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!

In old movies, they had to substitute small models for the real thing, so the physics were all wrong. Watch this video of the steamboat in the African Queen going over a waterfall. It’s clear the boat in the waterfall is about two feet long. With computer simulations and graphics, they can do much better these days. Here’s a clip from The Incredibles that involves a van speeding through traffic. Since they aren’t using a mechanical model, they can get the physics right, or close enough for a cartoon fantasy world.