Magnetic Finger Levitator
This is one early experiment we’ve been conducting – levitating magnets. Harder than it looks to get right too. Getting a magnet to stably levitate isn’t actually ‘allowed’.
Earnshaw’s theorem states that no stationary object made of magnets in a fixed configuration can be held in stable equilibrium by any combination of static magnetic or gravitational forces, but seeing as I’ve seen a frog levitating at the Faculty of Science of the University of Nijmegen we thought we’d have a go.
Earnshaw’s theorem is a kind of a consequence of the Maxwell equations, which don’t allow the magnitude of a magnetic field in a free space to possess a maximum, which is required for stable equilibrium.
Diamagnets (which respond to magnetic fields with mild repulsion) DO flout the theorem, as their negative susceptibility results in the requirement of a minimum rather than a maximum in the field’s magnitude. Nevertheless, we’d been told that this sort of levitation without a superconductor (which was used for the frog) was impossible. We found that the stable levitation of a magnet was achievable and portable using the feeble diamagnetism of even Simon’s fingers keeping the strong bismuth magnet hovering in midair without touching it. All the atoms inside Simon’s fingers created a very small magnetic field (2 gauss approx) which compensated for the effects of gravity and allowed the magnet to float.
In the case of diamagnetic levitation, the gravitational force is compensated on the level of individual atoms and molecules. –pretty close to an anti gravity machine. We’re now looking to see if we can scale things up so that it’s the human , not the magnet that levitates. Any help would as ever be greatly appreciated in the forum which will be up and running shortly. A streaming quicktime will also be available.