There's a greedy cup siphon in your washing machine fabric softener try. Also called a Pythagorean cup. It's also used in urinals and novelty drinking receptacles. It's an example of a fluid dynamic ...

Pythagorean cup, a cup that will spill all its contents if you don’t fill it just right, thanks to a hidden siphon mechanism. Elon Musk makes a bold prediction, says 'In 36 months, cheapest place to ...