"Over all the centuries in which humankind hasdone all sorts of things, I can't help but believethat there are quite a few Friday the 13ths whichhave seen very happy events," Herschbach said.

"Friday the 13th is probably a good time to trysomething that stretches the envelope. In otherwords, try something that requires good luck," hesaid.

The number 13 is still deemed very unlucky inAmerican society. Many apartment buildings skipthe 13th floor in their labeling.

"Are we really a ridiculous enough culture thatwe have to mislabel the floors of our buildings?Are we really that weak?" Kirchhoff asked.

In addition, the 13th day of the month isconsidered a risky travel day.

"It has been estimated that each year theAmerican economy loses a billion dollars fromplane and train reservation cancellations,absenteeism and reduced commerce on the 13th ofeach month," Araujo said.

The superstition is rooted in pagan traditionas well as a number of biblical citations. Mostnotably, Kirchhoff said, the Bible says that Jesuswas crucified on the 13th, the temple of Solomonwas destroyed on the 13th and Eve gave Adam theapple on the 13th.

"What would be fun to do would be to check upon some good things that happened on Friday the13th," Herschbach said, "Its reputation that itis unlucky might not stand up that well.