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Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS



 
 
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  #21  
Old August 28th 03, 10:25 AM
sean
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Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

"George Dishman" wrote in message ...
"sean" wrote in message om...

...
Refarding the resonance point I just did a google search on
`resonance` and the few things I found were all describing resonace as
a function of waves overlapping. thats why I couldnt understand dlzs
claim that resonance couldnt be described as waves


Hi Sean,
I happened to come across this recently, it might help:

http://colos1.fri.uni-lj.si/~colos/C...resonance.html

It's a long URL so you will probably have to cut&paste
onto a single line.

HTH
George



Hi George

Thanks for the url.

Read what I could without going into the details of the equations .It
still seems that david is wrong about resonace not being a wave
phenomena? as this url also explains resonance in terms of amplitude,
frequency, harmonics etc. All wave compatible descriptions
Sean
  #22  
Old August 28th 03, 01:27 PM
Aleksandr Timofeev
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Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

\(formerly\)" dlzc1.cox@net wrote in message news:4CV2b.17462$Qy4.1808@fed1read05...
Dear Aleksandr Timofeev:

"Aleksandr Timofeev" wrote in message
om...
\(formerly\)" dlzc1.cox@net wrote in message

news:xoy1b.8759$Qy4.7694@fed1read05...
...
Unbound electrons, Alexsandr. It might be like stopping a bus with a

fly,
but it should be able to be done.


Dear David, I have difficulties with physical interpretation
of your thoughts.


You and me both.

Please explain your thoughts more detail.


---electrons--- ---photons---
And the interesting and possibly detectable interactions would be with an
angle between the two beams.


It is promising and delightful idea.
For practical embodying of this idea,
probably, you can utillize a X-ray laser and electron beam
inside a cathode tube.

I do NOT know if this has been done.


It is promising and delightful idea.
As result you will probably have a very effective frequency
transformer of a X-rays with smoothly varying retuning of frequency...
It will be outbreak in new high technologies...

I do NOT know if this has EVER resulted in a detectable interaction.


It is promising and delightful idea.
It will be outbreak in new high technologies...
Can be...?

...
Done. Laser into an electron beam. Don't know if its been done, don't
know if a measureable result has been looked for. But an example.


The laser beam has too much individually of indistinguishable photons...

???

Ever look at the spoons in a drawer? They all tend to nest together.


But they do not interreact with each other ABSOLUTELY,
or i.e. they do not interreact almost absolute basically.

Photons are not like this. If they were, lasers would be easier. And they
would not dissipate (as they do for LLR measurements).

Lasers are like traffic lights (or better still, like traffic circles),
that release a batch of photons with the "noses" of the little "cars" all
lined up (within reason).


Dear David, I have difficulties with physical interpretation
of your thoughts again. Please explain your thoughts more detail.

What is the physical reason of a dispersing of photons?


To quote Uncle Al, you don't know if you don't look.


It is rather sad. I have lost confidence to expert
estimations of the physicochemical Uncle Al after his
fantastic and sci-fi verbiages

about GPS's precision.

He did not look at weight relations of errors of GPS's
constituents, but he is sure that the Fly sitting on
the Elephant determines a precision weight of composite System
" the Elephant - Fly ".


(And we may have
looked and found nothing.)


On what you do a hint?

David A. Smith

  #23  
Old August 28th 03, 03:18 PM
[email protected] \(formerly\)
external usenet poster
 
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Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

Dear Aleksandr Timofeev:

"Aleksandr Timofeev" wrote in message
om...
\(formerly\)" dlzc1.cox@net wrote in message

news:4CV2b.17462$Qy4.1808@fed1read05...
....
---electrons--- ---photons---
And the interesting and possibly detectable interactions would be with

an
angle between the two beams.


It is promising and delightful idea.
For practical embodying of this idea,
probably, you can utillize a X-ray laser and electron beam
inside a cathode tube.


It might be easier to detect the errant (scattered) electrons. Of couse
the only thing you may end up with is segments of the electron beam with
aligned spins. Or you may end up with nothing at all.

....
Ever look at the spoons in a drawer? They all tend to nest together.


But they do not interreact with each other ABSOLUTELY,
or i.e. they do not interreact almost absolute basically.


Just as photons do not interract absolutely. IMHO, they very rarely ever
interact. The photon-photon collisions are to which I refer.

Photons are not like this. If they were, lasers would be easier. And

they
would not dissipate (as they do for LLR measurements).

Lasers are like traffic lights (or better still, like traffic circles),
that release a batch of photons with the "noses" of the little "cars"

all
lined up (within reason).


What is the physical reason of a dispersing of photons?


