Physics demonstrations: the Pythagoras cup
This is the trick of the Pythagorus cup, also known as the Pythagorean cup or the Tantalus cup! It can be used as a nice prank to play on someone (don’t use red wine, unless you need to replace your carpeting anyway), but also serves as a nice demonstration of some physics of fluids.
Behold the analytical solution to any managerial or governmental function. Bloody know when enough is enough or it all goes down the drain.