Magnetic levitator

In 1842 Samuel Earnshaw stated, that there can be no such a thing as magnetic levitation done solely with stationary magnets. There has to exist at least one external force in order to sustain stable levitation. Nowadays we call it a Earnshaw’s theorem. This device allows stable levitation of a small magnet via external force created by diamagnetic surroundings (pyrolitic graphite (ebay)). Diamagnets reacts to the external magnetic field in such a way, that they repel the magnetic field (they act against it) thus creates an external stabilizing force for the small magnet. Small magnet is actually lifted by the big magnet in the top, but without graphite, there would be no stable position for the small magnet to levitate (it would stay on the bottom plate, or would be pressed against the graphite holder).

This device shows, how subtle diamagnetic force can be utilized for fun and education. Small magnet can be easily rotated by blowing air and it will rotate for quite a long time before it comes to a stop (https://youtu.be/QUugLxMSQSQ). Only thing needed is to stabilize the small magnet in small gap in-between the two graphites. You do it only by rotating the screw until you are in the equilibrium with the gravity.