The Greedy Cup Has Become Even More Devious - YouTube
Pythagorean Cup : 3 Steps (with Pictures) - Instructables
The Civilized Glass by Mr. Sci Science Toy Factory | The Civilized Glass: http://physicstoys.blogspot.com/p/physics-toy-store.html A most elegant version of the famous Pythagorean cup. Functions as a... | By Physicsfun | Facebook