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Question about "Another look at reflections" article.
On Thu, 27 May 2010 19:10:41 -0700 (PDT), lu6etj
wrote: 2) What would be Rs optical analog? Superman's cataracts with his xray vision. This is probably going to be your only direct answer. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On 28 mayo, 03:18, Richard Clark wrote:
On Thu, 27 May 2010 19:10:41 -0700 (PDT), lu6etj wrote: 2) What would be Rs optical analog? Superman's cataracts with his xray vision. *This is probably going to be your only direct answer. 73's Richard Clark, KB7QHC OK, good example. Cataracts presents absortion, transmission and reflection (they are whitish). To be analog I think should not have reflection. What do you think? (Perhaps seems maieutics but really I am trying to put my thoughts in order at first). What about the third point? I consider it important because light waves are in three dimensional space, so when they cancels in a region, reinforces in other and I can understand redistribution, but line travelling waves are in unidimensional space and here I can not visualize (realize?) the energy redistribution as in light interference. Sorry, when I put interrogation words inside parentheses is that I am not sure the better/adecuated translation. 73 Miguel Ghezzi LU6ETJ |
Question about "Another look at reflections" article.
On 28 mayo, 05:47, lu6etj wrote:
On 28 mayo, 03:18, Richard Clark wrote: On Thu, 27 May 2010 19:10:41 -0700 (PDT), lu6etj wrote: 2) What would be Rs optical analog? Superman's cataracts with his xray vision. *This is probably going to be your only direct answer. 73's Richard Clark, KB7QHC OK, good example. Cataracts presents absortion, transmission and reflection (they are whitish). To be analog I think should not have reflection. What do you think? (Perhaps seems maieutics but really I am trying to put my thoughts in order at first). What about the third point? I consider it important because light waves are in three dimensional space, so when they cancels in a region, reinforces in other and I can understand redistribution, but line travelling waves are in unidimensional space and here I can not visualize (realize?) the energy redistribution as in light interference. *Sorry, when I put interrogation words inside parentheses is that I am not sure the better/adecuated translation. 73 Miguel Ghezzi LU6ETJ Sorry I thought it was a very simple Cecil's answer. It was a joke, wasn't it?. It is my fault... I did not realize the signature and not translate well the paragraph :) Miguel |
Question about "Another look at reflections" article.
On May 27, 9:10*pm, lu6etj wrote:
1) I did not think of (or is think on?) a laser source, I was one step before, I think only of a "coherent" source to match monofrequency simple AC generator analogy. Let's consider an *ideal* single-frequency laser to be a coherent monofrequency source for the purposes of discussion. 2) What would be Rs optical analog? I don't know enough about lasers to answer that question. In any case, I don't think reflections incident upon a laser encounter whatever Rs that might exist. I think we are going to have to settle for what happens outside of the laser which in important because what happens to photons in free space and other mediums cannot be hidden inside a transmission line. Standing waves of photons cannot stand still in a coaxial transmission line any better than they can stand still in free space. What some people are missing is that visible light waves and RF waves are exactly the same phenomena, just at a different frequency. The laws of physics governing light waves also govern RF waves. When someone says, "RF waves are different from light waves" or "RF waves can stand still", they are just showing their ignorance. They must also prove that reflected visible light waves in free space contain no energy and can stand still or else they are just blowing smoke. 3) Superposition is a medium phenomenon ¿yes?, for example "eter". Interference an result of it on a other "thing", for example photographic plate or screen. Are we agree? K No, in our context, superposition is the merging of two or more EM waves in any medium. If the waves are coherent, constructive/ destructive interference can occur. If partial or complete wave cancellation (permanent destructive interference) occurs, then the energy in the waves that existed before cancellation must be redistributed in another direction AND there are only two directions in an RF transmission line. I believe that Walter Maxwell defines any reversal in direction of reflected energy flow in a transmission line to be a "re-reflection". I prefer to call what happens to a single reflected wave a 1. "re- reflection" and what happens when two waves cancel a 2. "redistribution" of reflected energy. What about the third point? I consider it important because light waves are in three dimensional space, ... Let's compare coax with 0.2 square inches of cross-sectional area to a laser beam with 0.2 square inches of cross-sectional area. For the same power level, the power density, watts/in^2, will be the same - therefore the Poynting vectors will be the same. With such a concept in place, we can talk about a 100w RF source or a 100w laser source. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 27, 10:34*am, Cecil Moore wrote:
Note that the reflection coefficient, r, is 1.0 for air. Sorry, I misspoke here. Instead of "reflection coefficient", I should have said "index of refraction". The two are related but they are not the same parameter. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On Fri, 28 May 2010 01:47:40 -0700 (PDT), lu6etj
wrote: On 28 mayo, 03:18, Richard Clark wrote: On Thu, 27 May 2010 19:10:41 -0700 (PDT), lu6etj wrote: 2) What would be Rs optical analog? Superman's cataracts with his xray vision. *This is probably going to be your only direct answer. 73's Richard Clark, KB7QHC OK, good example. Cataracts presents absortion, transmission and reflection (they are whitish). To be analog I think should not have reflection. What do you think? (Perhaps seems maieutics but really I am trying to put my thoughts in order at first). Whatever reflects, also absorbs and vice-versa. The notion that the interface is a singularity (infinitely thin) cannot be found in reality. Arguments that hinge on this non-existent property are made for the novice to intermediate student. Those who practice the science of optics at the bench never observe this metaphor in reality. What about the third point? I consider it important because light waves are in three dimensional space, so when they cancels in a region, reinforces in other and I can understand redistribution, but line travelling waves are in unidimensional space and here I can not visualize (realize?) the energy redistribution as in light interference. Sorry, when I put interrogation words inside parentheses is that I am not sure the better/adecuated translation. Superposition is the collapse of all possible solutions to a real one. To be real, we must have an observer. Frequently that is called a load. That load may be a transducer (light cell). Without the observer, both energies are present - nothing cancels. What is called redistribution is a superstitious necessity of trying to visualize the math. Redistribution is a strained term that is useful as a placebo, but nothing moves in the redistribution (an irony or a paradox which is more useful in entertainment). Traveling along the road of using optical metaphors is troubling for those who have never worked at an optic bench. Cut and paste theory from eminent authors occludes vision. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On Fri, 28 May 2010 02:03:51 -0700 (PDT), lu6etj
wrote: It was a joke, wasn't it?. It was the only explicit answer you will ever get. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On 28 mayo, 15:12, Richard Clark wrote:
On Fri, 28 May 2010 01:47:40 -0700 (PDT), lu6etj wrote: On 28 mayo, 03:18, Richard Clark wrote: On Thu, 27 May 2010 19:10:41 -0700 (PDT), lu6etj wrote: 2) What would be Rs optical analog? Superman's cataracts with his xray vision. *This is probably going to be your only direct answer. 73's Richard Clark, KB7QHC OK, good example. Cataracts presents absortion, transmission and reflection (they are whitish). To be analog I think should not have reflection. What do you think? (Perhaps seems maieutics but really I am trying to put my thoughts in order at first). Whatever reflects, also absorbs and vice-versa. *The notion that the interface is a singularity (infinitely thin) cannot be found in reality. *Arguments that hinge on this non-existent property are made for the novice to intermediate student. *Those who practice the science of optics at the bench never observe this metaphor in reality. What about the third point? I consider it important because light waves are in three dimensional space, so when they cancels in a region, reinforces in other and I can understand redistribution, but line travelling waves are in unidimensional space and here I can not visualize (realize?) the energy redistribution as in light interference. *Sorry, when I put interrogation words inside parentheses is that I am not sure the better/adecuated translation. Superposition is the collapse of all possible solutions to a real one. To be real, we must have an observer. *Frequently that is called a load. *That load may be a transducer (light cell). *Without the observer, both energies are present - nothing cancels. *What is called redistribution is a superstitious necessity of trying to visualize the math. *Redistribution is a strained term that is useful as a placebo, but nothing moves in the redistribution (an irony or a paradox which is more useful in entertainment). Traveling along the road of using optical metaphors is troubling for those who have never worked at an optic bench. *Cut and paste theory from eminent authors occludes vision. 73's Richard Clark, KB7QHC- Ocultar texto de la cita - - Mostrar texto de la cita - Hi Cecil and Richard (thanks for answer my questions Cecil, and add your technical comments Richard). I reply (is it OK "reply"?) to Richard first because it is part of my comment to Cecil. Yes, Richard. Tonight I said to me: -the worst term that you could use, Miguel, was "ether"- :), because "ether" is a hipotetical MATERIAL thing, so, as on other material mediums we usually can literally see interference because interference is manifested on matter, but we need photographic plates, screens, retinas, etc. to manifest electromagnetic interference, "loads" as say Richard, ("observer" it is more sutil and difficult concept, I dare not with "him"). I needed know what represent that in a line discontinuity (in a load seems obvious) to better understand Cecil's examples in web page (http://www.w5dxp.com/energy.htm). ..... Before continue I want to do a comment to know if we agree (more or less). We partially think with words or symbols, words and symbols represent concepts or perceptions, concepts are not "out there", as Einstein said they a "free creations of human mind". There is not energy out there, there is not velocity out there, that things are in our brains (or consciusness if you prefer). We need consensus to collective think on it, we need "sincrhonize" our minds to colectivelly think the world... You think in english, I think in spanish, I need translate "your" words to "my" words to understand what you say, I can not say: "whats the hell is a rig!", where are "rigs"! only there are "equipos" boys! :) For that I need understand what means Cecil with redistribution, I belieive I can understand his idea behind the word, I must make the effort because my own language barrier. Perhaps the consensus word to it may be not "redistribution", but... what Cecil tries explain to me? I try never identify the "map" (words, concepts) with the "territory" (hipotetical real world) because misleading me. ..... Cecil I want to ask you if you are using "photon" term to methaforically refer to "light". I am not qualified at all to address this issue in quantic physics terms I thougth we was fully inmersed in ondulatory theory. I do not have useful knowledge in laser either. but I can imagine (I believe) the properties of Rs analogy. I am interested in your optical analogy because analogies often are useful to visualize a new thing knowing old things, it does not matter if we use RF concepts to aproximate optical things or vice versa, analogies are useful crutches (muletas in spanish). Even I agree at our concept that electromagnetic spectrum includes RF waves and ligh waves and they are the same phenomenon, I think that is a result of great insight and efforts of the human mind, it is not so evident. We see light, we sense infrared radiaton, but we can not perceive well RF without instruments (unless we introduce ourselves in a micowave oven or burn with the antenna, of course ). To concentrate light we only need a piece of glass, to do the same on HF RF region we need large wire antenna arrays. Because of this we often need (or employ) very differents models to deal with the "same thing". Probably Maxwell equations solve all of them, but they are difficult ladies to deal :). Reconciling optcs models with electric models have its difficulties, but can be productive undoubtedly I believe. (Richard I do not think wathever reflects also absorbs (ideally at last), It can reflects an transmits but nor absorb, do you agree with it?) (I do not forget Roy's article, I'm still trying to sort out all the puzzle pieces). 73 Miguel Ghezzi LU6ETJ |
Question about "Another look at reflections" article.
