Jim Kelley wrote:
It was curious that someone would qualify his statement that way to
begin with - "treated as scalars". What's that supposed to imply if not
that there are other ways to treat "powers" sic.

You falsely accused me of treating powers other than
as scalars. Now you are trying to twist my denial into
something untoward. Just how low are you willing to
stoop to discredit Hecht, Born & Wolf, and Dr. Best?

Is there, or is there NOT a cosine term in the interference equation?

Yes, there is. Look in Born and Wolf and Hecht's "Optics".
There it is. I didn't put it there. The cosine term is
the angle between the two interfering voltages. All three
authorities, Hecht, Born, and Wolf, present the same
watts/unit-area equation with a term that they call the
interference term. Your argument is with them, not with me.
Watts/unit-area is certainly a scalar, yet all the experts
insert a cosine term into the scalar equation. That you don't
comprehend is somewhat ironic, wouldn't you say?

I wonder if you'd care to comment on the other mathematical techniques
you introduced to the group this week:

Subtracting power that isn't somewhere else from a number that's
apparently higher than it should be in order to get the right answer,
and averaging power with zero as a means for reducing an excessively
large number by a factor of two in order for the answer to come out
right.

Please don't blame me. Hecht says in "Optics" that destructive
interference somewhere else allows the constructive interference
that we are experiencing. I didn't invent the concept. It was
invented by optical physicists before I was born. That you
are completely ignorant of the concept is downright appalling.
It just goes to show that people who believe they know everything
rarely know anything.

I'm still trying to parse how neglecting units makes it ok to
use equations as you see fit. $100 + $100 + 2*SQRT($100*$100) = $400
(The third term represents the amount of money that isn't somewhere else
and should therefore be mine.) ;-)

Here's equation (15) on page 259 of Born and Wolf's, "Principles
of Optics". Intensity is certainly a scalar value in watts/unit-area.
Why do you think Born and Wolf would put a cosine function into a
scalar equation? Up until you discovered them doing such a
dastardly thing, they were your heroes.

Imax = I1 + I2 + 2*SQRT(I1*I2)*cos(A) (15)

Does watts/unit-area have a phase angle? No. But there is a
phase angle associated with the corresponding two E-fields.

As far as I know, a money equation doesn't possess an interference
term but intensity equations, irradiance equations, and Poynting
vector equations do indeed possess an inteference term. Here's
what Hecht says in "Optics". " Briefly then, optical interference
corresponds to the interaction of two or more lightwaves yielding
a resultant irradiance that DEVIATES FROM THE SUM OF THE COMPONENT
IRRADIANCES." You are objecting to the deviation from the sum of
the component power densities. Please take that up with Hecht.

Maybe the head of your department could explain the interference
term in the irradiance-intensity-Poynting vector equation to you.
But if I were you, I wouldn't expose your gross ignorance to him.

All anyone reading this posting has to do to see just how confused
Jim really is, is to read a copy of "Optics" by Hecht, or a copy
of "Principles of Optics", by Born and Wolf.
--
73, Cecil http://www.w5dxp.com