Cecil Moore wrote:
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?


[snip]


Cecil,

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.

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."


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



73,
Gene
W4SZ