On Fri, 28 May 2010 15:46:02 -0700 (PDT), lu6etj
wrote: I reply (is it OK "reply"?) Hi Miguel, Your usage is fine. to Richard first because it is part of my comment to Cecil. Yes, Richard. Tonight I said to me: -the worst term that you could use, Miguel, was "ether"- :), because "ether" is a hipotetical MATERIAL thing, Hypothetical. so, as on other material mediums we usually can literally see interference because interference is manifested on matter, but we need photographic plates, screens, retinas, etc. to manifest electromagnetic interference, "loads" as say Richard, ("observer" it is more sutil and difficult concept, I dare not with "him"). I needed know what represent that in a line discontinuity (in a load seems obvious) to better understand Cecil's examples in web page (http://www.w5dxp.com/energy.htm). Representing, representation, like the term redistribution, are all crutches for intellect. If you get stuck on one, you are forever behind. If it works - fine. When the crutch breaks, you have to be able to walk away without feeling cheated. (Amusing, being able to walk away means you never needed the crutch in the first place.) .... Before continue I want to do a comment to know if we agree (more or less). We partially think with words or symbols, words and symbols represent concepts or perceptions, concepts are not "out there", as Einstein said they a "free creations of human mind". There is not energy out there, there is not velocity out there, that things are in our brains (or consciusness if you prefer). We need consensus to collective think on it, we need "sincrhonize" our minds to Synchronize. colectivelly think the world... You think in english, I think in spanish, I need translate "your" words to "my" words to understand what you say, I can not say: "whats the hell is a rig!", where are "rigs"! only there are "equipos" boys! :) For that I need understand what means Cecil with redistribution, I belieive I can understand his idea behind the word, I must make the effort because my own language barrier. Perhaps the consensus word to it may be not "redistribution", but... what Cecil tries explain to me? I try never identify the "map" (words, concepts) with the "territory" (hipotetical real world) because misleading me. Redistribute is an action verb. Nothing happens until you measure it (you need a load). This speaks to your Ether (or Aether or Æther) being a medium, but there is no evidence of Ether existing. So for action, it is in the loading - nothing else happens (has action) without a load. The "concept" of redistribution collapses to zero if you do not take a measure, but it exists if you do? Logically, the causal relationship is with the observation, not with the energy. The load reveals a concept that does not exist without it. What you wonder about and call a map, or territory, is a forest of loads that give a population of varied responses that are a product of phase differences. Mathematical "representations" of this are called surface maps (your term of map is appropriate) or contour maps. Within these types of representation, you can see patterns. However, the patterns are those revealed by a multitude of loads. Take away the loads and you would see nothing. (Richard I do not think wathever reflects also absorbs (ideally at last), It can reflects an transmits but nor absorb, do you agree with it?) No. I have measured light at the bench, and I have studied its applications at many scales down to subwavelength dimensions. All materials absorb light without qualification. All materials reflect light without qualification. All materials transmit light without qualification. You may be tempted to tightly constrain what you call light to force an artificial solution. Do not do it, because that serves no useful purpose. Consider the sun, light (a photon) from its center has to penetrate its bulk before we see it. It takes something like 10,000 years for that light to reach the surface. Any material you think of here on our mud ball planet is inconsequential in comparison. Using an optical analogy for RF is very dangerous if you cannot measure it at the bench. Why try to understand two unknowns together? The greatest danger of an optical analogy is in your perception (I choose that word with care) that IF you are able to "see" it, THEN that means that you "understand" it. Sight is an illusion (another word chosen with care) that is most often clouded by the mind. This topic fills books from both academic and popular writers. In simple terms, there are optical events that you are certain you can see, but that you cannot measure or show anyone else. There are optical events you and others can measure, but you cannot see. A simple (but complex one to build) example is the conjugate mirror. It reflects light, but when you look into it, all you see is black. If you have no experience at the bench, then what I write is a puzzle. Although I have described why this happens, I doubt anyone remembers or knows the answer to this contradiction. If you want a hint, it relates ENTIRELY to your trying to tie together RF, reflection, and other transmission/transmitter topics. Look at the ongoing discussion on source resistance, and note the same word conjugate's appearance in that commentary. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On 28 mayo, 21:05, Richard Clark wrote:
On Fri, 28 May 2010 15:46:02 -0700 (PDT), lu6etj wrote: I reply (is it OK "reply"?) Hi Miguel, Your usage is fine. to Richard first because it is part of my comment to Cecil. Yes, Richard. Tonight I said to me: -the worst term that you could use, Miguel, was "ether"- *:), because "ether" is a hipotetical MATERIAL thing, Hypothetical. so, as on other material mediums we usually can literally see interference because interference is manifested on matter, but we need photographic plates, screens, retinas, etc. to manifest electromagnetic interference, "loads" as say Richard, ("observer" it is more sutil and difficult concept, I dare not with "him"). I needed know what represent that in a line discontinuity (in a load seems obvious) to better understand Cecil's examples in web page (http://www.w5dxp.com/energy.htm). Representing, representation, like the term redistribution, are all crutches for intellect. *If you get stuck on one, you are forever behind. *If it works - fine. *When the crutch breaks, you have to be able to walk away without feeling cheated. *(Amusing, being able to walk away means you never needed the crutch in the first place.) .... Before continue I want to do a comment to know if we agree (more or less). We partially think with words or symbols, words and symbols represent concepts or perceptions, concepts are not "out there", as Einstein said they a "free creations of human mind". There is not energy out there, there is not velocity out there, that things are in our brains (or consciusness if you prefer). We need consensus to collective think on it, we need "sincrhonize" our minds to Synchronize. colectivelly think the world... You think in english, I think in spanish, I need translate "your" words to "my" words to understand what you say, I can not say: "whats the hell is a rig!", where are "rigs"! *only there are "equipos" boys! :) For that I need understand what means Cecil with redistribution, I belieive I can understand his idea behind the word, I must make the effort because my own language barrier. Perhaps the consensus word to it may be not "redistribution", but... what Cecil tries explain to me? I try never identify the "map" (words, concepts) with the "territory" (hipotetical real world) because misleading me. Redistribute is an action verb. *Nothing happens until you measure it (you need a load). *This speaks to your Ether (or Aether or Æther) being a medium, but there is no evidence of Ether existing. *So for action, it is in the loading - nothing else happens (has action) without a load. The "concept" of redistribution collapses to zero if you do not take a measure, but it exists if you do? *Logically, the causal relationship is with the observation, not with the energy. *The load reveals a concept that does not exist without it. What you wonder about and call a map, or territory, is a forest of loads that give a population of varied responses that are a product of phase differences. *Mathematical "representations" of this are called surface maps (your term of map is appropriate) or contour maps. Within these types of representation, you can see patterns. *However, the patterns are those revealed by a multitude of loads. *Take away the loads and you would see nothing. (Richard I do not think wathever reflects also absorbs (ideally at last), It can reflects an transmits but nor absorb, do you agree with it?) No. *I have measured light at the bench, and I have studied its applications at many scales down to subwavelength dimensions. *All materials absorb light without qualification. *All materials reflect light without qualification. *All materials transmit light without qualification. * You may be tempted to tightly constrain what you call light to force an artificial solution. *Do not do it, because that serves no useful purpose. Consider the sun, light (a photon) from its center has to penetrate its bulk before we see it. *It takes something like 10,000 years for that light to reach the surface. *Any material you think of here on our mud ball planet is inconsequential in comparison. Using an optical analogy for RF is very dangerous if you cannot measure it at the bench. *Why try to understand two unknowns together? The greatest danger of an optical analogy is in your perception (I choose that word with care) that IF you are able to "see" it, THEN that means that you "understand" it. *Sight is an illusion (another word chosen with care) that is most often clouded by the mind. *This topic fills books from both academic and popular writers. In simple terms, there are optical events that you are certain you can see, but that you cannot measure or show anyone else. *There are optical events you and others can measure, but you cannot see. A simple (but complex one to build) example is the conjugate mirror. It reflects light, but when you look into it, all you see is black. If you have no experience at the bench, then what I write is a puzzle. Although I have described why this happens, I doubt anyone remembers or knows the answer to this contradiction. If you want a hint, it relates ENTIRELY to your trying to tie together RF, reflection, and other transmission/transmitter topics. *Look at the ongoing discussion on source resistance, and note the same word conjugate's appearance in that commentary. 73's Richard Clark, KB7QHC Hi Richard. Really brilliant and good arguments, it is a pleasure for me to read them. In certain dialog level I can agree with almost all of it (I said I am interested in knowledge theory or science philosophy) but, you know, they are philosophical and controversial topics. Reality, duality, consciousness, observer... In technics we are (or use) a much more naive vison of world and It works!, there is not strange Schrödinger cats in ham radio! (or in radio technics) :) Models Richard, all are models, mathematical models, physical models, naive models, "Ideas", representations of "reality" in our minds. We, humans, walk with our crutches -always- = simple crutches, elaborated crutches, little crutches, BIG crutches... :) All of my physics and electronics books have "representations", thousands of them, why not? they work...! -except when don't work :( - Well...when not work = chao with electron "little balls", chao with clasical electrodynamics, chao with Newton's laws, chao with Reality!, It is good for me... very exciting! I understand what you say Richard but also I think that you seems (to me) adscribe to a sort of, "right model" or "true model", I'm not, I am a little exceptical about "truths" o "rigth sciences", for that reason I like listen as carefully as I can, others ideas. Listen, this not a criticism to you, remember I said "In certain level of dialog I can agree..." The bench... all of my life spent on the bench. The bench it is a good friend, -probably an essential friend- but tends to be a fa little "gross" friend. We need also a rational friend (and -why not- an intuitive friend) to make a bingo. With "rational" friend we have, mathematics, calculus, idealized models,:real world is: this tree, that tree, it is not easy (for not tell impossible) to understand a world of individual trees. Rational friend invents the "ideal tree" (certainly not a "bench tree") and works...! we can operate very well with ideal trees!, we can put them into simbolic equations, inside computer memories, good thing (for me) ideal things, total reflection, full transparent thinghs, cuasi-infinitely thin things. Yes, analogies are dangerous, I know, women too... I dare to risk :D It reflects light, but when you look into it, all you see is black. Very interesting thing, I like to see one (better if I can understand it) Richard, I feel that I must to return to Ham radio world and try to see if it is possible compatibilize my old Terman model with yours. This dialog does not bother me at all, as I said It is a pleasure, but without wanting, I am going out off topic :) I truly enjoyed your comments. 73 Miguel PS: Certainly I did not postulate the existence of an ether, here we usually call it figuratively, like an old friend, as a kind of "Santa Claus". |
Question about "Another look at reflections" article.
