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Re: Displacement current
Tesla List wrote:
> Original Poster: "John H. Couture" <COUTUREJH-at-worldnet.att-dot-net>
>
> Richard could you give us more details on what you understand of the
> "lorentz law"?
>
> John Couture
>
The Lorentz law, at its core is dealing with I cross B and demands the right
angle current "I" and magnetic field "B" and is a force law. The pondermotive
force in the Lorentz law is always at right angles to the current flow.
Ampere in the 1830s noted this right angle force as did Oersted and others, but
from a series of ingenious null experiments, often called the "hat pin
experiments" found an attendent longitudinal pondermotive force as well. He
devolped a series of equations which predict both actions. The amperian
longitudinal force with is always the weaker of the two until very high current
levels in metallic circuits was dropped in an amazing series of blunders and
mathematical simplifications by sevral famous mid 1800's mathematicians to
culminate in the much simpler and broadly applicable Lorentz force law.
Unfortunately, the lorentz law can not predict the longitudinal force found in
conductors the way the bulkier equations of ampere does. Numerous modern
experiments show this force and fly in the face of Lorentz law circuit force
analysis which fails to explain them. Even Maxwell continued looking over his
shoulders at the Ampere equations, but the move was already under way to modify
them to be more simplistic and meaningfully apllicable to everyday engineering.
Slowly, by the early 1900's the study of the amperian work was no longer taught
to engineers in favor of Maxwell and Lorentz. Again, these worked for
engineering efforts at normal currents and in normal day to day efforts.
As it turns out, the longitudinal Ampere force between current elements in
metals is stronger by as much as an order of magnitude than the right angle
Lorentz/Amperian force we are all used to at current levels of thousands of
amperes. We just don't do a lot of normal engineering at these levels.
Richard Hull