On 16 Apr 2007 17:50:10 -0700, "K7ITM" wrote:

On Apr 16, 3:38 pm, Richard Clark wrote:
On 16 Apr 2007 14:29:01 -0700, "K7ITM" wrote:

In my mind I was qualifying it as being waves
propagating in the same direction, since the discussion centers around
propagating EM cancelling out in a finite (non-zero) volume, and as
far as I know, there hasn't been anyone suggesting that waves on a
line in opposite directions cancel over a non-zero distance.

Hi Tom,

Then the challenge devolves to a self-fulfilling proposition (which
may be your point at this turn) as it requires two sources to occupy
the same point.

Well, maybe I'm mistaken, but I was under the impression that there
was someone around here who was promoting the idea that two waves
propagating in a linear medium could cancel over some non-zero finite
volume, but not cancel everywhere along their path, even though that
path was uninterrupted by any discontinuities in the medium.

Hi Tom,

'T'warn't me.

Maybe
I'm mistaken, but I was under the impression that there was someone
around here who was promoting the idea that calculations based on
power rather than on voltage and current in a TEM transmission line
offered some inherent value.

'T'warn't me.

I posted my original, "I have yet to
see...," statements as a way of saying that I'm not convinced about
the truth of either of those ideas, and it would go a long ways toward
convincing me if someone posted examples. I'm still waiting.

'T'was me.

I still
don't have a reference that a fiber optic cable is a TEM transmission
line, though I have others that say that it's not.

That example of the non-TEM fiber optic would be rare species indeed.
I've seen them, but that hardly constitutes the sole species of the
breed.

I still don't have
information on whether a soliton wave can propagate in a linear
medium, though I have references that say it is a non-linear
phenomenon that occurs in non-linear media.

Of course it can propagate in a linear medium. Solitons were first
reported in linear media - water - something like one hundred seventy
years ago. Solitons can induce non-linearity in otherwise linear
media. Solitons also interact in collision with a phase shift
afterwards. Solitons have been applied to data transmission in fiber
optics for a dozen years or more.

Your references are pretty sparse.

If you can convince me
that a wavefront coming to a Magic T doesn't see it as an impedance
discontinuity, we could perhaps post more about that--or not.

Consult Terman. He is quite compelling when it comes to describing
microwave plumbing. This hardly constitutes more than 4 pages total
reading, if you choose to move on beyond the first page of discussion.

But so far, your responses make me think you don't disagree with my
implicit suggestions:

True enough to a point.

that it's impossible to distinguish between the
condition of two cancelled waves that somehow still exist (huh?)

The elliptical huh? seems to be a curious toe in the water for many
here. Strange how a concept draws borders around energy it to make it
"disappear" simply because both contributions cancel. This is like
saying gravity disappears on a 1 square inch patch of earth when the
falling apple has come to rest on the ground. This is also akin to
the misnomer of zero-gravity environment of the astronauts in the
space shuttle.

For example (drawing away from G and towards V), if I were to place
two batteries in series opposition
- + + -
and connect a load to the two free terminals; sure, no current would
flow because there is no potential difference, but that numerical
combination doesn't make the batteries disappear. Yes, the condition
is indistinguishable from a load floating in null space, but we have a
priori knowledge of existing energy that informs us otherwise. If we
choose to be ignorant of the knowledge in that specific locality, the
map of all phase combinations around it will certainly bring it to our
attention again.

Beyond that, you're of course welcome to go off on whatever tangents
you wish. Basenote drift is the expected norm here; I engage in it
all the time myself.

The point of my going into a basenote drift is to present examples
that demonstrate what is necessary to answer your objections (like
providing two sources at one point that cancel on one side, but exist
independently on the other side of an interface). If those who
present their "theories" cannot meet these demonstrated
characteristics, then it is reasonable to reject their claims barring
their offering treatments that are equally compelling.

73's
Richard Clark, KB7QHC