On Jun 5, 6:15*pm, Keith Dysart wrote:
Certainly a standing wave is not a wave that transfers energy.

Since a standing "wave" is not a wave, by definition, doesn't that
give you a clue that you may be being duped by an illusion?
--
73, Cecil, w5dxp.com

On Jun 5, 1:05 pm, lu6etj wrote:
Hi. ¡Good evening (here) to all..!

We need to carefully understand the meaning of the words. Power is
energy that is moving;

Since the energy can be dissipated also transmitted, If we talk in
power FLUX terms (instead power only), I think the issue it would be a
little more understandable because surfaces may have associated
vectors (with "power moving" I believe you are thinking about power
crossing an imaginary surface)
(Note: when I spoke about "unidimensional" nature of a TL space I am
pointing to "degrees of freedom" of energy flux circumscribed to its
physical path, of course).

For the sake of example we could imaginate a coaxial TL provided with
a resistive inner conductor and perfectly conductive outer one. On
such TL perhaps we could clearly visualize power flux vector (Poynting
vector) "slanted" towards inner conductor to "see" -through simple
vectorial decomposition on (over?) the inner wire and pependicular to
it directions both = transmission and dissipative nature of
phenomenom.
At the same time I believe will be also more ease to account for net
power FLUX of opposite directions traveling waves and do not confuse
with net power being zero, leading us to the idea of zero energy
stored in a ideal resonant TL. Note: In my last mensage I forget to
clear that with "resonant line" I was speaking about a section of TL
with its ends open or shorted (or a mix) to force a "chemically pure"
standing wave :)

I believe we always must escape from words as "real" or
"true" (outside of safe environments such mathematics or digital
logic), because "she" easily leads us to the Holy Inquisition
dangers :) Let us the Wave word to be free for jointing with
standing, sine, hand, etc, etc. and do we make efforts to understand
its conceptual meaning on each context :)

Good day Miguel,

I do not disagree with anything you have written, but I do think it
is much too early to introduce Poynting vectors and lossy conductors
to the discussion.

Some of the posters to this group have basic misunderstandings of
the behaviour of transmission lines and using Poynting to address
these misunderstandings is like trying to use quantum mechanics
to address misunderstandings of Newton’s third law. And it will
be just as unsuccessful.

The basic misunderstanding is believing that a reflected wave
necessarily and always transports energy. Rather than using
basic circuit theory to demonstrate that this assumption is
incorrect, these posters introduce Poynting, optics and
photons to reinforce their beliefs. Believing that a
reflected wave necessarily transports energy then begs the
question ‘where does this energy go?’. At one time it was
a commonly held belief that this reflected ‘energy’ entered
the transmitter and fried the final. This notion has generally
disappeared, but has been replaced by faulty concepts
attempting to explain how the reflected ‘energy’ is re-reflected
so that is does not enter the transmitter. And all this effort
is expended because of a misunderstanding of the nature of
reflected ‘energy’.

Until these basic behaviours are properly understood, optics,
photons and Poynting merely assist with obfuscation.

....Keith

On Jun 5, 6:28*pm, Keith Dysart wrote:
There are indeed negative values. These occur when the energy is
flowing in the other direction, ...

Let's take a close look at the illusion that you are seeing and not
comprehending. Observe a snapshot of the instantaneous power envelope
of a traveling wave. It is a sinusoidal envelope with peak
instantaneous power levels and zero instantaneous power levels. When
it is traveling in the forward direction we consider that to be
positive power. When it is traveling in the reverse direction, we
consider that to be negative power. It is only a directional
*convention* not proof that negative power exists. The only waves that
can exist as waves on a transmission line are traveling waves.

Since the forward wave and reverse wave do not interact while Z0
remains constant, they have zero effect on each other and we can just
simply algebraically add the two instantaneous powers to obtain the
net instantaneous power. Thus, when the instantaneous power in the
forward wave is a greater magnitude than the instantaneous power in
the reverse wave, the net instantaneous power is positive. When the
instantaneous power in the forward wave is a lesser magnitude than the
instantaneous power in the reverse wave, the net instantaneous power
is negative. At the point where they are equal, the net instantaneous
power is zero. This is the illusion, based on net instantaneous power,
that you are observing. Please note that net instantaneous power is an
oxymoron. Is it net or is it instantaneous? How can it be both?

All you are observing is that sometimes the instantaneous power in the
forward traveling wave is more, less, or equal to the instantaneous
power in the reverse traveling wave which causes the net instantaneous
Poynting vector direction to alternate. But it is all a moot point
because photons cannot perform the feats of magic that you are
ascribing to them. You are simply being fooled by an illusion based on
the misguided algebraic addition of two separate and distinct
instantaneous powers that you believe are interacting but while Z0
remains constant, they are not interacting in any way and it is
impossible for the photons to change direction without a physical
cause. Your mashed-potatoes version of energy doesn't even obey
Maxwell's equations. Why do you think the concept can possibly be
meaningful?

