Thirteen is regarded as an unlucky number in many cultures. Thirteen may be considered a “bad” number simply because it is one more than 12, which is a popularly used number in many cultures (possibly due to it being a highly composite number). When a group of 13 objects or persons is divided into two, three, four or six equal groups, there is always one leftover, “unlucky” object or person.
Unreasoned fear of the number 13 is termed triskaidekaphobia. Due to this fear, some tall buildings have resorted to skipping the “thirteenth floor”, either by numbering it “14″ (though it’s really still the thirteenth floor) or by designating the floor as “12a” or something similar. Similarly, some streets do not contain a house number 13. Few Asian countries are however known to openly consider the 13th floor as the way it is without disguising it. [citation needed]
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, and that for this reason 13 is considered to carry a curse of sorts. However, there is evidence that 13 may have been considered unlucky in the pre-Christian era: the Code of Hammurabi, a collection of laws created ca. 1760 BCE, does not contain a thirteenth law.
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. (http://www.obliquity.com/astro/bluemoon.… Says: “On average, there will be 41 months that have two Full Moons in every century, so you could say that once in a Blue Moon actually means once every two-and-a-half years.”
Early nursery rhymes stated there were thirteen months in a year because of the 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.
The thirteenth of a month is likewise ominous, particularly when it falls on a Friday (see Friday the 13th), a Tuesday in the Greek and Spanish-speaking world, or a Monday in Russia. Months with a Friday the 13th must always begin on a Sunday. Friday is the day named after the Great Goddess or one of her manifestations. In English it comes from the Old English frigedæg, meaning the day of Frige the Anglo-Saxon form of Frigga, the Germanic goddess of beauty. In most Germanic languages it is named after Freyja—such as Freitag in Modern German, vrijdag in Dutch, fredag in Swedish, Norwegian, and Danish—but Freyja and Frigga are frequently identified with each other. The word for Friday in most Romance languages is derived from the name of Venus, another manifestation of the goddess in triad, such as vendredi in French, venerdi in Italian, viernes in Spanish, and vineri in Romanian. A Friday that falls on the thirteenth would be especially taboo and likely to be the focus of special ceremonies among such cultures.
Women living in a natural environment tend to have their menses during a full moon.[citation needed] A twenty-eight day menstruation cycle is most typical, so a woman usually has 13 menses in a year. Supposedly, in the past, a woman who “bled” during a full moon might be thought a witch. The fear of women’s connection to the moon, through worship of the Great Goddess, as well as the unscientific association of the full moon with mental disorders has, according to this theory, caused the number 13 to be seen as bad luck, and connected to the powerful supernatural forces of women.
In the Persian culture, 13 is also considered an unlucky number. 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.
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.
A legendary athlete who wore the number 13 was Dan Marino, who passed for more yards than any other quarterback in NFL history, but has never won a Super Bowl. Another legendary athlete Wilt Chamberlain wore the number 13 on his jersey throughout his NBA career. It signified that the number 13 was not unlucky for him, but unlucky for his opponents.
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 most all Formula 1 teams opt out of carrying the number 13 when car numbers are given out to teams on basis of points.
