"gareth" wrote in message
...
"Brian Reay" wrote in message
...
Another name for the Magnetic Vector Potential is curl,

That's not correct. Curl is a vector field function applicable to many
things, and you have to have the curl of something.


Brian?



Back the Magnetic Vector Potential under the name of curl. Curl is used
in 3D Vector Calculus (essentially calculus applied to the three
orthogonal components of a vector) and is referred to as a vector
operator. Importantly, it is only applied to rotating vectors

That is very misleading. The flow in a stream has curl when the
middle of the stream flows faster than the edges, but the individual
flow vectors are linear and not rotating.


Brian?

(Put a stick transversely across the varying flow rates and the curl will
become
immediately apparent to you)


and, like like all calculus, assumes infinitesimally small changes (in
this case rotation). The curl is found by applying the curl operator, and
it yields a vector represents the instantaneous direction and rate of
change of the Magnetic field.

That is misleading as well. A linear magnetic field moving through
a medium of varying permeability will have a spatial rate of change but
it will not be revealed by curling.


Brian?




Thus, the Magnetic Vector Potential is a vector which represents the
instantaneous rate of change in the magnetic field.

That is complete nonsense. "Instantaneous" refers to a time element,
whereas curl is a spatial operator.



Brian?



To paraphrase your own remark, I find it to be unbelievable that someone
who boasts of two degrees, the first in electronics and the second in
mathematics, could be so ignorant of such matters; matters that prelie an
understanding of Maxwell's Equations. In my time, we studied grad, div
and curl and all the associated identities in the second year maths course.