In "Optics", Hecht says instantaneous power is "of limited utility."
You seem to have discovered that limit, stepped over it, and stepped
in it. :-)
--
73, Cecil, w5dxp.com

On Jun 5, 6:33*pm, Keith Dysart wrote:
This simplified form works for sinusoids. It is derived from
P(t)=V(t)I(t),
but loses information since the result is just the average value.

Note that P(t)=V(t)I(t) is just Pfor(t) - Pref(t) which loses
information when the subtraction is performed and is not important in
any meaningful way. If, as you say, loss of information is to be
avoided, you should be using Pfor(t) and Pref(t) instead of net P(t).
--
73, Cecil, w5dxp.com

On Jun 6, 7:54*am, Keith Dysart wrote:
Some of the posters to this group have basic misunderstandings of
the behaviour of transmission lines and using Poynting to address
these misunderstandings is like trying to use quantum mechanics
to address misunderstandings of Newton’s third law. And it will
be just as unsuccessful.

Translation: I object to anything, including technical references and
laws of physics, that shoots my argument down. :-)

The basic misunderstanding is believing that a reflected wave
necessarily and always transports energy.

Please define "transport". An EM wave cannot exist without ExH energy.
If the energy associated with an EM reflected wave is equal to zero,
then the reflected wave cannot be measured and doesn't exist. But we
know that reflected waves do exist just by looking in a mirror -
causing the reflected photonic energy to be incident upon our retinas.
All of the transported energy in the reflected wave in a transmission
line is recovered during the transient state immediately following key
down. Tracking reflected energy from beginning to end result is not
difficult - optical physicists have been doing it for decades. But,
unlike your ideas, their results do not require the violation of the
laws of physics.
--
73, Cecil, w5dxp.com

On Jun 6, 9:55*am, Cecil Moore wrote:
On Jun 5, 6:33*pm, Keith Dysart wrote:

This simplified form works for sinusoids. It is derived from
P(t)=V(t)I(t),
but loses information since the result is just the average value.

Note that P(t)=V(t)I(t) is just Pfor(t) - Pref(t) which loses
information when the subtraction is performed and is not important in
any meaningful way. If, as you say, loss of information is to be
avoided, you should be using Pfor(t) and Pref(t) instead of net P(t).
--
73, Cecil, w5dxp.com

In the past you have insisted that only average powers were relevent.
Does this mean you are ready to look at power (i.e. energy flow) in
the
time domain?

If so, you might appreciate
http://sites.google.com/site/keithdysart/radio6.

....Keith

On Jun 6, 10:09*am, Cecil Moore wrote:
On Jun 6, 7:54*am, Keith Dysart wrote:

Some of the posters to this group have basic misunderstandings of
the behaviour of transmission lines and using Poynting to address
these misunderstandings is like trying to use quantum mechanics
to address misunderstandings of Newton’s third law. And it will
be just as unsuccessful.

Translation: I object to anything, including technical references and
laws of physics, that shoots my argument down. :-)

A rather poor translation.

The basic misunderstanding is believing that a reflected wave
necessarily and always transports energy.

Please define "transport". An EM wave cannot exist without ExH energy.
If the energy associated with an EM reflected wave is equal to zero,
then the reflected wave cannot be measured and doesn't exist. But we
know that reflected waves do exist just by looking in a mirror -

You do seem to mention looking in the mirror quite frequently, as if
it
had something to do with understanding the behaviour of a
transmission
line.

causing the reflected photonic energy to be incident upon our retinas.
All of the transported energy in the reflected wave in a transmission
line is recovered during the transient state immediately following key
down. Tracking reflected energy from beginning to end result is not
difficult - optical physicists have been doing it for decades. But,
unlike your ideas, their results do not require the violation of the
laws of physics.

My main idea is basic electricity. If the voltage or current is
always 0, so is the power. This does not violate any physics of which
I am aware.

....Keith

On Jun 6, 9:45*am, Cecil Moore wrote:
On Jun 5, 6:28*pm, Keith Dysart wrote:

There are indeed negative values. These occur when the energy is
flowing in the other direction, ...

Let's take a close look at the illusion that you are seeing and not
comprehending. Observe a snapshot of the instantaneous power envelope
of a traveling wave. It is a sinusoidal envelope with peak
instantaneous power levels and zero instantaneous power levels. When
it is traveling in the forward direction we consider that to be
positive power. When it is traveling in the reverse direction, we
consider that to be negative power. It is only a directional
*convention* not proof that negative power exists. The only waves that
can exist as waves on a transmission line are traveling waves.

Ahhh. I see part of your problem. You are thinking envelopes.

You need to change your point of view to be a particular point on the
line.
At this point, there is a function that describes the voltage: V(t).
It
may or may not be a sinusoid. There is a function for the current:
I(t).
And from these can trivialy be derived a function for power:
P(t)=V(t)I(t).

