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OK Cecil. I understand that none of your discussion applies to instantaneous values, only average values.

I am examining Keith's spread sheet carefully. I found that Open Calc will open the spreadsheet so I can read Keith's cell directions. (Thanks for making the spread sheet available Keith.) I want to make sure that I fully understand what is happening here, to the best of my ability and time available.

On Fri, 07 Mar 2008 12:13:45 -0600
Cecil Moore wrote:

Roger Sparks wrote:
On Fri, 07 Mar 2008 15:15:08 GMT
Cecil Moore wrote:
My formula applies *only to average power*.

I find myself surprised at your insistance that the instantaneous
case must be seperated from the average case in our example of waves
on a transmission line.

You have misunderstood what I am objecting to - which is:
Please don't say or imply that I have said or implied
anything about instantaneous values. I have NOT done so!
The formulas and concepts being used in the discussion
of instantaneous values are NOT mine! My objection is
to the false statements being made about what I have
posted.

Please go ahead and have your instantaneous discussion with
Keith but please don't say or imply that anything associated
with that discussion is about anything I have posted. Saying
or implying such a thing is simply false.

It is informative to look at each problem from many angles.

I agree - just stop saying that it is based on my assertions.
You or Keith may be right or wrong but either way, it is not
associated with anything I have posted. Please leave my name
out of any discussion concerning instantaneous values.

Did I misunderstand your premise, and you were really trying to say that
the inclusion of a 50 ohm source resistor would prevent the source from
ever 'seeing' anything but a 100 ohm load? I don't think that was your
intent.

Please add a dimension to your thinking. No matter what the
value of the load resistor, the source delivers 100 watts.
There are an infinite number of loads that the source could
"see" besides 100+j0 ohms that will make that condition true.

When the load is 0 ohms, the source "sees" 50+j50 ohms.
When the load is 12.5 ohms, the source "sees" 73.5+j44.1 ohms.
When the load is 25 ohms, the source "sees" 90+j30 ohms.
Only when the load is 50 ohms, does the source "see" 100+j0 ohms.
--
73, Cecil http://www.w5dxp.com


--
73, Roger, W7WKB

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On Mar 7, 12:14 pm, Cecil Moore wrote:
....
OK Tom, here's a challenge for you.

The only thing more foolish than the "challenge" that followed that
would be the person who accepted it. Since I don't suppose you think
me a fool, I'll just ignore it.

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On Mar 7, 2:34 pm, Gene Fuller wrote:
Cecil Moore wrote:
K7ITM wrote:
Certainly, those who design and build FTIR spectrometers know
perfectly well that interference does not depend on a narrow-band
coherent source.

How narrow-band? How coherent? In the irradiance (power
density) equation, Ptot = P1 + P2 + 2*sqrt(P1*P2)cos(A),
if the angle 'A' is varying rapidly, what value do you
use for cos(A)?

A constant average sustained level of destructive
interference cannot be maintained between two waves
unless they are coherent. If they are not coherent
the interference will average out to zero.

Gee, I wonder if the experts may have moved beyond the elementary optics
textbook descriptions?

Are you suggesting that FTIR cannot work unless one has your nice 1-D
configurations with perfectly monochromatic waves? Does everything need
to be collinear and coherent?

73,
Gene
W4SZ

So--I have a classic Michelson interferometer, and I see the classic
ring pattern on the screen at the "output" port. I also have a
sensitive microchannel plate detector system that I propose to put in
place of the screen, so that I can reduce the light amplitude to where
it makes sense to be observing it with the very sensitive detector.
In fact, I propose to reduce the light level to the point that the
short wavelength light I'm using is only putting a few photons per
second into the interferometer. I'll count a significant fraction of
those photons and identify where they landed on the microchannel
plate. Do you suppose, Gene, that I'll still see the same
interference pattern that I saw with the much higher intensity light?
Is there any limit to how low a light level I can use and still see
the pattern?

If I do still see the pattern, there must be yet another "dimension" I
need to add to my understanding of the situation -- not rooted in
classical Maxwell e&m.

And of course a dimension that is removed if you think only of average
quantities is time; one who thinks only in terms of averages removes
the possibility of the deeper understanding that resolution as a
function of time allows.

Cheers,
Tom

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Keith Dysart wrote:
You are *not* claiming that the *energy* from the reflected wave
is dissipated in the source resistor, because for the *energy*
in the reflected wave to be dissipated in the source resistor,
the *energy* would have to dissipate at the same time that the
reflected wave delivered the *energy*, and the analysis of
instantaneous *energy* flows shows that this is not the case.

I clearly stated that my claim is based on a special case
zero interference condition - it's even in the title of the
article. The instantaneous energy that you (not I) introduced,
does not meet the zero interference precondition. Therefore,
anything that does not meet the zero interference precondition
that I enumerated is an irrelevant diversion. You introduced
that irrelevant straw man and tried to make hay out it. :-)

you are saying that the average reflected power is
numerically equal to the increase in the average dissipation
in the source resistor.

I can accept that as correct.

Finally, after a million words. :-)

You might consider rewriting the sentence "reflected energy
from the load is flowing through the source resistor, RS, and
is being dissipated there" since it refers to the energy in
the reflected wave and may mislead others in the same way it
mislead me.

Since "average reflected power" is dependent upon the
"reflected energy", I don't see any problem. Would
"average reflected energy" work for you? It should be
obvious that, associated with interference during each
cycle, destructive interference energy is stored during
part of the cycle and delivered back as constructive
interference energy during another part of the cycle.
The intra-cycle interference averages out to zero.

