Re: Physics of Wireless Transmission

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Original poster: "Gary Peterson" <gary@xxxxxxxxxxxx>

Subject: Re: Physics of Wireless Transmission


> Original poster: <davep@xxxxxxxx>
> > Original poster: "Gary Peterson" <gary@xxxxxxxxxxxx>

> > . . . The term "electric wave" is actually
> > synonymous with "electromagnetic wave."

>     Is it? . . .

Back in 1911 J.J. Thomson used the term "electric wave" to describe 
what we presently call the electromagnetic wave.  It is better to say 
the term "electric wave" as it was used 100 years ago is synonymous 
with the present day "electromagnetic wave."

>     My impressions:
>     1) Usage, expecially in popularizations is a little loose.

I agree.  Tightening up on the nomenclature will get everyone on the 
same page and eliminate unecessary disagreements based upon mutual 
misunderstanding.

>     2) There CAN BE 'pure electric waves'.
>        (variation in e field)

Are not your 'pure electric waves' associated with magnetic fields in 
this case?

>     3) These transform, over relatively short diatances
>        (cf Maxwell??) into the most common form, which
>        is the electromagnetic wave.
>
>     best
>      dwp

The term "electromagnetic wave" should only be used when you wish to 
broadly describe electrical energy propagated through either free 
space or a material medium.  You are describing "electromagnetic 
radiation."  The electromagnetic wave begins to assume this form from 
the moment the antenna's charge carriers begin to accelerate.

Regards,
Gary Peterson