Cecil Moore wrote:

Your concept that "canceled waves never existed in the
first place" requires a time machine to implement, not
to mention the paradox involved with time travel.

You either completely misunderstand, or you're deliberately misstating
the case. Perhaps both.

Here's what you should do: discover how waves can both cancel and
exist simultaneously at any point in time, and you will prove the
scientific world and their mathematics to be wrong, Cecil. It's
guaranteed martyrdom on scale not seen since Galileo. :-)

ac6xg

Cecil Moore wrote:
Jim Kelley wrote:

Cecil Moore wrote:
One wonders why you have not commented on the interferometer
experiment that intercepted the energy reflected from the
standard output during destructive interference and routed
it to the non-standard output thus illustrating an equal
amount of constructive interference.

I've used laboratory interferometers for over 20 years, Cecil. It
seems like I've been trying to explain how they work to you for almost
that long.

Translation: I am so afraid of that web page that I deleted
it and hope nobody notices. I refuse to discuss the interferometer
example because I am afraid to be proven wrong.

Please share your usual mealy-mouthing response about how I
don't understand that web page at:

http://www.teachspin.com/instruments...eriments.shtml

PLEASE NOTE THAT THE ENERGY REJECTED BY THE DESTRUCTIVE
INTERFERENCE PORT WAS ON ITS WAY BACK TO THE SOURCE BEFORE
IT WAS INTERCEPTED. CAN YOU SPELL R-E-F-L-E-C-T-I-O-N?

Cecil,

I looked at that web page, and my reaction was merely, "so what"? There
is nothing in there that is not well known to everyone who has ever used
or studied interferometry.

You seem to forget that the entire argument on RRAA in this theme is not
about *what* happens, it is about *how* it happens. There is not one
person who would seriously claim any violation of conservation of energy
to be valid. There is not one person who would be surprised to learn
about constructive and destructive interference and the redistribution
of energy. Anyone making competent physical measurements would find the
same, predictable results.

What *is* at issue is the mechanism involved. None of these web
references aimed at the Popular Science crowd even attempt to get into
those fine details. You love to quote a web page written by a Java-dude
and a lab technician. You love to quote a web page written by a
manufacturer of lenses and other optical components. Now you are quoting
a web page from a company who is "dedicated to the design, development,
manufacture, and marketing of apparatus appropriate for laboratory
instruction in physics and engineering." None of these are necessarily
wrong in what they are attempting to say. What *is* wrong is trying to
use these popular-level tales in support of your hair-splitting arguments.

Spend some time reading a serious reference on conservation of energy in
electromagnetic systems. You will come to understand that your concerns
about "wave cancellation" and related stuff at interfaces are not only
unimportant, they cannot even be determined by rational analysis. It
comes very close to counting the angels on pinheads.

If you really want to dig in further, you will need to start to look at
the detailed interactions of the waves with the interface materials,
including the scattering formalism. Reflection does not just "happen". I
do not suggest going there unless you need some sleep inducement.

73,
Gene
W4SZ

Roy Lewallen wrote:
Keith Dysart wrote:
On Jan 15, 2:24 am, Roy Lewallen wrote:
The little program I wrote shows that, on the line being analyzed, the
energy is changing -- moving -- on both sides of a point of zero power.
Energy is flowing into that point from both directions at equal rates,
then flowing out at equal rates. This causes the energy at that point to
increase and decrease. What zero power at a given point means is that
there is no *net* energy moving in either direction past that point.

"*net* energy moving" seems to be a bit of a dangerous notion.

If "*net* energy moving" is the time averaged power, then
it is zero at *every* point on the line under consideration.
And I do not mind this definition.

That was probably a bad choice of words on my part. By net I didn't mean
an average over some period of time. I meant energy moving past a single
point.

One possibility I envisioned was some energy moving past the point from
left to right, and at the same time an equal amount moving at the same
rate past the point from right to left, resulting in zero power at the
point. However, on reflection, this couldn't happen; energy flows
"downhill". But the phenomenon observed on the open circuited line does
occur, where energy flows into the point from both directions equally,
and out of the point to both directions equally, resulting in zero power
at the point. No energy is flowing past the point, period -- the
modifier "net" isn't necessary.

But at the points where the current or voltage is always
zero, it seems to me unnecessary to use the qualifier "*net*"
since the power IS always zero [from p(t)=v(t)*i(t)]. That
is, unless you are introducing another interpretation of
"*net*".

You're right. Please consider "net" retracted.

I got to thinking about this a little more, and want to reclaim the
"net" modifier.

Hopefully we all agree that on a line with a pure standing wave (unity
magnitude load reflection coefficient), there are nodes at which the
power is zero at all times, indicating that no (and I'll reinsert "net"
here) energy is moving past that point. But there's energy going into
that node at equal rates from both sides during half the energy cycle,
and out of the node during the other half cycle. We've used those
observations to conclude that no energy is going past the node.

But let's look at another equally plausible explanation. We know we have
a bundle of energy from the left and another equal bundle from the right
which flow into the node at the same time, resulting in zero power at
the node. But suppose that the bundle of energy from the left flows out
to the right, and the bundle from the right flows out to the left during
the next half cycle (rather than the one from the left flowing back to
the left, and the one from the right to the right, as we've been tacitly
assuming). Now we've moved energy across the node while retaining zero
power at the node (zero power because the amount of energy moving from
left to right always equals the energy moving from right to left at the
node). A nice thing about this interpretation is that it meshes neatly
with the concept of two traveling waves of equal amplitude moving in
opposite directions. Does that solve some of the conceptual problems
you've been having with the nodes?

