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#41
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#42
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"Porky" wrote in message ...
I agree with everything you've said, except that it doesn't apply to loudspeakers, you've just come up with a fancier variation of the train/whistle model, which doesn't apply to speakers because the speaker is reproducing a complex soundwave in toto from a single complex driving source, what you're doing is the same as picking up the speaker and moving it back and forth and that will certainly produce Doppler shift. It isn't that the motion is dynamic, it's that the motion is coming from a single source which producing a complex sound, that is the reason a speaker doesn't produce doppler shift when reproducing music. Since you fail to see the clear and obvious equivalence and relevance, all I can say is that you are an idiot. |
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#43
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If you set up your coupling tube so that the speaker cone pushes the
air completly and the air moves in the tube without loss and at the far end the air pushes the mic diaphram completly SO THAT THE SPEKAER CONE AND MIC DIPHRAM ARE MOVING TOGETHER IN LOCK STEP WITH THE SAME DISPLACEMENT, then you are correct, there is no Doppler effect. Note that in this case the distance between the Rx and Tx is constant and there is no Doppler effect. In any other case where the mic diaphram is not moving in lock step with the cone, there will be a Doppler effect. Your assessment is correct, but not exactly for the reason you state. The only way the transmitter and receiver can move in lock step is if the propagation time is zero; and the only way that the propagation time can be zero is if the sound velocity in the medium is infinite. Of course, this is exactly what the Doppler equation, fr/fs=1/(1-(vs/c)), predicts. For c--infinity, fr=fs. Contrary to Bob Cain's false and unsubstantiated belief, dynamic Doppler shift does occur in a tube, and a direct measurement of it will be forthcoming. Interesting, If the Tx is vibrating at 50 Hz and 4 kHz, and the couling through the tube is complete and lossless then the Rx cone will move with the same displacement. You are correct and I take your point regarding the prop delay. So the cones may not be in lock step due to the prop delay and the relative motion due to the 50 Hz cone vibrations which are not in phase may create Doppler to the 4 kHz...I agree. But consider a SPECIAL CASE, where the distance from Rx to Tx is such that the prop delay equals an integer number of wavelengths of 50Hz, then the cones will be in lock step at 50 Hz. So perhaps the correct answer for this special 100% coupled tube case, is that the Doppler is a critical function of the distance between the Rx and Tx. This is a very pathalogical case anyway. In nearly any real situation, the Rx and Tx cones will not be in lock step so the distance from Rx to Tx will be changing and Doppler will occur. Mark |
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#44
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#45
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The Ghost wrote: For Doppler shift not to exist, the propagation delay needs to be zero. But zero time delay is not the same as zero phase shfit. Doppler mixing occurs if and only if the coupling from Tx to Rx is frequency dependant. If it is independant, the distance between Tx and Rx, so long as it is fixed, is irrelevant. It won't happen with a piston in a terminated tube. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#46
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Bob Cain wrote: The Ghost wrote: For Doppler shift not to exist, the propagation delay needs to be zero. But zero time delay is not the same as zero phase shfit. Doppler mixing occurs if and only if the coupling from Tx to Rx is frequency dependant. If it is independant, the distance between Tx and Rx, so long as it is fixed, is irrelevant. It won't happen with a piston in a terminated tube. Bob As a quasi-final note with respect to this whole dispute I'd like to quote to this crossposted thread a response I just gave Jim Carr to a post that was only in alt.music.home-studio. This is all I've got to say until a lot more has matured. Jim Carr wrote: Bob, [compliment snipped] ... it looks like you're growing weary and a bit irritable, so maybe you might want to drop it. Yes, I have grown weary and irritable with respect to the ad hominem crap, as well as utterly convinced that the correct principle for Doppler mixing is that of frequency dependant coupling between Tx and Rx. What remains to be done is to take that principle to a full theory. That may not be at all easy because it will be a field theory and they are notoriously difficult to formulate from the principle on which they are based. If and when that theory is complete and boundry conditions are imposed and the differential equations are solved, if they are solvable, then we will have something predictive. The common equation for Doppler shift will fall out of one boundry condition, relative velocity of Rx relative to Tx being static rather than dynamic. Even that will only be valid for a single frequency under general conditions. You'll probably never get what you want. I haven't seen anyone post a formula that says, "If I put out a 50Hz tone and a 1200Hz tone from a speaker with an excursion of 3mm I will expect to see ..." and then follow it up with an experiment that showed the predicted results and provided a way to eliminate spurious information. I doubt anyone will come through at this point. Nor will anyone from any theory that uses the static Doppler shift equation as its basic principle. Those rec.audio.pro guys can get pretty arrogant and nasty. Yeah, I'm one of them. :-) I haven't seen that much blustering since the Blizzard of '79! If it were me I'd just take my ball and go home. Anyway, not everyone here thinks you're an arrogant, ignorant asshole. Well, at least not all three at once. _LOL!_ My ball with regard to Doppler mixing is the principle of frequency dependant coupling between Tx and Rx and I will indeed take it home until I or I and a collaborator who is facile with the necessasary math toolkit (div, grad, curl, infinitessimal volumes, and other vector calculus methods) can return with a fleshed out theory from first principles. I am confident that can be done but far less confident that I can do it. Thanks, Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#47
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Bob Cain wrote in message ...
