Re: E and B field nomenclature

["John S. Denker" <jsd@MONMOUTH.COM>]

At 06:18 PM 5/7/01 -0400, Ludwik Kowalski wrote:
> I wonder why E and B are called electric and magnetic fields.
> In general the term field refers to a collection of points in space.
> In physics we associate fields with physical quantities which
> may change gradually from one point in space to another.
>
> temperature           --> temperature field
> pressure              --> pressure field
> noise                 --> noise field
> velocity              --> velocity field
> gravitation           --> gravitational field
> electric polarization --> polarization field
>
> It is awkward to say "electric-field field" or "magnetic-field field".
> If E were called "electric intensity" then we would say "electric
> intensity field." If B was called "magnetic strength" then we would
> say "magnetic strength field."


I agree absolutely with the point Ludwik is making.

I would extend the line of thought by pointing out that
  A) The Coulomb potential, phi, is also a field, but it is awkward and
confusing to call it the "electric potential field".
  B) People rightly think of "temperature" as a simple scalar quantity,
and rightly contrast this with a temperature _field_ which gives the
temperature as a function of position.  By analogy, we need a word to
express the electric force-per-unit-charge at a point, in contrast with the
field that gives this quantity as a function of position.  Alas I don't
know of any such word.  People generally use the term "electric field" to
refer to this quantity, but there is something not quite right about that.

Half-baked but possibly constructive suggestions:

1) The E field could just be called the E field.  The value when this field
is evaluated at a given point x is not a field;  it is just a simple vector
E(x).  (Given many such points, we can construct the E field.)  Similarly
we have the B field.

2) The combination of E field plus B field is commonly called the Maxwell
field.

3) Similarly people often speak of the Coulomb field, but there does not
appear to be a consensus as to whether this name applies to E or phi.

4) Starting from "Electric Force per Unit Charge" we might try to create an
acronym.  Alas EFpUC is not particularly mellifluous.  Perhaps ElFo-pUnCh
would work better.  And then we need something for "Magnetic Force per Unit
Pole", perhaps MaFo-pUP.

5) Or maybe we can coin words like Electrosity and Magnetosity, as in "the
B field specifies the Magnetosity as a function of position".


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PS keep in mind that what physicists call a field has virtually nothing in
common with what algebraists call a field (i.e. a commutative division ring).