If you like physics and weird science facts and experiments, then Physics Girl’s the gal for you. In this video, she demonstrates a really crazy scientific quirk. Simply by briefly dragging a plate a few inches across the top of the water in a swimming pool, she creates what’s called a couple of ‘vortexes’ (don’t worry, she’ll explain what they are…). These vortexes then go on for AGES, creating weird little shadows that travel up the length of the pool for minutes at a time, totally in sync.
It’s cool, have a look: