Levitating Superconductor on a Möbius strip and Quantum Levitation: A mind-blowing demonstration and explanation. Bonus: More liquid nitrogen and more levitation vids.
Superconductors are materials that conduct electric current with no resistance. Electrical resistance is the property of a material to oppose current passing through and is found in nearly everything from light bulb filaments to your own body. Superconductivity occurs at extremely low temperatures and induces, or creates, a strong magnetic field. The current that flows at the surface of the superconducting material creates these magnetic fields. Inside the superconductor, the magnetic fields are canceled out, but outside they are strong and can levitate a magnet.