On Fri, 28 May 2010 21:36:02 -0700 (PDT), lu6etj
wrote: there is not strange Schrödinger cats in ham radio! (or in radio technics) :) Is yours dead? Maybe if you looked again.... It reflects light, but when you look into it, all you see is black. Very interesting thing, I like to see one (better if I can understand it) You can't see it! That is the point. It is also by definition. To understand it, you have to understand the conjugate match. Have you been following that story with Walt and myself? Like I said, trying to learn two things at the same time, when you cannot understand either of them singly, is foolish. Metaphors (RF as photon theory) often fail at the wrong time without being noticed. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On May 28, 5:46*pm, lu6etj wrote:
Tonight I said to me: -the worst term that you could use, Miguel, was "ether"- :), because "ether" is a hipotetical MATERIAL thing, ... The first guesses at the nature of the ether were obviously wrong. But we now know that if you replace the word "ether" with "quantum soup" in your statements about ether, that you will be technically correct as far as quantum physics can determine. Take a look at the Casimir Effect to see if empty space is really empty. In reality, totally empty space would be outside of the space/time of the known universe. http://www.answers.com/topic/casimir-effect I needed know what represent that in a line discontinuity (in a load seems obvious) to better understand Cecil's examples in web page (http://www.w5dxp.com/energy.htm). At the junction of two transmission lines, if the characteristic impedances (Z01 and Z02) are not the same value, then reflections and subsequent interference will usually occur. This is similar to saying: At the junction of two light mediums, if the index of refraction is not the same value in both mediums, then reflections will occur from a (laser) light beam normal to the two surfaces. I am specifying normal=90 deg. and ignoring refraction which is of little importance in an RF transmission line. Before continue I want to do a comment to know if we agree (more or less). We partially think with words or symbols, words and symbols represent concepts or perceptions, concepts are not "out there", as Einstein said they a "free creations of human mind". And Shakespeare said: "What's in a name? that which we call a rose By any other name would smell as sweet; ..." There's not much argument between the definition of "rose" and "rosal". I call that a 1st level abstraction. Things get a little more complicated at the Nth level abstraction. If in Texan I said, "Ah reckon Ah'm gonna amble over yonder directly", you might have trouble with the meaning (except for "amble". :-) Cecil I want to ask you if you are using "photon" term to methaforically refer to "light". No, EM (light and RF) waves are known to be quantized and therefore consist of photons. The reason that I refer to the photons is that photons must obey a certain set of laws of physics. For instance, they must move at the speed of light in a medium. Photons cannot stand still in a standing wave. Therefore, any theory of physics that requires photons to stand still is incorrect. That would include the particular interpretation of the lumped-impedance model that some folks are pushing here on this newsgroup. The only time I will refer to photons is when the presented EM wave theory contradicts the accepted laws of quantum physics. It is simply an attempt at trying to keep some folks honest. Even I agree at our concept that electromagnetic spectrum includes RF waves and ligh waves and they are the same phenomenon, I think that is a result of great insight and efforts of the human mind, it is not so evident. We see light, we sense infrared radiaton, but we can not perceive well RF without instruments (unless we introduce ourselves in a micowave oven or burn with the antenna, of course ). The point is that what we see at visible light frequencies also happens at RF frequencies but we cannot see RF. By switching to a visible light example, I can point out the errors of someone attempting to pull the wool over the eyes of the unwashed masses. (I do not forget Roy's article, I'm still trying to sort out all the puzzle pieces). Note that Roy seems to be completely ignorant of this fact of physics: "... the photons are redistributed to regions that permit constructive interference ..." as described on the Florida State web page at the bottom of the page: micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/ waveinteractions/index.html In an RF transmission line, the only "regions that permit constructive interference" is the single opposite direction in the transmission line from the direction of destructive interference. In the absence of a localized source of energy, any destructive interference in one direction (at an isolated impedance discontinuity in a transmission line) must be balanced by an equal magnitude of constructive interference in the opposite direction. The conservation of energy theorem will have it no other way. If you are familiar with the scattering parameter/matrix equations, much can be learned by analyzing them. Note that the equations are phasor math, not simple algebra equations. http://www.sss-mag.com/pdf/hpan95-1.pdf b1 = s11*a1 + s12*a2 b1, the total reflected voltage toward the load, is equal to the forward voltage (from the source) reflected from the impedance discontinuity, phasor added to the transmitted reflected voltage through the impedance discontinuity (from the load). b2 = s21*a1 + s22*a2 The total forward voltage toward the load, is equal to the transmitted forward voltage through the impedance discontinuity (from the source), phasor added to the reflected voltage (from the load) that is re- reflected back toward the load by the impedance discontinuity. The a and b parameters are voltages normalized to the square root of Z0. Squaring both sides of each equation will yield the interference terms in watts, that indicate where the energy goes, i.e. which of two directions in a transmission line. Note that if b1 = 0, there is (by definition) total destructive interference between s11*a1 and s12*a2, i.e. the same as a Z0-match in a transmission line. Even if no classic reflections (associated with a physical reflection coefficient) exist, as in Roy's foot-for-thought example, destructive interference at the source resistor will cause some or all of the energy in the reflected wave to be *redistributed* (redirected) back toward the load as constructive interference. Since the wave cancellation causes a reversal in direction of reflected energy (somewhat resembling a reflection) Walter Maxwell, in "Reflections" defines that reversal as a "reflection from a virtual short". Presumably the virtual short (or open) concept would also apply to a 1/4WL thin-film coating on non-reflective glass. Miguel, "redistribute" is not in my Spanish/English dictionary but "redirect" is and might be a reasonable mental substitute for you to conceptualize. From the FSU web page, ...the photons are redistributed (i.e. redirected) to regions that permit constructive interference ... . -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
"lu6etj" wrote news:19d6b598-32b4-468d-9b2a- PS: Certainly I did not postulate the existence of an ether, here we usually call it figuratively, like an old friend, as a kind of "Santa Claus". No Lorentz aether (motionless solid body). In space is plasma (ions and electrons) and dust. They rotate with the Sun. The electrons are the medium for the electric waves. S* |
Question about "Another look at reflections" article.
"lu6etj" wrote news:0d91fd84-c798-4391-8e90-I do not have useful knowledge in laser either. I am interested in your optical analogy because analogies often are useful to visualize a new thing knowing old things, it does not matter if we use RF concepts to aproximate optical things or vice versa, analogies are useful crutches (muletas in spanish). Even I agree at our concept that electromagnetic spectrum includes RF waves and ligh waves and they are the same phenomenon, I think that is a result of great insight and efforts of the human mind, it is not so evident. We see light, we sense infrared radiaton, but we can not perceive well RF without instruments (unless we introduce ourselves in a micowave oven or burn with the antenna, of course ). To concentrate light we only need a piece of glass, to do the same on HF RF region we need large wire antenna arrays. Because of this we often need (or employ) very differents models to deal with the "same thing". Probably Maxwell equations solve all of them, but they are difficult ladies to deal :). Maxwell equations are wrote by Heaviside. Reconciling optcs models with electric models have its difficulties, but can be productive undoubtedly I believe. Now light is produced with the electric device: "As the electrons are undergoing acceleration they radiate electromagnetic energy in their flight direction, and as they interact with the light already emitted, photons along its line are emitted in phase, resulting in a "laser-like" monocromatic and coherent beam. The mirrors show in the sketch below are superfluous, as all the light is emitted in one direction anyway." From: http://en.wikipedia.org/wiki/Halbach_array When electrons oscillate they disturb the "electron see" and that are waves. To achive the oscillations we use different devices. The Halbach array is for light. The dipole for RF. For radar and microwaves the another. S* |
Question about "Another look at reflections" article.
On 29 mayo, 14:27, "Szczepan Bialek" wrote:
*"lu6etj" wrote news:0d91fd84-c798-4391-8e90-I do not have useful knowledge in laser either. I am interested in your optical analogy because analogies often are useful to visualize a new thing knowing old things, it does not matter if we use RF concepts to aproximate optical things or vice versa, analogies are useful crutches (muletas in spanish). Even I agree at our concept that electromagnetic spectrum includes RF waves and ligh waves and they are the same phenomenon, I think that is a result of great insight and efforts of the human mind, it is not so evident. We see light, we sense infrared radiaton, but we can not perceive well RF without instruments (unless we introduce ourselves in a micowave oven or burn with the antenna, of course ). To concentrate light we only need a piece of glass, to do the same on HF RF region we need large wire antenna arrays. Because of this we often need (or employ) very differents models to deal with the "same thing". Probably Maxwell equations solve all of them, but they are difficult ladies to deal :). Maxwell equations are wrote by Heaviside. Reconciling optcs models with electric models have its difficulties, but can be productive undoubtedly I believe. Now light is produced with the electric device: "As the electrons are undergoing acceleration they radiate electromagnetic energy in their flight direction, and as they interact with the light already emitted, photons along its line are emitted in phase, resulting in a "laser-like" monocromatic and coherent beam. The mirrors show in the sketch below are superfluous, as all the light is emitted in one direction anyway." From:http://en.wikipedia.org/wiki/Halbach_array When electrons oscillate they disturb the "electron see" and that are waves. To achive the oscillations we use different devices. The Halbach array is for light. The dipole for RF. For radar and microwaves the another. S* I all Richard, I can not translate "Is yours dead?", I suppose means something as "if it is my last word about it". Well...I do not believe in witches but there are, there are! I shall not bet :) Have you been following that story with Walt and myself? Sorry, no. ocassionally I read the topic in this newsgroup long time ago. ..... I agree Cecil, be indulgent with my poor translations, I should have written "I don not postulate Ether, without 'an' before", pointing - with the capital "L"- to our old friend "luminiferous ether"; quantic ether it is a different and very interesting stuff, isn't it? I can not tranlate your Texan sentence, is a dialect? (patois?). Would you mind write it in basic "english for aliens" for me). I do not quite understand this = "Photons cannot stand still in a standing wave." -You do not ascribe to wave-particle duality notion?- As I understand quantic numbers of HF energy are a such extremely small quantities that have unmeasurable effects, I understood (or suppose) you wanted mean quantic physics born of fail of classical electrodynamics to explain all phenomena. When I pointed to dimensions of transmission line space vs tridimensional space I am thinking of what you called (named?) "redistribution" as meaning the only possible solution in such space is redirection (or reflection). Is it OK? From me understanding "reflection" is a way of "redirection" of light that obey to the reflection law of optics, in transmission line space I think would be synonymous (at last in spanish language). Do not you agree? Anyway, I think that classic physics is enough to explain phenomena on extremly low quantic number systems, as HF energy or cars in movement :) Returning to analogy. I can not realize how associate Zc changes to refraction because I learnt refraction as a differente speed of light medium phenomenom. Give me a hand. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". I bet it has same meaning in english] Before advance more. I am not yet quite discern your (plural) conceptual differences. Please remember that I did a question and you answer with concepts of advanced stages of your discussion. Until now - seems to me- Owen sustain our clasic Terman et al teachings and is critic of Walter's theory; you too but from different point of view (redistribution of energy, interference, photon laws, etc). I do not know yet Roy's differences, and Richard would support all Walter's hipothesis. Also seems to me that a piece of discussion revolves around "truthness" (in weak sense of word) of respective models more than capacity of each one to give correct results to empiric measurements. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) 73 and good weekend to all Miguel Ghezzi LU6ETJ PS: QSL to Szczepan comments |
Question about "Another look at reflections" article.
