Today is Pi Day. Pi Day is held to celebrate the mathematical constant pi in the mm/dd date notation: 3/14, since 3, 1 and 4 are the first three digits of pi.
Pi is the symbol for the ratio of the circumference of a circle to its diameter. With the use of computers, pi has been calculated to over 1 trillion digits past the decimal. Pi is an irrational number meaning it will continue infinitely without repeating. The symbol for pi was first used in 1706 by William Jones, but was popular after it was adopted by the Swiss mathematician Leonhard Euler in 1737.
Here's a nifty little way to visualize what the hell "Pi" actually means:
When a circle's diameter is 1 unit, its circumference is diameter is 1 unit, its circumference is "pi" units.
How many digits will it take until your birthday shows up in Pi?
To find out go here
The Secret of Pi
Wanna see what Pi looks like to 4 million digits?
(Me neither. But if you do, click here)
This is kind of cool. Each digit of pi is mapped to this color chart...
...and then stored to this picture!