13 (number)

"Thirteen" redirects here. For the station referred as Thirteen, formerly Channel 13, see WNET. For other uses, see 13 (disambiguation)

13	10	3

13 (thirteen) is the natural number following 12 and preceding 14. It is the smallest integer with eight letters in its spelled out name in English.

Template:Numbers (10s)
Cardinal	13 thirteen
Ordinal	13th thirteenth
Numeral system	tredecimal
Factorization	Prime
Divisors	1, 13
Roman numeral	XIII
Roman numeral (Unicode)	XIII, xiii
Binary	1101
Octal	15
Duodecimal	11
Hexadecimal	D

Mathematics

Let $_{p}\mathrm {log} _{g}x$ denote the discrete logarithm according to the prime number $p$, i.e., the number $l$ modulo $p-1$ such that

$g^{x}\equiv l{\pmod {p}}$

Then 13 is the only prime number $p$ such that for any two primitive roots $g$ and $h$,

$_{p}\mathrm {log} _{g}h\equiv \ _{p}\mathrm {log} _{h}g{\pmod {p-1}}$

Thirteen is the fifth lucky number. It is the fourth two-digit number in the number line. It is the eighth Fibonacci number. There exists an aperiodic set of thirteen Wang tiles.

In science

• The atomic number aluminium
• The number of dimensions in some theories of relativity

Astronomy

• Messier object M13, a magnitude 7.0 globular cluster in the constellation Hercules, also known as the Hercules cluster. It is one of the brightest and best-known of the globular clusters.

• The New General Catalogue object NGC 13, a spiral galaxy in the constellation Andromeda

• The Saros number of the solar eclipse series which began on -2561 September 12 and ended on -1046 March 9. The duration of Saros series 13 was 1514.5 years, and it contained 85 solar eclipses.

• The Saros number of the lunar eclipse series which began on -2313 May 20 and ended on -1015 July 6. The duration of Saros series 13 was 1298.1 years, and it contained 73 lunar eclipses.

• The 13th moon of Jupiter is Elara.

• The known universe is currently thought to be about 13.7 billion years old, with an error of about one percent.

• There are 13 zodiac constellations, which consist of the 12 signs in the astrological zodiac and Ophiuchus.

In religion

• The number of participants at the Last Supper
• Counting both Judas and Matthias, there were thirteen apostles
• Thirteen was once associated with the Epiphany by Christians, the child Jesus having received the Magi on his thirteenth day of life.
• In Judaism, 13 signifies the age of maturity for boys and girls (bar mitzvah for boys and bat mitzvah for girls).
• The number of principles of Jewish faith according to Maimonides
• According to the Torah, God has 13 Attributes of Mercy
• In modern day Wicca, thirteen is considered the maximum size of a coven, and in some traditions is the ideal number of members, and there are also 13 goals of a witch.
• In Sikhism, the number thirteen (13) is a number devoted to the remembrance of God, therefore it is also considered lucky by people who practice the Sikh faith.
• The ancient Maya used the number 13 in the development of their calendrical science which served as the basis of their cosmology as well. The 13:20 ratio expresses the frequencies and cycles of Creation, now scientifically verifiable through the latest discoveries about the classical period Mayan Calendar.

A Significant Number

For various reasons 13 is considered a number carrying a special significance in many cultures.

Unlucky 13

The stall numbers at the Santa Anita Park show that 13 is considered an unlucky number in horse racing.

Thirteen is regarded as an unlucky number in many cultures. Fear of the number 13 is termed triskaidekaphobia. The thirteenth of a month is likewise ominous, particularly when it falls on a Friday in some English-speaking cultures and Germany (see Friday the 13th), a Tuesday in the Greek and Spanish-speaking world, or a Monday in Russia.

Suggested explanations

Thirteen may be considered a "bad" number simply because when a group of 13 objects or people is divided into two, three, four or six equal groups, there is always one leftover, or "unlucky", object or person.

It was suggested by Charles Platt writing in 1925 that the reason 13 is considered unlucky is that a person can count from 1-12 with their 10 fingers and 2 feet, but not beyond that, so the number 13 is unknown, hence frightening, hence unlucky. This idea discounts the use of toes or other body parts in counting.

Some Christian traditions have it that at the Last Supper, Judas Iscariot, the disciple who betrayed Jesus, was the 13th to sit at the table.

