Xref: utzoo sci.physics:3468 sci.electronics:2989
Path: utzoo!attcan!uunet!husc6!mailrus!ames!pasteur!trinity!max
From: max@trinity.uucp (Max Hauser)
Newsgroups: sci.physics,sci.electronics
Subject: Re: capacitors
Summary: Ohhh nooooo! The infamous capacitor problem
Keywords: electromagnetism, capacitors, circuits
Message-ID: <3602@pasteur.Berkeley.Edu>
Date: 23 May 88 14:59:39 GMT
References: <2992@phoenix.Princeton.EDU>
Sender: news@pasteur.Berkeley.Edu
Reply-To: max@trinity.UUCP (Max Hauser)
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Organization: UC Berkeley
Lines: 37

In article <2992@phoenix.Princeton.EDU> tycchow@phoenix.Princeton.EDU
(Timothy Yi-chung Chow) writes:
|The following problem appears in many books on elementary physics,
|elementary electromagnetism, and elementary circuit theory:

... and, being a cliche, is also guaranteed to appear from time to 
time on the Usenet and similar media. I wish we could include it in 
the "answers to frequently asked questions" document and thence
relegate it to undergraduate homework problems where it belongs.

This being the Usenet -- where people argue to the echo about
whether lightning strikes up or down; and argue about skin effect
in conductors, breaking into two camps, both completely wrong;
do you really think it is the proper forum to ask such a slippery
question? Perhaps it was a meta-question, designed actually to
generate volume. Stand by for exciting and informed postings.

|Suppose we idealize the problem and assume zero resistance. 
|Surely energy is still lost somehow.  How do we explain this?
|
|My own tentative explanations include:
|
|1. It is meaningless to "idealize" the problem by assuming zero
|   resistance, because then an infinite current would flow.

No it wouldn't. But this being Usenet, why not start right, with
technical gaffes at the very beginning, albeit tentative.

|2. Charge would move from the plates of the capacitor that was
|   initially at the higher potential to the other capacitor, but
|   would not stop flowing the instant that the voltages equalized.
|   ...We would get an alternating current.  Eventually the energy
|   would get dissipated via electromagnetic radiation emitted by
|   the accelerating charges. 

Ahh, much better. But I look forward to no end of creative
alternative suggestions in the days to follow ...