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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
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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 |
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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 |
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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 |
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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 |
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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 |
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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
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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
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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
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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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