Cecil Moore wrote:
On Jan 8, 2:39 pm, Jim Kelley wrote:

But when you write the equation for the superposition of
traveling waves and claim that resultant standing wave is a different
kind of electromagnetic wave, that is a misguided point of view.


That's not true unless you consider Eugene Hecht to be misguided.

Of course it's true, and Dr. Hecht does post here.

He
said standing waves are so different from traveling waves that they
probably shouldn't even be considered to be waves at all since they
are not even moving.

On what page has Dr. Hecht written "a standing wave is a different
kind of electromagnetic wave"?

Those waveforms could hardly be any different yet you asserted that
they are linked by a trig identity.

I asserted that expression for the sum of traveling waves and the
expression for the resulting standing wave pattern are related by trig
identity, as per page 140 of the 28th Edition of the CRC Standard
Mathematical Tables Handbook.

A standing wave is not only different from an EM traveling wave, it
cannot correctly even be called an EM wave because it is not moving at
the speed of light in the medium, a technical requirement for EM
waves.

The 'wave' which stands is merely an amplitude envelope for the waves
which move. It's not a "different kind of electromagnetic wave." If
you were to instead characterize a 'standing wave' as a different kind
of interference pattern, then we would in fact be in agreement.

ac6xg