On 19 Dec 2006 07:46:21 -0800, "art" wrote:

In the thread Rain static I referred to a closed surface which is
clearly
defined by Gauss's law.

Hi Art,

A "closed" surface is described by its geometry, not Gauss's law. No
charges, Gaussian or otherwise, are required to "close" it. Rather,
what is defined by the "closed surface" is the charge. You measure
the charge by moving it through the surface. I will explain below how
this too is wrong.

If the surface is an
insulator type then it takes a long while to penetrate

A closed surface is not required to be of any substance to still be a
closed surface. Closing the surface is simply a mathematical
description of space, not what is within it.

but if the
surface
is a good conductor then the charges will penetrate very quickly

Now, if we were to consider a material that is bounded by an equation
(like a cycloid, or volume of revolution); then your two examples are
described BACKWARDS. Charge on a practical, conducting surface will
NOT penetrate to the inside because the mutual repulsion forces charge
to the point of least curvature (this is why spark gaps using sharp
pins have a lower breakdown than those using balls).

Another concept you have wrong is the nature of current and flux. Flux
is a vector of charge, not the movement of charge. Flux and closed
surfaces are used to prove if the charge is inside the surface (the
flux transits an odd number of surfaces) or outside the surface (the
flux transits an even number of surfaces).

Hence, the remainder of your discussion doesn't make much sense, does
it?

73's
Richard Clark, KB7QHC