, you have entranced the greatest minds humanity has ever produced. 3.14159 (and so on), you are an enigma, wrapped in infinity, wrapped in a beautiful wonder. Useful for computing the area of a circle (the elegant formula, Pi r [squared], says it all), you are also useful for explaining probability. Drop a needle on a piece of lined paper; the probability that the needle will cross one of the lines is very close to the truncated value of Pi, as noted in the classic Buffon's needle problem. You are irrational, like a beautiful woman, and yet we love you for it (like a beautiful woman). The Saint Louis Science Center (5050 Oakland Avenue; 314-289-4400 or www.slsc.org
) celebrates the intricacies of your nature today (3/14, natch) with all manner of Pi-themed games, trivia, hands-on activities and, more important, brain-on Pi activities. Get into the digits; admission and all Pi events are free, and the Science Center is open from 9:30 a.m. to 4:30 p.m.
Tue., March 14