemi, Helsinki, but later (1954--56) had a purpose-built office erected in the same neighbourhood -- now the former is a \"home museum\" and the latter the premises of the Alvar Aalto Academy. In 1926, the young Aaltos designed and had built for themselves a summer cottage in Alajärvi, Villa Flora.
Aino and Alvar had two children, a daughter, Johanna \"Hanni\" (married surname Alanen; born 1925), and a son, Hamilkar Aalto (born 1928). Aino Aalto died of cancer in 1949.
In 1952, Aalto married architect Elissa Mäkiniemi (died 1994). In 1952, he designed and built a summer cottage, the so-called Experimental House, for himself and his second wife, now Elissa Aalto, in Muuratsalo in Central Finland. Alvar Aalto died on 11 May 1976, in Helsinki, and is buried in the Hietaniemi cemetery in Helsinki. Elissa Aalto became the director of the practice, running the office from 1976 to 1994. In 1978, the Museum of Finnish Architecture in Helsinki arranged a major exhibition of Aalto\'s works.
| 626 |
Alvar Aalto
| 1 |
2,009 |
## Architecture career {#architecture_career}
### Early career: classicism {#early_career_classicism}
Although he is sometimes regarded as among the first and most influential architects of Nordic modernism, closer examination reveals that Aalto (while a pioneer in Finland) closely followed and had personal contacts with other pioneers in Sweden, in particular Gunnar Asplund and Sven Markelius. What they and many others of that generation in the Nordic countries shared was a classical education and an approach to classical architecture that historians now call Nordic Classicism. It was a style that had been a reaction to the previous dominant style of National Romanticism before moving, in the late 1920s, towards Modernism.
Upon returning to Jyväskylä in 1923 to establish his own architect\'s office, Aalto designed several single-family homes designed in the style of Nordic Classicism. For example, the manor-like house for his mother\'s cousin Terho Manner in Töysa (1923), a summer villa for the Jyväskylä chief constable (also from 1923) and the Alatalo farmhouse in Tarvaala (1924). During this period he completed his first public buildings, the Jyväskylä Workers\' Club in 1925, the Jyväskylä Defence Corps Building in 1926 and the Seinäjoki Civil Guard House building in 1924--29. He entered several architectural competitions for prestigious state public buildings, in Finland and abroad. This included two competitions for the Finnish Parliament building in 1923 and 1924, the extension to the University of Helsinki in 1931, and the building to house the League of Nations in Geneva, Switzerland, in 1926--27.
Aalto\'s first church design to be completed, Muurame church, illustrates his transition from Nordic Classicism to Functionalism.
This was the period when Aalto was most prolific in his writings, with articles for professional journals and newspapers. Among his most well-known essays from this period are \"Urban culture\" (1924), \"Temple baths on Jyväskylä ridge\" (1925), \"Abbé Coignard\'s sermon\" (1925), and \"From doorstep to living room\" (1926).
### Early career: functionalism {#early_career_functionalism}
The shift in Aalto\'s design approach from classicism to modernism is epitomised by the Viipuri Library in Vyborg (1927--35), which went through a transformation from an originally classical competition entry proposal to the completed high-modernist building. His humanistic approach is in full evidence in the library: the interior displays natural materials, warm colours, and undulating lines. Due to problems related to financing, compounded by a change of site, the Viipuri Library project lasted eight years. During that time, Aalto designed the Standard Apartment Building (1928--29) in Turku, the Turun Sanomat Building (1929--30), and the Paimio Sanatorium (1929--32), which he designed in collaboration with his first wife Aino Aalto. A number of factors contributed to Aalto\'s shift towards modernism: his increased familiarity with international trends, facilitated by his travels throughout Europe; the opportunity to experiment with concrete prefabrication in the Standard Apartment Building; the cutting-edge Le Corbusier-inspired formal language of the Turun Sanomat Building; and Aalto\'s application of both in the Paimio Sanatorium and in the ongoing design for the library. Although the Turun Sanomat Building and Paimio Sanatorium are comparatively pure modernist works, they carried the seeds of his questioning of such an orthodox modernist approach and a move to a more daring, synthetic attitude. It has been pointed out that the planning principle for Paimio Sanatorium -- the splayed wings -- was indebted to the Zonnestraal Sanatorium (1925--31) by Jan Duiker, which Aalto visited while it was under construction. While these early Functionalist bear hallmarks of influences from Le Corbusier, Walter Gropius, and other key modernist figures of central Europe, Aalto nevertheless started to show his individuality in a departure from such norms with the introduction of organic references.
Through Sven Markelius, Aalto became a member of the Congres Internationaux d\'Architecture Moderne (CIAM), attending the second congress in Frankfurt in 1929 and the fourth congress in Athens in 1933, where he established a close friendship with László Moholy-Nagy, Sigfried Giedion, and Philip Morton Shand. It was during this time that he closely followed the work of the main force driving the new modernism, Le Corbusier, visiting him in his Paris office several times in the following years.
It was not until the completion of the Paimio Sanatorium (1932) and Viipuri Library (1935) that Aalto first achieved world attention in architecture. His reputation grew in the US following the invitation to hold a retrospective exhibition of his works at MOMA in New York in 1938. (This was his first visit to the States.) The exhibition, which later went on a 12-city tour of the country, was a landmark: Aalto was the second-ever architect -- after Le Corbusier -- to have a solo exhibition at the museum. His reputation grew in the US following the critical reception of his design for the Finnish Pavilion at the 1939 New York World\'s Fair, described by Frank Lloyd Wright as a \"work of genius\". It could be said that Aalto\'s international reputation was sealed with his inclusion in the second edition of Sigfried Giedion\'s influential book on Modernist architecture, *Space, Time, and Architecture: The growth of a new tradition* (1949), in which Aalto received more attention than any other Modernist architect, including Le Corbusier. In his analysis of Aalto, Giedion gave primacy to qualities that depart from direct functionality, such as mood, atmosphere, intensity of life, and even national characteristics, declaring that \"Finland is with Aalto wherever he goes.\"
| 879 |
Alvar Aalto
| 2 |
2,009 |
## Architecture career {#architecture_career}
### Mid career: experimentation {#mid_career_experimentation}
During the 1930s Alvar spent some time experimenting with laminated wood, sculpture and abstract relief, characterized by irregular curved forms. Utilizing this knowledge, he was able to solve technical problems concerning the flexibility of wood while at the same time working out spatial issues in his designs. Aalto\'s early experiments with wood and his move away from a purist modernism would be tested in built form with the commission to design Villa Mairea (1939) in Noormarkku, the luxury home of young industrialist couple Harry and Maire Gullichsen. It was Maire Gullichsen who acted as the main client, and she worked closely not only with Alvar but also with Aino Aalto on the design, encouraging them to be more daring in their work. The building forms a U-shape around a central inner \'garden\' whose central feature is a kidney-shaped swimming pool. Adjacent to the pool is a sauna executed in a rustic style, alluding to both Finnish and Japanese precedents. The design of the house is a synthesis of numerous stylistic influences, from traditional Finnish vernacular to purist modernism, as well as influences from English and Japanese architecture. While the house is clearly intended for a wealthy family, Aalto nevertheless argued that it was also an experiment that would prove useful in the design of mass housing.
His increased fame led to offers and commissions outside Finland. In 1941, he accepted an invitation as a visiting professor to the Massachusetts Institute of Technology in the US. During the Second World War, he returned to Finland to direct the Reconstruction Office. After the war, he returned to MIT, where he designed the student dormitory Baker House, completed in 1949. The dormitory flanked the Charles River, and its undulating form provided maximum view and ventilation for each resident. This was the first building of Aalto\'s redbrick period. Originally used in Baker House to signify the Ivy League university tradition, Aalto went on to use it in a number of key buildings after his return to Finland, most notably in several of the buildings in the new Helsinki University of Technology campus (starting in 1950), Säynätsalo Town Hall (1952), Helsinki Pensions Institute (1954), Helsinki House of Culture (1958), as well as in his own summer house, the Experimental House in Muuratsalo (1957).
In the 1950s Aalto immersed himself in sculpting, exploring wood, bronze, marble, and mixed media. Among the notable works from this period is his 1960 memorial to the Battle of Suomussalmi. Located on the battlefield, it consists of a leaning bronze pillar on a pedestal.
| 432 |
Alvar Aalto
| 3 |
2,009 |
## Architecture career {#architecture_career}
### Mature career: monumentalism {#mature_career_monumentalism}
Foremost among Aalto\'s work from the early 1960s until his death in 1976 were his projects in Helsinki, in particular the huge town plan for the void in the centre of Helsinki adjacent to Töölö Bay and the vast railway yards, an area marked on the edges by significant buildings such as the National Museum and the main railway station, both by Eliel Saarinen. In his town plan, Aalto proposed a line of separate marble-clad buildings fronting the bay, which would house various cultural institutions, including a concert hall, opera, museum of architecture, and headquarters for the Finnish Academy. The scheme also extended into the Kamppi district with a series of tall office blocks. Aalto first presented his vision in 1961, but it went through various modifications during the early \'60s. Only two fragments of the overall plan were realized: the Finlandia Hall concert hall (1976) fronting on Töölö Bay and an office building in the Kamppi district for the Helsinki Electricity Company (1975). Aalto also employed the Miesian formal language of geometric grids used in those buildings for other sites in Helsinki, including the Enso-Gutzeit headquarters building (1962), the Academic Bookstore (1962), and the SYP Bank building (1969).
Following Aalto\'s death in 1976, his office continued to operate under the direction of his widow Elissa, who oversaw the completion of works already designed (to some extent), among them the Jyväskylä City Theatre and Essen opera house. Since the death of Elissa Aalto, the office has continued to operate as the Alvar Aalto Academy, giving advice on the restoration of Aalto buildings and organizing the practice\'s vast archives.
| 277 |
Alvar Aalto
| 4 |
2,009 |
## Furniture career {#furniture_career}
Although Aalto was famous for his architecture, his furniture designs were admired and are still popular today. He studied with the architect-designer Josef Hoffmann at the Wiener Werkstätte(engl.: \"Vienna Workshop\") and worked, for a time, under Eliel Saarinen. He also drew inspiration from Gebrüder Thonet. During the late 1920s and 1930s, he worked closely with Aino Aalto on his furniture designs, a focus due in part to his decision to design many of the individual furniture pieces and lamps for the Paimio Sanatorium. Of particular significance was the Aaltos\' experimentation in bent plywood chairs, most notably the so-called Paimio chair, designed for tuberculosis patients, and the Model 60 stacking stool. The Aaltos, together with visual arts promoter Maire Gullichsen and art historian Nils-Gustav Hahl, founded the Artek company in 1935, ostensibly to sell Aalto products but which also imported pieces by other designers. Aalto became the first furniture designer to use the cantilever principle in chair designs using wood.