According to another interpretation, the number 13 is unlucky because it is the number of full moons in a year. Actually two full moons in a single calendar month (referred to as a blue moon) only happens about every 2.5 years, so to say there are 13 full moons in a year is false. On average, there will be 41 months that have two full moons in a century, so a Blue Moon actually occurs about once every two-and-a-half years, and is in no way related to the number 13. Early nursery rhymes stated there were thirteen months in a year because of the natural moon cycle that was used to count the lunar year. In England, a calendar of thirteen months of 28 days each, plus one extra day, known as "a year and a day" was still in use up to Tudor times. The lunar year was the easiest to count for cultures before scientific methods existed to observe the movement of the earth around the sun, so it was associated with worship of the pagan Great Goddess for thousands of years, which may be another reason for 13 becoming a taboo number. Taboo often is misunderstood when only half of the totem and taboo relationship is recognized. Among religions having totem and taboo characteristics, that which is taboo on a regular basis may become quite sacred on special occasions.

In Tarot decks, the 13th card of the Major Arcana is Death. While Death is rarely interpreted literally, it is possible that this furthered the perception of 13 as an unlucky number.

Another theory about the origin of Friday the 13th as an unlucky day is attributed to this being the day that the Knights Templar were slaughtered in a colaboration between the king of France and the Pope finishing with the burning at the stake of Jaques De Molay.

The legion with which Julius Caesar crossed the Rubicon was the Legio XIII Gemina or the 13th legion.

If one considers 1 not to be a prime number, then 13 is the 6th prime number. 6 is sometimes considered an unlucky number due to its association with 666.

Examples

In Scotland, there is no terminal 13 in any airport, instead there is a terminal 12B.

Some aeroplanes skip a row 13, going straight from 12 to 14.

Some tall buildings have resorted to skipping the "thirteenth floor", either by numbering it "14" or as "12a".

Some streets do not contain a house number 13.

The Code of Hammurabi, a collection of laws created ca. 1760 BC, does not contain a thirteenth law.

On the 13th day of the Persian new year (Norouz), people consider staying at home unlucky, and go outside for a picnic in order to ward off the bad luck.

Most race car drivers consider 13 a very unlucky number, as a car carrying that number has never won the Indianapolis 500 or a NASCAR Nextel Cup race, and almost all Formula 1 teams are no longer given the number 13 when car numbers are given out to teams on basis of points. Usually the team finishing seventh in the previous year's championship will take numbers 14 and 15, instead of 13 and 14. Only once in recent years (1991, Ricky Johnson) has an AMA Motocross rider chosen #13 instead of #14. Some NASCAR tracks refuse to have a pit stall #13.

On the Universal Studios sound stages in California, there is no sound stage numbered 13.

The creators of the online game Kingdom of Loathing avoid the number 13 in all of their programming.

Lucky 13

In Sikhism, the number 13 is considered a special number since 13 is tera in Punjabi, which also means "yours" (as in, "I am yours, O Lord"). The legend goes that when Guru Nanak Dev was taking stock of items as part of his employment with a village merchant, he counted from 1 to 13 (in Punjabi) as one does normally; and thereafter he would just repeat "tera", since all items were God's creation. The merchant confronted Guru Nanak about this, but found everything to be in order after the inventory was checked.

Several successful athletes have worn the number 13. Alex Rodriguez is said to be one of the most talented baseball players ever, and he has also signed the biggest sports contract wears the number 13. Dan Marino, an American football player known for passing more yards than any other quarterback in NFL history, wore the number 13. Another athlete Wilt Chamberlain wore the number 13 on his jersey throughout his NBA career. Also, FIBA rules require a player to wear the number in international competitions (only numbers from 4 to 15 could be worn, and as there are 12 players, one must wear 13); Chris Mullin, who wore #20 in college and #17 in the NBA, wore #13 for both (1984 and 1992) of his Olympic appearances. Shaquille O'Neal wore #13 in 1996, Tim Duncan wore #13 in 2004, Steve Nash is currently wearing it for the Phoenix Suns, and Mats Sundin wears 13 in the NHL.

If one considers the number 1 to be prime, then 13 is the 7th prime number, and 7 is often considered a lucky number.

In mythology

• The number of circles, or "nodes", that make up Metatron's Cube.
• The number of Norse gods (there were 12) at a banquet that was crashed by the evil spirit Loki (making 13) who killed one of the guests with a poison arrow.
• The number of steps, according to Egyptian lore, between life and death.

Age 13

• It is at this point when a person officially becomes a teenager.

• In Jewish tradition a boy becomes a bar mitzvah at age 13, when a ceremony is held and the boy reads from the Torah for the first time.

