On Mar 7, 8:17 am, Gene Fuller wrote:
Cecil Moore wrote:

Coherency, non-coherency, and interference is covered well
in "Optics" by Hecht and other textbooks. Optical physicists
have been tracking the EM energy flow for centuries. This
information may be new to you but it is old hat in physics.

Cecil,

You may or may not already know this, but a lot of detailed optical
analysis these days is done with full 3-D electromagnetic simulation,
starting from Maxwell equations and boundary conditions. Interference,
coherence, energy flow, and all of the other stuff you like to discuss
can be *output* from that analysis, but those items are not part of the
input. The "centuries old" optics simply does not get the job done. The
"centuries old" stuff may work in the (impossible) cases where
everything is completely lossless and ideal, but it doesn't give the
right answers in the real world.

73,
Gene
W4SZ

You can sure say that again...in fact, Maxwell doesn't really do it
either when you get to quantum mechanical effects. But that's a story
for another day.

Certainly, those who design and build FTIR spectrometers know
perfectly well that interference does not depend on a narrow-band
coherent source. Blackbody radiation works just fine, thank you. But
it doesn't take much beyond belief in linear systems to understand
that. I recall explaining to a company VP how it worked in terms of a
linear system, and it was very gratifying to see the virtual light
bulb lighting up in his head...he really got it.

Cheers,
Tom