Jim Kelley wrote:

w5dxp wrote:
If it were total constructive interference, two 1/2W
beams would yield an intensity of 2 watts.

That should have been 2 watts per unit-area. Note that
I did NOT say two 1/2W beams would yield a power of 2
watts. The correct dimensions of intensity would be
2 watts/unit-area, a power density, not a power. I have
already apologized for that goof in dimensions.

It was pointed out to you that that notion violates conservation of
energy, but rather than admit that you were incorrect, you attempt to
revise history. Then there was this:

No, that notion *DOES NOT* violate the conservation of energy
principle which cannot be violated. That notion relies upon
one watt per unit area of total destructive interference
occurring somewhere else. The one watt of destructive
interference causes a flat black area. The energy from that
flat black area is redistributed to the area of constructive
interference and causes that area to be twice as bright as
the average area. Born and Wolf's equation is valid.

Itotal = 4I1 where I1 = I2 = 0.5W

2 watts/unit-area = 4(0.5) watts/unit-area

Again, I ask you to please cease from trying to twist my
words into a violation of the conservation of energy
principle. If you think I have uttered such words, you
are mistaken. Next time you are confused, instead of your
arrogant ASSumptions, please just ask me what I meant.
--
73, Cecil http://www.w5dxp.com