Gene Fuller wrote:
"the intensity varies between a maximum value Imax = 4I1, and a minimum
value Imin = 0"

Yes, that's essentially what I have been saying. The peak
intensity (irradiance) can be double the intensity of
the combined intensity of both superposed waves.

What B&W *don't* say is anything about two 1 watt waves interacting,
waves exhibiting constructive and destructive interference, cause and
effects relationships, or even energy conservation.

Eugene Hecht calls the last term in the irradiance equation
the "interference term". He talks about "total destructive
interference" and "total constructive interference". The sign
of the interference term indicates whether the interference
is destructive (-) or constructive (+).

All of those are things written by more casual writers, such as Hecht,
Melles-Griot, and the FSU Java dudes. There is nothing wrong with that
type of explanation for simple illustration, but it runs out of gas when
trying to support detailed analysis. One quickly ends up with silliness
such as waves that are launched and then cancel destructively within a
short (but undefined) distance. None of that nonsense occurs if one
simply applies the standard analysis techniques such as used by B&W.

Exactly what nonsense are you referring to? Please be specific. It
is difficult to defend myself from assertions of "nonsense" with no
specific allegations.

I gather from the above that wave cancellation due to superposition
is against your religion. Since all impedance discontinuities cause
reflections, exactly how and why do those reflected waves cease to
exist? Please be specific.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
"the intensity varies between a maximum value Imax = 4I1, and a
minimum value Imin = 0"

Yes, that's essentially what I have been saying. The peak
intensity (irradiance) can be double the intensity of
the combined intensity of both superposed waves.

What B&W *don't* say is anything about two 1 watt waves interacting,
waves exhibiting constructive and destructive interference, cause and
effects relationships, or even energy conservation.

Eugene Hecht calls the last term in the irradiance equation
the "interference term". He talks about "total destructive
interference" and "total constructive interference". The sign
of the interference term indicates whether the interference
is destructive (-) or constructive (+).

All of those are things written by more casual writers, such as Hecht,
Melles-Griot, and the FSU Java dudes. There is nothing wrong with that
type of explanation for simple illustration, but it runs out of gas
when trying to support detailed analysis. One quickly ends up with
silliness such as waves that are launched and then cancel
destructively within a short (but undefined) distance. None of that
nonsense occurs if one simply applies the standard analysis techniques
such as used by B&W.

Exactly what nonsense are you referring to? Please be specific. It
is difficult to defend myself from assertions of "nonsense" with no
specific allegations.

I gather from the above that wave cancellation due to superposition
is against your religion. Since all impedance discontinuities cause
reflections, exactly how and why do those reflected waves cease to
exist? Please be specific.

Cecil,

Waves are useful. However, they are not living objects. They have no
will to survive. There is nothing in the standard E&M science based on
Maxwell's laws that requires waves to be "canceled" if they no longer
exist. There is no conservation law of wave-ality.

If the proper equations are set up and the proper boundary conditions
are applied (not always easy to do), then waves will exist where they
are needed to describe the physical reality and they will not exist
where they are not needed.

There is no need to worry about waves that don't exist.

As for the "nonsense", we had this discussion a few times, including a
couple of months ago. I don't feel like finding the exact messages, but
the gist was something like:

"Wave 4 and wave 5 return toward the source from a match point, but they
are opposite phase and therefore cancel after a short journey."

If you don't recognize that exchange, let's just drop it.

73,
Gene
W4SZ

Gene Fuller wrote:
Cecil Moore wrote:

Cecil,

Waves are useful. However, they are not living objects. They have no
will to survive. There is nothing in the standard E&M science based on
Maxwell's laws that requires waves to be "canceled" if they no longer
exist. There is no conservation law of wave-ality.

If the proper equations are set up and the proper boundary conditions
are applied (not always easy to do), then waves will exist where they
are needed to describe the physical reality and they will not exist
where they are not needed.

There is no need to worry about waves that don't exist.

As for the "nonsense", we had this discussion a few times, including a
couple of months ago. I don't feel like finding the exact messages, but
the gist was something like:

"Wave 4 and wave 5 return toward the source from a match point, but they
are opposite phase and therefore cancel after a short journey."

If you don't recognize that exchange, let's just drop it.

73,
Gene
W4SZ

Hi Gene,

Yes. The short journey was described by the term "dt". According to
Cecil, that is the amount of time after energy is reflected and before
it 'turns around and goes the other way as it is required to do by the
law of conservation of energy'. You may recall that it is forced to
go the other way 'because there are only two directions in a
transmission line'.