The Ghost wrote: For Doppler shift not to exist, the propagation delay needs to be zero. But zero time delay is not the same as zero phase shfit. Doppler mixing occurs if and only if the coupling from Tx to Rx is frequency dependant. If it is independant, the distance between Tx and Rx, so long as it is fixed, is irrelevant. It won't happen with a piston in a terminated tube. And that is nothing more than another one of your nonsensical, umsubstantiated beliefs. |
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#48
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The Ghost wrote: Doppler mixing occurs if and only if the coupling from Tx to Rx is frequency dependant. If it is independant, the distance between Tx and Rx, so long as it is fixed, is irrelevant. It won't happen with a piston in a terminated tube. And that is nothing more than another one of your nonsensical, umsubstantiated beliefs. Then it should be quite easy for you to formally refute it. Have at it. Yeah, right. You're a washed up antisocial who once, long ago, did some hearing research with someone who actually was important but you've been isolated by your sociopathy to where your rage is all you have left and it simply reflects what you think you should have been but for all the idiots. You can use tables to give the answers to problems that have been solved by others but have no understanding at all below that level. You also seem incapable of learning. If that's wrong, prove otherwise with an actual display of any technical acumen. I can't figure out why you are even on usenet. You have nothing whatsoever to contribute other than insults that would get your head torn off with **** down the remaining food pipe were you to deliver them face to face. Probably why you're afraid to leave your room. If you can show you actually know anything by giving a logical proof of your theory with all axioms clearly stated and available for challenge and all non-axiomatic formulae dependant only on what has been already formally derived and with all constants and variables given precise physical meaning, I'll bow down before you. I can't see why such a thing should even be a challenge to one such as yourself. Or rage on, asshole, because that's all anyone expects from you anyway. Your "experiments" if you actually have performed any are such kludges that nothing at all can be concluded from them. They show an utter disregard for science, or more likely no understanding of what science is. I know one of your couple of sock puppets will step up to defend you and tell us that they know you really are an expert but that's pretty transparent by now. Sorry to take the gloves off in front of everybody else but I do feel a whole lot better after telling it like it is. I took alt.sci.physics.acoustics off this because they are all much too polite for such a reality check. You'll probably re-post it there anyway looking for sympathy. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#49
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Bob Cain wrote in message ...
