http://articles.orla...day-digits-math

**Pi Day! Geeks eat pie, honor the circle today**

**Pi Day -- a national holiday that honors π, one of world's most mysterious and awe-inspiring infinite mathematical constants.**

Pi Day is celebrated annually on March 14 at 1:59:26 p.m. That date and time correspond to the first eight digits of π or 3.1415926.

Pi Day is celebrated annually on March 14 at 1:59:26 p.m. That date and time correspond to the first eight digits of π or 3.1415926.

It may sound like a joke, but π lovers take it very seriously.

In fact, it also happens to be the birthday of the famous German physicist, Albert Einstein, who developed the theory of general relativity.

Pi is defined as the circumference of a circle (length around a circle) divided by its diameter (distance across the circle). It's an irrational number, meaning that it continues into infinity without repeating.

Heavy stuff.

Congress designated Pi Day a national holiday in 2009 as a lighthearted way to draw attention to improving math and science education. Several engineering and technology associations supported the measure.

Besides the educational background, Pi Day is a pop culture phenomenon.

Darren Aronofsky, the director behind the 2010 hit 'Black Swan,' directed and co-wrote the 1998 psychological thriller π, a film about an obsessed math genius who thinks everything in nature, the stock market, and God can be understood through numbers.

Math whizzes celebrate the day with pie-eating contests, featuring round pastries decorated with as many digits of π they can fit on the crust. Others design and wear clever T-shirts with π proudly displayed on the front.

Memorizing as many digits in π is a popular pastime among math lovers. Computers have calculated π to more than a trillion digits.

Here's a 100-digit sample:

3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067

A more "complete" calculation can be found at the official site for Pi Day.

Google, which often changes the design of its logo on special occasions, transposed its letters on March 14, 2010with formulas using π to compute the volume of a sphere and cylinder, circumference of a circle, the periodic function of sin (x), and Archimedes' calculation for approximating the value of π.

The greeting card industry is also taking a bite out of Pi Day.

Greeting Card Universe is offering a line of cards decorated with pie, π, and a small selection of the number's infinite string of digits.

The year 2015 presents an anomaly for Pi Day because it falls on a year included in the first few digits of π: 3.1415. That year it will be celebrated at 9:26:53 p.m.