## Awards
Aalto\'s awards included Honorary Royal Designer for Industry from the Royal Society of Arts in 1947, the Prince Eugen Medal in 1954, the Royal Gold Medal for Architecture from the Royal Institute of British Architects in 1957 and the Gold Medal from the American Institute of Architects in 1963. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1957. He also was a member of the Academy of Finland, and was its president from 1963 to 1968. From 1925 to 1956 he was a member of the Congrès International d\'Architecture Moderne. In 1960 he received an honorary doctorate at the Norwegian University of Science and Technology (NTNU).
| 279 |
Alvar Aalto
| 5 |
2,009 |
## Works
Aalto\'s career spans the changes in style from (Nordic Classicism) to purist International Style Modernism to a more personal, synthetic, and idiosyncratic Modernism. Aalto\'s wide field of design activity ranges from large-scale projects such as city planning and architecture to more intimate, human-scale work in interior design, furniture and glassware design, and painting. It has been estimated that during his entire career Aalto designed over 500 individual buildings, approximately 300 of which were built. The vast majority of them are in Finland. He also has a few buildings in France, Germany, Italy, and the US.
Aalto\'s work with wood was influenced by early Scandinavian architects. His experiments and bold departures from aesthetic norms brought attention to his ability to make wood do things not previously done. His techniques in the way he cut beech wood, for example, and his ability to use plywood as a structural element while at the same time exploiting its aesthetic properties, were at once technically innovative and artistically inspired. Other examples of his boundary-pushing sensibility include the vertical placement of rough-hewn logs at his pavilion at the Lapua expo, a design element that evoked a medieval barricade. At the orchestra platform at Turku and the Paris expo at the World Fair, he used varying sizes and shapes of planks. Also at Paris (and at Villa Mairea), he utilized birch boards in a vertical arrangement. His Vyborg Library, built in what was then Viipuri (it became Vyborg after Soviet annexation in 1944), is acclaimed for its stunning ceiling, with its undulating waves of red-hearted pine (which grows in the region ). In his roofing, he created massive spans (155-foot at the covered stadium at Otaniemi), all without tie rods. In his stairway at Villa Mairea, he evokes the feeling of a natural forest by binding beech wood with withes into columns.
Aalto claimed that his paintings were not made as individual artworks but as part of his process of architectural design, and many of his small-scale \"sculptural\" experiments with wood led to later larger architectural details and forms. These experiments also led to a number of patents: for example, he invented a new form of laminated bent-plywood furniture in 1932 (which was patented in 1933). His experimental method had been influenced by his meetings with various members of the Bauhaus design school, especially László Moholy-Nagy, whom he first met in 1930. Aalto\'s furniture was exhibited in London in 1935, to great critical acclaim. To cope with the consumer demand, Aalto, together with his wife Aino, Maire Gullichsen, and Nils-Gustav Hahl founded the company Artek that same year. Aalto glassware (Aino as well as Alvar) is manufactured by Iittala.
Aalto\'s \'High Stool\' and \'Stool E60\' (manufactured by Artek) are currently used in Apple Stores across the world to serve as seating for customers. Finished in black lacquer, the stools are used to seat customers at the \'Genius Bar\' and also in other areas of the store at times when seating is required for a product workshop or special event. Aalto was also influential in bringing modern art to the attention of the Finnish people, in particular the work of his friends Alexander Milne Calder and Fernand Léger.
| 532 |
Alvar Aalto
| 6 |
2,009 |
## Works
### Significant buildings {#significant_buildings}
- 1921--1923: Bell tower of Kauhajärvi Church, Lapua, Finland
- 1924--1926: Seinäjoki Civil Guard House, Seinäjoki, Finland
- 1924--1928: Municipal hospital, Alajärvi, Finland
- 1926--1929: Defence Corps Building, Jyväskylä, Finland
- 1927--1928: South-West Finland Agricultural Cooperative building, Turku, Finland
- 1927--1935: Municipal library, Viipuri, Finland (now Vyborg, Russia)
- 1928--1929, 1930: *Turun Sanomat* newspaper offices, Turku, Finland
- 1928--1933: Paimio Sanatorium, Tuberculosis sanatorium and staff housing, Paimio, Finland
- 1931: Toppila paper mill in Oulu, Finland
- 1931: Central University Hospital, Zagreb, Croatia (former Yugoslavia)
- 1932: Villa Tammekann, Tartu, Estonia
- 1934: Corso theatre, restaurant interior, Zürich, Switzerland
- 1936--1939: Ahlstrom Sunila Pulp Mill, Housing, and Town Plan, Kotka, Finland
- 1937--1939: Villa Mairea, Noormarkku, Finland
- 1939: Finnish Pavilion, at the 1939 New York World\'s Fair
- 1945: Sawmill at Varkaus, Finland
- 1947--1948: Baker House, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.
- 1949--1966: Helsinki University of Technology, Espoo, Finland
- 1949--1952: Säynätsalo Town Hall, Säynätsalo (now part of Jyväskylä), Finland; 1949 competition, built 1952
- 1950--1957: National Pension Institution office building, Helsinki, Finland
- 1951--1971: University of Jyväskylä various buildings and facilities on the university campus, Jyväskylä, Finland
- 1952--1958: House of Culture, Helsinki, Finland
- 1953: The Experimental House, Muuratsalo, Finland
- 1953--1955: Rautatalo office building, Helsinki, Finland
- 1956--1958: Home for Louis Carré, Bazoches, France
- 1956--1958: Church of the Three Crosses, Vuoksenniska, Imatra, Finland
- 1957--1967: city center (library, theatre, City Hall, Lakeuden Risti Church and central administrative buildings), Seinäjoki, Finland
- 1958: Post and telegraph office, Baghdad, Iraq
- 1958--1972: KUNSTEN Museum of Modern Art Aalborg, Aalborg, Denmark
- 1959--1962: Community Centre, Wolfsburg, Germany
- 1959--1962: Church of the Holy Ghost (Heilig-Geist-Gemeindezentrum), Wolfsburg, Germany
- 1959--1962: Enso-Gutzeit headquarters, Helsinki, Finland
- 1961--1975: Lappia Hall performing arts and conference venue, Rovaniemi, Finland; part of the city\'s \'Aalto Centre\'
- 1962: Aalto-Hochhaus, Bremen, Germany
- 1964--1965: Kaufmann Conference Center at the Institute of International Education, New York City, U.S.
- 1965: Rovaniemi library, Rovaniemi, Finland
- 1962--1971: Finlandia Hall, Helsinki, Finland
- 1963--1968: Church of St Stephen (Stephanus Kirche), Detmerode, Wolfsburg, Germany
- 1963--1965: Building for Västmanland-Dala nation, Uppsala, Sweden
- 1967--1970: Library at the Mount Angel Abbey, St. Benedict, Salem, Oregon, U.S.
- 1965--1968: Nordic House, Reykjavík, Iceland
- 1966: Church of the Assumption of Mary, Riola di Vergato, Italy (built 1975--1978)
- 1973: Alvar Aalto Museum, a.k.a. Taidemuseo, Jyväskylä, Finland
- 1970--1973: Sähkötalo, Helsinki, Finland
- 1978 (completed): Ristinkirkko, Lahti, Finland
- 1959--1988: Essen opera house, Essen, Germany
- 1986: Rovaniemi city hall, Rovaniemi, Finland
### Furniture and glassware {#furniture_and_glassware}
**Chairs**
- 1932: Paimio Chair
- 1933: Model 60 stacking stool
- 1933: Four-legged Stool E60
- 1935--36: Armchair 404 (a/k/a/ Zebra Tank Chair)
- 1939: Armchair 406
**Lamps**
- 1954: Floor lamp A805
- 1959: Floor lamp A810
**Vases**
- 1936: Aalto Vase
| 478 |
Alvar Aalto
| 7 |
2,009 |
## Critique of Aalto\'s architecture {#critique_of_aaltos_architecture}
As mentioned above, Aalto\'s international reputation was sealed with his inclusion in the second edition of Sigfried Giedion\'s influential book on Modernist architecture, *Space, Time and Architecture: The growth of a new tradition* (1949), in which Aalto received more attention than any other Modernist architect, including Le Corbusier. In his analysis of Aalto, Giedion gave primacy to qualities that depart from direct functionality, such as mood, atmosphere, intensity of life and even national characteristics, declaring that \"Finland is with Aalto wherever he goes.\"
More recently, however, some architecture critics and historians have questioned Aalto\'s influence on the historical canon. The Italian Marxist architecture historians Manfredo Tafuri and Francesco Dal Co contend that Aalto\'s \"historical significance has perhaps been rather exaggerated; with Aalto we are outside of the great themes that have made the course of contemporary architecture so dramatic. The qualities of his works have a meaning only as masterful distractions, not subject to reproduction outside the remote reality \[sic\] in which they have their roots.\" At the heart of their critique was the perception of Aalto\'s work as unsuited to the urban context: \"Essentially, his architecture is not appropriate to urban typologies.\"
At the other end of the political spectrum (though similarly concerned with the appropriateness of Aalto\'s formal language), the American cultural theorist and architectural historian Charles Jencks singled out his Pensions Institute as an example of what he termed the architect\'s \"soft paternalism\": \"Conceived as a fragmented mass to break up the feeling of bureaucracy, it succeeds all too well in being humane and killing the pensioner with kindness. The forms are familiar -- red brick and ribbon-strip windows broken by copper and bronze elements -- all carried through with a literal-mindedness that borders on the soporific.\"
During his lifetime, Aalto faced criticisms from his fellow architects in Finland, most notably Kirmo Mikkola and Juhani Pallasmaa. By the last decade of Aalto\'s life, his work was seen as unfashionably individualistic at a time when the opposing tendencies of rationalism and constructivism -- often championed under left-wing politics -- argued for anonymous, aggressively non-aesthetic architecture. Of Aalto\'s late works, Mikkola wrote, \"Aalto has moved to \[a\] baroque line\...\"
| 366 |
Alvar Aalto
| 8 |
2,009 |
## Memorials
Aalto has been commemorated in a number of ways:
- Alvar Aalto is the eponym of the Alvar Aalto Medal, an international architecture award.
- Aalto was featured in the 50 mk note in the last series of the Finnish markka (before its replacement by the Euro in 2002).