Yes, I have grown weary and irritable with respect to the ad hominem crap,...... Excuse me while I reach for an air sickness bag, you pathetic and contemptable piece of human waste. After all of the ad hominem attacks that you have bestowed upon me recently, and over the last 3-4 years, you are now whining about the so-called "ad hominem" crap. .......as well as utterly convinced that the correct principle for Doppler mixing is that of frequency dependant coupling between Tx and Rx. That is utter nonsensical drivel. What remains to be done is to take that principle to a full theory. The only thing that remains to be done is to discredit you entirely on the issue of dynamic Doppler shift/distiortion. As you well know, that is in process. It is baout time that you confront reality and admit that you have been wrong about every aspect of this issue. Anyway, not everyone here thinks you're an arrogant, ignorant asshole. Well, at least not all three at once. Yes, all three at once. And, anyone who doesn't is either in bed with this scumbag is brain dead (my unbiased opinion, of course). _LOL!_ My ball with regard to Doppler mixing is the principle of frequency dependant coupling between Tx and Rx and I will indeed take it home until I or I and a collaborator who is facile with the necessasary math toolkit (div, grad, curl, infinitessimal volumes, and other vector calculus methods) can return with a fleshed out theory from first principles. I am confident that can be done but far less confident that I can do it. At least you are right about one thing...you can't do it. And, since your so-called Doppler-mixing principle is nothing more than nonsensical drivel, neither can anyone else. Lastly, the only thing that you have grown weary about is the fact that your denial of dynamic Doppler shift in a tube has just been proven wrong.....and you know it. The theoretical analysis shows that dynamic Doppler shift does in fact exist in a tube. Direct measurements, confirming the theoretical analysis, will also be forthcoming. Bottom line, all of your unsubstantiated, mindless beliefs have been proven wrong and you have been discredited.....and you know it. But, rather than stand up like a man and admit it, you would like everone to believe that you have simply "grown weary and irritable." Please excuse me while I reach for another air sickness bag. |
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#50
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The Ghost wrote: Lastly, the only thing that you have grown weary about is the fact that your denial of dynamic Doppler shift in a tube has just been proven wrong.....and you know it. Nonsense. Prove its existence and its precise predictions on paper or shut up. You can't. You do know what a proof entails, right? All your crude posturing means absolutely nothing in light of your inability to do that. Give us a reason for your certainty that has a tad more credibility than your hateful spew. State your axioms so that their validity can be subject to verificaion and challenge; from them formally derive equations that rely on nothing but the axioms and equations already derived; define in precise physical terms what every variable and constant is and end up with an equation that precisely describes the effect. Two tones, one dimensinal analysis will do if a more general treatment escapes your razor sharp mind. You know the routine. Or do you? At one time aquiring a Ph.D. in anything technical required facility in that kind of proof. Falling back on your posture that you don't spoon feed the peanut gallery just won't do this time. You are in deep enough with this that your reputation is on the line. If you can't or won't prove your assertions, nothing you say from here on out about anything has a lick of credibility. Your experiments, if you have actually done any, are such kludges that they disclose nothing of the source of dynamic Doppler mixing. You know what you must do now and I have nothing further to say to you until you have done it or shown the intellectual honesty to disclose the false assumption in your theory. Should you succeed and should your proof stand up I will be the first to acknowlege your skill at doing something that has not been done before and I will do that as many places as this debate has raged in no uncertain terms. A diet of crow bothers me not in the least if something useful is accomplished along the way. I too will be attempting the same for mine and will shut up about it until I have accomplished the same kind of proof that I expect from you. Until such a proven theory emerges, the whole business of the source of dynamic Doppler mixing is speculation on all sides. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#51
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Bob Cain wrote in message ...
The Ghost wrote: Lastly, the only thing that you have grown weary about is the fact that your denial of dynamic Doppler shift in a tube has just been proven wrong.....and you know it. Nonsense. Prove its existence and its precise predictions on paper or shut up. You can't. You do know what a proof entails, right? All your crude posturing means absolutely nothing in light of your inability to do that. Give us a reason for your certainty that has a tad more credibility than your hateful spew. State your axioms so that their validity can be subject to verificaion and challenge; from them formally derive equations that rely on nothing but the axioms and equations already derived; define in precise physical terms what every variable and constant is and end up with an equation that precisely describes the effect. Two tones, one dimensinal analysis will do if a more general treatment escapes your razor sharp mind. You know the routine. Or do you? At one time aquiring a Ph.D. in anything technical required facility in that kind of proof. Bob, you have a big mouth, a small mind and virtually no character. You know that the idealized analysis of Doppler distortion produced by a piston in one end of an infinite tube has been done, and you know that the result disproves your unsubstantiated claim that Doppler distortion does not exist under such conditions. I know that you know the results of the analysis becasue I have been copied on email that you have