• A period of 13 years is called a tridecennial, although that word is rarely seen in print, and only appears in one dictionary, the Oxford English Dictionary.

In media

• In music:
  • "13 Angels Standing Guard 'round The Side Of Your Bed" is a song by Canadian band, A Silver Mt. Zion.
  • Wednesday 13 is a musician from North Carolina, who has a band under the same name.
  • XIII (band) is a metalcore band from the Netherlands - Hoorn.
  • 13 (Also, "thirteen") is a rock, funk, hip-hop band from San Francisco.
  • 13 is a 1998 album by German band Die Ärzte.
  • 13 is a 2005 album by American band Six Feet Under.
  • 13 is a 2003 album from heavy metal band Solace.
  • 13 is a 1999 album by British band Blur.
  • MJ13 are a British rock band who take their name from the Majestic 12 and the 13 months of the Mayan Calendar.
  • Thirteenth Step is a 2003 album by American rock band A Perfect Circle.
  • 13 is a 2006 album by Brian Setzer
  • John Mayer's album Room for Squares does not contain a track 13. Instead track 13 is one second of silence before skipping directly to track 14.
  • Pete Yorn's album Day I Forgot does not contain a track 13. Instead track 13 is four seconds of silence before skipping directly to track 14.
• In movie titles:
  • Ocean's Thirteen, the 2007 sequel to Ocean's Eleven and Ocean's Twelve.
  • Thirteen, a 2003 movie by Catherine Hardwicke;
  • Thirteen Days, a 2000 movie about the Cuban Missile Crisis;
  • The Thirteenth Floor a 1999 movie;
  • 13 Going on 30, a movie starring Jennifer Garner in which the protagonist is 13 years old at the outset;
  • Apollo 13, a movie starring Tom Hanks (13th Apollo mission);
  • Thirteen Ghosts, a 2001 horror movie starring Tony Shalhoub (a remake of 1960's 13 Ghosts, which starred Charles Herbert);
  • 13 Conversations About One Thing, starring Matthew McConaughey;
  • Assault on Precinct 13 (1976 movie), an action movie starring Austin Stoker and Darwin Joston;
  • Assault on Precinct 13 (2005 movie), a loose remake of the 1976 movie, starring Ethan Hawke and Laurence Fishburne
  • Dementia 13, a horror movie directed by Francis Ford Coppola; and
  • Ward 13, an animated short movie,
  • Friday the 13th, a series of movies dating from 1980 to 2003 starring a camp counselor killer and her masked killer son.
  • Friday the 13th: The Series, a television series that ran for three seasons, from September 1987 to May of 1990.
  • Nightmare on the 13th Floor, a 1990 horror movie in which the members of a satanic cult are sacrificing people on the hidden 13th floor of a hotel.
  • Golgo 13, an anime about a powerful hitman. The name comes from Golgotha, the site of Jesus's crucifixion.
  • 13 Tzameti, a 2005 film by Géla Babluan. A film where the main character finds himself in a game of Russian Roulette and is assigned the number 13. In this case the number turns out to bring him luck.
• "Thirteen Ways of Looking at a Blackbird" is a poem by Wallace Stevens.
• Strauss and Howe named Generation X the "Thirteenth Generation".
• In the episode of King of the Hill when Connie has her first period and she goes with Hank to the Megalomart to buy tampons, the feminine hygiene items are in Aisle 13. This was changed to Aisle 8A when the episode reran.
• The thirteenth episode of the animated TV program Danny Phantom is named, appropriately enough, "13" and centers around a bad luck charm.
• A song by the band Osker, also the title of a song by the band Bigwig
• A song in American Recordings by Johnny Cash (1994) (Glenn Danzig wrote the song "Thirteen")
• The 13 Ghosts of Scooby Doo, an animated TV series where the venerable cartoon dog finds and opens a chest containing 13 of the most powerful ghouls in the world, and is charged with putting them back.
• XIII, a French comic book about an assassin.
  • XIII, a video game based on the aforementioned comic book.
• Organization XIII, an organization of 13 non-existent beings dubbed "Nobodies" who star in the video games Kingdom Hearts: Chain of Memories and Kingdom Hearts II.
• Red XIII is a character from 1997 PlayStation video game Final Fantasy VII.
• Gotei 13, a military force that contains 13 divisions from Bleach (manga).
• The Movie 1408 a horror based on a short story by Stephen King, The numbers add up to 13.
• '13th Floor' (2006 film) Indias first Commercially Released Digital Film. the story is about two strangers who get stuck in an elevator between the 12th and the 14th floor.
• 'super android 13' A dragonball z movie which Dr geros computer creates a few new androids 13 being the main antagonist.

