A Hole in a Hole in a Hole
Audible: http://www.audible.com/numberphile
Cliff's glassware: http://bit.ly/ACME_Klein
Extras for this video: https://youtu.be/6Qpfv5y-7WU
More videos featuring Cliff Stoll: http://bit.ly/Cliff_Videos
Cliff references A Comprehensive Introduction to Differential Geometry by Michael Spivak: http://amzn.to/2cwmdB7
Animation: Pete McPartlan
Note from Cliff:
Original ideas & suggestions from Peter Nguyen of Coker College and Danny Stoll of U/Chicago
Amazing glasswork by Tom Adams, George Chittenden, Lucas Clarke, and Xing Wei