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Date: 9 Nov 1998 20:40:03 -0000 From: lcs Mixmaster Remailer
Subject: Re: Grounding (fwd)
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!
No, I didn't. First off your assumption that the charge in the battery is neutral is faulty. No such point was ever made. I also mentioned this fact when I brought up the Van DeGraff.
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.
Actualy, no it doesn't. What Gauss' Law does state is that if there is a neutral ball and there is a point charge within it there will be a contrary but equal charge imposed on the inside surface of the globe. As a result of charge conservation there must be a equal and opposite (hence negative) charge that is equal to the point charge inside the globe on the outside of the globe.
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.
And the anonymous person has forgotten that we never defined the mechanism of how the battery worked. It might very well have started out with a net-negative charge. I didn't invent the model, just simply worked within it. I also, on two seperate occassions, mentioned that I was not going to deal with the net charge that gets deposited on the globe because of the complexity it adds to the model.
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.
No, Gauss Law says at all times the charge on the sphere must stay equal for point charges. Since the spark gap is by defintion emitting electrons it doesn't qualify as a point charge. I brought this up as well in reference to the Van DeGraff. Gauss's Law does say that any excess charge on the inside of the globe will propogate to the outside of the globe. Now each of those free electrons IS a point charge. You follow Gauss's Law through the same process and what do you get....a charge equal to the electron on the outside of the surface.
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.
No, it wouldn't. The charge inside the sphere is exactly canceled by the charge induced on the inside of the sphere (+ + - = 0) by Gauss's Law. Now since the sphere is neutral, and we've induced that positive charge there must be a balancing negative charge. That charge rests on the other (outside) surface of the sphere. All that's taken place is that the universe has created a situation where you can't steal charge and hide it where it can't be found. That WOULD violate conservation of charge. ____________________________________________________________________ Lawyers ask the wrong questions when they don't want the right answers. Scully (X-Files) The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
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Jim Choate