What happens when you douse a superconducting urinal cake with liquid nitrogen? We haven't given it too much thought, to be honest, though we're guessing it would look a lot like the "levitating" disc pictured above. Developed by researchers at Tel-Aviv University, this device is actually a superconductor hovering over a "supercooled" magnet. While locked within the magnetic field, it can rotate around a vertical axis, turn upside down or do laps around a track -- all thanks to a phenomenon that Tel-Aviv's physicists call "quantum trapping." We're not really sure what that entails, but we do know that the results are pretty incredible. Check them out for
