This is one of those things that was introduced to me a couple years ago from TIAW contributor Matt Rawding and has preoccupied my thoughts on and off ever since. It is required viewing for anyone who likes to think. It definitely calls for multiple watches and is fascinating every time. Leave reactions in the comments section.

[Thanks to Rob Bryanton. This animation work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.]