• Question: in a magnetic force field could you levitate

    Asked by calum to James_M on 20 Jun 2011.
    • Photo: James M Monk

      James M Monk answered on 20 Jun 2011:

      If the magnetic field were strong enough, but it would have to be very strong. Andrew Geim did it with a frog.

      What happens is that all of the water molecules in your body have a magnetic field associated to them because of the electrons’ angular momenta. Normally there is no overall magnetic field because the water molecules are pointing in different directions.

      When a very strong magnetic field is applied it causes the water molecules to line up in the same direction, inducing an overall magnetic field. This field opposes the strong magnetic field, so the two magnets repel each other.

      This kind of effect is also used in MRI scanners, which use very powerful magnets to line all the water molecules in a patient’s body up. The magnets there aren’t powerful enough to levitate a person though.

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