The irrational number pi is the ratio of a circle's circumference to its diameter, and it starts off - as you no doubt know - with 3.14. Thus its celebration (according to American notation) on March 14, 3/14. Today also happens to be Albert Einstein's birthday, which makes the day even more mathematically festive.
Happy Pi(e) Day!
Celebrate the most famous irrational number with delicious pie.
Pi goes on from there, endlessly, in a bewitching manner that, as far as we know, never repeats itself. It has been calculated to over a trillion digits without a pattern ever having been manifested, although that doesn't stop people from looking for it. Pi is both unique and endless.
The earliest written record of pi was found in the city of Babylon dated somewhere between 1900 and 1600 BC. Pi may not be the central number of the universe, as the main character in one of Darren Aronofsky's earliest movies believed. But it is a fascinating and weird number, and it has to do with circles, which makes it doubly apt for being celebrated with pie.
The first Pi Day was organized by physicist Larry Shaw at the San Francisco Exploratorium in 1988. March 14 was recognized as Pi Day by the U.S. House of Representatives in a non-binding resolution that passed in 2009. And the Internet, which is a magnet for people who like both math and delicious desserts, is also a big fan of Pi Day.
There are a lot of ways to celebrate Pi Day, of course. One of my favorite easy pie recipes is to mix a box of chocolate pudding with milk and whipped cream, then pour it into a pre-made crust. Refrigerate it to set, and you've got yourself a quick and delicious pudding pie. This may be the best ratio of "effort involved" to "payoff deliciousness," and it can be yours for about five dollars out of pocket.
Of course, any kind of pie will do for Pi Day. You don't have to bake it yourself, either; you can buy a pie at the store, or have a slice at a restaurant. Apple pie is a common favorite, and apples have that connection with Newton, so you can ham that up as another mathematical angle. (Well, it's more about physics, but let's not mince words. And let's not discuss mincemeat pie; I detest it.)
But don't worry if you missed out on the Pi Day celebrations. You can always celebrate on July 22 (22/7 in the European notation) which is Pi Approximation Day.