- The centenary of Aalto\'s birth in 1998 was marked in Finland not only by several books and exhibitions, but also by the promotion of specially bottled red and white Aalto Wine and a specially designed cupcake.
- In 1976, the year of his death, Aalto was commemorated on a Finnish postage stamp.
- Piazza Alvar Aalto, a square named after Aalto, can be found in the Porta Nuova business district of Milan, Italy.
- Aalto University, a Finnish university formed by merging Helsinki University of Technology, Helsinki School of Economics and TaiK in 2010, is named after Alvar Aalto.
- An Alvar Aallon katu (Alvar Aalto Street) can be found in five different Finnish cities: Helsinki, Jyväskylä, Oulu, Kotka and Seinäjoki.
- In 2017, the Alvar Aalto Museum launched Alvar Aalto Cities, that is, a network of cities containing buildings by Alvar Aalto. The objective of the network is to increase awareness of Aalto\'s work both in Finland and abroad. It is hoped that by combining forces on communications and marketing, the visibility and accessibility of exhibitions, tourist attractions and events will be improved. To date, the network city members are: Aalborg, Alajärvi, Espoo, Eura, Hamina, Helsinki, Imatra, Jyväskylä, Järvenpää, Kotka, Kouvola, Lahti, Oulu, Paimio, Pori, Raseborg, Rovaniemi, Seinäjoki, Turku, Vantaa and Varkaus. It is estimated that in total there would be 40 cities worldwide that would qualify as an Alvar Aalto City
| 285 |
Alvar Aalto
| 9 |
2,014 |
**Atomic semantics** is a type of guarantee provided by a data register shared by several processors in a parallel machine or in a network of computers working together. Atomic semantics are very strong. An atomic register provides strong guarantees even when there is concurrency and failures.
A read/write register R stores a value and is accessed by two basic operations: read and write(v). A read returns the value stored in R and write(v) changes the value stored in R to v. A register is called atomic if it satisfies the two following properties:
1\) Each invocation op of a read or write operation:
•Must appear as if it were executed at a single point τ(op) in time.
•τ (op) works as follow: τb(op) ≤ τ (op) ≤ τe(op): where τb(op) and τe(op) indicate the time when the operation op begins and ends.
•If op1 ≠ op2, then τ (op1)≠τ (op2)
2\) Each read operation returns the value written by the last write operation before the read, in the sequence where all operations are ordered by their τ values.
**Atomic/Linearizable register:**
Termination: when a node is correct, sooner or later each read and write operation will complete.
**Safety Property** (Linearization points for read and write and failed operations):
Read operation:It appears as if happened at all nodes at some times between the invocation and response time.
Write operation: Similar to read operation, it appears as if happened at all nodes at some times between the invocation and response time.
Failed operation(The atomic term comes from this notion):It appears as if it is completed at every single node or it never happened at any node.
Example : We know that an atomic register is one that is linearizable to a sequential safe register.
The following picture shows where we should put the linearization point for each operation:
An atomic register could be defined for a variable with a single writer but multi- readers (SWMR), single-writer/single-reader (SWSR), or multi-writer/multi-reader (MWMR). Here is an example of a multi-reader multi-writer atomic register which is accessed by three processes (P1, P2, P3). Note that R. read() → v means that the corresponding read operation returns v, which is the value of the register. Therefore, the following execution of the register R could satisfies the definition of the atomic registers: R.write(1), R.read()→1, R.write(3), R.write(2), R.read()→2, R.read()→2
| 389 |
Atomic semantics
| 0 |
2,015 |
**Antarctic Circumpolar Current** (**ACC**) is an ocean current that flows clockwise (as seen from the South Pole) from west to east around Antarctica. An alternative name for the ACC is the **West Wind Drift**. The ACC is the dominant circulation feature of the Southern Ocean and has a mean transport estimated at 137 ± 7 Sverdrups (Sv, million m^3^/s), or possibly even higher, making it the largest ocean current. The current is circumpolar due to the lack of any landmass connecting with Antarctica and this keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet.
Associated with the Circumpolar Current is the Antarctic Convergence, where the cold Antarctic waters meet the warmer waters of the subantarctic, creating a zone of upwelling nutrients. These nurture high levels of phytoplankton with associated copepods and krill, and resultant food chains supporting fish, whales, seals, penguins, albatrosses, and a wealth of other species.
The ACC has been known to sailors for centuries; it greatly speeds up any travel from west to east, but makes sailing extremely difficult from east to west, although this is mostly due to the prevailing westerly winds. Jack London\'s story \"Make Westing\" and the circumstances preceding the mutiny on the *Bounty* poignantly illustrate the difficulty it caused for mariners seeking to round Cape Horn westbound on the clipper ship route from New York to California. The eastbound clipper route, which is the fastest sailing route around the world, follows the ACC around three continental capes -- Cape Agulhas (Africa), South East Cape (Australia), and Cape Horn (South America).
The current creates the Ross and Weddell Gyres.
| 272 |
Antarctic Circumpolar Current
| 0 |
2,015 |
## Structure
The ACC connects the Atlantic, Pacific, and Indian Oceans, and serves as a principal pathway of exchange among them. The current is strongly constrained by landform and bathymetric features. To trace it starting arbitrarily at South America, it flows through the Drake Passage between South America and the Antarctic Peninsula and then is split by the Scotia Arc to the east, with a shallow warm branch flowing to the north in the Falkland Current and a deeper branch passing through the Arc more to the east before also turning to the north. Passing through the Indian Ocean, the current first retroflects the Agulhas Current to form the Agulhas Return Current before it is split by the Kerguelen Plateau, and then moving northward again. Deflection is also seen as it passes over the mid-ocean ridge in the Southeast Pacific.
### Fronts
The current is accompanied by three fronts: the Subantarctic front (SAF), the Polar front (PF), and the Southern ACC front (SACC). Furthermore, the waters of the Southern Ocean are separated from the warmer and saltier subtropical waters by the subtropical front (STF).
The northern boundary of the ACC is defined by the northern edge of the SAF, this being the most northerly water to pass through Drake Passage and therefore be circumpolar. Much of the ACC transport is carried in this front, which is defined as the latitude at which a subsurface salinity minimum or a thick layer of unstratified Subantarctic mode water first appears, allowed by temperature dominating density stratification. Still further south lies the PF, which is marked by a transition to very cold, relatively fresh, Antarctic Surface Water at the surface. Here a temperature minimum is allowed by salinity dominating density stratification, due to the lower temperatures. Farther south still is the SACC, which is determined as the southernmost extent of Circumpolar deep water (temperature of about 2 °C at 400 m). This water mass flows along the shelfbreak of the western Antarctic Peninsula and thus marks the most southerly water flowing through Drake Passage and therefore circumpolar. The bulk of the transport is carried in the middle two fronts.
The total transport of the ACC at Drake Passage is estimated to be around 135 Sv, or about 135 times the transport of all the world\'s rivers combined. There is a relatively small addition of flow in the Indian Ocean, with the transport south of Tasmania reaching around 147 Sv, at which point the current is probably the largest on the planet.
| 417 |
Antarctic Circumpolar Current
| 1 |
2,015 |
## Dynamics
The circumpolar current is driven by the strong westerly winds in the latitudes of the Southern Ocean.
In latitudes where there are continents, winds blowing on light surface water can simply pile up light water against these continents. But in the Southern Ocean, the momentum imparted to the surface waters cannot be offset in this way. There are different theories on how the Circumpolar Current balances the momentum imparted by the winds. The increasing eastward momentum imparted by the winds causes water parcels to drift outward from the axis of the Earth\'s rotation (in other words, northward) as a result of the Coriolis force. This northward Ekman transport is balanced by a southward, pressure-driven flow below the depths of the major ridge systems. Some theories connect these flows directly, implying that there is significant upwelling of dense deep waters within the Southern Ocean, transformation of these waters into light surface waters, and a transformation of waters in the opposite direction to the north. Such theories link the magnitude of the Circumpolar Current with the global thermohaline circulation, particularly the properties of the North Atlantic.
Alternatively, ocean eddies, the oceanic equivalent of atmospheric storms, or the large-scale meanders of the Circumpolar Current may directly transport momentum downward in the water column. This is because such flows can produce a net southward flow in the troughs and a net northward flow over the ridges without requiring any transformation of density. In practice both the thermohaline and the eddy/meander mechanisms are likely to be important.
The current flows at a rate of about 4 km/h over the Macquarie Ridge south of New Zealand. The ACC varies with time. Evidence of this is the Antarctic Circumpolar Wave, a periodic oscillation that affects the climate of much of the southern hemisphere. There is also the Antarctic oscillation, which involves changes in the location and strength of Antarctic winds. Trends in the Antarctic Oscillation have been hypothesized to account for an increase in the transport of the Circumpolar Current over the past two decades.
## Formation
Published estimates of the onset of the Antarctic Circumpolar Current vary, but it is commonly considered to have started at the Eocene/Oligocene boundary. The isolation of Antarctica and formation of the ACC occurred with the openings of the Tasmanian Passage and the Drake Passage, following the fragmentation of the Antarctic land bridge. The Tasmanian Seaway separates East Antarctica and Australia, and is reported to have opened to water circulation 33.5 million years ago (Ma). The timing of the opening of the Drake Passage, between South America and the Antarctic Peninsula, is more disputed. Tectonic and sediment evidence show that it could have been open as early as pre-34 Ma; estimates of the opening of the Drake passage are between 20 and 40 Ma. The isolation of Antarctica by the current is credited by many researchers with causing the glaciation of Antarctica and global cooling in the Eocene epoch. Oceanic models have shown that the opening of these two passages limited polar heat convergence and caused a cooling of sea surface temperatures by several degrees; other models have shown that CO~2~ levels also played a significant role in the glaciation of Antarctica.
| 533 |
Antarctic Circumpolar Current
| 2 |
2,015 |
## Phytoplankton
Antarctic sea ice cycles seasonally, in February--March the amount of sea ice is lowest, and in August--September the sea ice is at its greatest extent. Ice levels have been monitored by satellite since 1973. Upwelling of deep water under the sea ice brings substantial amounts of nutrients. As the ice melts, the melt water provides stability and the critical depth is well below the mixing depth, which allows for a positive net primary production. As the sea ice recedes epontic algae dominate the first phase of the bloom, and a strong bloom dominate by diatoms follows the ice melt south.
