Have you heard of the Leidenfrost effect? If not, it’s about to be your favorite effect. If yes, same.
The basic idea is, when a liquid comes in contact with something really hot–about twice as hot as the liquid’s boiling point, although it changes on certain factors like the size of the drop–the liquid never comes in direct contact with the surface; vapor acts as a barrier that keeps the two separated. When you flick drops of water on to a pan to check the heat, that skittering you see and hear is because of this effect.
Got it? Great. One more thing: by using a surface with jagged edges, you can control the direction the water moves in. (You know those tire traps that slash your wheels when you reverse? They’re sort of like that.) That’s what University of Bath undergraduate students Carmen Cheng and Matthew Guy did when they created this Leidenfrost maze. Without giving away too much, it’s the coolest science-y thing you’ll see today.