In fiction

• The number of Stepchildren in the Noon Universe created by Arkady and Boris Strugatsky
• The number of apostles who divided Earth into Stark and Arcadia in the alternate universe of The Longest Journey as well as the time, in millennia, that the Balance between the twin worlds was projected to last.
• Countless references in the award winning series A Series of Unfortunate Events.
• In the manga Black Cat, the main character has a tattoo of the number 13 (XIII) on his chest with the same symbol engraved on his gun.

United States of America

• The number of original colonies the United States was founded from. The original flag had thirteen stars, one for each state. New stars have since been added whenever a new state joins the union, but the idea of adding stripes for new states was soon dropped, so the American flag to this day has thirteen horizontal stripes: six white ones and seven red ones.
• The Great Seal of the United States has:
  • 13 levels of the truncated pyramid,
  • 13 letters in "E Pluribus Unum", which appears in the banner running through the eagle's beak on the right side of the bill's reverse.
  • 13 letters in the phrase "Annuit Coeptis", which appears over the pyramid on the left side of the bill's reverse.
  • 13 stars above the Eagle,
  • 13 leaves on the olive branch,
  • 13 olives on the olive branch,
  • 13 arrows held by the Eagle, and
  • 13 bars on the shield.
• The number of guns in a gun salute to U.S. Army, Air Force and Marine Corps Major Generals, and Navy and Coast Guard Rear Admirals Upper Half.
• The Naval Jack of the United States has 13 stripes, 7 red and 6 white, the rattlesnake has 13 buttons on its rattle, and the motto "Don't Tread on Me" has 13 letters

In other fields

• The original number of members of The Thirteen Club.
• The number of loaves in a "baker's dozen"
• The expression, "A year and a day" refers to 13 28-day lunar months plus 1 day
• The number of Popes named Innocent, for which an honor society containing 13 members at the University of Nebraska is named ("The Society of Innocents")
• The number of cards in a single suit of a standard deck of playing cards
• The ASCII and Unicode value for carriage return
• "Unlucky for some", according to bingo callers
• The number of players in a rugby league team
• The number of Plutonium slugs in Fat Man, the atomic bomb dropped on Nagasaki
• The number 13 on a Hells Angel's, Ton-Up or other biker patch or tattoo refers to the thirteenth letter of the alphabet, M, which signified their link with a motorcycle club (13th letter is M), not marijuana as many suspect.
• 13, or "X3", is the number of the Mexican street gang Sureños. It refers to the thirteenth letter of the alphabet, M, for the Mexican Mafia.
• In rugby union one of the centres, most often but not always the outside centre, wears the 13 shirt
• Israel Naval covert unit - Shayetet 13
• Former professional wrestler Tazz used the number 13 in his ring gear, merchandise, and Titantron video, signifying the 13 years he wrestled in the independent circuit and ECW before being signed by WWE
• A card game very similar to Tien len.
• The ancient card game 'Boumpha' has 13 different cards
• Though some football (soccer) clubs omit the number 13 shirt, it is the current shirt number of the following notable players:
  • Michael Ballack of Chelsea (previously William Gallas)
  • Cristian Chivu of A.S. Roma
  • Aliaksandr Hleb of Arsenal
  • Alessandro Nesta of AC Milan
  • Ji-Sung Park of Manchester United
• There are traditionally thirteen steps leading up to a gallows. It is, however, an urban myth that there are thirteen turns in a hangman's noose (there are most commonly eight turns.)
• There are thirteen letters in macabre-fiction writer Edgar Allan Poe's name.
• Colgate University, in New York State, has a certain liking for the number thirteen. The University was founded in 1819 by thirteen men, with thirteen dollars and thirteen prayers. Colgate is located in Hamilton, whose zip code, 13346, has both the number "13" in it, as well as its last three numbers adding up to thirteen.
• The jersey number of notable athletes Bill Guerin, Pavel Datsyuk, Slava Kozlov and Anthony Calvillo.
• Rondeau is a poem with 13 lines.
• Julius Caesar crossed the Rubicon with the 13th Legion, marking the beginning of Caesar's civil war and the eventual death of the Roman Republic.
• Trece is the Spanish word for thirteen; the number 13 is used to identify members of Sureños - chicano gang members in the U.S. that identify themselves with la Eme - the Mexican Mafia.

Historical years

A.D. 13, 13 B.C., 1913, 2013, 13th century (1201-1300), 1300s (14th century)