Cecil Moore wrote:
On Apr 7, 5:51 pm, Gene Fuller wrote:
The beams "interfere" but they do not "interact".

Of course, you can give examples where the waves survive the
superposition. But what we are talking about is when the waves do
NOT survive the superposition.

How about wave cancellation, Gene? When two coherent waves traveling
in the same direction in the same path with equal magnitudes and
opposite
phases interact, they cease to exist in the direction of the original
travel.
Ir's senseless to argue that waves that cease to exist during the
process
of superposition have not interacted with each other, don't you think?
--
73, Cecil, w5dxp.com


Cecil,

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?

I must have missed class the day they went over the theory of
"cancellation". Is this another one of those convenient descriptions of
results that you keep trying to remold into fundamental physical laws?

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". As
Owen pointed out a little while ago, we generally don't want to carry
around lots of zero components in an analysis.

The bottom line is that EM waves do not interact in free space.
Linearity and superposition could not hold if that were the case.
Maxwell's equations would need to be recast.

There are exactly enough physical laws and principles now. There is no
need to invent more on RRAA.

73,
Gene
W4SZ