Video of a Super-Cooled Magnet Floating Around a Moebius Strip Track
I love this so so so much. It’s all explained in the video (starting around two minutes in) but in case you missed it:
1) There exists a kind of material that, if you chill it down to very low temperatures, becomes a superconductor, meaning electrons can flow through it freely without resistance. What that means is that a lot of weird stuff can occur. For one thing, if you induce an electric current in a superconductor, that current will flow forever without resistance.
As an analogy, imagine filling your sink with water. If you give the water a brief swirl with your hand the water will flow around the sink. Eventually, though, friction slows it and the water will be still once again. But if the water were frictionless, it would swirl forever. A superconductor is like a frictionless sink, filled with electrons instead of water. Once electrons start to flow, making a current, they never stop.
2) Another important thing is that if you stick a conductor in a moving magnetic field (or move a magnet over a conductor), it will induce a current in the conductor, which will electrons flowing. One of the basic laws of electricity and magnetism is that the flowing electron current (which we call electricity) will itself generate a magnetic field, and it’ll do so in a way to resist the original changing magnetic field. It’s a bit like if you feel yourself falling over, and you flail your arms (or grip something quickly) to get your balance back.
3) Still with me? Now combine this. In a superconductor, if it’s set up properly, you can generate a flow of electrons that’ll whiz around inside it. If you then put that superconductor on a track, it will levitate above the track because gravity pulls it down, changing the magnetic field it feels, so it sets up its own magnetic field to resist that. Same thing if you hang it upside down; gravity pulls it away from the track, so it changes its own field to hold on to the track tighter.
More: Möbius Magnet: Video of a Magnet Floating Around a Möbius Strip Track.