From: lcs Mixmaster Remailer <mix@anon.lcs.mit.edu>
Date: Tue, 10 Nov 1998 05:20:38 +0800
To: cypherpunks@cyberpass.net
Subject: Re: Grounding (fwd)
Message-ID: <19981109204003.20193.qmail@nym.alias.net>
MIME-Version: 1.0
Content-Type: text/plain



Jim Dolt writes:

> The spark gap generates sparks and that builds up free electrons in the
> space inside the sphere (whether it is gas filled or a vacuum is
> irrelevant). As that charge builds up it will be all of one type, electrons.
> Now the electrons repel each other and therefor move in a circular motion
> with the spark gap as the center. They strike the surface of the sphere and
> tunnel through to the outside surface where they reside. The amount of
> charge at any one point is related to the curvature of the surface at that
> point. Since a sphere is constant curvature the charge will be evenly
> distributed. It will continue to build up so long as you supply power to the
> spark gap. In an ideal world it will get bigger and bigger. In the real
> world at some point insulation breaks down and normal current flow takes
> place.

Listen to this.  Jim Dolt thinks that a spark gap inside a conductive sphere
will cause charge to build up on the surface of the sphere!  The dunderhead
has forgotten about conservation of charge!

Gauss' law says that the charge on the outer surface of a closed
conductive sphere will be equal to the net charge inside the sphere.
The spark gap can't change the net charge inside the sphere, it can just
move charge around.  Jim Dolt has conveniently forgotten about the net
positive charge which will build up on the spark gap as it (supposedly)
emits electrons.

His Doltish notion that electrons will hit the inside of the sphere
and "tunnel through" to the outside is totally confused.  Suppose this
happened.  We've removed negative charges from the interior of the sphere
and put them on the outside, where they would give the sphere a negative
charge.  Now, what is the net charge on the interior of the sphere?
We started neutral and removed negatives, hence it's positive!  Gauss'
law would imply that the sphere must have a positive charge.  But Jim
Dolt tried to give it a negative charge from all those electrons that
"tunneled through."

The whole idea is ludicrous.  No charge can spontaneously appear on
the outside of an ideal closed conductive sphere.  This would be a
violation of the law of conservation of charge.  By Gauss' law, the
charge on the outside is equal to the net charge on the inside.  If a
sphere, just sitting there in empty space, suddenly develops a charge,
then that means that the interior has manufactured charge out of nothing.
It is impossible.

The fundamental misconception that started this whole sad comedy of
Doltish errors was Jim Dolt's belief that a Faraday cage has to be
grounded in order to suppress electromagnetic radiation.  This has led us
to his revelation of his further misunderstandings of how charge behaves
inside a conductive surface, not to mention his numerous errors about
the mechanism by which a spark gap transmitter generates EM radiation.
(Hint: it has nothing to do with a cloud of electrons spreading out from
the spark gap!)

The fact is, Jim Choate knows nothing about this topic, and the same is
true for most subjects that he writes about.  He loves the attention
he gets, but if more people told him they knew how worthless his
contributions are, he just might go bother someone else.