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Re: Common Science Knowledge




I'm posting this for Ludwik, whose computer is down today. My comment
earlier didn't indicate that I was tired of electrostatics talk, but
wondering whether the continued discussion meant that the earlier solution
was felt inaqequate by some.

-- Donald

From kowalskiL@worldnet.att.net Fri Mar 28 20:53:13 1997
Date: Fri, 28 Mar 1997 15:02:29 -0500
From: Ludwik Kowalski <kowalskiL@worldnet.att.net>

Hi Don: 3/28/97
The college computer I use for e-mailing is down today. Can you
kindly post this message to phys-L-ers from your machine? I
sens that you are not the only one who is sick and tired of the
volts thread. But, as you pointed out earlier, a problem can lead
to many critical thinking considerations. This is one of them.
Should it be posted under a different subject name? I do not
think so. A message inspired by what has already been posted
under a chosen name should, when reasonable, belong to that
name. How else can we recognize links among messages in
the directories of old mail-files? The author of a reply is in
the best position to make a good decision. Please include this
paragraph. Thanks in advace, Ludwik
***************************************************

In electorstatics the E flux lines are always perpendicular to
metallic surfaces. Charges would not remain in fixed positions
without this being true. But metallic surfaces are never perfectly
smooth and charges are not in perfect rest. In optics (mirrors) we
say that surface irregularities can be ignored when they are very
small in comparison with wavelengths. Is there an equivalent
qualification about local irregularities in electrostatics?
Electric lines are like "rays"; they have no finite diameters.

E lines are not perpendicular to "overall average surfaces" they
are perpendicular to "local average surfaces". This is obvious for
very deep scratches and other large deviations from smoothness.
Is there an objective demarcation line between significance and
non-significance of local metallic irregularities for electric
considerations? Sould the non-zero resistivity play a role in
a distribution of charges?
*************************************************
P.S. Please reply to confirm that this message was received;
I did not use this mailer before. Thanks again, L.K.