Hey DarthRage,
Cool, it sounds like we have some common background.
Darth Rage said:
Noble collection did it with those Harry Potter pens didn't they? I thought they worked with magnets.
These are interesting! - I had never seen them. I googled them to check what you were talking about. They do certainly seem to use magnets for the levitation, but note that one end of the pen is physically touching the base -- I think that is the loophole.
Darth Rage said:
I imagine there is a solution somewhere, but it would probably be very expensive, and as you said out of the realm of PF. My initial thought for it would be to have more than one magnet in the base (probably three) and only one in the rock. This way you would have multiple magnetic fields acting in concert to keep the rock centered and stable between the three. Just a thought. I have a pretty good idea how magnets work, especially the supercons. Did I mention I am an MRI supervisor and taught radiation physics on the university level?
Thanks for complimenting the idea though!
Definitely - I think it's a fantastic idea from an aesthetic point of view.
The superconductor scenario I was referring to is an example of the
Meissner Effect where a (non-permanently magnetized) superconductor rejectss any external field in an extreme implementation of Faraday's law. The superconductor is then placed on top of a permanent magnet. Surface currents are induced to expel the external field, which results in a secondary field in direct opposition to the primary, and a net repulsion. This one was originally suggested as a joke.
I did a little more looking around on the topic though, to double check my intuition/memory. As usual,
Wikipedia has an excellent article. It confirms that there is no way (even in principle) to set up a *stable* equilibrium with only static magnetic fields. There will always be a tendency to flip, or accelerate to the side, from just the smallest random jitter - Like trying to balance a pencil on the tip. But they do mention some interesting alternate scenarios.
This is an example of the spin-stabilized motion I was referring to, which is not practical here.
But the MOST
interesting
thing I found has to do with alternating fields produced by dual coils carrying AC current. This will apparently suspend a conducting ball stably, in a manner somewhat similar to the Superconducting effect mentioned previously. But here, since the external field is continuously changing, a persistent current can be set up even in a normal conductor (with non-zero resistance). I think this could possibly (would need a bit more reading/research/consideration of overheating dangers, etc.) feasible for a sculpture implementation. There is nothing complicated about the circuitry at all. We are already plugging these things into the wall for saber effects, so why not? I doubt the rock could be made to float very high practically, but even just a quarter inch would be very impressive, especially once you noticed that it is freely turning with no material contact whatsoever.
So - Maybe it could be fantastic!
OR a superconductor ... I fear this is outside even PF buck-range 