The laser beams are created by letting the photons bounce back and forth a
lot of times, then letting those that hit the "release point" in-phase,
exit. The number of times they bounce is finite, and the width of the
channel they bounce in is finite. Therefore they are only aimed very
closely with each other, not identically aimed. And depending on where
they are in the free path, there are other things that can deflect
individual members of the beam differently. If they had 'hair', as
previously discussed, a whole Universe of "other things" could be had.

To quote Uncle Al, you don't know if you don't look.


It is rather sad. I have lost confidence to expert
estimations of the physicochemical Uncle Al after his
fantastic and sci-fi verbiages

about GPS's precision.

He did not look at weight relations of errors of GPS's
constituents, but he is sure that the Fly sitting on
the Elephant determines a precision weight of composite System
" the Elephant - Fly ".


Sometimes thoughts are not born into our brains fully formed. Sometimes
these half-formed ideas sneak out. Perhaps he was looking to us to poke
the "doughboy" in its soft spots. Peer review and all that.

(And we may have
looked and found nothing.)


On what you do a hint?


This experiment (free electron - photon interactions) may have been tried
and found to provide no measureable result. I really can't remember.

David A. Smith


  #24  
Old August 29th 03, 08:39 AM
Aleksandr Timofeev
external usenet poster
 
Posts: n/a
Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

"George Dishman" wrote in message ...
"sean" wrote in message om...
"George Dishman" wrote in message ...
"sean" wrote in message om...

...
Refarding the resonance point I just did a google search on
`resonance` and the few things I found were all describing resonace as
a function of waves overlapping. thats why I couldnt understand dlzs
claim that resonance couldnt be described as waves

I happened to come across this recently, it might help:

http://colos1.fri.uni-lj.si/~colos/C...resonance.html


Read what I could without going into the details of the equations .It
still seems that david is wrong about resonace not being a wave
phenomena? as this url also explains resonance in terms of amplitude,
frequency, harmonics etc. All wave compatible descriptions



While the two concepts are related, they are not the same.
Resonance is a term that relates to a fixed system such as
a pendulum, mass and spring, etc as listed on the web page.
It refers to a system that has a natural mode of oscillation
that can store energy in one place.

When people talk about waves, they usually mean something
with a repetitive characteristic that also moves. Waves can
carry energy from one place to another.

Consider an example of a weighted buoy on the sea. In flat
calm water, if you hit the buoy, it will bob up and down at
some rate. The energy you gave it in the initial impact is
stored as a combination of kinetic and potential energy and
is slowly lost to heat in the water.

If waves hit the buoy at that same rate as it bobs, then
they can give it more energy than it loses in each cycle so
the amplitude will increase. At any other rate the waves may
at first add energy but as they get out of phase they tend
to remove it.

So David is right, a pendulum for example is a resonant
system but it is not a 'wave phenomenon'. To put it crudely,
waves travel, pendulums don't.

The equation for the swing is:

y(t) = a * sin(w*t + p)

where a is the amplitude, w is the angular frequency, t is
time and p is the initial phase. For a wave it is:

y(x,t) = a * sin(w*(t-x/v) + p)

where v is the speed of the wave and x is a distance.


Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


George

  #25  
Old August 29th 03, 03:06 PM
[email protected] \(formerly\)
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Posts: n/a
Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

Dear Aleksandr Timofeev:

"Aleksandr Timofeev" wrote in message
om...
"George Dishman" wrote in message

...
....
The equation for the swing is:

y(t) = a * sin(w*t + p)

where a is the amplitude, w is the angular frequency, t is
time and p is the initial phase. For a wave it is:

y(x,t) = a * sin(w*(t-x/v) + p)

where v is the speed of the wave and x is a distance.


Whether you can describe physical principles of operation of the

RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Real systems also have self-impedance, which *do* provide for resonant
behaviour. Electrons have mass, and therefore there is a "momentum
storage" term. You'll also find that the amplitude in an RC circuit
diminishes as frequency is increased.

This also does not conform to the behaviour of the photoelectric effect.
An RC circuit would be a poor model.

David A. Smith


  #26  
Old August 29th 03, 04:10 PM
George Dishman
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Posts: n/a
Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS


"Aleksandr Timofeev" wrote in message om...

Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Although a capacitor stores energy an RC circuit is not a
resonant system. The voltage and current in an RC circuit
decay exponentially and have no natural oscillation. The
differential equation is first order while resonance
requires second order.

To make an oscillator using an RC requires a separate
non-linear gain stage (a 'relaxation' oscillator) or you
need multiple RC stages.

HTH
George


  #27  
Old August 29th 03, 08:49 PM
Craig Markwardt
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Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS


Hi George!