On Sat, 29 May 2010 14:24:47 -0700 (PDT), lu6etj
wrote: Richard, I can not translate "Is yours dead?", I suppose means something as "if it is my last word about it". Well...I do not believe in witches but there are, there are! I shall not bet :) It was a Quantum joke. It has groans AND laughs until you read it. Have you been following that story with Walt and myself? Sorry, no. ocassionally I read the topic in this newsgroup long time ago. Too bad. I find plate resistance an interesting application of macro and micro action. I thought you would too. "Photons cannot stand still in a standing wave." Gad, what an awful statement. As I understand quantic numbers of HF energy are a such extremely small quantities that have unmeasurable effects, They are measured. Your "understanding" is an example of how a metaphor can throw you into the ditch. Trying to go down the optical path to discuss RF will find you walking in the bushes. Zc changes to refraction Gad, another awful statement. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". I bet it has same meaning in english] Your English is fine. Richard would support all Walter's hipothesis. No, I don't support Walt's hypothesis, I support his data. Walt and I disagree about Plate resistance being "real." It is a very small step over a very large boulder. (Quantum tunneling would make it easier.) The "problem" with Plate resistance seems to have arrived through creationism - a novel superstition instead of a simple superposition. Also seems to me that a piece of discussion revolves around "truthness" (in weak sense of word) of respective models more than capacity of each one to give correct results to empiric measurements. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) The word you are trying to find is "validity," that is, if this is a scientific issue. You are right about "truthfulness" if it is a religious issue. Or possibly a boolean logical result if we left the realm of analog. Validity is a result of testing results (scientific method) against expectations. Truth is a result of burning someone (auto de fé) until they agree with you. Choose your company with care. Do they work at the bench, or do they play with matches? :-) 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On May 29, 4:24*pm, lu6etj wrote:
I agree Cecil, be indulgent with my poor translations, I should have written "I don not postulate Ether, without 'an' before", pointing - with the capital "L"- to our old friend "luminiferous ether"; quantic ether it is a different and very interesting stuff, isn't it? Miguel, your English is a magnitude better than my Spanish so don't worry about it. "Quantum ether" are two words that I have never seen together before. Maybe you will be famous for that concept. I can not tranlate your Texan sentence, is a dialect? (patois?). Would you mind write it in basic "english for aliens" for me). Northern Americans cannot understand it either. :-) The translation is: "I think I will walk over there after awhile." The Texan word "amble" came from the Spanish word "amblar". I do not quite understand this = "Photons cannot stand still in a standing wave." -You do not ascribe to wave-particle duality notion?- Some of the RF gurus will try to convince you that the energy in RF standing waves is standing still. But since those RF waves consist of photons which must necessarily move at the speed of light in the medium, they are dead wrong. The correct concept is that a pure standing wave doesn't transfer any *net* energy but the two equal component traveling waves, forward and reverse, are still moving at the speed of light in opposite. As I understand quantic numbers of HF energy are a such extremely small quantities that have unmeasurable effects, I understood (or suppose) you wanted mean quantic physics born of fail of classical electrodynamics to explain all phenomena. The point is that the photonic energy in an RF wave cannot stand still. That defeats the argument that reflected waves don't exist or don't contain any energy. Such is simply nonsense. When I pointed to dimensions of transmission line space vs tridimensional space I am thinking of what you called (named?) "redistribution" as meaning the only possible solution in such space is redirection (or reflection). Is it OK? Light waves can be reflected, refracted, and/or redistributed in any 3D direction. RF waves in a transmission line can only flow in two directions, forward and reverse. That simplifies things considerably. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. From me understanding "reflection" is a way of "redirection" of light that obey to the reflection law of optics, in transmission line space I think would be synonymous (at last in spanish language). Do not you agree? Yes, but wave cancellation accompanied by destructive interference can also redirect EM energy. Wave cancellation is what w7el is missing in his food-for-thought article. Anyway, I think that classic physics is enough to explain phenomena on extremly low quantic number systems, as HF energy or cars in movement :) Yes, but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Returning to analogy. I can not realize how associate Zc changes to refraction because I learnt refraction as a differente speed of light medium phenomenom. Give me a hand. For the purposes of RF waves in a transmission line, you can forget refraction as an irrelevant effect. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". *I bet it has same meaning in english] Yes, that is probably correct. ... you too but from different point of view (redistribution of energy, interference, photon laws, etc). My concepts are directly from the field of optical physics. You might want to obtain a copy of "Optics", by Hecht. It is available in Spanish: http://www.astronomyinspanish.org/sl...l/optica_hecht This book will teach you more about EM *energy flow* than any RF engineering book that I know of. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) The model that w7el uses for his food-for-thought article on forward and reflected power is obviously wrong because it doesn't indicate where the reflected energy goes. When a model confuses the user and obviously doesn't represent reality, it's time to upgrade to a better model. The EM wave model used in optics does necessarily track the reflected energy because optical physicists cannot easily measure voltage. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On 29 mayo, 22:21, Cecil Moore wrote:
On May 29, 4:24*pm, lu6etj wrote: I agree Cecil, be indulgent with my poor translations, I should have written "I don not postulate Ether, without 'an' before", pointing - with the capital "L"- to our old friend "luminiferous ether"; quantic ether it is a different and very interesting stuff, isn't it? Miguel, your English is a magnitude better than my Spanish so don't worry about it. "Quantum ether" are two words that I have never seen together before. Maybe you will be famous for that concept. I can not tranlate your Texan sentence, is a dialect? (patois?). Would you mind write it in basic "english for aliens" for me). Northern Americans cannot understand it either. :-) The translation is: "I think I will walk over there after awhile." The Texan word "amble" came from the Spanish word "amblar". I do not quite understand this = "Photons cannot stand still in a standing wave." -You do not ascribe to wave-particle duality notion?- Some of the RF gurus will try to convince you that the energy in RF standing waves is standing still. But since those RF waves consist of photons which must necessarily move at the speed of light in the medium, they are dead wrong. The correct concept is that a pure standing wave doesn't transfer any *net* energy but the two equal component traveling waves, forward and reverse, are still moving at the speed of light in opposite. As I understand quantic numbers of HF energy are a such extremely small quantities that have unmeasurable effects, I understood (or suppose) you wanted mean quantic physics born of fail of classical electrodynamics to explain all phenomena. The point is that the photonic energy in an RF wave cannot stand still. That defeats the argument that reflected waves don't exist or don't contain any energy. Such is simply nonsense. When I pointed to dimensions of transmission line space vs tridimensional space I am thinking of what you called (named?) "redistribution" as meaning the only possible solution in such space is redirection (or reflection). Is it OK? Light waves can be reflected, refracted, and/or redistributed in any 3D direction. RF waves in a transmission line can only flow in two directions, forward and reverse. That simplifies things considerably. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. From me understanding "reflection" is a way of "redirection" of light that obey to the reflection law of optics, in transmission line space I think would be synonymous (at last in spanish language). Do not you agree? Yes, but wave cancellation accompanied by destructive interference can also redirect EM energy. Wave cancellation is what w7el is missing in his food-for-thought article. Anyway, I think that classic physics is enough to explain phenomena on extremly low quantic number systems, as HF energy or cars in movement :) Yes, but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Returning to analogy. I can not realize how associate Zc changes to refraction because I learnt refraction as a differente speed of light medium phenomenom. Give me a hand. For the purposes of RF waves in a transmission line, you can forget refraction as an irrelevant effect. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". *I bet it has same meaning in english] Yes, that is probably correct. ... you too but from different point of view (redistribution of energy, interference, photon laws, etc). My concepts are directly from the field of optical physics. You might want to obtain a copy of "Optics", by Hecht. It is available in Spanish: http://www.astronomyinspanish.org/sl...l/optica_hecht This book will teach you more about EM *energy flow* than any RF engineering book that I know of. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) The model that w7el uses for his food-for-thought article on forward and reflected power is obviously wrong because it doesn't indicate where the reflected energy goes. When a model confuses the user and obviously doesn't represent reality, it's time to upgrade to a better model. The EM wave model used in optics does necessarily track the reflected energy because optical physicists cannot easily measure voltage. -- 73, Cecil, w5dxp.com Hi to all... Richard, do you agree with Walter's theory on "Another look at reflections" in reflections topic -out of plate resistance differences-? The word you are trying to find is "validity," No, it was more near of your second = "Truth", or "The Truth", the metaphysical "truth" :) Walt and I disagree about Plate resistance being "real" What is "real" for you? For me it is a slippery word ever ready to disputes, in knowledge matters makes us think of the "thing itself" and with it, we quickly fall into endless scholastic discussions. With models "the thing" it is a little more ease, models only must be internal and measurements consistent. Models are neither "True" nor "Real", they are modestly "valid" :) What do you think? ........ I believe I am in a privileged position because my english weakness : when I am about to disagree with you, I tell me -"probably you do not translate well, Miguel, ask again"- and when you answer to me then voilá! I do not disagree... Viceversa, perhaps language give me a second chance with you because you are more forgiving with me :) Example: Miguel = I do not quite understand this = "Photons cannot stand still in a standing wave." -You do not ascribe to wave-particle duality notion?- Cecil = Some of the RF gurus will try to convince you that the energy in RF standing waves is standing still. But since those RF waves consist of photons which must necessarily move at the speed of light in the medium, So, now I believe what he is trying to tell me is stationary wave is a measured time dependent magnitude resulting of two near speed of light traveling waves, manifestating in our measurement apparatus (observer or "load" as said Richard)... It is good to me.. Then, I do not care anymore the ugly (nasty?) word "photon" :), and finally to my joy, next Cecil sentence confirms my translation/interpretation!. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. It is difficult to me reconcile superposition principle with "interaction", because in spanish "interacción" word means: "Action exerted MUTUALLY between two or more objects, agents, forces, functions, etc" (capitals are mine) And I learnt two or more electromagnetic waves can pass one through other by same point of the SPACE without recognizing themselves (unlike particles that "collide"), then, by definition, they not interactuate themselves at all. We do not "see" any standing wave in space when two same path opposite direction RF rays cross themselves and there is not contradiction. Are you agree? In transmission lines instead it is not easy to think that because more "tangible" standing wave voltages and currents make us think they are "interacting". What do you think about it?, but wave cancellation accompanied by destructive interference can also redirect EM energy To satisfy the energy conservation principle, isn' it? This produces a reflection, right? but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Could be classic electrodynamics be right but we are not applying correctly, and then classic model not become a losser in this matter? I see you do not agree with some Roy Lewallen proposition: do you agree with Walter Maxwell on this topic? Sorry (for me) Cecil "quantum ether" is not mine :( Thanks for optics book recommendation. 73 Miguel Ghezzi - LU6ETJ |
Question about "Another look at reflections" article.
