Jim Kelley wrote:

Cecil Moore wrote:
Set the two waves to equal magnitudes and opposite phases.
Hint: there can be no wave cancellation without waves.

More to the point, there can be no waves under the conditions you
describe.

Therefore, thin-film anti-reflective coatings are
a waste of time since there were no reflections to
begin with. Again, you have an effect reaching back
in time to change its own cause. If that works in
your mind, who am I to try to change it?
--
73, Cecil http://www.w5dxp.com