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Re: Why Do We use B for the Magnetic Field?



I have traced the "B-field" back as far as James Clerk Maxwell. It
doesn't seem to have originated with Oliver Heaviside, who whipped
Maxwell's difficult original equations into more usable form after
Maxwell's death. If anyone has a copy of Maxwell's "An Elementary
Treatise on Electricity and Magnetism" where he first published his
version of the EM equations, perhaps there are clues there.

It's possible Maxwell might have inherited "B" from either Ampere or
Gauss. Equations were not widely used in mid-19th century science, and
the cast of characters who would have coined "B" is a pretty much
limited to those three. The Phys-L'er who traces it back to its origin
is likely to have done some serious digging in 19th century source
material.

Best wishes,

Larry
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright <exit60@ia4u.net>
Physics and Physical Science Teacher
Charlotte HS, Charlotte MI USA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Doug Craigen wrote:

"Paul O. Johnson" wrote:

Bruce,

I reckon it's for the same reason that we use p for momentum or L for
angular momentum; i.e. it's completely arbitrary but also completely
conventional. Given most conventional symbols, why should you expect M for
magnetic field strength?

My supposition has been that historically M was already being used for
some kind of measure of how magnetized something was before concepts of
magnetic fields were well defined. Whether or not this is the case, it
strikes me as a toss-up whether M would go to the magnetic field (B or
H, depending on my mood and who I'm talking to) or to the magnetization
of a material. Somehow, even though we physicists are more interested
in the former, it strikes me that more people would be interested in the
latter - hence I'm not surprised that's where it is used.

----- Original Message -----
From: "Oldaker, B. COL PHYSICS" <hb6805@EXMAIL.USMA.ARMY.MIL>
To: <PHYS-L@lists.nau.edu>
Sent: Sunday, April 29, 2001 5:46 PM
Subject: Why Do We use B for the Magnetic Field?

Hello from a new subscriber.

Why do we use "B" for the magnetic field? One of my inquiring instructors
wants to know and I can't find it in my weird files.