English: Magnetic Levitation experiment as part of the Magical Material exhibit in the Science Gallery, Dublin. This disc is made of a superconducting material as well as a sapphire crystal. It is cooled with liquid nitrogen as this is when the material becomes superconducting. This results in the material floating stabiliy above a magnet. The track of magnets it is floating on is made in such a way, that the superconductor moves along them like a track. Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled below a characteristic critical temperature.