On Thursday March 14 nerds around the world rejoiced for Pi Day, a once per year celebration of the infamous number representing the ratio of a circle's circumference to its diameter.
Calculated to over one trillion digits past its decimal point, the number is usually written as 3.14 for short. It dates back to ancient Babylon and Egypt, where it may have been used to calculate measurements in building the Great Pyramid at Giza between 2589 and 2566 B.C. We begin using the number in geometry at a young age and the U.S. House of Representatives declared March 14 "Pi Day" in 2009.
But what of the number's standing in pop culture? We're not just talking about Pi Day. The number was the title of a film by Darren Aronofsky as well as Yann Martel's book (and now movie) "Life of Pi." There's even a cologne by Givenchy named after it.
"Pi is ubiquitous in pop culture," says author of "The Joy of Pi" David Blatner. "That's weird for a number, for something out of math. It strikes a dissonant chord within us. How can something so simple as a circle - the most simple shape in a universe - how can it be defined by something we cannot know?"
Nerdy celebrations abound on Pi Day. At First Slice Pie Café in Chicago, free slices of pizza were given out at 3:14 p.m. Dell offered 3.14 percent off its tablets and MIT has been known to postpone acceptance letters until March 14. The day also coincides with Albert Einstein's birthday, and in Einstein's home town of Princeton, N.J. you can find a four-day festival featuring pie judging, a pie-throwing contest, a pi recitation contest and an Einstein look-alike competition. At 1:59 a.m. Thursday morning, students at Cal Tech held a massive pie-eating party, featuring 130 pies divided by 26 into five different types (get it? Pi = 3.14159265).
"It's a celebration of nerdiness," says president of Cal Tech's math club Christopher Perez. "Pi literally shows up everywhere - in science, in math and nature. A circle is such a fundamental concept."
For more information on Pi Day, visit www.piday.org, which features "all things Pi" including Pi t-shirts, "Trader Joe's Pi(e)s" and a "Pi(ano) Song" video.