Pi and Bouncing Balls

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.Check out Brilliant (get 20% off their premium service): https://brillian...

Our Pi Playlist (more videos): http://bit.ly/PiPlaylist
Professor Ed Copeland on a strange occurrence of Pi involving bouncing balls.

More details from Ed at: http://www.numberphile.com/pi/Pi_Balls_Ed.pdf

See his calculations at: http://www.flickr.com/photos/numberphile/6976718861/in/photostream

Check out a computer simulation at http://periodicvideos.blogspot.com/2012/03/pi-and-simulated-bouncing-balls.html (made by a viewer!)

OUR PI VIDEOS ---
ALEX BELLOS AND ROGER DISCUSS ITS HISTORY http://www.youtube.com/watch?v=yJ-HwrOpIps
BOUNCING BALLS AND A STRANGE PROPERTY http://www.youtube.com/watch?v=abv4Fz7oNr0
MATCHES HELP FIND PI http://www.youtube.com/watch?v=sJVivjuMfWA
THE SOUND OF PI http://www.youtube.com/watch?v=wPn4tgmU8ek