March 14, when written as 3/14, it represents the first three digits of pi. It is the ratio of the circumference of a circle to its diameter. Every year we honor the world's most famous mathematical constant. Pi enthusiasts around the world embrace their inner nerdiness. They celebrate Pi Day.

The date also happens to be Einstein's birthday. It inspires a variety of events every year. Last year was the ultimate Pi Day. When you added the year to the date notation, 3/14/15, it encompassed even more digits in the sequence. We won't see this happen again for 100 years.

Why are people crazy about pi? The number is 3 followed by a never-ending string of random numbers after the decimal point.

It is irrational. That means it cannot be expressed through the division of two whole numbers.

It is also a transcendental number. That means that it isn't the root of any algebraic number.

This irrational and transcendental nature appeals to people. Perhaps it is because pi's endless flow of digits reflects the unending circle it helps to trace.

Pi has held an almost mystical quality to humans throughout time. Its unspoken presence can be felt in the circular ruins of Stonehenge. It can be felt in the vaulted ceilings of domed Roman temples. It can also be seen in the celestial spheres of Plato and Ptolemy.

It has inspired centuries of mathematical puzzles. And it has inspired some of humanity's most iconic artwork.

People spend years of their lives attempting to memorize its digits. Contests are held to see who knows the most numbers after the decimal. Some people write "piaku." Those are poems in which the number of letters in each word represents subsequent digits of pi.

Other people create complex works of art. They are inspired by the randomness of pi. The list goes on and on. Not unlike pi itself.

How are you celebrating Pi Day?

I don't like pie