On Sat, 29 May 2010 22:59:49 -0700 (PDT), lu6etj
wrote: Hi to all... Richard, do you agree with Walter's theory on "Another look at reflections" in reflections topic -out of plate resistance differences-? Hi Miguel, Walt is not espousing a theory. The word you are trying to find is "validity," No, it was more near of your second = "Truth", or "The Truth", the metaphysical "truth" :) Then this will be great sport. (sport: from Old French desport , pleasure , from desporter , to divert - I assume it is not very different from the Spanish desportes) Walt and I disagree about Plate resistance being "real" What is "real" for you? Children. For me it is a slippery word ever ready to disputes, in knowledge matters makes us think of the "thing itself" and with it, we quickly fall into endless scholastic discussions. With models "the thing" it is a little more ease, models only must be internal and measurements consistent. Models are neither "True" nor "Real", they are modestly "valid" :) What do you think? They have what is called "internal consistency." ....... I believe I am in a privileged position because my english weakness : I have designed natural language parsers (NLP). Non-native speakers of English know the language far better than native born speakers. That is your privilege. when I am about to disagree with you, I tell me -"probably you do not translate well, Miguel, ask again"- and when you answer to me then voilá! I do not disagree... Viceversa, perhaps language give me a second chance with you because you are more forgiving with me :) I have lived in more countries and spoken more languages than most here. There are many here that speak and write perfectly poor English that makes better sense that some of the strange statements you are trying to parse. Example: Miguel = I do not quite understand this = "Photons cannot stand still in a standing wave." -You do not ascribe to wave-particle duality notion?- Cecil = Some of the RF gurus will try to convince you that the energy in RF standing waves is standing still. But since those RF waves consist of photons which must necessarily move at the speed of light in the medium, So, now I believe what he is trying to tell me is stationary wave is a measured time dependent magnitude resulting of two near speed of light traveling waves, manifestating in our measurement apparatus (observer or "load" as said Richard)... It is good to me.. Then, I do not care anymore the ugly (nasty?) word "photon" :), and finally to my joy, next Cecil sentence confirms my translation/interpretation!. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. It is difficult to me reconcile superposition principle with "interaction", because in spanish "interacción" word means: "Action exerted MUTUALLY between two or more objects, agents, forces, functions, etc" (capitals are mine) And I learnt two or more electromagnetic waves can pass one through other by same point of the SPACE without recognizing themselves (unlike particles that "collide"), then, by definition, they not interactuate themselves at all. You have the second privilege of understanding a confused statement when you see it. This is language independent. We do not "see" any standing wave in space when two same path opposite direction RF rays cross themselves and there is not contradiction. Are you agree? To see is to witness, or be an observer (from the Latin observare, ob- over, -servare watch). When two light waves illuminate the same load, and the load is observable, you see the combination of two energies at that load. A standing wave does not exist until you measure the combination of the contributions at a point. You can, of course, populate a large area with many point-loads if you wish to map a region. Under very controlled circumstances, you will get to see a nice pattern. The sport is found he Of course, you could see the same pattern at the same points by the projection of an image upon them from one source. Could you tell the difference between (1) that single source projected image and (2) the standing wave combination of several sources? This is too much fun already, but..... So, for Truth: Is a movie projector acted upon by the movie it projects? Was your camera happy because your photograph shows a smile? The Truth would say yes. What would Schrodinger see? Does that help? In transmission lines instead it is not easy to think that because more "tangible" standing wave voltages and currents make us think they are "interacting". What do you think about it?, A confused statement. but wave cancellation accompanied by destructive interference can also redirect EM energy To satisfy the energy conservation principle, isn' it? This produces a reflection, right? You are in the bushes. but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Could be classic electrodynamics be right but we are not applying correctly, and then classic model not become a losser in this matter? Let's see now. You have three things to figure out. RF, Light, and QED. I hestitate to wonder what could possibly follow if you prove to be to slow to figure these out. Perhaps sudoko patterns revealing the entanglement of strange attractors. (Sorry for the translation overload.) And this started with Truth? :-) Write when you receive more inspiration. (A supernatural divine influence on the prophets, apostles, or sacred writers, by which they were qualified to communicate moral or religious truth with authority; a supernatural influence which qualifies men to receive and communicate divine truth; also, the truth communicated.) 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
Uzytkownik "Cecil Moore" napisal w wiadomosci ... On May 29, 4:24 pm, lu6etj wrote: Light waves can be reflected, refracted, and/or redistributed in any 3D direction. In optics are mirrors which reflect and transmit the desired proportion of light. RF waves in a transmission line can only flow in two directions, forward and reverse. It can also transmit. That simplifies things considerably. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. But the reflected is weaker. From me understanding "reflection" is a way of "redirection" of light that obey to the reflection law of optics, in transmission line space I think would be synonymous (at last in spanish language). Do not you agree? Yes, but wave cancellation accompanied by destructive interference can also redirect EM energy. Wave cancellation is what w7el is missing in his food-for-thought article. Anyway, I think that classic physics is enough to explain phenomena on extremly low quantic number systems, as HF energy or cars in movement :) Yes, but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Returning to analogy. I can not realize how associate Zc changes to refraction because I learnt refraction as a differente speed of light medium phenomenom. Give me a hand. For the purposes of RF waves in a transmission line, you can forget refraction as an irrelevant effect. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". I bet it has same meaning in english] Yes, that is probably correct. ... you too but from different point of view (redistribution of energy, interference, photon laws, etc). My concepts are directly from the field of optical physics. You might want to obtain a copy of "Optics", by Hecht. It is available in Spanish: http://www.astronomyinspanish.org/sl...l/optica_hecht This book will teach you more about EM *energy flow* than any RF engineering book that I know of. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) The model that w7el uses for his food-for-thought article on forward and reflected power is obviously wrong because it doesn't indicate where the reflected energy goes. When a model confuses the user and obviously doesn't represent reality, it's time to upgrade to a better model. The EM wave model used in optics does necessarily track the reflected energy because optical physicists cannot easily measure voltage. The intensity is also accurate. The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. S* 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 30, 9:55*am, "Szczepan Bialek" wrote:
Uzytkownik "Cecil Moore" napisal w ... On May 29, 4:24 pm, lu6etj wrote: Light waves can be reflected, refracted, and/or redistributed in any 3D direction. In optics are mirrors which reflect and transmit the desired proportion of light. RF waves in a transmission line can only flow in two directions, forward and reverse. It can also transmit. That simplifies things considerably. Coherent waves flowing in the same direction in a transmission line suffer permanent interaction. But the reflected is weaker. From me understanding "reflection" is a way of "redirection" of light that obey to the reflection law of optics, in transmission line space I think would be synonymous (at last in spanish language). Do not you agree? Yes, but wave cancellation accompanied by destructive interference can also redirect EM energy. Wave cancellation is what w7el is missing in his food-for-thought article. Anyway, I think that classic physics is enough to explain phenomena on extremly low quantic number systems, as HF energy or cars in movement :) Yes, but when classic physics allegedly doesn't obey the laws of quantum electrodynamics, something is wrong, and quantum electrodynamics wins every time. Returning to analogy. I can not realize how associate Zc changes to refraction because I learnt refraction as a differente speed of light medium phenomenom. Give me a hand. For the purposes of RF waves in a transmission line, you can forget refraction as an irrelevant effect. ["re" it is only a prefix, look for "distribute" (or verb "distribuir" in spanish = "Give something its timely placement or convenient location". I bet it has same meaning in english] Yes, that is probably correct. ... you too but from different point of view (redistribution of energy, interference, photon laws, etc). My concepts are directly from the field of optical physics. You might want to obtain a copy of "Optics", by Hecht. It is available in Spanish: http://www.astronomyinspanish.org/sl...l/optica_hecht This book will teach you more about EM *energy flow* than any RF engineering book that I know of. Perhaps a little summary of coincidences and differences can serve to other readers, and me, obviously :) The model that w7el uses for his food-for-thought article on forward and reflected power is obviously wrong because it doesn't indicate where the reflected energy goes. When a model confuses the user and obviously doesn't represent reality, it's time to upgrade to a better model. The EM wave model used in optics does necessarily track the reflected energy because optical physicists cannot easily measure voltage. The intensity is also accurate. The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. S* 73, Cecil, w5dxp.com Mr. S... please, you need to do 2 things... first, get a better newsgroup editor or use the groups.google.com web site to post replies, whatever you are using now messes up the indentation for quoted text and makes it impossible to figure out what you wrote and what is quoted. second, keep your 150 year old theories in threads where they belong, they will only cause confusion to those who are trying to discuss modern methods. |
Question about "Another look at reflections" article.
