This is totally cool. Watch as graphite is plunked down on a floor of magnets and guided around by a laser. The laser can even get it to spin in place! We'll tell you how it works.
Researchers have created a little laser-guided graphite hoverboard. It scoots along a layer of magnets, seemingly guided by the light. Graphite is a diamagnetic material — which means it will become magnetized, but at a 180 degree angle to the existing magnetic field. Put it on magnets, and it can become magnetized so it lifts right up off of them. This explains the hovering, but not the directional movement.
As the graphite heats, it attains slightly different magnetic properties. These interact with the magnets below in different ways, shoving the magnet one way or another. With the right kind of set-up, the researchers can even get the graphite spinning in place over a stack of magnets. It's light, being converted into heat, being converted into motion. And it's very, very cool.