Gene Fuller wrote:
It is easy to give examples where the waves survive the superposition,
because they always do. It is rather strange that you are making this
argument after all the back and forth about traveling waves and standing
waves. Do we now have multiple flavors of EM waves? Some that obey
superposition and some that don't?

They all obey superposition which can occur with or
without interference. And you are wrong about all
waves surviving superposition. Canceled waves do
not survive wave cancellation in the direction that
they are traveling. Access this web page and set
the two waves to equal frequencies, equal magnitudes,
and opposite phases, i.e. 0 and 180 degrees.

http://micro.magnet.fsu.edu/primer/j...ons/index.html

When you do that, the waves are canceled in their
original direction of travel. The energy in those
canceled waves certainly survives, but those two
original waves cease to exist never to be seen
again.

I must have missed class the day they went over the theory of
"cancellation".

You must have. Please run the above java application
and alleviate your ignorance about what you missed. Why
do the waves disappear when they are of equal magnitude
and opposite phase?

I stand 100% behind my two messages to Walt. If you actually read them
you would note that I said for most cases it makes no difference whether
the waves interfere forever or whether they interact and "cancel".

Of course it makes all the difference in the world. That's
what the entire argument is all about. You simply cannot
sweep the truth under the "does not matter" rug. And until
you can say "all cases" instead of "most cases" your
argument is irrelevant. If it doesn't work for all, it
doesn't work at all.

The bottom line is that EM waves do not interact in free space.

It is indeed difficult to get two beams of light collinear
in space space. But it is not difficult at all to get two
RF waves collinear in a transmission line. It happens every
time someone adjusts his antenna tuner for a Z0-match.
--
73, Cecil http://www.w5dxp.com