"George Dishman" writes:

"Aleksandr Timofeev" wrote in message om...

Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Although a capacitor stores energy an RC circuit is not a
resonant system. The voltage and current in an RC circuit
decay exponentially and have no natural oscillation. The
differential equation is first order while resonance
requires second order.


However, an LC circuit can be a resonant system. [inductor-capacitor]
No "waves" are involved in an LC circuit.

Craig

--
--------------------------------------------------------------------------
Craig B. Markwardt, Ph.D. EMAIL:
--------------------------------------------------------------------------
  #28  
Old August 29th 03, 09:50 PM
George Dishman
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Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS


"Craig Markwardt" wrote in message news

Hi George!


Hi Craig! SIRTF's

"George Dishman" writes:

"Aleksandr Timofeev" wrote in message om...

Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Although a capacitor stores energy an RC circuit is not a
resonant system. The voltage and current in an RC circuit
decay exponentially and have no natural oscillation. The
differential equation is first order while resonance
requires second order.


However, an LC circuit can be a resonant system. [inductor-capacitor]
No "waves" are involved in an LC circuit.


I assumed Aleksandr was familiar with that but it's a good example
of the differential form. The voltage across the inductor depends
on the rate of change of current while for the capacitor it depends
on the integral. For a series configuration:

L * d^2I/dt^2 + R * dI/dt + I / C = dV/dt

The Q is 1/R * sqrt(L/C) and the circuit is resonant for Q 0.5

best regards
George


  #29  
Old August 30th 03, 09:07 AM
Aleksandr Timofeev
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Posts: n/a
Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS

"George Dishman" wrote in message ...
"Aleksandr Timofeev" wrote in message om...

Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Although a capacitor stores energy an RC circuit is not a
resonant system. The voltage and current in an RC circuit
decay exponentially and have no natural oscillation. The
differential equation is first order while resonance
requires second order.


Then you should explain the physical mechanism of the RC-generator,
which one ensures on an output of the RC-generator (RC-oscillator)
only sine-wave oscillations. ;-)


To make an oscillator using an RC requires a separate
non-linear gain stage (a 'relaxation' oscillator) or you
need multiple RC stages.

HTH
George

  #30  
Old August 30th 03, 09:40 AM
George Dishman
external usenet poster
 
Posts: n/a
Default Gravitation and Maxwell's Electrodynamics, BOUNDARY CONDITIONS


"Aleksandr Timofeev" wrote in message om...
"George Dishman" wrote in message ...
"Aleksandr Timofeev" wrote in message om...

Whether you can describe physical principles of operation of the RC-oscillator
(capacitance-resistance oscillator) from a point of view of a resonance?


Although a capacitor stores energy an RC circuit is not a
resonant system. The voltage and current in an RC circuit
decay exponentially and have no natural oscillation. The
differential equation is first order while resonance
requires second order.


Then you should explain the physical mechanism of the RC-generator,
which one ensures on an output of the RC-generator (RC-oscillator)
only sine-wave oscillations. ;-)


You mean as I mentioned in the next paragraph? ;-)

To make an oscillator using an RC requires a separate
non-linear gain stage (a 'relaxation' oscillator)


This doesn't give a sine wave but just for completeness:

http://www.ee.polyu.edu.hk/staff/een.../ee251lab2.htm

or you
need multiple RC stages.


This is the one you are thinking of and does give a
sine wave:

http://home.earthlink.net/~doncox/wec/Oscillators.html

Note that you need at least three stages. You need to get
180 degrees phase shift from the RC delays to produce an
in-phase signal into the inverting amplifier. In theory a
single RC stage will produce 90 degrees shift but only
when the gain is zero. The oscillator as a whole can have
a similar frequency characteristic to a resonant system
but the initial energy in the capacitors is lost as heat
in the resistors and base of the transistors and has to
be continually replaced from the power supply. The
individual RC sections only provide phase shift, not
useable power storage so it is not resonant in the
physical sense. (Some electronics texts may describe it
as resonant because of the response, not the mechanism.)

As Craig pointed out a simple LCR circuit can be resonant
provided the resistance is low enough (series mode) or
high enough (parallel mode) to avoid excessive damping.
This is a good description of that (9 page PDF):

http://faculty.washington.edu/maniso.../resonance.pdf

The key difference is that in an LC circuit, energy can
be stored in the magnetic field in the inductor and in the
electric field in the capacitor. The collapse of the
magnetic field induces a voltages that charges the
capacitor, the voltage across the capacitor then builds
the current in the inductor in the opposite sense to the
original and so on. Without resistive losses this could
go on indefinitely.

With just an RC, the energy in the capacitor is turned
into heat in the resistor and that is the end.

George


 




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