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Old November 10th 08, 06:24 PM posted to rec.radio.amateur.antenna
Frank Frank is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 19
Default "Unwashed" hams and "washed" hams

I am also pleased that the present generation are using up to date
material and not the books of 50 years ago
where those taught at that time all was thought to be known and all
change was resisted.


Art, I am not sure what you mean. This material has not changed
in over 100 years. To quote from Ida's text, pp 731, 732: "Based
on the inroduction of the displacement currents in Ampere's law,
Maxwell predicted the existence of propagating waves, a prediction
that was verified experimetally in 1888 by Heinrich Hertz. This prediction
was based on the nature of the equations one obtains by using Maxwell's
equations. We will show here that Maxwell's equations result, in general,
in wave equations". This proof is shown in "Example 12.3", which is
posted on my previously referenced web link:
http://www3.telus.net/nighttrainexpress/maxwell_1.htm
Unless you can show, by manipulation of Maxwell's equations, that it
is possible to obtain a 2nd order partial differential equation where the
independant variable is time; what is the point? I should also note
that a course I took in electromagetics (About 1983) has an almost
identical development of a wave equation. For reference the text is:
"Introduction to Electromagnetic Fields", Clayton R Paul, and
Syed A Nasar, published in 1982, ISBN 0-07-045884-7, pp 241 - 243

73,

Frank.