Of course, I don't know of any way to put a tag on any particular bundle
of energy, so one explanation is really as good as the other from a
mathematical standpoint. But I think that the idea of moving the energy
past the node relieves us of the necessity, or temptation, of devising
various wave interactions to explain how the energy can just stop at the
nodes.

And, maybe it'll allow me to resurrect my *net* modifier. If you go
along with the new interpretation, energy is moving from left to right
through the node and from right to left through the node -- there is
energy moving past the node, but no *net* energy movement through the node.

Roy Lewallen, W7EL

Jim Kelley wrote:
Here's what you should do: discover how waves can both cancel and exist
simultaneously at any point in time, ...

b1 = s11*a1 + s12*a2 = 0

It happens all the time.
--
73, Cecil http://www.w5dxp.com

Gene Fuller wrote:
I looked at that web page, and my reaction was merely, "so what"? There
is nothing in there that is not well known to everyone who has ever used
or studied interferometry.

That's what I have been telling you guys for years. Everything
we need to know about RF waves has already been discovered
centuries ago by optical physicists. I used those centuries
old laws of physics in my energy analysis article which produces
voltage and current results identical to any conventional analysis.

http://www.w5dxp.com/energy.htm

You will come to understand that your concerns
about "wave cancellation" and related stuff at interfaces are not only
unimportant, ...

This is so typical of gurus on this newsgroup. When they lose
the argument, they invariably say it was not important to
begin with.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
I looked at that web page, and my reaction was merely, "so what"?
There is nothing in there that is not well known to everyone who has
ever used or studied interferometry.

That's what I have been telling you guys for years. Everything
we need to know about RF waves has already been discovered
centuries ago by optical physicists. I used those centuries
old laws of physics in my energy analysis article which produces
voltage and current results identical to any conventional analysis.

http://www.w5dxp.com/energy.htm

You will come to understand that your concerns about "wave
cancellation" and related stuff at interfaces are not only
unimportant, ...

This is so typical of gurus on this newsgroup. When they lose
the argument, they invariably say it was not important to
begin with.

Although I have not completely thought it out, I would be surprised if
the same did not hold true for sound waves in a sonic/audio
resonator--and, this obviously is ONLY a wave which transverses a media
and doesn't harm/displace any photons in the process.

You know those d*mn "photon advocates", worse than the animal rights
advocates, actually. :-D

Regards,
JS

Roy Lewallen wrote:
But I think that the idea of moving the energy
past the node relieves us of the necessity, or temptation, of devising
various wave interactions to explain how the energy can just stop at the
nodes.

It also satisfies the wave reflection model which tells
us that no reflections can occur in a homogeneous medium.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
I looked at that web page, and my reaction was merely, "so what"?
There is nothing in there that is not well known to everyone who has
ever used or studied interferometry.

That's what I have been telling you guys for years. Everything
we need to know about RF waves has already been discovered
centuries ago by optical physicists. I used those centuries
old laws of physics in my energy analysis article which produces
voltage and current results identical to any conventional analysis.

http://www.w5dxp.com/energy.htm

You will come to understand that your concerns about "wave
cancellation" and related stuff at interfaces are not only
unimportant, ...

This is so typical of gurus on this newsgroup. When they lose
the argument, they invariably say it was not important to
begin with.

1. Nice job of selective quoting to completely change the meaning of a
message. Is that sort of like a line item veto?

2. As for the wave cancellation part, you have many times noted that
stuff happens at interfaces or discontinuities. So why is it that you
never ever consider what is happening inside those interfaces and
discontinuities? Do you suppose the waves simply cancel, reflect, or
whatever without assistance from the materials in the interface or
discontinuity? Do you suppose that any energy or momentum considerations
may need to include the materials?

This is akin to the concept of Thevenin equivalents. The view from the
outside is correct and useful. There is no information about what is
actually happening on the inside of the Thevenin box. In the same way
the wave reflection model as seen from outside the interface or
discontinuity works just fine. There is virtually no disagreement about
what one would observe if correct measurements were done. On the other
hand there is no possibility of figuring out how the waves actually
"cancel" or what happens to the energy and momentum without considering
the actual physical configuration. That sort of analysis has been done,
of course. It gets into all sorts of details on electrons and Fermi
surfaces, but strangely enough, it does not require Java applets on web
pages.

Unless you want to look at the interactions of waves with materials in
some detail, the concern about exactly what happens during a
"reflection" is unimportant. The external equations work just fine.

73,
Gene
W4SZ

Cecil Moore wrote:

Jim Kelley wrote:

Here's what you should do: discover how waves can both cancel and
exist simultaneously at any point in time, ...


b1 = s11*a1 + s12*a2 = 0

It happens all the time.

Next time it does be sure to capture a scope trace of them and post it
to your web site.

Thanks,

ac6xg

Cecil, W5DXP wrote:
"That`s what I have been telling you guys for years."

OK. I subscribe to World Radio and Cecil`s story isn`t in the February
issue but there is an antenna cover story.

When will Cecil`s story be published?

I disagree that W2DU recently was first to coin the expressions, virtual
open and virtual short. We were using them in 1950 when I was still in
college.

It is rumored that the 3rd edition of "Reflections" will emerge soon.
When and where can I order it?

Best regards, Richard Harrison, KB5WZI

5123 Lymbar Dr. Houston, TX 77096-5317