Pi In The Sky, Literally
Ishky, a California-born artists collaborated with programmers and scientists to do one of the most compelling stunts: to write the first 1000 digits of the irrational number pi (or 
The stunt was done in San Francisco Bay Area using five planes at 10,000 feet. The five synchronized planes wrote the digits of
H/T: Gizmodo.com
) is probably the most popular among all the irrational numbers. It is seen in almost all fields of mathematics and it often appears in places that you least expect it to be (like in birthday party perhaps?).
) of a circle and its diameter (
). That is, if we take a circle of any size, measure its circumference, measure its centimeter and divide them*, then