In this video, Youtuber Physics Girl teaches us how to create an amazingly cool pool vortex and explains the science behind the phenomenon. Unfortunately, it’s Winter over here in Canada, so I guess I’ll have to wait until next summer to try this out. I know you could create one in an indoor pool, but I don’t think you’d see it since the sun needs to shine in your pool for you to observe the shadows going across the water.

[Physics Girl]