Many have objected to the term "reflected power" saying
it is not power that is reflected but instead is "reflected
energy". So I stopped talking about "reflected power" and
started talking about "reflected energy". Now you object
to the use of the term "reflected energy". Would you and
the rest of the guru attack gang please get together on
what term you would like for me to use?
--
73, Cecil http://www.w5dxp.com

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Roger Sparks wrote:
OK Cecil. I understand that none of your discussion applies
to instantaneous values, only average values.

Indeed, instantaneous values are a diversion away from
my discussion/article/example using average values.

I am examining Keith's spread sheet carefully. I found that
Open Calc will open the spreadsheet so I can read Keith's cell
directions. (Thanks for making the spread sheet available
Keith.) I want to make sure that I fully understand what is
happening here, to the best of my ability and time available.

Given the superposition of two voltages, when the two
voltages have the same sign, constructive interference
is present. When the two voltages have opposite signs,
destructive interference is present. The destructive
interference during each cycle exactly equals (and
supplies) the constructive interference during the
same cycle so the average interference is zero.
--
73, Cecil http://www.w5dxp.com

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K7ITM wrote:
Cecil Moore wrote:
OK Tom, here's a challenge for you.

The only thing more foolish than the "challenge" that followed that
would be the person who accepted it. Since I don't suppose you think
me a fool, I'll just ignore it.

Tom, you are the one who implied that coherency or
incoherency doesn't matter. The challenge would have
proved it doesn't matter. Since you refused the
challenge, can we assume that it does matter?
--
73, Cecil http://www.w5dxp.com

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K7ITM wrote:
On Mar 7, 2:34 pm, Gene Fuller wrote:
Cecil Moore wrote:
K7ITM wrote:
Certainly, those who design and build FTIR spectrometers know
perfectly well that interference does not depend on a narrow-band
coherent source.
How narrow-band? How coherent? In the irradiance (power
density) equation, Ptot = P1 + P2 + 2*sqrt(P1*P2)cos(A),
if the angle 'A' is varying rapidly, what value do you
use for cos(A)?
A constant average sustained level of destructive
interference cannot be maintained between two waves
unless they are coherent. If they are not coherent
the interference will average out to zero.
Gee, I wonder if the experts may have moved beyond the elementary optics
textbook descriptions?

Are you suggesting that FTIR cannot work unless one has your nice 1-D
configurations with perfectly monochromatic waves? Does everything need
to be collinear and coherent?

73,
Gene
W4SZ

So--I have a classic Michelson interferometer, and I see the classic
ring pattern on the screen at the "output" port. I also have a
sensitive microchannel plate detector system that I propose to put in
place of the screen, so that I can reduce the light amplitude to where
it makes sense to be observing it with the very sensitive detector.
In fact, I propose to reduce the light level to the point that the
short wavelength light I'm using is only putting a few photons per
second into the interferometer. I'll count a significant fraction of
those photons and identify where they landed on the microchannel
plate. Do you suppose, Gene, that I'll still see the same
interference pattern that I saw with the much higher intensity light?
Is there any limit to how low a light level I can use and still see
the pattern?

If I do still see the pattern, there must be yet another "dimension" I
need to add to my understanding of the situation -- not rooted in
classical Maxwell e&m.

And of course a dimension that is removed if you think only of average
quantities is time; one who thinks only in terms of averages removes
the possibility of the deeper understanding that resolution as a
function of time allows.

Cheers,
Tom

Tom,

One step at a time. Cecil has not yet accepted the real world in the
classical state. The quantum state will need to wait.

8-)

73,
Gene
W4SZ

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Gene Fuller wrote:
Cecil has not yet accepted the real world in the
classical state.

I know there is no such thing as a lossless transmission
line, Gene. That doesn't prohibit me from using lossless
transmission lines in an example, does it? Every textbook
on transmission lines that I have ever seen does the same
thing.
--
73, Cecil http://www.w5dxp.com

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On Sat, 8 Mar 2008 10:12:04 -0800 (PST), K7ITM wrote:

Is there any limit to how low a light level I can use and still see
the pattern?

Hi Tom,

The Quantum Efficiency of the eye is between 40% and 50%. The time to
convert one photon in a visual receptor is roughly 14 femtoseconds.

I have seen no component that can match the bandwidth, dynamic range,
AND sensitivity of the eye.

73's
Richard Clark, KB7QHC

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On Sat, 08 Mar 2008 14:21:59 -0800, Richard Clark wrote:

On Sat, 8 Mar 2008 10:12:04 -0800 (PST), K7ITM wrote:

Is there any limit to how low a light level I can use and still see the
pattern?

Hi Tom,

The Quantum Efficiency of the eye is between 40% and 50%. The time to
convert one photon in a visual receptor is roughly 14 femtoseconds.

I have seen no component that can match the bandwidth, dynamic range,
AND sensitivity of the eye.

Side note:

Back in the day, when I did a lot of color processing and printing, I
would spend log hours in the darkroom in total darkness.

The only light shedding items were the old Gra-Lab timers, and
luminescent tape on the dangerous corners. After several hours, the light
output from them was just about nil.

My eyes were totally adapted, full visual purple. At this time, the
luminescent tape and dials seemed to scintillate discretely, not the
typical overall glow.

I always wondered if I was possibly seeing individual photon effects.

- 73 de Mike N3LI -