On 16 Apr 2007 10:07:55 -0700, "K7ITM" wrote:

I have yet to see Cecil, or anyone else, post an example of how waves
can become perfectly collinear, except at an interface: a
discontinuity in a transmission line, a partially-reflecting surface
in an interferometer, ... -- a physical interface of some sort.

Two sources impinging upon each other? If we take a specialized
example of lasers, their being bore sight in opposition. If we take
two antennas, where their -ahem- waves meet, again in opposition.
Nothing physical but the sources are required. As for perfection....

I have yet to see Cecil, or anyone else, post an example of perfectly
collinear waves that perfectly cancel over some small finite volume
which do not also cancel perfectly at all points up to their point of
origin: a physical interface. In other words, lacking that example,
I see NO physical evidence that those waves exist beyond that "point
of origin." Specifically, I have not seen an example of a uniform TEM
line on which it is supposed that two waves cancel perfectly over some
distance, but over some other length on the same line with no
interposed interfaces, the two do not perfectly cancel.

This one is extremely simple to reveal. Those familiar with
microwaves would immediately sputter "Magic T!" Tom, if you have not
seen this offered in several many posts by me, it stands to reason you
must have filters set (but how is it you are reading this?). Of
course, this like the "rat race" coupler (or hybrid ring) all share
the same dynamics. However, for the "Magic T" the cancellation port
is fed by two apparent sources wherein their phases combine to a null
(given the appropriate phases, of course) at this "point of origin."
This may beg what is meant by interface as the "Magic T" is replete in
transmission line arms - however, all are identical in characteristic
Z (a uniformity), all can be Zload matched (a uniformity which then
discards the useful illustration of cancellation), and all are TEM (a
uniformity). As for perfection....

I have yet to see Cecil, or anyone else, post an example wherein the
behaviour of a uniform, linear TEM transmission line is not adequately
explained by the propagation constant of the line, the concept that Vf/
If=-Vr/Ir=Zo, Vtotal=Vf+Vr, and Itotal=If+Ir, and the boundary
conditions at any transitions or interfaces.

Hmmm, those filters must have been a brick wall: In times past I've
offered Soliton waves in fiber optics (TEM lines, of course) wherein
there is no dispersion as would be typically found. This, of course,
stretches the concept of "linear" TEM lines insofar as NONE are! So
much for perfection, or practicality....

Whether or not any claims about power and energy formulas are accurate
or not, I don't know. I'd have to be convinced they're actually
useful before I looked at them more closely. So far, I've not been
convinced of their utility. But then maybe I'm just slow. I could
never see how the current at two ends of a wire (with no other
conductive paths between the ends) could be different unless the wire
in between was storing or giving up charge, either, and I was LAUGHED
AT and told that was just flat-out wrong. The laughing didn't seem to
help; I still don't see it.

I don't trust claims, and measurements proving them even less so. If
this statement above is about perfection; then, again, the last word
has yet to be made such that accuracy can be guaranteed. [Even Ohm's
law isn't accurate. Hence any power statement made in regard to it
fails at some digit to the right of the decimal.]

When I brought up that applet a few days ago, the same thing jumped
out at me, and gave ME a good laugh. Yes, it shows waves cancelling,
but it never shows how they got there.

When a sudden galactic Gamma burst hit us in the past, it too was of
unknown origin (meaning no one knew how they got here). Later, we put
up satellites to warn detectors an event was coming so we could
roughly triangulate any new Gamma burst. One such event suggested a
galactic black hole. Back of the envelope calculations have suggested
similar Gamma burst sources (millions of light years away, but bore
sight on us) could obliterate life in an entire solar systems in the
space of milliseconds. Some might call that canceling waves - or a
cosmic laugh.

OK, so admittedly all responses above entail exotic, rare, or strained
examples. Some are ordinary within the context of experience. If all
of your provisos were combined, then yes, nothing would satisify by
virtue of a self-fulfilling definition.

Copy made in accordance with "Fair Use."

73's
Richard Clark, KB7QHC