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Question about a magnet and normal force.

  1. Nov 10, 2012 #1
    Lets assume that liquid superconductors exist. Now I place a magnet above a pool of the
    liquid. Now will the surface of the liquid remain level or will it appear to have dent in it.
    Im not sure I kind of back and forth in my head.
  2. jcsd
  3. Nov 10, 2012 #2


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    Science Advisor

    If there was a fluid that was superconducting and would remain superconducting throughout its volume despite deformations and flows, then yes, there would be a dent, because that would reduce energy in magnetic field, allowing gravitational potential energy to increase.

    However, theories of superconductivity I am familiar with require a lattice. Therefore, a conventional superconductor will not be able to exist in a fluid state.

    There are some hypothetical ways around that. Option one. We might be dealing with superfluid. An ionic superfluid would also be a superconductor. If like Helium such a superfluid would exist as combination of superfluid and normal phases, the magnetic field would only expel the superfluid phase. So fluid surface would remain level, but properties of the fluid near and away from magnet would be different. I am not aware of any material, even a hypothetical one, that would fit the bill. So this is pure conjecture.

    Option two is supersolid. It's effectively a superfluid with a lattice. In principle, it could be a superconductor. The only material to have been theorized to be a supersolid superconductor is metallic hydrogen, and by that point we are in crazy territory. If such a phase of hydrogen exists, its interaction with magnetic field would be absolutely bizarre, and I wouldn't even try to make a prediction.
  4. Nov 10, 2012 #3
    Its not clear to me why the gravitational potential energy would increase or why
    it would reduce energy in the B field.
    thanks for your post
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