# Happy PI Day!

Today the world celebrates a rare event: PI Day, an invention of an American scientist to commemorate mathematical science, which has gained some importance to the point such that the search engine Google has decided to modify – as in other opportunities – their logo in honor of the date.

PI day was officially declared last year in the United States and the March 14 selection is due to the way that American culture describes the calendar: 3/14 – month, in this case March, registers first – to coincide with the mathematical expression 3.14, which indicates the radius of the circumference of the circle and first used in 1706.

With this designation, the physicist Larry Shaw wanted to honor the importance of mathematics in modern science and in today’s economy. The date has been included in the Geek calendar and is usually held at 1.59 pm, coinciding with an approximation of Pi to the value 3.14.

Here are some fun facts about this irrational number.

- The Babylonians knew of PI’s existence nearly 4,000 years ago. A Babylonian tablet dating back to 1900 and 1680 BC calculated PI as 3.125
- There is a pi language known as Pilish. The objective to write using words that contain a certain number of letters that would coincide with PI. One book written in Pilish is «Not A Wake» by Mike Keith.
- Although we know PI is 3.14, computers are hard at work trying to figure out the complete number. As of December 2013, they had calculated PI to 12 trillion digits.