On May 30, 7:28*pm, lu6etj wrote:

Miguel, please see my above posting in reply to Richard's posting.

As I learned, the superposition principle does not depend on collinearity..

Please change "collinear" to "collimated". The results of
superposition can be reversible or irreversible. If the photons are
not coherent and/or not collimated, the results of superposition are
reversible in the sense that each separate wave can be recovered. The
results of superposition of coherent and collimated waves (traveling
in the same direction) are not reversible, i.e. the ability to recover
the separate waves has been lost forever. Two coherent/collimated
waves that are superposed indeed do interact. Non-reflective glass is
a typical example. The external reflection interacts with the internal
reflection causing the reflections to undergo wave cancellation and
the total energy in the two superposed (canceled) waves to change
direction and make the picture brighter. The Melles-Groit web page
says:

"This important fact has been confirmed experimentally."

As I understand, two or more superposed waves can be added or
subtracted to render a resultant but we do not call that interaction.

I call it interaction when the identity of both waves is lost which is
what happens during wave cancellation. It is not interaction when the
identity of both waves is not lost. The results of superposition can
have either outcome.

For my conceptual notions adding or subtraction are not interaction.

If you add a pint of water to a pint of water, the two pints of
identical molecules interact, analogous to one joule of coherent/
collimated photons added to another joule of the *identical* photons.
The results is two joules of identical photons, indistinguishable from
each other. If the superposition process is reversible, interaction
has not taken place. If the superposition process is irreversible,
interaction has taken place. Both outcomes are possible depending upon
the initial conditions.

Why do not you agree in a simple initial Thevenin model?

It was Roy's idea to avoid the abstract Thevenin model and go with a
similar real-world source, probably because of the admonition in
"Fields and Waves ...": "... significance cannot be automatically
attached to a calculation of power loss in the internal impedance of
the equivalent circuit."

Transmission/reflection notions (about energy) do not represent that
concept?

The mistake that virtually all RF gurus are making, including w7el in
his food-for-thought article, is assuming that reflection is the only
mechanism capable of redistributing reflected energy back toward the
load. But it has been known for decades in the field of optical
physics that EM wave cancellation can also redistribute reflected
energy back toward the load. It is well known that the reflected
energy lost through the use of non-reflective glass causes the picture
(load) to be brighter. If w7el would simply take the time to calculate
the wave cancellation energy (constructive or destructive
interference) at the source resistor, he would understand exactly
where the reflected energy goes. The conservation of energy principle
allows nothing magic (like reflected waves containing no energy or EM
waves that do not move at the speed of light).

Suppose we are not capable to
perceive any light (or realize of it), only HF spectrum; could you
share (agree?) concepts with our other "blinded" colleagues *:) to
analize this stuff?

It is very useful to say: If our eyes could see the RF waves, what
would we see? We would see the same thing we see with visible light
waves, just at a different frequency (wavelength).

In perfect vacuum free space without any material stuff to reflect
light or bring our retinas into the region in some way?

Of course, we would need some sort of irradiance detector more
sensitive than human retinas. Partially mirrored glass is often used
to route a sample to a detector. If we detect standing waves in a 10%
sample, we are pretty sure that standing waves exist in the rest of
the sample.
--
73, Cecil, w5dxp.com