“That is VERY freaky. Espically the really dark video on the bottom. That just shouldn’t oughtta be happening like that there...”
This was posted a few weeks ago as well. So weird I had to learn more. It turns out that it is not all that unexpected when it comes to fluid dynamics. The rotation of one thing at one density bound by another medium of a different density is the cause. Various speeds and densities will give all sorts of types of polygons. Pretty cool though, and pretty amazing that we can get images of it.
Google ‘cymatics’. I suspect that has a lot to do with this phenomenon.