Re: Electrostatics problem

[Bob Sciamanda <trebor@VELOCITY.NET>]

-----Original Message-----
From: John S. Denker <jsd@MONMOUTH.COM>
To: PHYS-L@LISTS.NAU.EDU <PHYS-L@LISTS.NAU.EDU>
Date: Monday, March 01, 1999 10:46 AM
Subject: Re: Electrostatics problem
> . . .
> 1) We must be careful when dealing with infinite quantities.  In
> electrostatics, conductors make me nervous because they have infinite
> conductivity.
> . . .
> Cheers --- jsd

Hi John,
It is my experience that the typical "ideal" electrostatic situation simply
requires that electrostatic equilibrium has been achieved.  This does not
require perfect conductors; it only requires waiting a sufficient time.  Of
course the better the conductor the shorter the wait.  Eg: for copper the
"relaxation time" (permittivity/conductivity) is of the order of 10^(-18)
seconds!

OTOH, electrodynamic idealizations do sometimes presume perfect conductors.

Bob Sciamanda
Physics, Edinboro Univ of PA (ret)
trebor@velocity.net
http://www.velocity.net/~trebor