The Pythagorean Cup
Pythagoras is mostly known for his theorem and not his practical jokes. I want to change this. The Pythagorean cup is a simple device designed to make people look like idiots. It contains a thin pipe that runs from the bottom of the vessel up to the top of a central column. As the cup is filled the level of liquid within the pipe matches that of the surrounding cup according to Pascal’s principle of communicating vessels. If the cup is filled above the turn in the pipe then the liquid begins to pour out the bottom. Not only that but it creates a siphon in the process, which empties the entire contents of the cup right into the gluttonous drinker’s lap. Hilarious.