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Re: Physics of Wireless Transmission



Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Godfrey,

Hi Godfrey,

That was what I was suggesting. It was a fleeting thought. Special Relativity should suffice I would think :-)) My book "Electromagnetic Waves and Radiating Systems" by Jordan Balmain has a section on the relativity of Maxwells equations, but I havent studied this. What is the correct answer??

Gerry R.

Original poster: "Godfrey Loudner" <ggreen@xxxxxxxx>

Hello Gerry

Maybe I'm not sure what your asking, but I'll take a shot. Fix a charge
Q and an observer A at the origin of a rectangular coordinate system.
Observer A sees E as a static field that varies inversely as the square
of the distance from the origin (varies with position). Now fix an
observer B in a rectangular coordinate system that is moving relative to
the other. Observer B will see a non-static field with nonzero H. If
observer B is moving uniformly along a straight line, then the Es and Hs
of the two systems can be exchanged by the Lorentz transformations. If
Observer B with accelerating relative to observer A, then I would have
to dust off a relativity book and study to see what are the exchange
transformations (that's general relativity).

Godfrey Loudner

 > I believe, there can be a static e field that varies with
 > position and be a "pure electric field".  However, any E
 > field that varies with time (aka electric wave) involves
 > movement of charge that in turn creates an H field. Time
 > varying E fields are always accompanied by a time varying H field.  >
> Even a static E field in one frame of reference will be a  > time
varying E field in another moving frame of reference.

Gerry