It looks like I am being my usual confusing self.
What I mean by a non-conducting sphere is a spherical cavity without a conductive lining. Not a sphere filled with a dielectric.
My original contention could be summed up in that Gauss' law will break down when you use electrons in place of continuous charge. Specifically at the boundary. Gauss' law assumes this nice continuous, uniform distribution of charge when you start talking about the field being zero inside a spherical shell of charge.
Let me pose a question (or two...), to Steve or studiot, or both, or anyone. Lets create a 1 meter radius, spherical universe. Now, put 2 electrons in that universe. As expected, the electrons will move to diametrically opposite points at the outer boundary of the universe. We now have a uniform (so to speak), but discontinuous, distribution of charge in our little sphere. Now, will there be zero field at every point within that universe?
Now what happens if we push another electron in? Will it be able to wander to any point on the outer boundary of this universe, or are there areas it is more likely to head toward? Will the other 2 electrons assert an influence on it? Will they possibly have to move to accommodate it? Does this take some of the energy that was expended in getting the 3rd electron in there?
Now, we can continue to add electrons. At what point does the field absolutely disappear everywhere in this little universe? Does the charge distribution ever truly become continuous? How about arbitrarily close to the boundary layer, full of discrete localized charges??
Do you see where I'm going with this? Am I making any sense?
What I mean by a non-conducting sphere is a spherical cavity without a conductive lining. Not a sphere filled with a dielectric.
My original contention could be summed up in that Gauss' law will break down when you use electrons in place of continuous charge. Specifically at the boundary. Gauss' law assumes this nice continuous, uniform distribution of charge when you start talking about the field being zero inside a spherical shell of charge.
Let me pose a question (or two...), to Steve or studiot, or both, or anyone. Lets create a 1 meter radius, spherical universe. Now, put 2 electrons in that universe. As expected, the electrons will move to diametrically opposite points at the outer boundary of the universe. We now have a uniform (so to speak), but discontinuous, distribution of charge in our little sphere. Now, will there be zero field at every point within that universe?
Now what happens if we push another electron in? Will it be able to wander to any point on the outer boundary of this universe, or are there areas it is more likely to head toward? Will the other 2 electrons assert an influence on it? Will they possibly have to move to accommodate it? Does this take some of the energy that was expended in getting the 3rd electron in there?
Now, we can continue to add electrons. At what point does the field absolutely disappear everywhere in this little universe? Does the charge distribution ever truly become continuous? How about arbitrarily close to the boundary layer, full of discrete localized charges??
Do you see where I'm going with this? Am I making any sense?
Last edited: