Today is the 25th birthday of Pi Day! Yes, believe it or not, we actually set aside a day to celebrate the numerical constant that represents the ratio of a circle's circumference to its diameter, on a flat plane surface. Why was March 14th selected? Because while Pi has been calculated to one trillion digits past the decimal point, we all simply recognize it as 3.14, which also happens to be, today's date.

Started in 1988 by San Francisco's Exploratorium Museum to commemorate the importance of mathematics in our everyday lives, the date also coincides with the birthday of 20th century's most influential physicist - Albert Einstein!

Today, In celebration of the 25th anniversary, the San Francisco museum invited math lovers to parade down the city's waterfront to a newly installed Pi shrine - A brass plate about a foot in diameter engraved with the first 108 digits of Pi - All whilst, singing Happy Birthday to the German scientist.

If the word Pi makes you wanting for the edible version, you are not alone - Early this morning at 1.59 am, the students of Cal Tech in Los Angeles, hosted a pie-eating party with a total of 130 pies - 26 each, of five different varieties - Didn't catch the significance? Then line up the numbers 3.14(date), 159(time), 26(#of pies) 5(variety) - Put them all together and you get 3.14159265 or the first digits of Pi!

Then there are those that create Pi bracelets, musicians who dream up Pi music and even corporations like Microsoft Corp., which is offering a 3.14% discount on Dell tablets today!

So why are we all so fascinated with this number? Apparently, because it is a mystery even to mathematicians who have tried to crack Pi's code with the help of super computers. However, even after calculating it to the trillionth decimal place, they are unable to find a pattern or, an end to it.

And, though the celebration is just twenty five years old, the number itself is almost 4,000 years old. The ancient Babylonians first calculated the area of a circle by taking 3 times the square of its radius, giving Pi the value of 3. They later got closer to the real number with an approximation of 3.124. Egyptian mathematicians overestimated the value slightly, arriving at a number of 3.165 in 1650 BC. Given that they just had rudimentary measurement tools at their disposal, the results are super impressive!

The first person to actually calculate Pi mathematically was one of ancient world's most brilliant mathematicians, Archimedes of Syracuse. However, he was smart enough to realize that his number was also an approximation and concluded that Pi could vary between 3 1/7 and 3 10/71. The fascination of calculating this elusive number accurately has continued since then and so far, no one has cracked the code!

Happy Pi Day! Be sure to let us know, if you did anything special to celebrate this fun day.

Resources: now.msn.com,exploratorium.edu, time.com, npr.com