Happy Friday the 13th!

Do you suffer from triskaidekaphobia? If so, today is your holiday! This is the only Friday the 13th of the year, so be sure to celebrate by walking under ladders and smashing mirrors. I honor of Friday the 13th, National Geographic takes a look back at the superstition's secret history and the mathematics of the calendar. From National Geographic:


(Donald Dossey, author of Holiday Folklore, Phobias and Fun,) traces the fear of the number 13–aka, triskaidekaphobia–to a Norse myth about 12 gods having a dinner party at Valhalla, Norse mythology's heaven. In walked the uninvited 13th guest, the mischievous god Loki. Once there, Loki arranged for Hoder, the blind god of darkness, to shoot Balder the Beautiful, the god of joy and gladness, with a mistletoe-tipped arrow.

"Balder died, and the whole Earth got dark. The whole Earth mourned. It was a bad, unlucky day," Dossey said.

Thomas Fernsler, an associate policy scientist in the Mathematics and Science Education Resource Center at the University of Delaware in Newark, said the number 13 suffers because of its position after 12.

According to Fernsler, numerologists consider 12 a "complete" number. There are 12 months in a year, 12 signs of the zodiac, 12 gods of Olympus, 12 labors of Hercules, 12 tribes of Israel, and 12 apostles of Jesus.

In exceeding 12 by 1, Fernsler said 13's association with bad luck "has to do with just being a little beyond completeness. The number becomes restless or squirmy"–not unlike some folks with triskaidekaphobia today.

Some people are so paralyzed by Friday the 13th superstitions that they refuse to fly, buy a house, or act on a hot stock tip, for example.

"It's been estimated that [U.S] $800 or $900 million is lost in business on this day because people will not fly or do business they would normally do," said Dossey, the historian, who is also the founder of the Stress Management Center and Phobia Institute in Asheville, North Carolina.

"Friday the 13th Superstitions Rooted in Bible and More"

(CC-licensed image from queenie13)