If I were to freeze a superconductor, the ones made up of yttrium barium copper oxide, with liquid nitrogen and placed it on one of those strong neodymium magnets, it should float right?
Now what would happen if I made a Mobius strip of steel and lined it up with those magnets and then place the superconductors on them and place the whole setup in some cold place (like Neptune or anywhere with temperature less than $4K$), would the moving superconductors make it a perpetual motion machine?
PS: I know perpetual motion does not exist, so please tell me what would stop it from achieving perpetual motion.
Best Answer
One thing that would happen is that the "permanent" magnet, say comprised of any rare earth, would slowly degrade and the magnet would fall.
Recall also that at potentially 'Zero' Kelvin there is still the Heisenberg effect in operation - you cannot have zero momentum - there will either be wiggling due to delta x or delta v - you cannot predict 0x and 0v - the uncertainty principle says something's got to wiggle, even if minisculely, and system energy would gradually degrade.
Why do you thing that twisting the steel strip into a Moebius ring would extend the life of the system? Do you think the superconducted current flow would cause the magnetic field to flip-flop? No such luck. Think of the current flowing down the centerline of the strip - one direction only, and no change in magnetic polarity. Or maybe you think the twist would have some other effect. Not one that simple me can come up with.