received regarding this matter. For you to pretend at this point that you are still right about this issue is about as personally and intellectually dishonest as it gets. Nothing would give me greater pleasure right now than to post the personal email that you have received regarding thiis issue and to expose you for the slime ball that you are. However, out of respect for the wishes of the person who has done the analysis, I am not going to do that at this time. Nonetheless, the analysis, the predictions of the analysis and the experimental results to confirm the predictions of the analysis will be presented here in due time. The outcome is known and certain and you know it, but you are a scumbag and you simply don't have the character to stand up right now and admit that you are wrong. Falling back on your posture that you don't spoon feed the peanut gallery just won't do this time. You are in deep enough with this that your reputation is on the line. If you can't or won't prove your assertions, nothing you say from here on out about anything has a lick of credibility. Please, give me a break with the absurd rhetoric. This is little more than a side game that I play with you solely for relaxation and amusement. Your experiments, if you have actually done any, are such kludges that they disclose nothing of the source of dynamic Doppler mixing. For whatever reason, it seems that all you are able to do is make outrageous, unsubstantiated assertions. Below is a contrary opinion from an esteemed member of the acoustics community. He refers to my experiment as "pure" and challenges you to cite so-called "spurious" elements that you claimed existed. Naturally, like the technically inept coward that you are, you dropped that challenge like a hot potato. --------------------------------------- Subject: Experimental Evidence for Dynamic Doppler Shift From: Angelo Campanella Newsgroups: alt.sci.physics.acoustics Reply-To: Bob Cain wrote in message ... Evidence for existence of a phenomenon requires elimination of spurious causes one way or another, either by experimental setup or by having a _good_ characterization of the spurious phenomena so that their effect can be removed from the test data. How does your "experiment" do either so that what remains can be legitimately regarded as evidence of Doppler distortion? OK. So specify the "spurious" elements in this otherwise pure experiment. If you cannot cite any, perhaps there aren't any other than the nonlinear distortion that occurs in speakers whose voice coil is swung out of the uniform magnetic field of the magnet system. But that distortion is readily detected by measuring the 2nd and 3rd harmonic level (which is not of concern other that it not exist). ------------------------------------ You know what you must do now and I have nothing further to say to you until you have done it or shown the intellectual honesty to disclose the false assumption in your theory. Should you succeed and should your proof stand up I will be the first to acknowlege your skill at doing something that has not been done before and I will do that as many places as this debate has raged in no uncertain terms. A diet of crow bothers me not in the least if something useful is accomplished along the way. I'll believe that when I see it. Given that you already know the outcome of the analysis of the piston in a tube, I suggest that you start writing your concession speech right now. I too will be attempting the same for mine and will shut up about it until I have accomplished the same kind of proof that I expect from you. Shut up please, but otherwise don't waste your time attempting to fight a battle that you have already lost. Until such a proven theory emerges, the whole business of the source of dynamic Doppler mixing is speculation on all sides. The theory exists and its confirmation is forthcoming. You just don't have the personal integrity to admit it. |
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#52
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Bob Cain wrote in message ...
The Ghost wrote: Lastly, the only thing that you have grown weary about is the fact that your denial of dynamic Doppler shift in a tube has just been proven wrong.....and you know it. Nonsense. Prove its existence and its precise predictions on paper or shut up. You can't. You do know what a proof entails, right? All your crude posturing means absolutely nothing in light of your inability to do that. ......additional mindless, nonsensical drivel deleted...... For those who are interested, an exact mathematical analysis of the Doppler distorton that is produced by a vibrating pistion in a tube can be found at: http://www.silcom.com/~aludwig/Physi...on/dopdist.htm Bob Cain has been aware of this all along, but his ego has prevented him from admitting it. |
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#53
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Bob and the rest of the group still reading this thread,
I can appreciate anyone who wants to see specifics, especially in a controversial issue such as this. However, what keeps me from pursuing this with you further is that I sense in you a higher desire to prove yourself right than to find out the truth. For example, anytime someone presents some equation or evidence, you knock it down by invalidating the assumptions or other details that seem fairly self-evident. Since, as I stated in another response in this thread quite some time ago (to which I don't recall getting any responses), ALL theories rest at some point on assumptions, this kind of dissipative arguing can go on ad-infinitum. The goal should be to find out the truth. I'm willing to admit I may be wrong and examine other evidence. Can you? --RY Bob Cain writes: The Ghost wrote: Lastly, the only thing that you have grown weary about is the fact that your denial of dynamic Doppler shift in a tube has just been proven wrong.....and you know it. Nonsense. Prove its existence and its precise predictions on paper or shut up. You can't. You do know what a proof entails, right? All your crude posturing means absolutely nothing in light of your inability to do that. Give us a reason for your certainty that has a tad more credibility than your hateful spew. State your axioms so that their