created 23 years ago by physicist Larry Shaw to celebrate March 14, or 3/14 ... a date that gives you the first three digits of the mysterious irrational number known as pi. It also happens to be Albert Einstein's birthday. But most of all, it's a day to get silly over science ... by throwing pies, or marching in a circle or enjoying a nice slice of pizza. As every geometry student knows, pi is the ratio of a circle's circumference to its diameter. Its value has been calculated to 5 trillion digits, and there's no end in sight. You could spend the whole day, or the whole year, reciting the digits of pi, but the Web links below will point you to some more enjoyable ways to celebrate the day:Happy Pi Day! The mathematically minded holiday was
Michael Paulsen / Houston Chronicle / AP
Sammy Godfrey, 9, bottom left, strategizes with his little brother, Sammy, 6, at the start of a shaving-cream pie fight in celebration of Pi Day at the Children's Museum of Houston. The event began today (3/14) at 1:59 p.m. Lining up the date and time produces the first digits of pi: 3.14159. Approximately 50 people took part in the event, throwing more than 500 pies that were made using 55 cans of shaving cream.