K7ITM wrote:
On Mar 5, 1:27 pm, Cecil Moore wrote:
The rules change between non-coherent,
non-interfering sources and coherent, interfering sources.

And exactly which part of "linear system" do you fail to understand?

Tom, I am ready to eat crow and apologize to you on this
one. My false statement above was a rash assumption based
on my aversion to instantaneous values.

Last night, while puppy siting my girlfriend's dog in
a Walmart parking lot, I realized that the power density
(irradiance) equation as presented by Hecht and others
does work at the instantaneous level. Mea Culpa.

The difference between coherent and incoherent signals
is not in the rules but in the timing. Keith and I
were making essentially the same mistake. Thanks for
making me think this one through.
--
73, Cecil http://www.w5dxp.com