Another phytoplankton bloom occurs more to the north near the Antarctic Convergence, here nutrients are present from thermohaline circulation. Phytoplankton blooms are dominated by diatoms and grazed by copepods in the open ocean, and by krill closer to the continent. Diatom production continues through the summer, and populations of krill are sustained, bringing large numbers of cetaceans, cephalopods, seals, birds, and fish to the area.
Phytoplankton blooms are believed to be limited by irradiance in the austral (southern hemisphere) spring, and by biologically available iron in the summer. Much of the biology in the area occurs along the major fronts of the current, the Subtropical, Subantarctic, and the Antarctic Polar fronts, these are areas associated with well defined temperature changes. Size and distribution of phytoplankton are also related to fronts. Microphytoplankton (\>20 μm) are found at fronts and at sea ice boundaries, while nanophytoplankton (\<20 μm) are found between fronts.
Studies of phytoplankton stocks in the southern sea have shown that the Antarctic Circumpolar Current is dominated by diatoms, while the Weddell Sea has abundant coccolithophorids and silicoflagellates. Surveys of the SW Indian Ocean have shown phytoplankton group variation based on their location relative to the Polar Front, with diatoms dominating South of the front, and dinoflagellates and flagellates in higher populations North of the front.
Some research has been conducted on Antarctic phytoplankton as a carbon sink. Areas of open water left from ice melt are good areas for phytoplankton blooms. The phytoplankton takes carbon from the atmosphere during photosynthesis. As the blooms die and sink, the carbon can be stored in sediments for thousands of years. This natural carbon sink is estimated to remove 3.5 million tonnes from the ocean each year. 3.5 million tonnes of carbon taken from the ocean and atmosphere is equivalent to 12.8 million tonnes of carbon dioxide.
| 406 |
Antarctic Circumpolar Current
| 3 |
2,015 |
## Studies
An expedition in May 2008 by 19 scientists studied the geology and biology of eight Macquarie Ridge sea mounts, as well as the Antarctic Circumpolar Current to investigate the effects of climate change of the Southern Ocean. The circumpolar current merges the waters of the Atlantic, Indian, and Pacific Oceans and carries up to 150 times the volume of water flowing in all of the world\'s rivers. The study found that any damage on the cold-water corals nourished by the current will have a long-lasting effect. After studying the circumpolar current it is clear that it strongly influences regional and global climate as well as underwater biodiversity. The subject has been characterized recently as \"the spectral peak of the global extra-tropical circulation at ≈ 10\^4 kilometers\".
The current helps preserve wooden shipwrecks by preventing wood-boring \"ship worms\" from reaching targets such as Ernest Shackleton\'s ship, the *Endurance*.
The \"State of the Cryosphere\" report found, that the Antarctic Circumpolar Current became weaker. By 2050 it expected to lose 20% of its strength with \"widespread impacts on ocean circulation and climate.\" The Weddell Sea Bottom Water has lost 30% of its volume in the latest 32 years, and the Antarctic Bottom Water is expected to shrink. This will impact ocean circulation, nutrients, heat content and carbon sequestration. UNESCO mentions that the report in the first time \"notes a growing scientific consensus that melting Greenland and Antarctic ice sheets, among other factors, may be slowing important ocean currents at both poles, with potentially dire consequences for a much colder northern Europe and greater sea-level rise along the U.S. East Coast.\" The findings were bolstered by a 2025 study published in Environmental Research Letters
| 282 |
Antarctic Circumpolar Current
| 4 |
2,018 |
**Sir Alfred Jules** \"**Freddie**\" **Ayer** `{{post-nominals|country=GBR|FBA}}`{=mediawiki} (`{{IPAc-en|ɛər}}`{=mediawiki} `{{respell|AIR}}`{=mediawiki}; 29 October 1910 -- 27 June 1989) was an English philosopher known for his promotion of logical positivism, particularly in his books *Language, Truth, and Logic* (1936) and *The Problem of Knowledge* (1956).
Ayer was educated at Eton College and the University of Oxford, after which he studied the philosophy of logical positivism at the University of Vienna. From 1933 to 1940 he lectured on philosophy at Christ Church, Oxford.
During the Second World War Ayer was a Special Operations Executive and MI6 agent.
Ayer was Grote Professor of the Philosophy of Mind and Logic at University College London from 1946 until 1959, after which he returned to Oxford to become Wykeham Professor of Logic at New College. He was president of the Aristotelian Society from 1951 to 1952 and knighted in 1970. He was known for his advocacy of humanism, and was the second president of the British Humanist Association (now known as Humanists UK).
Ayer was president of the Homosexual Law Reform Society for a time; he remarked, \"as a notorious heterosexual I could never be accused of feathering my own nest.\"
## Life
Ayer was born in St John\'s Wood, in north west London, to Jules Louis Cyprien Ayer and Reine (née Citroen), wealthy parents from continental Europe. His mother was from the Dutch-Jewish family that founded the Citroën car company in France; his father was a Swiss Calvinist financier who worked for the Rothschild family, including for their bank and as secretary to Alfred Rothschild.
Ayer was educated at Ascham St Vincent\'s School, a former boarding preparatory school for boys in the seaside town of Eastbourne in Sussex, where he started boarding at the relatively early age of seven for reasons to do with the First World War, and at Eton College, where he was a King\'s Scholar. At Eton Ayer first became known for his characteristic bravado and precocity. Though primarily interested in his intellectual pursuits, he was very keen on sports, particularly rugby, and reputedly played the Eton Wall Game very well. In the final examinations at Eton, Ayer came second in his year, and first in classics. In his final year, as a member of Eton\'s senior council, he unsuccessfully campaigned for the abolition of corporal punishment at the school. He won a classics scholarship to Christ Church, Oxford. He graduated with a BA with first-class honours.
After graduating from Oxford, Ayer spent a year in Vienna, returned to England and published his first book, *Language, Truth and Logic*, in 1936. This first exposition in English of logical positivism as newly developed by the Vienna Circle, made Ayer at age 26 the *enfant terrible* of British philosophy. As a newly famous intellectual, he played a prominent role in the Oxford by-election campaign of 1938. Ayer campaigned first for the Labour candidate Patrick Gordon Walker, and then for the joint Labour-Liberal \"Independent Progressive\" candidate Sandie Lindsay, who ran on an anti-appeasement platform against the Conservative candidate, Quintin Hogg, who ran as the appeasement candidate. The by-election, held on 27 October 1938, was quite close, with Hogg winning narrowly.
In the Second World War, Ayer served as an officer in the Welsh Guards, chiefly in intelligence (Special Operations Executive (SOE) and MI6). He was commissioned as a second lieutenant into the Welsh Guards from the Officer Cadet Training Unit on 21 September 1940.
After the war, Ayer briefly returned to the University of Oxford where he became a fellow and Dean of Wadham College. He then taught philosophy at University College London from 1946 until 1959, during which time he started to appear on radio and television. He was an extrovert and social mixer who liked dancing and attending clubs in London and New York. He was also obsessed with sport: he had played rugby for Eton, and was a noted cricketer and a keen supporter of Tottenham Hotspur football team, where he was for many years a season ticket holder. For an academic, Ayer was an unusually well-connected figure in his time, with close links to \'high society\' and the establishment. Presiding over Oxford high-tables, he is often described as charming, but could also be intimidating.
Ayer was married four times to three women. His first marriage was from 1932 to 1941, to (Grace Isabel) Renée, with whom he had a son`{{snd}}`{=mediawiki}allegedly the son of Ayer\'s friend and colleague Stuart Hampshire`{{snd}}`{=mediawiki}and a daughter. Renée subsequently married Hampshire. In 1960, Ayer married Alberta Constance (Dee) Wells, with whom he had one son. That marriage was dissolved in 1983, and the same year, Ayer married Vanessa Salmon, the former wife of politician Nigel Lawson. She died in 1985, and in 1989 Ayer remarried Wells, who survived him. He also had a daughter with Hollywood columnist Sheilah Graham Westbrook.
In 1950, Ayer attended the founding meeting of the Congress for Cultural Freedom in West Berlin, though he later said he went only because of the offer of a \"free trip\". He gave a speech on why John Stuart Mill\'s conceptions of liberty and freedom were still valid in the 20th century. Together with the historian Hugh Trevor-Roper, Ayer fought against Arthur Koestler and Franz Borkenau, arguing that they were far too dogmatic and extreme in their anti-communism, in fact proposing illiberal measures in the defence of liberty. Adding to the tension was the location of the congress in West Berlin, together with the fact that the Korean War began on 25 June 1950, the fourth day of the congress, giving a feeling that the world was on the brink of war.
From 1959 to his retirement in 1978, Ayer held the Wykeham Chair, Professor of Logic at Oxford. He was knighted in 1970. After his retirement, Ayer taught or lectured several times in the United States, including as a visiting professor at Bard College in 1987. At a party that same year held by fashion designer Fernando Sanchez, Ayer confronted Mike Tyson, who was forcing himself upon the then little-known model Naomi Campbell. When Ayer demanded that Tyson stop, Tyson reportedly asked, \"Do you know who the fuck I am? I\'m the heavyweight champion of the world\", to which Ayer replied, \"And I am the former Wykeham Professor of Logic. We are both pre-eminent in our field. I suggest that we talk about this like rational men\". Ayer and Tyson then began to talk, allowing Campbell to slip out. Gully Wells, Ayer\'s stepdaughter via Dee Wells, records the same event with some slight variation of detail.
Ayer was also involved in politics, including anti-Vietnam War activism, supporting the Labour Party (and later the Social Democratic Party), chairing the Campaign Against Racial Discrimination in Sport, and serving as president of the Homosexual Law Reform Society.
In 1988, a year before his death, Ayer wrote an article titled \"What I saw when I was dead\", describing an unusual near-death experience after his heart stopped for four minutes as he choked on smoked salmon. Of the experience, he first said that it \"slightly weakened my conviction that my genuine death \... will be the end of me, though I continue to hope that it will be.\" A few weeks later, he revised this, saying, \"what I should have said is that my experiences have weakened, not my belief that there is no life after death, but my inflexible attitude towards that belief\".
Ayer died on 27 June 1989. From 1980 to 1989 he lived at 51 York Street, Marylebone, where a memorial plaque was unveiled on 19 November 1995.
| 1,257 |
A. J. Ayer
| 0 |
2,018 |
## Philosophical ideas {#philosophical_ideas}
In *Language, Truth and Logic* (1936), Ayer presents the verification principle as the only valid basis for philosophy. Unless logical or empirical verification is possible, statements like \"God exists\" or \"charity is good\" are not true or untrue but meaningless, and may thus be excluded or ignored. Religious language in particular is unverifiable and as such literally nonsense. He also criticises C. A. Mace\'s opinion that metaphysics is a form of intellectual poetry. The stance that a belief in God denotes no verifiable hypothesis is sometimes referred to as igtheism (for example, by Paul Kurtz). In later years, Ayer reiterated that he did not believe in God and began to call himself an atheist. He followed in the footsteps of Bertrand Russell by debating religion with the Jesuit scholar Frederick Copleston.
