I ran into the sources for today's post while searching for the answer to a great question posed by +Bruce Elliott regarding yesterday's post [1] about flux pinning and stable superconductor levitation. Bruce's question was: "...Of course, like any good post, it leads to more questions. So here's my next one: I would think that since the the induced currents resist any change to the magnetic field, that they would have an effect analogous to friction, i.e. any attempt to change the position of the conductor (or magnet) would be similar to moving an object through a very viscous fluid - hard to do, but once done, the object stays put in the new position. What we see in the NASA video, however, is that when the levitating magnet is poked, it oscillates slightly. This looks more like the motion of an object in a potential well, like a mass on a spring. This suggests that the superconductor "remembers" the equilibrium position (and the corresponding ma...