I caught this little gem on NPR’s Science Friday. It describes the concept of the Leidenfrost Effect whereby droplets of water hover on a thin layer of steam when placed on a surface heated to optimum temperatures. A group of creative undergraduate scientists discovered that with just the right texturing of the surface, the droplet can be made to climb stairs and, in fact, move in prescribed directions when moving over heated blocks with different textures. Hence, the Leidenfrost water maze. The effect is quite beautiful.