I had to flip a coin between thermo and quantum for this one, so forgive me if the coin made the wrong decision. :) I've been thinking about the Meissner Effect. (Well, a girl's got to think about something, anyway.) Suppose you take a piece of lead and shape it into a paraboloid. Chill it until it transitions to superconducting. If you drop a magnet into it, it will "support" itself on its field lines. This is true - I've seen it, and it's easy to find pictures of it on the Internet. Two questions occur to me: 1) It seems to me - and this is just "feel" - that can't be a permanent state. If you were somehow to keep the lead chilled forever, it still seems like something should give way eventually and the magnet should sink down into the bowl. Would it be right to say that the repulsion of the field lines eventually disarranges the domains in the magnet, turning it into just a lump of iron? If so, would that derangement occur faster if the magnet were pushed down deeper into the bowl? Or am I just out in left field somewhere? 2) Suppose you did this with an electromagnet, with the power off. Once it's in the bottom of the bowl, you turn on the power. There'll be a little bit of a power surge - partly until the back EMF of the coil builds up, but partly too (I should think) as the magnet "lifts" itself out of the bowl. The energy to raise it must come from somewhere, after all, and the battery is the logical candidate. Suppose you then turn off the power by switching the coil from a battery to a load of some sort. Would you get back the additional power that went into the magnet from raising it up as it sank back down? If so, what is the specific mechanism of that part of it - it feels like it should be an induction effect, but induction by what, through what? I'm sure I could figure this out if I sat down and played with it, but it's been some time since my EM classes, so I figured I'd try here first. Thanks for your patience.