Scientists levitate gold coins Scientists have shown that levitation is not just a trick from a Harry Potter book. Researchers at the University of Nottingham have used magnetism to make solid objects such as coins float in the air. Scientists have already proven strong, varying magnetic fields could exert an upward force on objects in their path. The Nottingham team found this effect could be dramatically enhanced in cold, magnetised oxygen. Magnetic levitation occurs when the magnetic force is strong enough to overcome gravity and balance a body's weight. Cold oxygen provides extra buoyancy through the "magneto-Archimedes" effect -...