Can You Swim in Shade Balls? - Veritasium

If you want to know why Dr Derek is head-deep in what looks like a ball pit (a la xkcd), you probably should watch this video (which might lead you down the rabbit hole into a fascinating video about what going viral and chasing YouTube's algorithm means for YouTubers).

But if not, you should check out the fifteen seconds starting at 2:40 above. Dr Derek mentions that the shade balls (not actually play balls) have "sort of arranged themselves in crystal structures where they're close packed, and there are boundaries between those grains".

There are a few more mentions of close packing efficiency (at 3:55) when it's mentioned that the spheres only cover 91% of the surface area, and you can see the grains reform as Dr Derek and his friends swim through the pool. There's also some physics mentioned about drag being proportional to the square of velocity.

Mostly, though, this is a stunt video, but c'mon, who needs a crystal demonstrator?

Becky, can I put a pool in the budget for next year?