Gene Fuller wrote:
That's really funny. A grad student and a programmer put together a
simply java applet to try to illustrate the concept of interference, and
you treat it as a new bible. I bet the authors would be appalled by your
interpretation.

One more example of an ignorant person making fun of something
he doesn't understand. One of those signals is s11(a1). The
other is s12(a2). Added together they equal zero. That's the
S-Parameter equation for reflections toward the source.

b1 = s11(a1) + s12(a2) = 0

If s11, a1, s12, and a2 are all not zero, the above equation
describes wave cancellation, something you say never happens.

By the way, did you look beyond the pretty pictures and read the section
where the authors said,

"All of the wave examples presented in Figure 1 portray waves
propagating in the same direction, but in many cases, light waves
traveling in different directions can briefly meet and undergo
interference. After the waves have passed each other, however, they will
resume their original course, having the same amplitude, wavelength, and
phase that they had before meeting."

Yes, that happens "in many cases" but NOT IN ALL CASES. You
apparently missed the point which is the part where they said:

"... when two waves of equal amplitude and wavelength that are
180-degrees ... out of phase with each other meet, they are not
actually annihilated, ... All of the photon energy present in
these waves must somehow be recovered or redistributed in a
new direction, according to the law of energy conservation ...
Instead, upon meeting, the photons are redistributed to regions
that permit constructive interference, so the effect should be
considered as a redistribution of light waves and photon energy
rather than the spontaneous construction or destruction of light."

Hmmm, I think that is exactly what I said in this thread on RRAA.

No, what you have said on RRAA is that wave cancellation never
happens because wave cancellation doesn't occur in many
cases. That is obviously faulty logic and all it takes to prove
you wrong is one case of wave cancellation. That case happens
every time a ham adjusts his antenna tuner for zero reflected
power. If we consider the java ap as the reflected waves flowing
toward the source, setting them to 0 and 180 degrees is exactly
what happens at the antenna tuner.
--
73, Cecil http://www.w5dxp.com