73, ac6xg

On Tue, 20 Nov 2007 14:37:41 -0800, Jim Kelley
wrote:

The short journey was described by the term "dt".

Ah, suffering the dt's.

As Ed McMahon would prompt Johnny:
"Just how short was that journey?"

My guess it will either be too short to do the job, or much too large
to be true.

This thread should be called:
"Supposition"
or
"Imposition"
or
"Superstition"

73's
Richard Clark, KB7QHC

Jim Kelley wrote:
Yes. The short journey was described by the term "dt". According to
Cecil, that is the amount of time after energy is reflected and before
it 'turns around and goes the other way as it is required to do by the
law of conservation of energy'. You may recall that it is forced to go
the other way 'because there are only two directions in a transmission
line'.

So you don't even accept differential calculus? :-)
Jim, you have never answered the tough questions so I
will keep asking. I just posted an example with one
question that should be easy for you to answer.

In the example, what happens to the energy and momentum
in Pref1 when the load is switched from 300 ohms to 50
ohms? It's a simple question. Please be specific in your
answer.
--
73, Cecil http://www.w5dxp.com

Gene Fuller wrote:
Waves are useful. However, they are not living objects. They have no
will to survive. There is nothing in the standard E&M science based on
Maxwell's laws that requires waves to be "canceled" if they no longer
exist. There is no conservation law of wave-ality.

All EM waves must obey the conservation of energy and
conservation of momentum principles. It is not a will
to survive - it is simply the laws of physics.

Here is an example for you to explain. The source is
a signal generator equipped with an ideal circulator
and a load resistor:

Steady-state #1: Rho at '+' equals 0.7143. Load equals
300 ohms.

100w SGCL--50 ohm feedline--+--1/2WL 300 ohm feedline--300 ohm load
Pfor1=100w-- Pfor2=49w--
--Pref1=51w --Pref2=0w

Pref1 is an 51w EM wave whose energy and momentum must be
conserved.

Steady-state #2: Rho at '+' equals 0.7143. Load is switched
to 50 ohms.

100w SGCL--50 ohm feedline--+--1/2WL 300 ohm feedline--50 ohm load
Pfor1=100w-- Pfor2=204W--
--Pref1=0w --Pref2=104w

*Note that Rho has NOT changed!*

The only question that you need to answer is during the
process that changes Pref1 from 51 joules/sec in the direction
of the source to 0 joules/sec (canceled), *exactly* what happens
to the energy and momentum? Please be specific.
--
73, Cecil http://www.w5dxp.com

On Wed, 21 Nov 2007 14:00:39 GMT, Cecil Moore
wrote:

What is the momentum of 50.95 W?

momentum? Please be specific.
ditto. :-)

Richard Clark wrote:
On Wed, 21 Nov 2007 14:00:39 GMT, Cecil Moore
wrote:

What is the momentum of 50.95 W?

momentum? Please be specific.
ditto. :-)

If 50.95 watts is the Poynting vector, actually
watts/unit-area, then the momentum is 50.95/c^2.
Please reference pages 56,57 of "Optics", by Hecht,
4th edition.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Richard Clark wrote:
On Wed, 21 Nov 2007 14:00:39 GMT, Cecil Moore
wrote:

What is the momentum of 50.95 W?

momentum? Please be specific.
ditto. :-)

If 50.95 watts is the Poynting vector, actually
watts/unit-area, then the momentum is 50.95/c^2.
Please reference pages 56,57 of "Optics", by Hecht,
4th edition.

50.95 divided by the speed of light squared? So, for all
practical purposes - if that's right - it's zero. Why not
just say so?
73,
Tom Donaly, KA6RUH

Tom Donaly wrote:
Cecil Moore wrote:
Richard Clark wrote:
On Wed, 21 Nov 2007 14:00:39 GMT, Cecil Moore
wrote:

What is the momentum of 50.95 W?

momentum? Please be specific.
ditto. :-)

If 50.95 watts is the Poynting vector, actually
watts/unit-area, then the momentum is 50.95/c^2.
Please reference pages 56,57 of "Optics", by Hecht,
4th edition.

50.95 divided by the speed of light squared? So, for all
practical purposes - if that's right - it's zero. Why not
just say so?

The percentage difference between zero and that momentum
is infinite. And whatever value it is must be conserved.
Sweeping it under the rug in violation of the laws of
physics is just not acceptable.
--
73, Cecil http://www.w5dxp.com