Re: Capacitor problem

[LUDWIK KOWALSKI <kowalskil@alpha.montclair.edu>]

In a message posted 30 minutes ago Ludwik Kowalski wrote:
> ....  My intuition tells me it is much less than one percent (nearly 
> all becomes heat), but this is only a guess.

Actually one should make a distiction between a guess, which is more or
less random choice, from a prediction based on intuition. That is why the
term "an educated guess" would be more appropriate. People who argued for
e.m. waves (resulting from oscillations of charges back and forth along
wires) were correct because you can, in principle, reduce R as much as
you want, for example, by using wires which are thick and short. 

But will a charge flowing toward the initially uncharged plate concentrate 
there and start flowing back? (I think about a sudden change of C). In 
principle yes but in practice no. Why? Because you can not reduce R by 
making plates thicker. Positive and negative charges attract and for that 
reason the the redistribution current will always encounter a large 
resistance. My educated guess is that, even for a sudden change of C, the 
damping by R will be too strong to allow oscillations. 

And no oscillations would not be allowed, even when R=0, if changes in C
are very slow. In that case the evolution is from one equilibrated state to
another. Yes, I know that an educated guess has a low status. That is why
I hope somebody will support or contradict me with real quantitative 
arguments. Many of us are likely to benefit from this.
                                                         Ludwik Kowalski