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Re: B versus H



I will diverge from the spirit of the list and try to answer
the question that was asked. The usage seems to go back to Maxwell,
according to Sommerfeld (Electrodynamics), who uses B for magnetic
induction (="magnetic field strength), M for "magnetism", and H for
"magnetic excitation". He writes, (chap 2, fn 1):
"Maxwell employed gothic letters (rather than bold-face letters)
for the vectors of the elecromagnetic field (see Vol. II of the Treatise,
art. 618). Except for this distinction we use the symbols here given."

If there was some mnemonic purpose underlying Maxwell's choice of
symbols, one must look to his papers for and explanation.
Regards,
Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
Mark Twain, <Extract from Eve's Autobiography>

On Thu, 27 Jul 2000, Doug Craigen wrote:


I remember reading about this a few years ago, but I no longer have the
book. I would be interested in having my memory refreshed without a
digression into the proper wording - just for once on this list.


Nearly a decade of experience on this list suggests you will be waiting
a while...

I hadn't intended to go off on a wording tangent, its just that every EM
text I have from Jackson on down refers to H as the magnetic field and B
as something else. If we want to know why the letters H and B are used,
then it is likely important to know what title each letter refers to.
For all I know "B" is a reference to "flux" or "induction", not
"magnetic" - so that there is no reason to associate it with the title
"magnetic field".

\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\

Doug Craigen
http://www.dctech.com/physics/about_dc.html