A gas pump will shut off when the tank is full; we’ve always taken that for granted. It’s a fine feature that keeps gas from spilling all over us. But how does it know? The mechanism is a low-tech yet surprisingly complicated system. It’s easy to understand the way Brain Stuff explains it in this video, but later on when you try to explain it to someone else, you’ll end up just showing them this video. -via Geeks Are Sexy
Source: neatorama