Simple, neat video of the Meissner effect in action. At the beginning of the movie, the black block just sits there inertly. When the disembodied hand adds liquid nitrogen, the block (possibly yttrium) goes below its critical temperature, becomes superconducting, and expels all magnetic field lines, causing the magnetic chip to levitate. Now if only we had some kind of hover-vehicle using the Meissner effect! Ohwait...