Cecil Moore wrote:
Jim Kelley wrote:
Cecil Moore wrote:
Ptotal = P1 + P2 + 2*SQRT(P1*P2)*cos(A)

According to fig. 7.1 in Born and Wolf, that's useful for showing how
light intensity varies as a function of phase, and hence position.
It's just that there's no valid way to multiply by the cosine of the
angle between two scalars.

You are pretty confused.

I think you know that I'm just pointing out the problem inherent in
using a valid equation in the way you describe without considering the
many assumptions being made. It led you, for example, to write that
there is a 4th mechanism of reflection - even in violation of Maxwell's
equations! Do you still believe that interference actually moves power
from one place to another? It is that kind of nonsense that amateur
radio would be better off without.

Hecht calls it the "interference term" and I am only quoting
him.

I'll bet he'd prefer that you didn't. :-)

73, ac6xg