Ayer\'s version of emotivism divides \"the ordinary system of ethics\" into four classes:
1. \"Propositions that express definitions of ethical terms, or judgements about the legitimacy or possibility of certain definitions\"
2. \"Propositions describing the phenomena of moral experience, and their causes\"
3. \"Exhortations to moral virtue\"
4. \"Actual ethical judgements\"
He focuses on propositions of the first class`{{snd}}`{=mediawiki}moral judgements`{{snd}}`{=mediawiki}saying that those of the second class belong to science, those of the third are mere commands, and those of the fourth (which are considered normative ethics as opposed to meta-ethics) are too concrete for ethical philosophy.
Ayer argues that moral judgements cannot be translated into non-ethical, empirical terms and thus cannot be verified; in this he agrees with ethical intuitionists. But he differs from intuitionists by discarding appeals to intuition of non-empirical moral truths as \"worthless\" since the intuition of one person often contradicts that of another. Instead, Ayer concludes that ethical concepts are \"mere pseudo-concepts\":
Between 1945 and 1947, together with Russell and George Orwell, Ayer contributed a series of articles to *Polemic*, a short-lived British *Magazine of Philosophy, Psychology, and Aesthetics* edited by the ex-Communist Humphrey Slater.
Ayer was closely associated with the British humanist movement. He was an Honorary Associate of the Rationalist Press Association from 1947 until his death. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1963. In 1965, he became the first president of the Agnostics\' Adoption Society and in the same year succeeded Julian Huxley as president of the British Humanist Association, a post he held until 1970. In 1968 he edited *The Humanist Outlook*, a collection of essays on the meaning of humanism. He was one of the signers of the Humanist Manifesto.
| 424 |
A. J. Ayer
| 1 |
2,018 |
## Works
Ayer is best known for popularising the verification principle, in particular through his presentation of it in *Language, Truth, and Logic*. The principle was at the time at the heart of the debates of the so-called Vienna Circle, which Ayer had visited as a young guest. Others, including the circle\'s leading light, Moritz Schlick, were already writing papers on the issue. Ayer\'s formulation was that a sentence can be meaningful only if it has verifiable empirical import; otherwise, it is either \"analytical\" if tautologous or \"metaphysical\" (i.e. meaningless, or \"literally senseless\"). He started to work on the book at the age of 23 and it was published when he was 26. Ayer\'s philosophical ideas were deeply influenced by those of the Vienna Circle and David Hume. His clear, vibrant and polemical exposition of them makes *Language, Truth and Logic* essential reading on the tenets of logical empiricism; the book is regarded as a classic of 20th-century analytic philosophy and is widely read in philosophy courses around the world. In it, Ayer also proposes that the distinction between a conscious man and an unconscious machine resolves itself into a distinction between \"different types of perceptible behaviour\", an argument that anticipates the Turing test published in 1950 to test a machine\'s capability to demonstrate intelligence.
Ayer wrote two books on the philosopher Bertrand Russell, *Russell and Moore: The Analytic Heritage* (1971) and *Russell* (1972). He also wrote an introductory book on the philosophy of David Hume and a short biography of Voltaire.
Ayer was a strong critic of the German philosopher Martin Heidegger. As a logical positivist, Ayer was in conflict with Heidegger\'s vast, overarching theories of existence. Ayer considered them completely unverifiable through empirical demonstration and logical analysis, and this sort of philosophy an unfortunate strain in modern thought. He considered Heidegger the worst example of such philosophy, which Ayer believed entirely useless. In *Philosophy in the Twentieth Century*, Ayer accuses Heidegger of \"surprising ignorance\" or \"unscrupulous distortion\" and \"what can fairly be described as charlatanism.\"
In 1972--73, Ayer gave the Gifford Lectures at the University of St Andrews, later published as *The Central Questions of Philosophy*. In the book\'s preface, he defends his selection to hold the lectureship on the basis that Lord Gifford wished to promote \"natural theology, in the widest sense of that term\", and that non-believers are allowed to give the lectures if they are \"able reverent men, true thinkers, sincere lovers of and earnest inquirers after truth\". He still believed in the viewpoint he shared with the logical positivists: that large parts of what was traditionally called philosophy`{{mdash}}`{=mediawiki}including metaphysics, theology and aesthetics`{{mdash}}`{=mediawiki}were not matters that could be judged true or false, and that it was thus meaningless to discuss them.
In *The Concept of a Person and Other Essays* (1963), Ayer heavily criticised Wittgenstein\'s private language argument.
Ayer\'s sense-data theory in *Foundations of Empirical Knowledge* was famously criticised by fellow Oxonian J. L. Austin in *Sense and Sensibilia*, a landmark 1950s work of ordinary language philosophy. Ayer responded in the essay \"Has Austin Refuted the Sense-datum Theory?\", which can be found in his *Metaphysics and Common Sense* (1969).
## Awards
Ayer was awarded a knighthood as Knight Bachelor in the London Gazette on 1 January 1970.
## Collections
Ayer\'s biographer, Ben Rogers, deposited 7 boxes of research material accumulated through the writing process at University College London in 2007. The material was donated in collaboration with Ayer\'s family.
| 574 |
A. J. Ayer
| 2 |
2,018 |
## Selected publications {#selected_publications}
- 1936, *Language, Truth, and Logic*, London: Gollancz., 2nd ed., with new introduction (1946) `{{oclc|416788667}}`{=mediawiki} `{{ISBN|978-0-14-118604-7}}`{=mediawiki}
- 1936, \"Causation and free will\", *The Aryan Path*.
- 1940, *The Foundations of Empirical Knowledge*, London: Macmillan. `{{oclc|2028651}}`{=mediawiki}
- 1954, *Philosophical Essays*, London: Macmillan. (Essays on freedom, phenomenalism, basic propositions, utilitarianism, other minds, the past, ontology.) `{{oclc|186636305}}`{=mediawiki}
- 1957, \"The conception of probability as a logical relation\", in S. Korner, ed., *Observation and Interpretation in the Philosophy of Physics*, New York: Dover Publications.
- 1956, *The Problem of Knowledge*, London: Macmillan. `{{oclc|557578816}}`{=mediawiki}
- 1957, \"Logical Positivism - A Debate\" (with F. C. Copleston) in: Edwards, Paul, Pap, Arthur (eds.), *A Modern Introduction to Philosophy; readings from classical and contemporary sources*
- 1963, *The Concept of a Person and Other Essays*, London: Macmillan. (Essays on truth, privacy and private languages, laws of nature, the concept of a person, probability.) `{{oclc|3573935}}`{=mediawiki}
- 1967, [\"Has Austin Refuted the Sense-Datum Theory?\"](https://www.jstor.org/stable/20114547) *Synthese* vol. XVIII, pp. 117--140. (Reprinted in Ayer 1969).
- 1968, *The Origins of Pragmatism*, London: Macmillan. `{{oclc|641463982}}`{=mediawiki}
- 1969, *Metaphysics and Common Sense*, London: Macmillan. (Essays on knowledge, man as a subject for science, chance, philosophy and politics, existentialism, metaphysics, and a reply to Austin on sense-data theory \[Ayer 1967\].) `{{ISBN|978-0-333-10517-7}}`{=mediawiki}
- 1971, *Russell and Moore: The Analytical Heritage*, London: Macmillan. `{{oclc|464766212}}`{=mediawiki}
- 1972, *Probability and Evidence*, London: Macmillan. `{{ISBN|978-0-333-12756-8}}`{=mediawiki}
- 1972, *Russell*, London: Fontana Modern Masters. `{{oclc|186128708}}`{=mediawiki}
- 1973, *The Central Questions of Philosophy*, London: Weidenfeld. `{{ISBN|978-0-297-76634-6}}`{=mediawiki}
- 1977, *Part of My Life*, London: Collins. `{{ISBN|978-0-00-216017-9}}`{=mediawiki}
- 1979, \"Replies\", in G. F. Macdonald, ed., *Perception and Identity: Essays Presented to A. J. Ayer, With His Replies*, London: Macmillan; Ithaca, N.Y.: Cornell University Press.
- 1980, *Hume*, Oxford: Oxford University Press
- 1982, *Philosophy in the Twentieth Century*, London: Weidenfeld.
- 1984, *Freedom and Morality and Other Essays*, Oxford: Clarendon Press.
- 1984, *More of My Life*, London: Collins.
- 1986, *Ludwig Wittgenstein*, London: Penguin.
- 1986, *Voltaire*, New York: Random House.
- 1988, *Thomas Paine*, London: Secker & Warburg.
- 1990, *The Meaning of Life and Other Essays*, Weidenfeld & Nicolson.
- 1991, \"A Defence of Empiricism\" in: Griffiths, A. Phillips (ed.), *A. J. Ayer: Memorial Essays* (Royal Institute of Philosophy Supplements). Cambridge University Press.
- 1992, \"Intellectual Autobiography\" and Replies in: Lewis Edwin Hahn (ed.), *The Philosophy of A.J. Ayer (The Library of Living Philosophers Volume XXI)*, Open Court Publishing Co.
\*For more complete publication details see [\"The Philosophical Works of A. J. Ayer\"](https://link.springer.com/content/pdf/bbm%3A978-1-349-04862-5%2F1.pdf) (1979) and \"Bibliography of the writings of A.J. Ayer\" (1992)
| 425 |
A. J. Ayer
| 3 |
2,037 |
Delyan}}
The **Delian League** was a confederacy of Greek city-states, numbering between 150 and 330, founded in 478 BC under the leadership (hegemony) of Athens, whose purpose was to continue fighting the Persian Empire after the Greek victory in the Battle of Plataea at the end of the Second Persian invasion of Greece. The League functioned as a dual --offensive and defensive-- alliance (*symmachia*) of autonomous states, similar to its rival association, the Peloponnesian League. The League\'s modern name derives from its official meeting place, the island of Delos, where congresses were held within the sanctuary of the Temple of Apollo; contemporary authors referred to the organization simply as \"the Athenians and their Allies\".
