2. Passive levitation of permanent magnets: diamagnetic levitation

On a practical level, if we consider the experiment of suspending a permanent magnet in a magnetic field created by a second magnet, we'll soon realize that this is impossible. On a theoretical level, Earnshaw in 1842 demonstrated that it is not possible to obtain a stable equilibrium point with a configuration made up of elements interacting with forces that are inversely proportional to the square of the distance. The magnetic forces produced by magnets have just this property. He also demonstrated that the only way to obtain a stable equilibrium point while keeping the same configuration is to use materials with a relative permeabilityµ...