Re: electrostatic shielding

[Leigh Palmer <palmer@SFU.CA>]

> I guess John Mallinckrodt's reminder of the uniqueness principle finally
> provides a convincing requirement that the charge on the outside of the
> sphere must remain uniformly distributed, provided that rearrangement of the
> inner surface charge alone can cancel the off-center point charge's field
> within the conducting shell.  (As Bob Sciamanda pointed out, no one here
> seems to have shown that this is possible, but it surely seems reasonable.)
>
> Now can I extend this result to another situation?:
>
> Suppose a very large isolated flat conducting sheet carries a net negative
> charge.  Will the charge be uniformly distributed on both surfaces,
> producing a uniform field pointing straight toward the sheet on both sides?
> And if a positive point charge is brought near one side of the sheet, will
> the charge only on that side of the sheet be rearranged and the field on
> that side "distorted", while the charge and field on the opposite side
> remain uniform?

There is a serious problem here. If by "very large" you mean a finite sheet,
then all (hypothetically infinitessimally thick) flat sheets of the
same shape have the same geometry, whether one considers them to be
large or not. If you mean an infinite sheet, then it is difficult to
see what you mean by "isolated".
May we speak of, say, a charged disk and consider your questions?

Leigh