Hey Cecil,

The superposition of waves which are equal in amplitude and out of phase
equals zero at any time t. There is no time t in the steady state when
reflected waves to the left of the discontinuity can exist. The whole
point of the exercise is to prevent reflections. You're proposing that
the reflection is first allowed, and then it gets cancelled, but not
really cuz then it has to turn around somehow and go back the other way.
Let it drop man.

ac6xg

Cecil Moore wrote:

Jim Kelley wrote:

You mean that bit about how you think the waves first move in the
reflected direction a little tiny bit and THEN cancel? Yes, you do
need to rethink that. If they're equal in amplitude and opposite in
phase, there's cancellation - at any value of t. In other words, the
waves are prevented from reflecting. They don't reflect first, then
disappear.


If they don't reflect first and then disappear, they don't exist
at all. But we know that reflected waves indeed exist and through
deduction can see how they must exist or else cause-and-effect is
violated. So your assertion that they never existed in the first
place is riddled with contradictions that I am unable to resolve.

So I ask again for the umteenth time. Given the rearward-traveling
reflected wave from the mismatched load encountering the match point,
exactly what turns that energy and momentum around and causes it to
flow back toward the load in the opposite direction? If not wave
cancellation, then what?

You simply cannot have it both ways. If the canceled waves don't
exist before they are cancel, they never existed at all and
therefore wave cancellation cannot exist at all. What you propose
is clearly a violation of cause-and-effect.