Message-Id: <199905041947.MAA04748@noontide.lick.pvt.k12.ca.us>
Date: Tue, 4 May 1999 12:55:25 -0800
To: "Pinhole Listserv" <pinhole@exploratorium.edu>
From: swise@lwhs.org (bliss)
Subject: Re: pinhole Mars Magnetism with picture pointer
Here's a question from a couple of my top students: We've been discussing
Ohm's law and the fact that some materials are nonohmic. In superconducting
materials, is it true that the statement R=V/I doesn't apply? If this is
true, then is there a more generally applicable definition of resistance
that doesn't rely on voltage and current? How do superconducting materials
fit into these definitions (one of my students, using data from a recent
superconductivity test, used a definition of resistance that R=pL/A and
calculated a resistivity constant that was in the range of typical
insulators -- baffling)?
Sarah Wise
İİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİİ
Sarah Wise
Lick-Wilmerding H.S.
755 Ocean Avenue
San Francisco, CA 94112
swise@lick.pvt.k12.ca.us
"Not everything that can be counted counts,
and not everything that counts can be counted."
--Albert Einstein