Friday, June 13, 2008

Tell me the date again

Today is that day that shows up 1.72 times per calendar year. Yep; Friday the thirteenth.

One point seven two times; that’s a statistic, and if studied from a statistical point of view, there’s nothing spooky about Friday the thirteenth. It’s a predictable event brought about by the fact that the Gregorian calendar follows a leap-year pattern that repeats itself every 400 years.

That’s 146,097 days, which is divisible by seven, which produces an even number of weeks, and that means that the thirteenth day is spread across the calendar almost equally. In four hundred years, it falls 688 times on Friday, 687 times on Sunday and Wednesday, 685 times on Tuesday and 684 times on Thursday and Saturday.

If you won’t buy that, then consider this. Thirteen is not universally considered to be unlucky. The Italians think just the opposite. In Sikhism, thirteen is believed to be a special number. April thirteen turns out to be Vaisakhi, almost every year, which is the Sikh New Year and the major Sikh Holiday. And the Dutch Centre for Insurance Statistics reports that fewer accidents and reports of fire and theft occur on Friday the thirteenth than on any other Friday.

Here, at home, there were thirteen original states and the Great Seal of the United States has are thirteen olive leaves (with thirteen olives), thirteen arrows, and thirteen stars. These form a triangle over the eagle with the number thirteen at each point.

In addition, Colgate University, in Hamilton, New York, was founded by thirteen men with thirteen dollars, thirteen prayers and thirteen articles. The campus address is 13 Oak Drive and Colgate’s all-men a capella choir is called the Colgate Thirteen. It has, you guessed it, thirteen members.

In Judaism, thirteen is the age at which a boy becomes a Bar Mitzvah. That’s Hebrew for one to whom the commandments apply, which may or may not be a lucky time of life. It is, I suppose, what you make of it, if you’re Jewish.

There are supposed to be thirteen crystal skulls scattered around the world, against the day, according to the ancient Mayans, that they were needed to save humanity from a horrible catastrophe. I don’t know about that one; those crystal skulls didn’t seem to have the power to save the fourth Indiana Jones movie. (I already complained about that, didn’t I?)

And, of course, thirteen is the atomic number of aluminum, which has nothing to do with luck—good or bad—but then, neither does Friday the thirteenth.