On 21/02/13 12:20 AM, john mcandrew wrote:
> Does anyone know of a reference that finds the fields of a charged sphere moving in a constant magnetic field?
> My initial thoughts is that there will be a constant circulating current of non-uniform charge density induced in the sphere which becomes a static polarized electric field in its rest frame. It's an interesting problem so I'm pretty sure this is already well known but I can't see it mentioned in Jackson or Griffiths as a problem.
You don't say it's an accelerated sphere this time! So then I
think it essentially is in Jackson. You certainly can find the
transformation of the B-field to the sphere's rest frame there
(where indeed a electric component will be present which will
create a static polarization of the sphere).
But also, it should be clear from Jackson how you then can
transform back the polarized sphere to the frame in which the
sphere is moving (and there you'll still have nothing more than
a static polarization and no circulating current, if the sphere
is not superconducting at least..)
The case may not be explicitly mentioned but all you need for
it is there. (Now if you could make it a uniformly accelerated
sphere it might be more interesting.. in that case I'd also
expect a combination of circulating current and increasing