If you look closely at a puddle during a rainstorm, you see a weird thing: little balls of water skating around as though the are being rejected by the receiving pool. They disappear quickly, so it’s hard to keep your eye on them. What’s going on? What would it look like if you had faster eyes?
Via Steve Crandall I came across this lovely slow motion video of bouncing water drops. For an instant, before the intervening air is squeezed out, the taut surface of the puddle is essentially a trampoline for descending droplets. I’ve always wondered about the physics of this. Watch!