Triskaidekaphobia
Triskaidekaphobia ( , ; ) is fear or avoidance of the number . It is also a reason for the fear of Friday the 13th, called "paraskevidekatriaphobia" () or "friggatriskaidekaphobia" (). The term was used as early as in 1910 by Isador Coriat in "Abnormal Psychology". Origins. Norse mythology. According to folklore historian Donald Dossey, the unlucky nature of the number "13" originated with a Norse myth about 12 gods having a dinner party in Valhalla. The trickster god Loki, who was not invited, arrived as the 13th guest, and arranged for Höðr to shoot Balder with a mistletoe-tipped arrow. Dossey: "Balder died, and the  whole Earth got dark. The whole Earth mourned. It was a bad, unlucky day." This major event in Norse mythology caused the number 13 to be considered unlucky. Judas theory. From the 1890s, a number of English language sources have related the "unlucky" number thirteen to an idea that at the Last Supper, Judas, the disciple who betrayed Jesus, was the 13th to sit at the table. The Bible says nothing about the order in which the Apostles sat, but there were thirteen people at the table. Events related to "unlucky" 13. Effect on US Shuttle program mission naming. The  disaster that occurred on Apollo 13 may have been a factor that led to a renaming that prevented a mission called STS-13. STS-41-G was the name of the thirteenth Space Shuttle flight. However, originally STS-41-C was the mission originally numbered STS-13 STS-41-C was the eleventh orbital flight of the space shuttle program. The numbering system of the Space Shuttle was changed to a new one after STS-9. The new naming scheme started with STS-41B, the previous mission was STS-9, and the thirteenth mission (what would have been STS-13) would be STS-41C. The new scheme had first number  stand for the U.S. fiscal year, the next number was a launch site (1 or 2), and the next was the number of the mission numbered with a letter for that period. In the case of the actual 13th flight, the crew was apparently not superstitious and made a humorous mission patch that had a black cat on it. Also, that mission re-entered and landed on Friday the 13th which one crew described as being "pretty cool". Because of the way the designations and launch manifest work, the mission numbered STS-13 might not have actually been the 13th to  launch as was common throughout the shuttle program; indeed it turned out to be the eleventh. One of the reasons for this was when a launch had to be scrubbed, which delayed its mission. NASA said in a 2016 news article it was due to a much higher frequency of planned launches (pre-Challenger disaster). As it was, the Shuttle program did have a disaster on its "one-hundred" and thirteenth mission going by date of launch, which was STS-107. The actual mission STS-113 was successful, and had actually launched earlier due to the nature of the launch manifest. Omission  of 13th rooms, floors and decks. Many ships, including cruise liners have omitted having a 13th deck due to triskaidekaphobia. Instead, the decks are numbered up to 12 and skip straight to number 14. Hotels, buildings and elevator manufacturers have also avoided using the number 13 for rooms and floors based on triskaidekaphobia. Lucky 13. In some regions, 13 is or has been considered a lucky number. For example, prior to the First World War, 13 was considered to be a lucky number in France, even being featured on postcards and charms. In more modern times, 13 is lucky in  Italy except in some contexts, such as sitting at the dinner table. In Cantonese-speaking areas, including Hong Kong and Macau, the number 13 is considered lucky because it sounds similar to the Cantonese words meaning "sure to live" (as opposed to the unlucky number 14 which in Cantonese sounds like the words meaning "sure to die"). Colgate University was started by 13 men with $13 and 13 prayers, so 13 is considered a lucky number. Friday the 13th is the luckiest day at Colgate. A number of sportspeople are known for wearing the number 13 jersey and performing  successfully. On November 23, 2003, the Miami Dolphins retired the number 13 for Dan Marino, who played quarterback for the Dolphins from 1983 to 1999. Kurt Warner, St. Louis Rams quarterback (NFL MVP, 1999 & 2001, and Super Bowl XXXIV MVP) also wore number 13. Wilt Chamberlain, 13-time NBA All-Star, has had his No. 13 Jersey retired by the NBA'a Golden State Warriors, Philadelphia 76ers; Los Angeles Lakers, Harlem Globetrotters, and Kansas University Jayhawks, all of which he played for. In 1966, the Portugal national football team achieved their best-ever result at the World Cup final tournaments by  finishing third, thanks to a Mozambican-born striker, Eusebio, who has scored nine goals at World Cup – four of them in a 5-3 quarterfinal win over North Korea – and won the Golden Boot award as the tournament's top scorer while wearing the number 13. In the 1954 and 1974 World Cup finals, Germany's Max Morlock and Gerd Müller, respectively, played and scored in the final, wearing the number 13. More recent footballers playing successfully despite wearing number 13, include Michael Ballack, Alessandro Nesta, and Rafinha. Among other sportspeople who have chosen 13 as their number, are Venezuelans  Dave Concepción, Omar Vizquel, Oswaldo Guillén and Pastor Maldonado due to the number being considered lucky in Venezuelan culture. Swedish-born hockey player Mats Sundin, who played 14 of his 18 NHL seasons for the Toronto Maple Leafs, setting team records for goals and points, had his number 13 retired by the team on 15 October 2016.