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 \pi) in the sky. Yes, literally.

The stunt was done in San Francisco Bay Area using five planes  at 10,000 feet.  The five synchronized planes wrote the digits of \pi using some  dot matrix technology. The stunt was part of the Zero1 Biennial celebration.

H/T: Gizmodo.com