I’m a sucker for videos that show us new ways to appreciate simple motion, and this video does just that. It lets us see how a ball, falling onto fine sand, makes an air bubble underneath the sand that rises up and erupts.
I’ve seen objects falling in sand many times, but this video shows details I’ve never seen before. The best detail is the fact that, with a fast enough collision, an air bubble forms under sand and travels upwards, just the way air bubbles do under water.
I also like that the collisions between sand particles causes the sand to group together in clumps even as it’s falling through the air. This is very, very cool.