While Sparta excelled as Greece\'s greatest power on land, Athens turned to the seas becoming the dominant naval power of the Greek world. Following Sparta\'s withdrawal from the conflict with Persia, Athens took the lead of the Hellenic alliance accompanied by several states around the Aegean and the Anatolian coast. The Delian League was formed as an anti-Persian defensive association of equal city-states seeking protection under Athens, as the latter wished to extend its support towards the Ionian Greek colonies of Anatolia. By the mid-fifth century BC, the alliance had developed into a naval imperial power, called the **Athenian Empire**, where Athens established complete dominion and the allies became increasingly less autonomous. The alliance held an assembly of representatives in order to shape its policy, while the members swore an oath of loyalty to the coalition. The Delian League successfully accomplished its principal strategic goal by decisively expelling the remaining Persian forces from the Aegean. As a result, Persia would cease to pose a major threat to Greece for the following fifty years.
From its inception, Athens became the League\'s biggest source of military power, while more and more allies preferred to pay the dues in cash. Athens began to use the League\'s funds for its own purposes, like the reinforcement of its naval supremacy, which led to conflicts between the city and its less powerful allies, at times culminating in rebellions, like that of Thasos in 465 BC. The League\'s treasury initially stood in Delos until, in a symbolic gesture, Pericles moved it to Athens in 454 BC. By 431 BC, the threat that the League presented to Spartan hegemony combined with Athens\'s heavy-handed control of the Delian League prompted the outbreak of the Peloponnesian War; the League was dissolved upon the war\'s conclusion in 404 BC under the direction of Lysander, the Spartan commander. Witnessing Sparta\'s growing hegemony in the first half of the 4th century BC, Athens went on to partly revive the alliance, this time called the Second Athenian League, reestablishing its naval dominance in the eastern Mediterranean.
| 456 |
Delian League
| 0 |
2,037 |
## Background
thumb\|upright=1.5\|Athenian Empire in 445 BC, according to the Tribute Lists. The islands of Lesbos, Chios and Samos (shaded on the map) did not pay tribute. The Greco-Persian Wars had their roots in the conquest of the Greek cities of Asia Minor, and particularly Ionia, by the Achaemenid Persian Empire of Cyrus the Great shortly after 550 BC. The Persians found the Ionians difficult to rule, eventually settling for sponsoring a tyrant in each Ionian city. While Greek states had in the past often been ruled by tyrants, this form of government was on the decline. By 500 BC, Ionia appears to have been ripe for rebellion against these Persian clients. The simmering tension finally broke into open revolt due to the actions of the tyrant of Miletus, Aristagoras. Attempting to save himself after a disastrous Persian-sponsored expedition in 499 BC, Aristagoras chose to declare Miletus a democracy. This triggered similar revolutions across Ionia, extending to Doris and Aeolis, beginning the Ionian Revolt.
The Greek states of Athens and Eretria allowed themselves to be drawn into this conflict by Aristagoras, and during their only campaigning season (498 BC) they contributed to the capture and burning of the Persian regional capital of Sardis. After this, the Ionian revolt carried on (without further outside aid) for a further five years, until it was finally completely crushed by the Persians. However, in a decision of great historic significance, the Persian king Darius the Great decided that, despite having subdued the revolt, there remained the unfinished business of exacting punishment on Athens and Eretria for supporting the revolt. The Ionian revolt had severely threatened the stability of Darius\'s empire, and the states of mainland Greece would continue to threaten that stability unless dealt with. Darius thus began to contemplate the complete conquest of Greece, beginning with the destruction of Athens and Eretria.
In the next two decades, there would be two Persian invasions of Greece, occasioning, thanks to Greek historians, some of the most famous battles in history. During the first invasion, Thrace, Macedon and the Aegean Islands were added to the Persian Empire, and Eretria was duly destroyed. However, the invasion ended in 490 BC with the decisive Athenian victory at the Battle of Marathon. After this invasion, Darius died, and responsibility for the war passed to his son Xerxes I.
Xerxes then personally led a second Persian invasion of Greece in 480 BC, taking an enormous (although oft-exaggerated) army and navy to Greece. Those Greeks who chose to resist (the \'Allies\') were defeated in the twin simultaneous battles of Thermopylae on land and Artemisium at sea. All of Greece except the Peloponnesus thus having fallen into Persian hands, the Persians then seeking to destroy the Allied navy once and for all, suffered a decisive defeat at the Battle of Salamis. The following year, 479 BC, the Allies assembled the largest Greek army yet seen and defeated the Persian invasion force at the Battle of Plataea, ending the invasion and the threat to Greece.
The Allied fleet defeated the remnants of the Persian fleet in the Battle of Mycale near the island of Samos---on the same day as Plataea, according to tradition. This action marks the end of the Persian invasion, and the beginning of the next phase in the Greco-Persian wars, the Greek counterattack. After Mycale, the Greek cities of Asia Minor again revolted, with the Persians now powerless to stop them. The Allied fleet then sailed to the Thracian Chersonese, still held by the Persians, and besieged and captured the town of Sestos. The following year, 478 BC, the Allies sent a force to capture the city of Byzantion (modern day Istanbul). The siege was successful, but the behaviour of the Spartan general Pausanias alienated many of the Allies, and resulted in Pausanias\'s recall.
| 634 |
Delian League
| 1 |
2,037 |
## Formation
After Byzantion, Sparta was eager to end its involvement in the war. The Spartans greatly feared the rise of the Athenians as a challenge to their power. Additionally, the Spartans were of the view that, with the liberation of mainland Greece, and the Greek cities of Asia Minor, the war\'s purpose had already been achieved. There was also perhaps a feeling that establishing long-term security for the Asian Greeks would prove impossible. In the aftermath of Mycale, the Spartan king Leotychidas had proposed transplanting all the Greeks from Asia Minor to Europe as the only method of permanently freeing them from Persian dominion.
Xanthippus, the Athenian commander at Mycale, had furiously rejected this; the Ionian cities had been Athenian colonies, and the Athenians, if no one else, would protect the Ionians. This marked the point at which the leadership of the Greek alliance effectively passed to the Athenians. With the Spartan withdrawal after Byzantion, the leadership of the Athenians became explicit.
The loose alliance of city states which had fought against Xerxes\'s invasion had been dominated by Sparta and the Peloponnesian league. With the withdrawal of these states, a congress was called on the holy island of Delos to institute a new alliance to continue the fight against the Persians; hence the modern designation \"Delian League\". According to Thucydides, the official aim of the League was to \"avenge the wrongs they suffered by ravaging the territory of the king.\"
In reality, this goal was divided into three main efforts---to prepare for future invasion, to seek revenge against Persia, and to organize a means of dividing spoils of war. The members were given a choice of either offering armed forces or paying a tax to the joint treasury; most states chose the tax. League members swore to have the same friends and enemies, and dropped ingots of iron into the sea to symbolize the permanence of their alliance. The Athenian politician Aristides would spend the rest of his life occupied in the affairs of the alliance, dying (according to Plutarch) a few years later in Pontus, whilst determining what the tax of new members was to be.
| 358 |
Delian League
| 2 |
2,037 |
## Members
The Delian League, also known as the Athenian Empire, was a collection of Greek city-states largely based around the Aegean Sea which operated under the hegemony of Athens. This alliance initially served the purpose of coordinating a united Greek front against a perceived looming Persian threat against the Ionian city-states which bordered it. The members of the Delian League were made to swear an oath of loyalty to the league and contributed mostly monetarily but in some instances donated ships or other forces. It was also the case that many democratic members of the League owed their freedom from oligarchic or tyrannical rule to Athens. Because of this, Athens gained an overwhelming advantage in the voting system conducted by relying on the support of democratic city-states Athens had helped into being. By 454 Athens moved the treasury of the Delian League from the Island of Delos to the Parthenon in Athens. Benefitting greatly from the influx of cash coming out of the 150-330 members, Athens used the money to reinforce its own naval supremacy and used the remaining funds to embellish the city with art and architecture. In order to maintain the new synoecism, Athens began using its greatly expanded military to enforce membership in the League. City-states who wished to leave the alliance were punished by Athens with force such as Mytilene and Melos. No longer considered her allies, Athens eventually began to refer to the members of the Delian League as \"all the cities Athens rules.\" Athens also extended its authority over members of the League through judicial decisions. Synoecism under the Athenian Empire was enforced by resolving matters of and between states in Athens by courts composed of Athenian citizens and enforcing those decisions through the Athenian military.
## Composition and expansion {#composition_and_expansion}
In the first ten years of the league\'s existence, Cimon/Kimon forced Karystos in Euboea to join the league, conquered the island of Skyros and sent Athenian colonists there.
Over time, especially with the suppression of rebellions, Athens exercised hegemony over the rest of the league. Thucydides describes how Athens\'s control over the League grew:
> Of all the causes of defection, that connected with arrears of tribute and vessels, and with failure of service, was the chief; for the Athenians were very severe and exacting, and made themselves offensive by applying the screw of necessity to men who were not used to and in fact not disposed for any continuous labor. In some other respects the Athenians were not the old popular rulers they had been at first; and if they had more than their fair share of service, it was correspondingly easy for them to reduce any that tried to leave the confederacy. The Athenians also arranged for the other members of the league to pay its share of the expense in money instead of in ships and men, and for this the subject city-states had themselves to blame, their wish to get out of giving service making most leave their homes. Thus while Athens was increasing her navy with the funds they contributed, a revolt always found itself without enough resources or experienced leaders for war.
## Rebellion
### Naxos
The first member of the league to attempt to secede was the island of Naxos in c. 471 BC. After being defeated, Naxos is believed (based on similar, later revolts) to have been forced to tear down its walls along with losing its fleet and vote in the League.
### Thasos
In 465 BC, Athens founded the colony of Amphipolis on the Strymon river. Thasos, a member of the League, saw her interests in the mines of Mt. Pangaion threatened and defected from the League to Persia. She called to Sparta for assistance but was denied, as Sparta was facing the largest helot revolt in its history.
After more than two years of siege, Thasos surrendered to the Athenian leader Aristides and was forced back into the league. As a result, the fortification walls of Thasos were torn down, and they had to pay yearly tribute and fines. Additionally, their land, naval ships, and the mines of Thasos were confiscated by Athens. The siege of Thasos marks the transformation of the Delian league from an alliance into, in the words of Thucydides, a hegemony.
| 714 |
Delian League
| 3 |
2,037 |
## Policies of the League {#policies_of_the_league}
In 461 BC, Cimon was ostracized and was succeeded in his influence by democrats such as Ephialtes and Pericles. This signaled a complete change in Athenian foreign policy, neglecting the alliance with the Spartans and instead allying with her enemies, Argos and Thessaly. Megara deserted the Spartan-led Peloponnesian League and allied herself with Athens, allowing construction of a double line of walls across the Isthmus of Corinth and protecting Athens from attack from that quarter. Roughly a decade earlier, due to encouragement from influential speaker Themistocles, the Athenians had also constructed the Long Walls connecting their city to the Piraeus, its port, making it effectively invulnerable to attack by land.
