Billy Burpelson wrote:


Billy Burpelson wrote:


What I -did- speculate on is that a *portion* of the echo (the
echo's leading edge) will be QRM'd *right as it leaves the moon*
(the first 0.75 seconds of the echo) by the trailing edge of the
incident wave (its last 0.75 seconds). Therefore, either a
shortened echo (due to full cancellation of the 'overlap', which is
unlikely) or an echo with a distorted or weakened leading edge
(more likely) will ultimately reach the earth, depending on how
much out-of-phase cancellation at the moon end of the circuit
occured.

craigm wrote:

Your error is assuming that echo is modified by the incident wave. The
waves pass by each other without interacting.

You seem to be contradicting yourself here. Above, you say they will
"pass by each other without interacting". Below, you say "anywhere they
'overlap' you *will* see interference". [emphasis added].

When you try to observe the waves, using any method, you get the sum of
the two signals. So anywhere they 'overlap' you will see interference.
This is superposition.

I agree -- and if you read what I said above (or tried to say) was
addressing the overlap, which due to superposition, will either
constructively or destructively add; in either case, the 'overlap'
portion of the echo (leading edge) -will- be modified (or degraded or
interfered with, however you want to look at it) by the trailing edge of
the incident signal, and that portion of the echo, when received on
earth, will be perceived as such.

Aren't we really saying the same thing???


No it is not the same. The waves do not interact with each other. It is the
ability to observe them that is the problem. Where they overlap you are
seeing the sum of two independent waves. When the wave moves beyond the
overlap, it has not been changed. Outside of the area of the overlap, there
is no evidence of the prior overlapping.