validity can be subject to verificaion and challenge; from them formally derive equations that rely on nothing but the axioms and equations already derived; define in precise physical terms what every variable and constant is and end up with an equation that precisely describes the effect. Two tones, one dimensinal analysis will do if a more general treatment escapes your razor sharp mind. You know the routine. Or do you? At one time aquiring a Ph.D. in anything technical required facility in that kind of proof. Falling back on your posture that you don't spoon feed the peanut gallery just won't do this time. You are in deep enough with this that your reputation is on the line. If you can't or won't prove your assertions, nothing you say from here on out about anything has a lick of credibility. Your experiments, if you have actually done any, are such kludges that they disclose nothing of the source of dynamic Doppler mixing. You know what you must do now and I have nothing further to say to you until you have done it or shown the intellectual honesty to disclose the false assumption in your theory. Should you succeed and should your proof stand up I will be the first to acknowlege your skill at doing something that has not been done before and I will do that as many places as this debate has raged in no uncertain terms. A diet of crow bothers me not in the least if something useful is accomplished along the way. I too will be attempting the same for mine and will shut up about it until I have accomplished the same kind of proof that I expect from you. Until such a proven theory emerges, the whole business of the source of dynamic Doppler mixing is speculation on all sides. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein -- % Randy Yates % "My Shangri-la has gone away, fading like %% Fuquay-Varina, NC % the Beatles on 'Hey Jude'" %%% 919-577-9882 % %%%% % 'Shangri-La', *A New World Record*, ELO http://home.earthlink.net/~yatescr |
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#54
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The Ghost wrote: http://www.silcom.com/~aludwig/Physi...on/dopdist.htm Bob Cain has been aware of this all along, but his ego has prevented him from admitting it. He just put it up there today, fool, and you know that because you were copied on the email I received telling me about it. I'll have at it. He told me it is just the type of proof I'm asking for and if it is and it stands up to criticism, which he has solicited, then I'm wrong. That process, if I find anything to question, will occur privately between he and I. However that resolves, or stalemates, I will report the result. I have said nothing about the private correspondence that has gone on between us because it has been inconclusive. I am _very_ pleased that Art is willing to engage at a tecnical level on this. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#55
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Randy Yates wrote: For example, anytime someone presents some equation or evidence, you knock it down by invalidating the assumptions or other details that seem fairly self-evident. But that is the whole point. Things that seem self evident are all too often incorrect on deeper analysis. Since, as I stated in another response in this thread quite some time ago (to which I don't recall getting any responses), ALL theories rest at some point on assumptions, this kind of dissipative arguing can go on ad-infinitum. They rest on axioms that are in fact self evident. That the Doppler equation for static velocities is applicable to time varying ones without modification is by no means self evident. That underpins most arguments for Doppler distortion and is deserving of proof. Sokolich says it is so proven in Pierces book. I am awaiting delivery of it now to see if and how that was actually done. The other argument for it appeals to the longitudinal nature of acoustic waves, yet every acoustic case we have looked at has an EM wave equivalent which gives the same results and EM is transverse. What's up with that? I'm no longer trying to determine whether it exists, I was rather quickly persuaded of that. Now it is about why it exists and I believe the reasons that have been given are wrong. The goal should be to find out the truth. I'm willing to admit I may be wrong and examine other evidence. Can you? Does it sound like it yet? I've ordered a book that is said to prove one of the axioms and Art Ludwig has consented to engage in the kind of proof I think this deserves and to enter into discussion with me about its specifics. That he wishes to continue our discussion several weeks after it began should indicate that at least he sees a real desire in me to find and understand the truth as he obviously does himself. However his in depth analysis turns out I admire him greatly (and am very grateful) for his willingness to perform it in public. OTOH, if all your criticism means is that I haven't agreed with you then perhaps a look in the mirror is appropriate. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#56
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Bob Cain writes:
[...] Does it sound like it yet? I've ordered a book that is said to prove one of the axioms and Art Ludwig has consented to engage in the kind of proof I think this deserves and to enter into discussion with me about its specifics. That he wishes to continue our discussion several weeks after it began should indicate that at least he sees a p real desire in me to find and understand the truth as he obviously does himself. However his in depth analysis turns out I admire him greatly (and am very grateful) for his willingness to perform it in public. I agree - I appreciate what Art is doing as well. OTOH, if all your criticism means is that I haven't agreed with you Not at all, Bob. In fact, I get a charge out of seeing a false belief of my own get overturned. Makes me realize the universe is even more wondrous than I thought. then perhaps a look in the mirror is appropriate. As Aerosmith said in a song once, "All those lines in my face getting clearer..." -- % Randy Yates % "Ticket to the moon, flight leaves here today %% Fuquay-Varina, NC % from Satellite 2" %%% 919-577-9882 % 'Ticket To The Moon' %%%% % *Time*, Electric Light Orchestra http://home.earthlink.net/~yatescr |