In 454 BC, the Athenian general Pericles moved the Delian League\'s treasury from Delos to Athens, allegedly to keep it safe from Persia. However, Plutarch indicates that many of Pericles\'s rivals viewed the transfer to Athens as usurping monetary resources to fund elaborate building projects. Athens also switched from accepting ships, men and weapons as dues from league members, to only accepting money.
The new treasury established in Athens was used for many purposes, not all relating to the defence of members of the league. It was from tribute paid to the league that Pericles set to building the Parthenon on the Acropolis, replacing an older temple, as well as many other non-defense related expenditures. The Delian League was turning from an alliance into an empire.
## Wars against Persia {#wars_against_persia}
War with the Persians continued. In 460 BC, Egypt revolted under local leaders the Hellenes called Inaros and Amyrtaeus, who requested aid from Athens. Pericles led 250 ships, intended to attack Cyprus, to their aid because it would further damage Persia. After four years, however, the Egyptian rebellion was defeated by the Achaemenid general Megabyzus, who captured the greater part of the Athenian forces. In fact, according to Isocrates, the Athenians and their allies lost some 20,000 men in the expedition, while modern estimates place the figure at 50,000 men and 250 ships including reinforcements. The remainder escaped to Cyrene and thence returned home.
This was the Athenians\' main (public) reason for moving the treasury of the League from Delos to Athens, further consolidating their control over the League. The Persians followed up their victory by sending a fleet to re-establish their control over Cyprus, and 200 ships were sent out to counter them under Cimon, who returned from ostracism in 451 BC. He died during the blockade of Citium, though the fleet won a double victory by land and sea over the Persians off Salamis, Cyprus.
This battle was the last major one fought against the Persians. Many writers report that a peace treaty, known as the Peace of Callias, was formalized in 450 BC, but some writers believe that the treaty was a myth created later to inflate the stature of Athens. However, an understanding was definitely reached, enabling the Athenians to focus their attention on events in Greece proper.
| 499 |
Delian League
| 4 |
2,037 |
## Wars in Greece {#wars_in_greece}
Soon, war with the Peloponnesians broke out. In 458 BC, the Athenians blockaded the island of Aegina, and simultaneously defended Megara from the Corinthians by sending out an army composed of those too young or old for regular military service. The following year, Sparta sent an army into Boeotia, reviving the power of Thebes in order to help hold the Athenians in check. Their return was blocked, and they resolved to march on Athens, where the Long Walls were not yet completed, winning a victory at the Battle of Tanagra. All this accomplished, however, was to allow them to return home via the Megarid. Two months later, the Athenians under Myronides invaded Boeotia, and winning the Battle of Oenophyta gained control of the whole country except Thebes.
Reverses followed peace with Persia in 449 BC. The Battle of Coronea, in 447 BC, led to the abandonment of Boeotia. Euboea and Megara revolted, and while the former was restored to its status as a tributary ally, the latter was a permanent loss. The Delian and Peloponnesian Leagues signed a peace treaty, which was set to endure for thirty years. It only lasted until 431 BC, when the Peloponnesian War broke out.
Those who revolted unsuccessfully during the war saw the example made of the Mytilenians, the principal people on Lesbos. After an unsuccessful revolt, the Athenians ordered the death of the entire male population. After some thought, they rescinded this order, and only put to death the leading 1000 ringleaders of the revolt, and redistributed the land of the entire island to Athenian shareholders, who were sent out to reside on Lesbos.
This type of treatment was not reserved solely for those who revolted. Thucydides documents the example of Melos, a small island, neutral in the war, though founded by Spartans. The Melians were offered a choice to join the Athenians, or be conquered. Choosing to resist, their town was besieged and conquered; the males were put to death and the women sold into slavery (see Melian dialogue).
| 342 |
Delian League
| 5 |
2,037 |
## Athenian Empire (454--404 BC) {#athenian_empire_454404_bc}
By 454 BC, the Delian League could be fairly characterised as an Athenian Empire; a key event of 454 BC was the moving of the treasury of the Delian League from Delos to Athens. This is often seen as a key marker of the transition from alliance to empire, but while it is significant, it is important to view the period as a whole when considering the development of Athenian imperialism, and not to focus on a single event as being the main contributor to it. At the start of the Peloponnesian War, only Chios and Lesbos were left to contribute ships, and these states were by now far too weak to secede without support. Lesbos tried to revolt first, and failed completely. Chios, the most powerful of the original members of the Delian League save Athens, was the last to revolt, and in the aftermath of the Syracusan Expedition enjoyed success for several years, inspiring all of Ionia to revolt. Athens was nonetheless eventually able to suppress these revolts.
To further strengthen Athens\'s grip on its empire, Pericles in 450 BC began a policy of establishing *kleruchiai*---quasi-colonies that remained tied to Athens and which served as garrisons to maintain control of the League\'s vast territory. Furthermore, Pericles employed a number of offices to maintain Athens\' empire: *proxenoi*, who fostered good relations between Athens and League members; *episkopoi* and *archontes*, who oversaw the collection of tribute; and *hellenotamiai*, who received the tribute on Athens\' behalf.
Athens\'s empire was not very stable and after 27 years of war, the Spartans, aided by the Persians and Athenian internal strife, were able to defeat it. However, it did not remain defeated for long. The Second Athenian League, a maritime self-defense league, was founded in 377 BC and was led by Athens. The Athenians would never recover the full extent of their power, and their enemies were now far stronger and more varied
| 325 |
Delian League
| 6 |
2,038 |
**August Horch** (12 October 1868 -- 3 February 1951) was a German engineer and automobile pioneer, the founder of the manufacturing giant that eventually became Audi.
## Beginnings
Horch was born in Winningen, Rhenish Prussia. His initial trade was as a blacksmith, and then was educated at *italic=no* (Mittweida Technical College). After receiving a degree in engineering, he worked in shipbuilding. Horch worked for Karl Benz from 1896, before founding *A. Horch & Co.* in November 1899, in Ehrenfeld, Cologne, Germany.
## Manufacturing
The first Horch automobile was built in 1901. The company moved to Reichenbach in 1902 and Zwickau in 1904. Horch left the company in 1909 after a dispute, and set up in competition in Zwickau. His new firm was initially called *Horch Automobil-Werke GmbH*, but following a legal dispute over the *Horch* name, he decided to make another automobile company. (The court decided that *Horch* was a registered trademark on behalf of August\'s former partners and August was not entitled to use it any more). Consequently, Horch named his new company *Audi Automobilwerke GmbH* in 1910, *Audi* being the Latinization of Horch.
## Post Audi {#post_audi}
Horch left Audi in 1920 and went to Berlin and took various jobs. He published his autobiography, *I Built Cars (*Ich Baute Autos*)* in 1937. He also served on the board of Auto Union, the successor to Audi Automobilwerke GmbH he had founded. Horch remained an honorary executive at Auto Union during and after its reincorporation in Ingolstadt, Bavaria in the late 1940s until his death in 1951, ultimately not living to see the later resurrection of his Audi brand a decade later under the ownership of Volkswagen.
He was an honorary citizen of Zwickau and had a street named for his Audi cars in both Zwickau and his birthplace Winningen. He was made an honorary professor at Braunschweig University of Technology. There is an *August Horchstrasse* (August Horch Street) at Audi\'s main manufacturing plant in Ingolstadt
| 326 |
August Horch
| 0 |
2,039 |
**Avionics** (a portmanteau of *aviation* and *electronics*) are the electronic systems used on aircraft. Avionic systems include communications, navigation, the display and management of multiple systems, and the hundreds of systems that are fitted to aircraft to perform individual functions. These can be as simple as a searchlight for a police helicopter or as complicated as the tactical system for an airborne early warning platform.
## History
The term \"avionics\" was coined in 1949 by Philip J. Klass, senior editor at *Aviation Week & Space Technology* magazine as a portmanteau of \"**aviation electronics**\".
Radio communication was first used in aircraft just prior to World War I. The first airborne radios were in zeppelins, but the military sparked development of light radio sets that could be carried by heavier-than-air craft, so that aerial reconnaissance biplanes could report their observations immediately in case they were shot down. The first experimental radio transmission from an airplane was conducted by the U.S. Navy in August 1910. The first aircraft radios transmitted by radiotelegraphy. They required a two-seat aircraft with a second crewman who operated a telegraph key to spell out messages in Morse code. During World War I, amplitude modulation voice two way radio sets were made possible in 1917 (see TM (triode)) by the development of the triode vacuum tube, which were simple enough that the pilot in a single seat aircraft could use it while flying.
Radar, the central technology used today in aircraft navigation and air traffic control, was developed by several nations, mainly in secret, as an air defense system in the 1930s during the runup to World War II. Many modern avionics have their origins in World War II wartime developments. For example, autopilot systems that are commonplace today began as specialized systems to help bomber planes fly steadily enough to hit precision targets from high altitudes. Britain\'s 1940 decision to share its radar technology with its U.S. ally, particularly the magnetron vacuum tube, in the famous Tizard Mission, significantly shortened the war. Modern avionics is a substantial portion of military aircraft spending. Aircraft like the F-15E and the now retired F-14 have roughly 20 percent of their budget spent on avionics. Most modern helicopters now have budget splits of 60/40 in favour of avionics.
The civilian market has also seen a growth in cost of avionics. Flight control systems (fly-by-wire) and new navigation needs brought on by tighter airspaces, have pushed up development costs. The major change has been the recent boom in consumer flying. As more people begin to use planes as their primary method of transportation, more elaborate methods of controlling aircraft safely in these high restrictive airspaces have been invented.
