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Re: Physics of Wireless Transmission



Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>

Oops
The last line should read "General Relativity"
Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, April 22, 2006 1:24 PM
Subject: Re: Physics of Wireless Transmission


> Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>
>
> Hi,
>
> We are getting a bit off topic perhaps our esteemed  and tireless
Moderator
> (blatant attempt to curry favor with Terry) will indulge us.
>
> Yes I believe your right. The laws of electromagnetic are invariant in any
> constant motion frame.
> Perhaps this is not so surprising given this was one of the clues Einstein
> used to derive his theory.
>
> In an article or letter in Wireless World it described the forces between
> two moving electrons in both a stationary frame and in the moving frame of
> the electrons. Which ever frame was chosen the laws of physics remained
the
> same.  I did not understand at the time that is precisely what Special
> Relativity predicts or perhaps more accurately Special Relativity is
derived
> or confirmed by the invariance of physics in any constant motion frame.
>
> I think it was also in Wireless World that I read how magnetic fields
where
> just relativistic effects of electrostatic fields. It derived the magnetic
> force between parallel wires carrying a current using only electrostatics
> and relativistic effects. So (according the article) a magnetic field is
> just the effects of motion in a electrostatic field i.e. pick the right
> frame of reference and the magnetic field disappears. Again this may not
be
> surprising as presumable Special Relativity would not be true if it was
any
> other way.
>
> Accelerating charges emit electromagnetic waves not charges in constant
> motion or perceived to be in a particular frame..
> So as perceived in the accelerating frame no radiation ???  Presumable
> that's  resolved special Relativity.
>
> Robert (R. A.) Jones
> A1 Accounting, Inc., Fl
> 407 649 6400
> ----- Original Message -----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Friday, April 21, 2006 6:48 PM
> Subject: RE: Physics of Wireless Transmission
>
>
>  > 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
>  >
>  >
>
>