- "Twenty" redirects here. For the village in England, see Twenty, Lincolnshire.
20 (twenty) is the natural number following 19 and preceding 21. A group of twenty units may also be referred to as a score.[1]
[edit] In mathematics - An icosahedron has 20 faces. A dodecahedron has 20 vertices.
- 20 can be written as the sum of three Fibonacci Numbers uniquely, i.e. 20 = 13 + 5 + 2.
- The product of the number of divisors and the number of proper divisors of 20 is exactly 20.
[edit] In science [edit] Biology - The number of proteinogenic amino acids that are encoded by the standard genetic code.
- In some countries, the number 20 is used as an index in measuring visual acuity. 20/20 indicates normal vision at 20 feet, although it is commonly used to mean "perfect vision" (Note that this applies only to countries using the Imperial system. The metric equivalent is 6/6). When someone is able to see only after an event how things turned out, that person is often said to have had "20/20 hindsight".
- There are 20 baby teeth in the deciduous dentition.
[edit] In religion [edit] In sports
[edit] Age 20 - Twenty is the age of majority in Japanese tradition. Someone who is exactly twenty years old is described as hatachi
- The age to be a adult in some cultures.
[edit] In other fields - The number of twenty can also be called a score (as Abraham Lincoln did in his Gettysburg Address).
- Twenty questions is a popular party game
- The Twenty Year Curse refers to the pattern of presidents of the United States who were elected to office in 1840, 1860, 1880, 1900, 1920, 1940, and 1960 to die in office. This pattern ended with the 1980 presidency of Reagan, who survived his time in office and, notably, an attempted assassination.
- Bands with the number twenty in their name include Matchbox Twenty
- In the 1974 sci-fi film Dark Star, Exponential Thermostellar Bomb number 20 threatens to detonate in the Dark Star's bomb bay
- A 20-minute-long program of advertisements and trailers shown before some films playing in American movie theaters is called "The Twenty" (spelled "The 20wenty")
- Yan Tan Tethera is a 20-word jingle for counting sheep
- The ordinal adjective is vicenary
- 20/20 is a late-night newsmagazine program on the ABC network, that has been hosted by Barbara Walters, Hugh Downs, Elizabeth Vargas, and others
- In the roleplaying game Dungeons and Dragons (as well as other RPGs that use twenty-sided dice), twenty-sided dice play a pivotal role in gameplay, and to "roll a twenty" is significant to the point that it is sometimes used in other, usually related, contexts, similar to the use of "doubles" in reference to Monopoly.
- Cigarettes are usually packaged with 20 in each pack.
- "T" is the 20th letter in the alphabet.
- According to The Strokes in the song You Only Live Once there are 20 ways to see the world, and 20 ways to start a fight.
20 is: - Twenty, a village in Lincolnshire
- In the United States Constitution, $20 is the threshold value of civil disputes above which the right to trial by jury is preserved
- A denomination of U.S. dollar featuring Andrew Jackson's portrait
- A denomination of Pound sterling featuring Adam Smith's portrait
- The code for international direct dial phone calls to Egypt
- The designation of Interstate 20, a freeway that runs from Texas to South Carolina
- 20 (album), a 1988 album by Harry Connick, Jr.
- Twenty (album), a 1997 album by Lynyrd Skynyrd
- 20 (Terminaator album), a 2007 album by Terminaator
- Twenty (concert), a 2006 concert celebrating the 20th Anniversary of Regine Velasquez held at the Araneta Coliseum, Philippines. It was awarded Best Major Concert Act by the Aliw Awards.
- CB slang for "a place", being short for "10-20", used in reference to a person or object's location
- One of the TCP/IP "well-known ports", port 20 being used for File Transfer Protocol
- In the French and Portuguese education system, grades are given out of 20. Giving 20/20 is a very rare occasion.
[edit] Historical years 20 A.D., 20 B.C., 1920, 2020, etc. [edit] References - ^ John H. Conway and Richard K. Guy, The Book of Numbers. New York: Copernicus (1996): 11. ""Score" is related to "share" and comes from the Old Norse "skor" meaning a "notch" or "tally" on a stick used for counting. ... Often people counted in 20s; every 20th notch was larger, and so "score" also came to mean 20."
|