When I clip my instantaneous voltmeter across a line and measure 0 for
all time, I can confidently say that no energy is flowing, for there
is
not. I am curious as to what you would answer?

In "Optics", Hecht says instantaneous power is "of limited utility."
You seem to have discovered that limit, stepped over it, and stepped
in it. :-)

Well, Hecht may have his limitations when dealing with Optics, but
there
is no reason to expect these same limitations to apply to circuit
analysis.

....Keith

On 6 jun, 18:00, Keith Dysart wrote:
On Jun 6, 9:45*am, Cecil Moore wrote:

On Jun 5, 6:28*pm, Keith Dysart wrote:

There are indeed negative values. These occur when the energy is
flowing in the other direction, ...

Let's take a close look at the illusion that you are seeing and not
comprehending. Observe a snapshot of the instantaneous power envelope
of a traveling wave. It is a sinusoidal envelope with peak
instantaneous power levels and zero instantaneous power levels. When
it is traveling in the forward direction we consider that to be
positive power. When it is traveling in the reverse direction, we
consider that to be negative power. It is only a directional
*convention* not proof that negative power exists. The only waves that
can exist as waves on a transmission line are traveling waves.

Ahhh. I see part of your problem. You are thinking envelopes.

You need to change your point of view to be a particular point on the
line.
At this point, there is a function that describes the voltage: V(t).
It
may or may not be a sinusoid. There is a function for the current:
I(t).
And from these can trivialy be derived a function for power:
P(t)=V(t)I(t).

When I clip my instantaneous voltmeter across a line and measure 0 for
all time, I can confidently say that no energy is flowing, for there
is
not. I am curious as to what you would answer?

In "Optics", Hecht says instantaneous power is "of limited utility."
You seem to have discovered that limit, stepped over it, and stepped
in it. :-)

Well, Hecht may have his limitations when dealing with Optics, but
there
is no reason to expect these same limitations to apply to circuit
analysis.

...Keith

Hi folks, good night (from here).

I do not disagree with anything you have written, but I do think it
is much too early to introduce Poynting vectors and lossy conductors
to the discussion.

Hello Keith, Yes, I understand your comment, I introduced Poynting
vector only because both, energy and power, are scalars and we can not
talk about scalars having direction without get in conceptual
troubles; flux of power instead, have direction because surface vector
presence in its definition gives directive characteristics to power
crossing an imaginary surface.
Slanted flux of electromagnetic power (Poynting) due resistive
conductor simply seems to me a good example of a power flux in a TL
not totally coincident with axial direction to provide a little more
supporting to "directive" notion of Power Flux.
However IMHO power flux do not seems to me more complicated than
power, work, voltage, potential, energy, E and H fields, etc. All of
them -I believe- are not very simple stuff :(, but they are very
funny and interesting, indeed...!! :D. What do you think?
......
Please would you mind tell me why "sine wave" it is not a correct use
of "wave" word. The only dictionary I have = "Oxford advanced
english dictionary of current english defines wave as: "move to and
fro, up and down", I believe also in english there are word qualifiers
(sine, traveling, standing, etc) who specify the precise meaning of
them in diverse contexts. Am I wrong about this?.
.....
Sorry by my insistence about convenience of discuss about "models".
Please let me bring a citation:
"At times, two quite differents models may serve equally well, but
eventually one is usually found to prevail, not because it is right,
but because it is both more convenient and more logically constructed.
After all, models are constructed for convenience in thinking and
recording, not as photographic images of nature"
(From "Electromagnetic Engineering", Ronold W.P. King (PhD), page 94.
McGraw Hill.1946).
.....
I studied "Principle of Conjugates Impedance Matching" in my early
student days and the "mirror reflection" explained by Walter Maxwell
in his article agree with my undestanding about "where the reflected
waves go" because to balance magnitudes it is necessary that they
found a full mismatch on its way (path?) to generator. My own limited
analisis led me to the same notion even without conjugate match if I
calculate Incident and reflected voltages values in a half wave TL (as
my early thread example),
As I said, reading Cecil's web page quarter wave line examples led me
to considerate another possible representations of the problem, in
addition Owen's own ideas about it also made me consider the issue
from another point of view.

Thank you very nuch.

Miguel Ghezzi - LU6ETJ

"lu6etj" wrote
...
.....
Please would you mind tell me why "sine wave" it is not a correct use
of "wave" word. The only dictionary I have = "Oxford advanced
english dictionary of current english defines wave as: "move to and
fro, up and down", I believe also in english there are word qualifiers
(sine, traveling, standing, etc) who specify the precise meaning of
them in diverse contexts. Am I wrong about this?.

Sine wave is an ideal wave. The motion to and fro are simmetrical.
In reality no such. The wave source push the medium strongly but it come
back with the lower intensity.
For this reason the wave flow transmits the energy from the source to
distant places.
In fluids take place also the mass flow.
S*