Triskaidekaphobia

  Triskaidekaphobia (from Greek tris=three, kai=and, deka=ten) is a fear of the number 13. It is a superstition. A specific fear of Friday the 13th is called paraskavedekatriaphobia or friggatriskaidekaphobia.

Additional recommended knowledge

What is the Correct Way to Check Repeatability in Balances?

Don't let static charges disrupt your weighing accuracy

How to quickly check pipettes?

Origins

Some Christian traditions have it that at the Last Supper, Judas, 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, the number 13 is not uniformly bad in the Judeo-Christian tradition. For example, the 13 attributes of God (also called the thirteen attributes of mercy) are enumerated in the Torah (Exodus 34: 6-7).^[1] Some modern Christian churches also use 13 attributes of God in sermons.^[2]

Triskaidekaphobia may have also affected the Vikings — it is believed that Loki in the Norse pantheon was the 13th god. More specifically, Loki was believed to have engineered the murder of Baldr, and was the 13th guest to arrive at the funeral. This is perhaps related to the superstition that if thirteen people gather, one of them will die in the following year. This was later Christianized in some traditions into saying that Satan was the 13th angel.

The Mesopotamian Code of Hammurabi (ca. 1760 BC) omits 13 in its numbered list.^[3] This seems to indicate a superstition existed long before the Christian era.

See also Friday the 13th for information concerning the traditions and superstitions surrounding this supposedly unlucky day.

Examples

• The arrest and murder of the Knights Templar occurred on Friday October 13 1307. This event is incorrectly said to be the origin of the supposed unluckiness of Friday the 13th.^{[citation needed]}

• In the US and Canada, many tall buildings do not have a floor numbered "13" (see picture at left for an example).

• On some passenger aircraft such as Continental Airlines, there is no seating row numbered "13" (see picture at right for an example).

• Some airport terminals do not have gates numbered 13.^{[citation needed]}

• In Formula One and many other racing categories, no vehicle carries the number 13.^[4]

• In Buffalo, New York, the downtown city hall has no 13th floor. The number buttons in the elevators have 12, then P, then 14. The "P" floor is like the cellar, with cement walls and floors, and is a storage unit.

• Many apartments and other buildings use "M" as the thirteenth floor (12, M, 14) because it is the 13th letter in the alphabet and many times you would see 12, 12A, 14. The "A" just makes it a different floor.

• Some merchants - a certain, U.S.west-coast tool importer/retailer^{[citation needed]} is one example - avoid the number 13 when pricing wares, preventing the number from appearing on any merchandise, or display-shelf, price label. This practice could leave observant customers to wonder, whether they paid a dollar too much or received a (fearfully gratuitous) markdown when making purchases of $14.xx or $12.xx, respectively.

Similar phobias

• Tetraphobia, fear of the number 4 — in Korea, China, and Japan as well as in many East-Asian and some Southeast-Asian countries, it is not uncommon for buildings (including offices, apartments, hotels) to lack floors with the number 4 and mobile phone manufacturer Nokia's 1xxx-9xxx series of mobile phones does not include any model numbers beginning with a 4.
• In Italy the number 17 is considered the unlucky number.
• Paraskavedekatriaphobia is the fear of Friday the 13th, which is considered to be a day of bad luck in English, German, Polish, Dutch and Portuguese-speaking cultures. In Spanish-speaking cultures, it is Tuesday the 13th that is considered unlucky.

References

• Lachenmeyer, Nathaniel (2004). 13: The Story of the World's Most Popular Superstition. New York: Four Walls Eight Windows. ISBN 1-56858-306-0.
• Havil, Julian (2007). Nonplussed: Mathematical Proof of Implausible Ideas (Hardcover). Princeton University Press, p.152. ISBN 0691120560. 
• Thea, Christopher: What A Dollar Has To Tell You -13 Gentle Reminders- / Lo Que Un Dólar Tiene Para Decirte -13 Sutiles Sugerencias-Outskirts Press (2004) ISBN 9781932672497