### Modern avionics {#modern_avionics}
Avionics plays a heavy role in modernization initiatives like the Federal Aviation Administration\'s (FAA) Next Generation Air Transportation System project in the United States and the Single European Sky ATM Research (SESAR) initiative in Europe. The Joint Planning and Development Office put forth a roadmap for avionics in six areas:
- Published Routes and Procedures -- Improved navigation and routing
- Negotiated Trajectories -- Adding data communications to create preferred routes dynamically
- Delegated Separation -- Enhanced situational awareness in the air and on the ground
- LowVisibility/CeilingApproach/Departure -- Allowing operations with weather constraints with less ground infrastructure
- Surface Operations -- To increase safety in approach and departure
- ATM Efficiencies -- Improving the air traffic management (ATM) process
### Market
The Aircraft Electronics Association reports \$1.73 billion avionics sales for the first three quarters of 2017 in business and general aviation, a 4.1% yearly improvement: 73.5% came from North America, forward-fit represented 42.3% while 57.7% were retrofits as the U.S. deadline of January 1, 2020 for mandatory ADS-B out approach.
| 620 |
Avionics
| 0 |
2,039 |
## Aircraft avionics {#aircraft_avionics}
The cockpit or, in larger aircraft, under the cockpit of an aircraft or in a movable nosecone, is a typical location for avionic bay equipment, including control, monitoring, communication, navigation, weather, and anti-collision systems. The majority of aircraft power their avionics using 14- or 28‑volt DC electrical systems; however, larger, more sophisticated aircraft (such as airliners or military combat aircraft) have AC systems operating at 115 volts 400 Hz, AC. There are several major vendors of flight avionics, including The Boeing Company, Panasonic Avionics Corporation, Honeywell (which now owns Bendix/King), Universal Avionics Systems Corporation, Rockwell Collins (now Collins Aerospace), Thales Group, GE Aviation Systems, Garmin, Raytheon, Parker Hannifin, UTC Aerospace Systems (now Collins Aerospace), Selex ES (now Leonardo), Shadin Avionics, and Avidyne Corporation.
International standards for avionics equipment are prepared by the Airlines Electronic Engineering Committee and published by ARINC.
### Avionics Installation {#avionics_installation}
Avionics installation is a critical aspect of modern aviation, ensuring that aircraft are equipped with the necessary electronic systems for safe and efficient operation. These systems encompass a wide range of functions, including communication, navigation, monitoring, flight control, and weather detection. Avionics installations are performed on all types of aircraft, from small general aviation planes to large commercial jets and military aircraft.
#### Installation Process {#installation_process}
The installation of avionics requires a combination of technical expertise, precision, and adherence to stringent regulatory standards. The process typically involves:
1. **Planning and Design**: Before installation, the avionics shop works closely with the aircraft owner to determine the required systems based on the aircraft type, intended use, and regulatory requirements. Custom instrument panels are often designed to accommodate the new systems.
2. **Wiring and Integration**: Avionics systems are integrated into the aircraft\'s electrical and control systems, with wiring often requiring laser marking for durability and identification. Shops use detailed schematics to ensure correct installation.
3. **Testing and Calibration**: After installation, each system must be thoroughly tested and calibrated to ensure proper function. This includes ground testing, flight testing, and system alignment with regulatory standards such as those set by the FAA.
4. **Certification**: Once the systems are installed and tested, the avionics shop completes the necessary certifications. In the U.S., this often involves compliance with FAA Part 91.411 and 91.413 for IFR (Instrument Flight Rules) operations, as well as RVSM (Reduced Vertical Separation Minimum) certification.
#### Regulatory Standards {#regulatory_standards}
Avionics installation is governed by strict regulatory frameworks to ensure the safety and reliability of aircraft systems. In the United States, the Federal Aviation Administration (FAA) sets the standards for avionics installations. These include guidelines for:
- **System Performance**: Avionics systems must meet performance benchmarks as defined by the FAA, ensuring they function correctly in all phases of flight.
- **Certification**: Shops performing installations must be FAA-certified, and their technicians often hold certifications such as the General Radiotelephone Operator License (GROL).
- **Inspections**: Aircraft equipped with newly installed avionics systems must undergo rigorous inspections before being cleared for flight, including both ground and flight tests.
#### Advancements in Avionics Technology {#advancements_in_avionics_technology}
The field of avionics has seen rapid technological advancements in recent years, leading to more integrated and automated systems. Key trends include:
- **Glass Cockpits**: Traditional analog gauges are being replaced by fully integrated glass cockpit displays, providing pilots with a centralized view of all flight parameters.
- **NextGen Technologies**: ADS-B and satellite-based navigation are part of the FAA\'s NextGen initiative, aimed at modernizing air traffic control and improving the efficiency of the national airspace.
- **Autonomous Systems**: Advanced automation systems are paving the way for more autonomous aircraft systems, enhancing safety, efficiency, and reducing pilot workload.
### Communications
Communications connect the flight deck to the ground and the flight deck to the passengers. On‑board communications are provided by public-address systems and aircraft intercoms.
The VHF aviation communication system works on the airband of 118.000 MHz to 136.975 MHz. Each channel is spaced from the adjacent ones by 8.33 kHz in Europe, 25 kHz elsewhere. VHF is also used for line of sight communication such as aircraft-to-aircraft and aircraft-to-ATC. Amplitude modulation is used, and the conversation is performed in simplex mode. Aircraft communication can also take place using HF (especially for trans-oceanic flights) or satellite communication.
### Navigation
Air navigation is the determination of position and direction on or above the surface of the Earth. Avionics can use satellite navigation systems (such as GPS and WAAS), inertial navigation system (INS), ground-based radio navigation systems (such as VOR or LORAN), or any combination thereof. Some navigation systems such as GPS calculate the position automatically and display it to the flight crew on moving map displays. Older ground-based Navigation systems such as VOR or LORAN requires a pilot or navigator to plot the intersection of signals on a paper map to determine an aircraft\'s location; modern systems calculate the position automatically and display it to the flight crew on moving map displays.
| 815 |
Avionics
| 1 |
2,039 |
## Aircraft avionics {#aircraft_avionics}
### Monitoring
The first hints of glass cockpits emerged in the 1970s when flight-worthy cathode-ray tube (CRT) screens began to replace electromechanical displays, gauges and instruments. A \"glass\" cockpit refers to the use of computer monitors instead of gauges and other analog displays. Aircraft were getting progressively more displays, dials and information dashboards that eventually competed for space and pilot attention. In the 1970s, the average aircraft had more than 100 cockpit instruments and controls. Glass cockpits started to come into being with the Gulfstream G‑IV private jet in 1985. One of the key challenges in glass cockpits is to balance how much control is automated and how much the pilot should do manually. Generally they try to automate flight operations while keeping the pilot constantly informed.
### Aircraft flight-control system {#aircraft_flight_control_system}
Aircraft have means of automatically controlling flight. Autopilot was first invented by Lawrence Sperry during World War I to fly bomber planes steady enough to hit accurate targets from 25,000 feet. When it was first adopted by the U.S. military, a Honeywell engineer sat in the back seat with bolt cutters to disconnect the autopilot in case of emergency. Nowadays most commercial planes are equipped with aircraft flight control systems in order to reduce pilot error and workload at landing or takeoff.
The first simple commercial auto-pilots were used to control heading and altitude and had limited authority on things like thrust and flight control surfaces. In helicopters, auto-stabilization was used in a similar way. The first systems were electromechanical. The advent of fly-by-wire and electro-actuated flight surfaces (rather than the traditional hydraulic) has increased safety. As with displays and instruments, critical devices that were electro-mechanical had a finite life. With safety critical systems, the software is very strictly tested.
### Fuel Systems {#fuel_systems}
Fuel Quantity Indication System (FQIS) monitors the amount of fuel aboard. Using various sensors, such as capacitance tubes, temperature sensors, densitometers & level sensors, the FQIS computer calculates the mass of fuel remaining on board.
Fuel Control and Monitoring System (FCMS) reports fuel remaining on board in a similar manner, but, by controlling pumps & valves, also manages fuel transfers around various tanks.
- Refuelling control to upload to a certain total mass of fuel and distribute it automatically.
- Transfers during flight to the tanks that feed the engines. E.G. from fuselage to wing tanks
- Centre of gravity control transfers from the tail (trim) tanks forward to the wings as fuel is expended
- Maintaining fuel in the wing tips (to alleviate wing bending due to lift in flight) & transferring to the main tanks after landing
- Controlling fuel jettison during an emergency to reduce the aircraft weight.
### Collision-avoidance systems {#collision_avoidance_systems}
To supplement air traffic control, most large transport aircraft and many smaller ones use a traffic alert and collision avoidance system (TCAS), which can detect the location of nearby aircraft, and provide instructions for avoiding a midair collision. Smaller aircraft may use simpler traffic alerting systems such as TPAS, which are passive (they do not actively interrogate the transponders of other aircraft) and do not provide advisories for conflict resolution.
To help avoid controlled flight into terrain (CFIT), aircraft use systems such as ground-proximity warning systems (GPWS), which use radar altimeters as a key element. One of the major weaknesses of GPWS is the lack of \"look-ahead\" information, because it only provides altitude above terrain \"look-down\". In order to overcome this weakness, modern aircraft use a terrain awareness warning system (TAWS).
### Flight recorders {#flight_recorders}
Commercial aircraft cockpit data recorders, commonly known as \"black boxes\", store flight information and audio from the cockpit. They are often recovered from an aircraft after a crash to determine control settings and other parameters during the incident.
### Weather systems {#weather_systems}
Weather systems such as weather radar (typically Arinc 708 on commercial aircraft) and lightning detectors are important for aircraft flying at night or in instrument meteorological conditions, where it is not possible for pilots to see the weather ahead. Heavy precipitation (as sensed by radar) or severe turbulence (as sensed by lightning activity) are both indications of strong convective activity and severe turbulence, and weather systems allow pilots to deviate around these areas.
Lightning detectors like the Stormscope or Strikefinder have become inexpensive enough that they are practical for light aircraft. In addition to radar and lightning detection, observations and extended radar pictures (such as NEXRAD) are now available through satellite data connections, allowing pilots to see weather conditions far beyond the range of their own in-flight systems. Modern displays allow weather information to be integrated with moving maps, terrain, and traffic onto a single screen, greatly simplifying navigation.
Modern weather systems also include wind shear and turbulence detection and terrain and traffic warning systems. In‑plane weather avionics are especially popular in Africa, India, and other countries where air-travel is a growing market, but ground support is not as well developed.
### Aircraft management systems {#aircraft_management_systems}
There has been a progression towards centralized control of the multiple complex systems fitted to aircraft, including engine monitoring and management. Health and usage monitoring systems (HUMS) are integrated with aircraft management computers to give maintainers early warnings of parts that will need replacement.
The integrated modular avionics concept proposes an integrated architecture with application software portable across an assembly of common hardware modules. It has been used in fourth generation jet fighters and the latest generation of airliners.
| 904 |
Avionics
| 2 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.