Yay! It's Pi Day! March 14, when the first three digits of π, 3/14 are the date. Pi Day is exciting more than the usual amount of nerdy interest this year because today is the Pi Day of the Century, the only date this century when the first five digits of Pi will line up in a row: 3/14/15. And at 9:26 and 53 seconds you'll get to experience pi in ten digits.
So what is π, besides a Greek letter and something good to eat with ice cream? Pi, also called Archimedes' Constant, represents the ratio between the circumference and the diameter of a circle, or roughly 3.14. That's about 22/7 so for those of you who like multiple celebrations,you could also celebrate Pi Approximation Day on July 22.
The pi ratio, though not named π until the early 18th century, was known to the ancient Babylonians and Egyptians as a way of calculating the area of a circle. It was the