Re: Wave Cancellation

Gene Fuller wrote:

Unfortunately it appears that Hecht was writing for ordinary people, not RRAA nit-pickers.

That's not my problem, but it appears that you have made it
yours. Seems one of the .science.physics newsgroups would be
the appropriate place to argue that Eugene Hecht is/was wrong.

OK, lets suppose waves interact, or by the dual nature, that photons interact. What are the equations that govern such interactions?

The FSU web page explains it thusly: "Instead, upon meeting, the
photons are redistributed to regions that permit constructive
interference, ..."

The irradiance equation explains where the quantized energy
goes in joules/sec/unit-area. I will try to ascertain what
quantum physics says about "interaction of photons".

Here is an interesting quote from Feynman. "e - the amplitude
for a real electron to emit or absorb a real photon. ...
It's one of the *greatest* damn mysteries of physics: a
*magic number* that comes to us with no understanding by man.
You might say the 'hand of God' wrote that number, and 'we
don't know how He pushed His pencil'." emphasis Feynman's

Assuming that two photons interact (with an electron as the
'middle-man') I doubt that you or I can ever understand it
better than Feynman. I would make a W*A*G that if two coherent
photons with opposite phases and equal momentum are absorbed
by an electron, then two coherent in-phase electrons are emitted
in the *opposite direction* in a transmission line. It's only
slightly more complicated than ordinary quantum reflections.

If we cross two laser beams it appears that the photons pass right by each other and continue on with no apparent interaction.

Yes, that is true. I have said that superposition can occur
with or without interference and that interference can occur
with or without wave "cancellation" or "reinforcement" (to
put it in Hecht's words). Proving that wave cancellation does
not occur for ten examples is obviously not good enough. You
must prove that it is impossible for wave cancellation to
ever occur. Since it occurs every time I tune my antenna
tuner to cancel reflected waves toward the transceiver,
good luck on that one.

You often claim that the interaction occurs only when the photons are traveling in exactly parallel paths or anti-parallel paths. OK, that is a bit unusual compared to the other forces in nature, but perhaps it happens. Even so, one should be able to describe this interaction in some specific and quantitative manner.

A forward wave normal to a surface (where the index of
refraction changes) results in a reflected wave that is
also normal to that surface and traveling in the opposite
direction. That fact of physics is explained in every
optics textbook that I have ever seen. There is no easily
measurable voltage associated with a light wave, so irradiance
is used to measure the intensity of the light wave.
Superposition allows us to introduce a second light wave.
The interference term in the total irradiance equation
describes things in a quantitative manner when two coherent
waves are superposed.

As a self-proclaimed scholar of quantum electrodynamics you ...

I am afraid you have me confused with someone else.
It was you, not I, who paraded your credentials in
front of this newsgroup so everyone could see how
omniscient you therefore must be. I am but a
grasshopper, trying to learn something new in the
process of correcting my mistakes.

I cannot recall every seeing one in which two of the wiggly lines representing photons simply bounce off of each other. There is always an electron or some other particle involved when the photon wiggly line changes direction

The wave reflection model is compatible with quantum
physics. Since wave cancellation can only occur at
an impedance discontinuity (a changing medium interface)
there are always electrons around to act as "middle-men"
especially in a copper transmission line.

Hint: You keep ignoring the role of the materials at the impedance discontinuity, ...

NO! I DO NOT! You guys seem to have an obsessive-compulsive
tendency to falsify what I have said. I have said numerous
times that wave cancellation can *ONLY* occur at an impedance
discontinuity, i.e. a change in mediums, where materials do
exist.

Who is forcing you into ad hominem attacks and innuendo in
order to present your case?
--
73, Cecil http://www.w5dxp.com
.

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