On May 30, 12:59*am, lu6etj wrote:
It is difficult to me reconcile superposition principle with "interaction", because in spanish "interacción" word means: "Action exerted MUTUALLY between two or more objects, agents, forces, functions, etc" (capitals are mine) And I learnt two or more electromagnetic waves can pass one through other by same point of the SPACE without recognizing themselves (unlike particles that "collide"), then, by definition, they not interactuate themselves at all. What you learned is usually true in free space. Two light waves can pass through each other at the same point in space without affecting or interacting with each other because they are *not collinear*. It is very difficult to align two light beams in free space such that they are collinear. However, it can be done in an interferometer. http://www.teachspin.com/instruments...eriments.shtml But in an RF transmission line, please understand that there is *no way to keep the RF waves from being collinear* since it is primarily a one-dimensional space with only two possible directions. Therefore, any two coherent RF waves traveling in the same direction in an RF transmission line, will interact and have a permanent effect. For pure sinusoidal waves, the transmitted wave, the re-reflected wave, and the constructive interference wave are all coherent and collinear and merge into a single forward wave flowing toward the load. The component waves become inseparable. We do not "see" any standing wave in space when two same path opposite direction RF rays cross themselves and there is not contradiction. Are you agree? Eugene Hecht, in "Optics", describes standing waves of visible light in free space. I'm not sure that humans can "see" the standing wave detail because the frequency is so high, but standing waves of visible light can certainly exist in free space. If you can, please obtain a copy of "Optics". If one routed a standing-wave of light through a cloud chamber, it would become visible. I don't know if the human eye can resolve the high and low interference patterns but I'm sure instruments could detect it. In transmission lines instead it is not easy to think that because more "tangible" standing wave voltages and currents make us think they are "interacting". What do you think about it?, Coherent collinear waves traveling the same direction in a transmission line superpose, merge, and interact. This invariably occurs at an impedance discontinuity point during interference immediately after normal reflections have taken place. RF waves traveling in opposite directions in a transmission line with a constant Z0, do not interact. To satisfy the energy conservation principle, isn' it? This produces a reflection, right? Walter Maxwell defines it as a reflection. I am a little more careful and have adopted the following standards from optical physics. A "reflection" is something that happens to a single wave and corresponds to a physical reflection coefficient. A "redistribution" can be a reflection but can also involve interference between two or more waves. If superposition is involved, I use the word "redistribution" rather than "reflection". Walt lumps the concepts of normal reflection with wave cancellation and introduces the concept of a virtual reflection coefficient. Both approaches work. IMO, mine is slightly more detailed. In "Reflections", under the 1/4WL matching stub section, Walt proves that he fully understands the role of constructive/destructive interference in the redistribution of energy. Could be classic electrodynamics be right but we are not applying correctly, and then classic model not become a losser in this matter? Yes, if w7el would recognize the energy content (V^2/Z0 watts) that exists in the voltages that he is superposing, he would be able to track the reflected energy from the load back to the source and then back to the load as a component of forward power. I see you do not agree with some Roy Lewallen proposition: do you agree with Walter Maxwell on this topic? In his food-for-thought article, Roy neglected to include the effects of wave-cancellation/interference at the source resistor in his example. I don't think that Walter Maxwell has expressed an opinion on this particular subject of dissipation in the source resistor of a voltage source as specified by w7el. In a real-world amplifier, Walt asserts that the source resistance is non-dissipative while, for his food-for-thought examples, Roy specified a dissipative source resistance designed to eliminate reflections. Again, what he forgot to include is redistribution of energy due to wave cancellation, a concept well understood in the field of EM wave optical physics. He apparently does not understand the mechanism whereby the conservation of energy principle is honored so he is forced to falsely assume that reflected energy is not incident upon the source resistor. Nothing could be farther from the facts of physics as understood for decades in the field of optical physics. I was taught constructive/destructive interference energy concepts in my vector analysis classes at Texas A&M University during the 50's. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
"K1TTT" wrote ... On May 30, 9:55 am, "Szczepan Bialek" wrote: In optics are mirrors which reflect and transmit the desired proportion of light. The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. S* Mr. S... please, you need to do 2 things... first, get a better newsgroup editor or use the groups.google.com web site to post replies, whatever you are using now messes up the indentation for quoted text For you and Cecil I must make by hand the indentation for quoted text . The rest are O.K. and makes it impossible to figure out what you wrote and what is quoted. second, keep your 150 year old theories in threads where they belong, they will only cause confusion to those who are trying to discuss modern methods. They should know that the physics and the math go together. Maxwell did the aether model and the math for it. In the model were the rotational oscillations of massive, compressible magnetic substance. The electricity was masless and incompressible. Now we know that no magnetics substance and that the electricity (electrons) has mass and that the electron gas is compressible. It means that light is exactly like sound. The above was obvious for Royal Society. But the math for the oscillating whirls was the new. In result in the science history is wrote "that Maxwell's model was stripped away and just the equations remain". The math for whirls was done by Helmholtz but without the oscillations. The math for the oscillating whirls (EM) must be in schools. In schools are all theories. Modern metods are in the plasma physics. S* |
Question about "Another look at reflections" article.
On May 30, 5:05*pm, "Szczepan Bialek" wrote:
*"K1TTT" ... On May 30, 9:55 am, "Szczepan Bialek" wrote: In optics are mirrors which reflect and transmit the desired proportion of light. The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. S* Mr. S... please, you need to do 2 things... first, get a better newsgroup editor or use the groups.google.com web site to post replies, whatever you are using now messes up the indentation for quoted text For you and Cecil I must make by hand the *indentation for quoted text . The rest are O.K. no they aren't... look above, which text did you write and which did i write? i used to use outlook express like you are using, and it is bad. get something better if you like to quote lots of text. In schools are all theories. the only purpose for disproved theories in schools is for historical context. sometimes it is useful to show students what doesn't work so they don't waste time repeating past mistakes. aether theories are one that is taught and then demonstrated in class as incorrect. once the student makes the measurements they get a better feeling why aethers are bogus. |
Question about "Another look at reflections" article.
On 30 mayo, 15:41, K1TTT wrote:
On May 30, 5:05*pm, "Szczepan Bialek" wrote: *"K1TTT" ... On May 30, 9:55 am, "Szczepan Bialek" wrote: In optics are mirrors which reflect and transmit the desired proportion of light. The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. S* Mr. S... please, you need to do 2 things... first, get a better newsgroup editor or use the groups.google.com web site to post replies, whatever you are using now messes up the indentation for quoted text For you and Cecil I must make by hand the *indentation for quoted text . The rest are O.K. no they aren't... look above, which text did you write and which did i write? i used to use outlook express like you are using, and it is bad. *get something better if you like to quote lots of text. *In schools are all theories. the only purpose for disproved theories in schools is for historical context. *sometimes it is useful to show students what doesn't work so they don't waste time repeating past mistakes. *aether theories are one that is taught and then demonstrated in class as incorrect. *once the student makes the measurements they get a better feeling why aethers are bogus.- Ocultar texto de la cita - - Mostrar texto de la cita - Hi all Walt is not espousing a theory Please, give me a name to name it. They have what is called "internal consistency." Who are "they", Walter's propositions? Before advance more Richard. All off you share or ascribe a "existence" notion determinated by observator measurements? It is long time philosophical question remember, trees, sounds... A confused statement I know. Communicate minds takes its time. It is more easy as we share the basic assumptions neccesary for that. It's what I'm trying. ------------- Two light waves can pass through each other at the same point in space without affecting or interacting with each other because they are *not collinear*. Why? As I learnt superposition principle not depends of collinearity. English Oxford dictionary I have, define "Interact" as "act on each other", similar concept in spanish I think. I learnt superposition as involving 'no interaction'. both waves still identical to itself in superposition (in nonlineal systems they certainly can interact). For pure sinusoidal waves, the transmitted wave, the re-reflected wave, and the constructive interference wave are all coherent and collinear and merge into a single forward wave flowing toward the load. The component waves become inseparable. I can agree with above paragraph but, for that I just said, I think not with this... Therefore, any two coherent RF waves traveling in the same direction in an RF transmission line, will interact and have a permanent effect. As I undestand, two o more superposed waves can be added or substracted to render a resultant but we do not call that interaction (I am excude here the observer -Richard's observations- notion for not to get out of point). Two traveling waves with same direction, frequency and phase would be certainly indistinguishable of a single one equal to the vectorial sum of the two cited, by our instruments. For my conceptual notions adding or substraction are not interaction. I am not dare to advance more on your kindly answers because this notions are hardly vinculated to our issue. Would be appropiate "slow down" a little and work on it?, what do you think? ...... About Roy's differences, At two opportunities I read here issues (problems?) about Rs. Why do not you agree in a simple initial Thevenin model? (it is a question not a suggestion, I don't know how correctly translate my sentence). Cecil, can you find a "energy distribution" concept compatible with special case of unidirectional line space where all of you can agree? Transmission/reflection notions (about energy) do not represent that concept? A mental exercise (it is doesn't a criticism, only a idea, remember I am interesed in your analogies): Suppose we are not capable to perceive any light (or realize of it), only HF spectrum; could you share (agree?) concepts with our other "blinded" colleagues :) to analize this stuff?. I believe that is absolutly a "Yes" (of course you could use your knowledge in optics to devise good RF arguments, but you have to silence it, because you know they "antenna senses" are note light sensitive. ..... Eugene Hecht, in "Optics", describes standing waves of visible light in free space. I'm not sure that humans can "see" the standing wave detail because the frequency is so high, but standing waves of visible light can certainly exist in free space. In perfect vacuum free space without any material stuff to reflect light or bring our retinas into the region in some way? ...... 73 to K1TTT. Several years ago I visited your web page, (I have got them in my hard disk). Sorry to Szczepan for not answer your comments I hard trying don't run out so much off topic :) 73 Miguel Ghezzi - LU6ETJ |
Question about "Another look at reflections" article.