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#57
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"Randy Yates" wrote in message ... Bob and the rest of the group still reading this thread, I can appreciate anyone who wants to see specifics, especially in a controversial issue such as this. However, what keeps me from pursuing this with you further is that I sense in you a higher desire to prove yourself right than to find out the truth. For example, anytime someone presents some equation or evidence, you knock it down by invalidating the assumptions or other details that seem fairly self-evident. Since, as I stated in another response in this thread quite some time ago (to which I don't recall getting any responses), ALL theories rest at some point on assumptions, this kind of dissipative arguing can go on ad-infinitum. The goal should be to find out the truth. I'm willing to admit I may be wrong and examine other evidence. Can you? I think the problem is that the basic assumptions that everyone has, are just that, assumptions: 1) based on the original Doppler equation, which is for constant velocity, and 2) based on the train/whistle analogy which simply does not hold up with the speaker producing a complex soundwave. The problem I see with item (1) is that a speaker's cone motion represents a continuously varying velocity and direction, which is something not covered directly by the Doppler equation, and in item (2), the train's motion affects the whistle by moving it through space, but the whistle's vibration in producing the sound source affects the train's motion not at all in any practical way. This can be represented by a speaker with a peizo transducer mounted at its apex, with the speaker driven by a LF tone, and the peizo element being driven by a HF tone. The peizo transducer, being solidly mounted to the cone, travels back and forth with it, but the peizo element's vibration, its diaphragm being much, much lower in mass than the cone affects the cone in so small a way as to be insignificant, and thus you have a sound source riding on some other motion, so there will be Doppler shift of the HF tone. In the case of a speaker cone producing a complex soundwave, the LH tone(s) and HF tone(s) not only affect each other, but are coupled tightly together with no discernable coupling loss, thus producing, not a HF tone riding on an LF tone (as is the case of the train and whistle), but a single complex motion that results in the generation of a single complex soundwave containing both (or all) frequencies, and thus not subject to Doppler distortion in any normal sense. In other words, if the LF is coupled to the HF, but the HF is not coupled back to the LF, there will be Doppler shift in some form, but if both LF and HF are solidly coupled in both directions the soundwave generaated is a single coherent complex wave that isn't subject to Doppler shift in any normal sense. The difference between the two is may seem small, but I think it is critically important when considering Doppler distortion. Not being a mathematician or physicist, I don't have the math background to produce the necessary equations, but the mechanics are relatively simple so I can visualize both models and see the differences, and I can assure you that there are important differences in the two models. If those with the above two assumptions will look at what makes them think both assumptions apply to the speaker reproducing multiple frequencies, and thoroughly analyze the two models I presented, I think things may become a bit clearer for everyone. I'm not postulating about pistons in closed or open chambers, I'm trying to model real speakers in the real world. |
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#58
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"Randy Yates" wrote in message ... Bob Cain writes: [...] Does it sound like it yet? I've ordered a book that is said to prove one of the axioms and Art Ludwig has consented to engage in the kind of proof I think this deserves and to enter into discussion with me about its specifics. That he wishes to continue our discussion several weeks after it began should indicate that at least he sees a p real desire in me to find and understand the truth as he obviously does himself. However his in depth analysis turns out I admire him greatly (and am very grateful) for his willingness to perform it in public. I agree - I appreciate what Art is doing as well. OTOH, if all your criticism means is that I haven't agreed with you Not at all, Bob. In fact, I get a charge out of seeing a false belief of my own get overturned. Makes me realize the universe is even more wondrous than I thought. then perhaps a look in the mirror is appropriate. As Aerosmith said in a song once, "All those lines in my face getting clearer..." "Isn't that the way everybody's got their dues in life to pay...." We're paying our Doppler dues right now. :-) I've spent 'way too many hours on this, but I can't quit 'til I know how it turns out. The bad part is that I may provide some clues here and there, right or wrong, but unless I want to go back to school for several more years, I won't be providing the mathematical proof, and I very well may not be able to understand the equations that show the proof. I'll just have to hope that folks are honest enough to admit the truth when they see it and tell me what it all means.... *L* |
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#60
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Randy Yates wrote: Not at all, Bob. In fact, I get a charge out of seeing a false belief of my own get overturned. Makes me realize the universe is even more wondrous than I thought. Believe it or not, I will get the same charge if my belief on this can be overturned by solid theoretical proof. No way do I think I know everything and if there proves to be a gap in my understanding, I very much welcome it being filled. Of course it is nothing like the charge I'm going to feel when I'm ultimately proved correct. :-) Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#61
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#62
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Bob Cain wrote in message ...