On Sun, 30 May 2010 17:28:41 -0700 (PDT), lu6etj
wrote: Hi all Walt is not espousing a theory Please, give me a name to name it. Hi Miguel, Walt is presenting data to support a hypothesis (explanation for the occurrence of some specified group of phenomena). They have what is called "internal consistency." Who are "they", Walter's propositions? Models have what is called "internal consistency." Before advance more Richard. All off you share or ascribe a "existence" notion determinated by observator measurements? It is long time philosophical question remember, trees, sounds... You are getting into intederminancy. Is this more about Truth again? Truth is funny and sad, but not very useful. A confused statement I know. Communicate minds takes its time. It is more easy as we share the basic assumptions neccesary for that. It's what I'm trying. ------------- Two light waves can pass through each other at the same point in space without affecting or interacting with each other because they are *not collinear*. You don't need "because" or anything that comes after it. It sounds like superstition. Why? As I learnt superposition principle not depends of collinearity. English Oxford dictionary I have, define "Interact" as "act on each other", similar concept in spanish I think. I learnt superposition as involving 'no interaction'. both waves still identical to itself in superposition (in nonlineal systems they certainly can interact). Yes. For pure sinusoidal waves, the transmitted wave, the re-reflected wave, and the constructive interference wave are all coherent and collinear and merge into a single forward wave flowing toward the load. The component waves become inseparable. More superstition. There is nothing about sinusoidal waves that make them coherent or colinear. This is probable a problem of poor English from a native speaker - very common. I can agree with above paragraph but, for that I just said, I think not with this... Therefore, any two coherent RF waves traveling in the same direction in an RF transmission line, will interact and have a permanent effect. Permanent - another superstition (until the end of time + 1 day?). As I undestand, two o more superposed waves can be added or substracted to render a resultant but we do not call that interaction (I am excude here the observer -Richard's observations- notion for not to get out of point). Two traveling waves with same direction, frequency and phase would be certainly indistinguishable of a single one equal to the vectorial sum of the two cited, by our instruments. For my conceptual notions adding or substraction are not interaction. They interact on the load, not on each other. But as you now phrase it, being colinear as an initial condition rather than as a subsequent result, then the possibility of both sources (acting as opposing loads) cancelling each other may follow. This says nothing of waves interacting, however. That is sheer nonsense. Let's put it another way and agree entirely! Accept that two coherent waves that are colinear do interact - but only if colinear. That must be some very, very special mathematics that allows no error in colinearity (perfection is demanded). Perfection does not exist, the necessary colinearity does not exist, interaction does not exist. OK, so near perfection is suitable. -sigh- How much is "near perfection?" Within one millirad? What is it about 1.000001 millirad that extinguishes interaction? Oh, 1.000001 millirad works too, but not more. OK, what is it about 1.000002 millirad that extinguishes interaction? Oh, 1.000002 works too, but.... Pretty sloppy argument, I don't see a formula for when interaction stops working, this means that all angles cause interaction, but we do not see interaction at any angles. This "take it on faith" kind of creation (create it as you go) science returns us to vaudeville (Miguel, maybe I should use the term Commedia dell'Arte to explain our vaudeville). "God said let there be a photon... go forth and multiply" [- low budget creation science definition for the Sun(s) taken from the first printing of "How to Kick Start Genesis on One Quanta a Day."] (Adam, muttering) what a day.... what a day.... (suddenly inspired) What a beautiful photon-set we are having this, this, this. I think I shall name this "evening" Eve! What a beautiful photon-se.... Damn! (whoops - oh I beseech thee to forgive my utterance) it got dark quick. How long before photon-rise? Are we on photon savings time? Suppose we are not capable to perceive any light (or realize of it), only HF spectrum; could you share (agree?) concepts with our other "blinded" colleagues :) to analize this stuff?. I believe that is absolutly a "Yes" (of course you could use your knowledge in optics to devise good RF arguments, but you have to silence it, because you know they "antenna senses" are note light sensitive. Lost in the bushes again. 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
"lu6etj" wrot ... On 30 mayo, 15:41, K1TTT wrote: On May 30, 5:05 pm, "Szczepan Bialek" wrote: The end of the dipole reflect and transmit. The proportion is measured as VWSR. But for this you need the Electric Wave Model. EM was stripped away by Royal Society in 1864. Sorry to Szczepan for not answer your comments I hard trying don't run out so much off topic :) I am not out of topics. It is to your: "To concentrate light we only need a piece of glass, to do the same on HF RF region we need large wire antenna arrays. Because of this we often need (or employ) very differents models to deal with the "same thing". Probably Maxwell equations solve all of them, but they are difficult ladies to deal :)." You should read the Maxwell: http://en.wikisource.org/wiki/On_Phy...Lines_of_Force Maxwell described the model in English and in the math. English is not difficult ladies to deal for you. After this you understand why: "that Maxwell's model was stripped away and just the equations remain". Light and radio waves are exactly like sound. S* 73 Miguel Ghezzi - LU6ETJ |
Question about "Another look at reflections" article.
how about this, i'll really mess things up. all comments assume linear media or circuit elements and sinusoidal stead state conditions (all transients ignored). Standing Waves are a figment of your instrumentation... it is a well known method to choose either voltage or current to do calculations in a circuit, knowing that the other can always be calculated given the impedance. this works for distributed as well as lumped circuits. it is a consequence of superposition and ohms law in the generalized complex form. This is a trap when looking at traveling and 'standing' waves when there are reflections. Since you are only seeing one of the components of the wave you get the impression that the standing wave is indeed concentrating the energy and all the resultant effects at 180 degree intervals. you must however look at both components to get a full picture. Wherever there are standing voltage wave peaks there are also standing current waves 90 degrees (in distance) along the line from them. And while you can calculate the power of the voltage wave peaks as V^2/Z, you can also calculate the energy of the current wave peaks as I^2*Z. Of course you can really get yourself confused if you consider the lossless transmission line with a perfect short or open end... in that case at those peak voltage and current points the Z is infinite or zero respectively which gives you zero power in either case. Now to REALLY have fun, integrate the power at those points into the energy, of course the integral of zero is always zero. Want to get even more confused. Look at an animation of the standing waves (EITHER current OR voltage) over one full cycle in time, there is a peak where the standing waves along the line all reach a peak value at once, then 90 degrees later the whole line is zero, then another 90 degrees and there is an opposite peak. Think carefully about the zero point, where did the energy go? Surely it doesn't mean that all the energy stored in those waves has left the line? that would require some external storage and faster than light energy transfer, a mean trick if you can do it! Ah, but wait, the current wave is 90 degrees out of phase with the voltage, so the energy has a place to go, into the other component! but remember, when that component peaks the impedance is wrong so there is still no energy. But of course then everything does balance out, no energy in one standing wave transfers perfectly to the other standing wave 90 degrees later in time and space. conclusion: Standing waves are a figment of your instrumentation, be that eyes seeing the peaks and valleys of a physical manifestation of them, a fluorescent lamp showing them as you run it along an open wire line, or a voltmeter measuring them... they don't exist except when they are observed, therefore they have no physical existence... much like whats his name's cat. |
Question about "Another look at reflections" article.
On May 30, 9:04*pm, Richard Clark wrote:
There is nothing about sinusoidal waves that make them coherent or colinear. Please Google the two words: I probably should have use "collimated" instead of "collinear". "Electromagnetic radiation is coherent when the photons are produced in such a way that they are in phase with one another and incoherent when the phases of the photons are random." "Collimated light is light whose rays are nearly parallel, and therefore will spread slowly as it propagates. The word is related to "colinear" and implies light that does not disperse with distance (ideally), or that will disperse minimally (in reality)." Note that a coaxial transmission line results in minimal dispersion for an RF wave. Coherent photons are identical except for direction. Collimation makes their direction close to identical. Permanent - another superstition (until the end of time + 1 day?). Wrong definition of "permanent". Not permanent in time - permanent in the sense that the process is irreversible in time. As I undestand, two o more superposed waves can be added or substracted to render a resultant but we do not call that interaction We do call it interaction when the two waves are coherent and collimated. Again, here is what Florida State University has to say: "... when two waves of equal amplitude and wavelength that are 180- degrees ... out of phase with each other meet, they are not actually annihilated, ... All of the photon energy present in these waves must somehow be recovered or redistributed in a new direction, according to the law of energy conservation ... Instead, upon meeting, the photons are redistributed to regions that permit constructive interference, so the effect should be considered as a redistribution of light waves and photon energy rather than the spontaneous construction or destruction of light." They are talking about wave cancellation such that happens at the surface of the thin-film on non-reflective glass. The result of wave cancellation is permanent and the energy that would have been reflected is reversed in direction actually making the underlying picture brighter. That sounds permanent to me. They interact on the load, not on each other. If that were a fact, you could separate them on their way to the load but such is impossible. It doesn't matter where they came from, two coherent, collimated waves interact when they are superposed and become inseparable from that point on. Only incoherent or uncollimated photonic waves can be separated. And if you allow interaction at the load, why not allow interaction at an impedance discontinuity which is much like a load and is indeed where the interaction happens. This says nothing of waves interacting, however. *That is sheer nonsense. Wave cancellation is an obvious proof of interaction. Let's see you recover two waves that have been canceled. Let's put it another way and agree entirely! *Accept that two coherent waves that are colinear do interact - but only if colinear. *That must be some very, very special mathematics that allows no error in colinearity (perfection is demanded). *Perfection does not exist, the necessary colinearity does not exist, interaction does not exist. "Perfection does not exist" is the self-fullfilling last gasp non- perfect argument of the ignorant. Close enough to collimation perfection does exist in an RF transmission line or in an interferometer. The coherent photons in an ideal coaxial transmission line are forced into a state of collimation. Is it perfect single-file collimation? Of course not, but it doesn't have to be perfect. Confining the photons to a certain cross-sectional area is all that is required in the real world. Do all the photons have to be perfectly coherent? No, just the majority of photons from the transmitter. Does a 1/4WL non-reflective coating on glass perfectly cancel 100$ of the single-frequency coherent incident laser light? Not in the real world, but you can use your own eyes to detect that it is doing a pretty good job. The Melles-Groit web page says: "In the absence of absorption or scatter, the principle of conservation of energy indicates all 'lost' reflected intensity will appear as enhanced intensity in the (forward) transmitted beam. The sum of the reflected and transmitted beam intensities is always equal to the incident intensity. This important fact has been confirmed experimentally." Those above alluded-to experiments seem to contradict what you are asserting. Do your own experiments disprove what that web page is saying? If so, where did they go wrong? -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 30, 7:28*pm, lu6etj wrote:
Miguel, please see my above posting in reply to Richard's posting. As I learned, the superposition principle does not depend on collinearity.. Please change "collinear" to "collimated". The results of superposition can be reversible or irreversible. If the photons are not coherent and/or not collimated, the results of superposition are reversible in the sense that each separate wave can be recovered. The results of superposition of coherent and collimated waves (traveling in the same direction) are not reversible, i.e. the ability to recover the separate waves has been lost forever. Two coherent/collimated waves that are superposed indeed do interact. Non-reflective glass is a typical example. The external reflection interacts with the internal reflection causing the reflections to undergo wave cancellation and the total energy in the two superposed (canceled) waves to change direction and make the picture brighter. The Melles-Groit web page says: "This important fact has been confirmed experimentally." As I understand, two or more superposed waves can be added or subtracted to render a resultant but we do not call that interaction. I call it interaction when the identity of both waves is lost which is what happens during wave cancellation. It is not interaction when the identity of both waves is not lost. The results of superposition can have either outcome. For my conceptual notions adding or subtraction are not interaction. If you add a pint of water to a pint of water, the two pints of identical molecules interact, analogous to one joule of coherent/ collimated photons added to another joule of the *identical* photons. The results is two joules of identical photons, indistinguishable from each other. If the superposition process is reversible, interaction has not taken place. If the superposition process is irreversible, interaction has taken place. Both outcomes are possible depending upon the initial conditions. Why do not you agree in a simple initial Thevenin model? It was Roy's idea to avoid the abstract Thevenin model and go with a similar real-world source, probably because of the admonition in "Fields and Waves ...": "... significance cannot be automatically attached to a calculation of power loss in the internal impedance of the equivalent circuit." Transmission/reflection notions (about energy) do not represent that concept? The mistake that virtually all RF gurus are making, including w7el in his food-for-thought article, is assuming that reflection is the only mechanism capable of redistributing reflected energy back toward the load. But it has been known for decades in the field of optical physics that EM wave cancellation can also redistribute reflected energy back toward the load. It is well known that the reflected energy lost through the use of non-reflective glass causes the picture (load) to be brighter. If w7el would simply take the time to calculate the wave cancellation energy (constructive or destructive interference) at the source resistor, he would understand exactly where the reflected energy goes. The conservation of energy principle allows nothing magic (like reflected waves containing no energy or EM waves that do not move at the speed of light). Suppose we are not capable to perceive any light (or realize of it), only HF spectrum; could you share (agree?) concepts with our other "blinded" colleagues *:) to analize this stuff? It is very useful to say: If our eyes could see the RF waves, what would we see? We would see the same thing we see with visible light waves, just at a different frequency (wavelength). In perfect vacuum free space without any material stuff to reflect light or bring our retinas into the region in some way? Of course, we would need some sort of irradiance detector more sensitive than human retinas. Partially mirrored glass is often used to route a sample to a detector. If we detect standing waves in a 10% sample, we are pretty sure that standing waves exist in the rest of the sample. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 31, 6:16*am, K1TTT wrote:
conclusion: Standing waves are a figment of your instrumentation, ... I would say: Standing waves are a virtual image caused by the two traveling waves (forward and reverse). I wonder if we could see a visible light standing wave in a cloud chamber if we used a microscope? -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 31, 12:42*pm, Cecil Moore wrote:
If you add a pint of water to a pint of water, the two pints of identical molecules interact, analogous to one joule of coherent/ collimated photons added to another joule of the *identical* photons. The results is two joules of identical photons, indistinguishable from each other. If the superposition process is reversible, interaction has not taken place. If the superposition process is irreversible, interaction has taken place. Both outcomes are possible depending upon the initial conditions. ah, but in this case consider that you have a pint of blue water moving to the right and a pint of red water moving to the left to be a better analogy to currents of the waves moving forward and backward in the coax. there are then 3 possibilities: 1. the two mix and cancel giving you 2 pints of purple water not going anywhere. 2. the two bounce off of each other now giving you red water moving right and blue water moving left. 3. the two pass by each other not mixing at all and continue on their way. if 1 happened you would indeed cancel the waves and end up with a spare pile of electrons not going anywhere. while this may be adequate for a mechanical analogy it doesn't say where the energy of those two moving pints went so is obviously wrong. number 2 conserves energy at least. number 3 also conserves energy and gives the same energy distribution as 2. since electrons aren't colored it makes number 2 and 3 indistinguishable, so clearly the result is that both waves continue on their way undisturbed by the other... which is what is observed in all cases of em wave interaction in linear media. |
Question about "Another look at reflections" article.
On May 31, 1:04*pm, Cecil Moore wrote:
On May 31, 6:16*am, K1TTT wrote: conclusion: Standing waves are a figment of your instrumentation, ... I would say: Standing waves are a virtual image caused by the two traveling waves (forward and reverse). I wonder if we could see a visible light standing wave in a cloud chamber if we used a microscope? -- 73, Cecil, w5dxp.com no need, just look at the lines on a hologram, that is the map of the interference patterns from the reflected and reference laser beams. |
Question about "Another look at reflections" article.
On May 31, 9:09*am, K1TTT wrote:
ah, but in this case consider that you have a pint of blue water moving to the right and a pint of red water moving to the left to be a better analogy to currents of the waves moving forward and backward in the coax. *there are then 3 possibilities: No, no, no. I am NOT talking about forward and reflected waves moving in opposite directions. I am talking about two coherent, collimated waves *MOVING IN THE SAME DIRECTION* in an RF transmission line away from an impedance discontinuity - either two waves moving forward toward the load or two waves moving backwards in the opposite direction toward the source. Such multiple wavefronts occur at impedance discontinuities because of multiple reflections. Forward and reflected waves (waves moving in opposite directions in a constant Z0 environment) do NOT interact. At an impedance discontinuity, the component reflections and transmissive waves do interact if they are coherent, collimated, and MOVING IN THE SAME DIRECTION. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 31, 9:12*am, K1TTT wrote:
no need, just look at the lines on a hologram, that is the map of the interference patterns from the reflected and reference laser beams. Oh yeah, duh ... brain fart - if one slants the partial mirror detector, one can spread the interference patterns out to an optimum pattern for viewing by a human eye. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On Mon, 31 May 2010 07:09:49 -0700 (PDT), K1TTT
wrote: ah, but in this case consider that you have a pint of blue water moving to the right and a pint of red water moving to the left to be a better analogy to currents of the waves moving forward and backward in the coax. .... the result is that both waves continue on their way undisturbed by the other... which is what is observed in all cases of em wave interaction in linear media. Miguel, I want you to note how David clearly exposes the failure of a metaphor, using the metaphor's own analogy. This is the danger of trying to explain one system in terms of another without knowing how either work. It also reveals in shades of deep purple, how the visual system lies to us, and we believe we see the Truth. So, for metaphors and analogies, when the reader knows better, its a lark (an amusing adventure or escapade); or when the writer knows better, its a lark (behavior in a mischievous way). If you both don't know better, its a lark (activity regarded as foolish or a waste of time by the rest of us). Carefully parse the following: "Truth is a lark." 73's Richard Clark, KB7QHC |
Question about "Another look at reflections" article.
On May 31, 11:57*am, Richard Clark wrote:
Miguel, I want you to note how David clearly exposes the failure of a metaphor, using the metaphor's own analogy. Actually Miguel, I want you to note how a simple semantic misunderstanding can lead to false assumptions that propagate to: 1. false assertions, 2. accusations, and 3. character assignation. I said earlier that I was referring only to coherent/collimated waves that are TRAVELING IN THE SAME DIRECTION. K1TTT apparently missed that caveat and was simply confused about what I had said. Based on that false assumption, Richard, as usual, jumped on the "kill the messenger" bandwagon. He doesn't seem to realize that he has to prove quantum electrodynamics to be wrong to prove me wrong, a feat that no mortal has yet accomplished. -- 73, Cecil, w5dxp.com |
Question about "Another look at reflections" article.
On May 31, 2:42*pm, Cecil Moore wrote:
On May 31, 9:09*am, K1TTT wrote: ah, but in this case consider that you have a pint of blue water moving to the right and a pint of red water moving to the left to be a better analogy to currents of the waves moving forward and backward in the coax. *there are then 3 possibilities: No, no, no. I am NOT talking about forward and reflected waves moving in opposite directions. I am talking about two coherent, collimated waves *MOVING IN THE SAME DIRECTION* in an RF transmission line away from an impedance discontinuity - either two waves moving forward toward the load or two waves moving backwards in the opposite direction toward the source. Such multiple wavefronts occur at impedance discontinuities because of multiple reflections. Forward and reflected waves (waves moving in opposite directions in a constant Z0 environment) do NOT interact. At an impedance discontinuity, the component reflections and transmissive waves do interact if they are coherent, collimated, and MOVING IN THE SAME DIRECTION. -- 73, Cecil, w5dxp.com add another condition and i might buy it... their polarization must be the same... if you satisfy ALL those conditions then i believe you would not be able to separate the waves and you could combine their amplitudes. but that still doesn't mean they are interacting, just that their fields always happen to be aligned... now if you are an engineer like i am and deal with macroscopic processes i would consider it perfectly logical to add the fields in a linear medium and carry on with a single wave in each direction created by an infinite series of reflections... HOWEVER, if i switch my hat to the scientist part of my job title and i was working in photons I would come to a point where it would be impossible to divide the last photon and things would fall apart.... fortunately the ham/engineer side usually outvotes the scientist part and i take the infinite summation and call it a day. |
Question about "Another look at reflections" article.
On May 31, 5:20*pm, Cecil Moore wrote:
On May 31, 11:57*am, Richard Clark wrote: Miguel, I want you to note how David clearly exposes the failure of a metaphor, using the metaphor's own analogy. Actually Miguel, I want you to note how a simple semantic misunderstanding can lead to false assumptions that propagate to: 1. false assertions, 2. accusations, and 3. character assignation. I said earlier that I was referring only to coherent/collimated waves that are TRAVELING IN THE SAME DIRECTION. K1TTT apparently missed that caveat and was simply confused about what I had said. Based on that false assumption, Richard, as usual, jumped on the "kill the messenger" bandwagon. He doesn't seem to realize that he has to prove quantum electrodynamics to be wrong to prove me wrong, a feat that no mortal has yet accomplished. -- 73, Cecil, w5dxp.com what does happen to that last photon in the infinite series of smaller and smaller reflections between discontinuities?? |
Question about "Another look at reflections" article.
On May 31, 12:32*pm, K1TTT wrote:
add another condition and i might buy it... their polarization must be the same... If they are coherent, their polarization must necessarily be the same at the same point at the same time. I specified that they are coherent, collimated, and traveling in the same direction. I'm not omniscient so if that's not enough boundary conditions, please enlighten me. -- 73, Cecil, w5dxp.com |
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