The Ghost wrote: Doppler mixing occurs if and only if the coupling from Tx to Rx is frequency dependant. If it is independant, the distance between Tx and Rx, so long as it is fixed, is irrelevant. It won't happen with a piston in a terminated tube. And that is nothing more than another one of your nonsensical, umsubstantiated beliefs. Then it should be quite easy for you to formally refute it. Have at it. Yeah, right. You're a washed up antisocial who once, long ago, did some hearing research with someone who actually was important but you've been isolated by your sociopathy to where your rage is all you have left and it simply reflects what you think you should have been but for all the idiots. You can use tables to give the answers to problems that have been solved by others but have no understanding at all below that level. You also seem incapable of learning. If that's wrong, prove otherwise with an actual display of any technical acumen. I can't figure out why you are even on usenet. You have nothing whatsoever to contribute other than insults that would get your head torn off with **** down the remaining food pipe were you to deliver them face to face. Probably why you're afraid to leave your room. If you can show you actually know anything by giving a logical proof of your theory with all axioms clearly stated and available for challenge and all non-axiomatic formulae dependant only on what has been already formally derived and with all constants and variables given precise physical meaning, I'll bow down before you. I can't see why such a thing should even be a challenge to one such as yourself. Or rage on, asshole, because that's all anyone expects from you anyway. Your "experiments" if you actually have performed any are such kludges that nothing at all can be concluded from them. They show an utter disregard for science, or more likely no understanding of what science is. I know one of your couple of sock puppets will step up to defend you and tell us that they know you really are an expert but that's pretty transparent by now. Sorry to take the gloves off in front of everybody else but I do feel a whole lot better after telling it like it is. I took alt.sci.physics.acoustics off this because they are all much too polite for such a reality check. You'll probably re-post it there anyway looking for sympathy. Bob You are right, Bob. I am going to re-post it. I want to make sure that everyone reading these newsgroups from now until the end of time is fully aware of the sort of human being that Bob Cain really is. |
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Bob Cain wrote in message ...
Valid and meaningful experiment always trumps theory. A _valid_ experiment is one with acceptable measurement of signal and in which no extraneous signal is admited or else any extraneous signal can be exactly accounted for. The experimenter is responsible for the proof of this. Peer review is usually required for acceptance of the proof. BULL CRAP. The experimenter is only responsible for reporting honestly the measurement methodology that he used and the results that he obtained. If other experimenters do not believe the results, it is up to them to repeat the experiment, identify the purported error, correct it and obtain and present the corrected result. Also, you mindless jackass, peer review is only required for acceptance for publication. It is quite common for opposing articles on controvercial topics to be accepted for publication even though the issue in dispute remains unresolved. A _meaningful_ experiment is one that has been repeated with the same results by an independant experimenter with credentials and credibility among peers. No. A meaningful experiment is one that yields the correct result. And someone like yourself who is technically inept is not in a postition to make that assessment. If testing a theory, which is the usual use of experiment in science, the parameter space of the theory must also be sampled at more than one point, if it is possible to control the parameters, and the results remain in agreement with theory at all of them. Just another one of your mindless, irrational assertions/diversions. A valid demonstranted inconsistency between theory and experimental result is all that is required to disprove a theory. However, a valid, demonstrated agreement at one point in n-dimensional paramater space does not require that a theory be rejected. It simply means is that the theory is still viable and that it can not be dismissed simply because jackasses like you refuse to accept it until/unless the theory has been proven to be to be in agreement with all possible variation in parameters. I look forward very much to such an experimental test of whatever predictive theory emerges from this discussion. I would wish it were in the hands of one not so invested in a particular result but that's what the requirement of repeatability by a disinterested party is for. More BULL CRAP. The theory is there, but you refuse to accept it. Also, you are in serious need of a reality check. The way science works is one group of scientists trying to to prove that their theory is correct, or that the theory of another group of scientists is incorrect. You are a naive and totally midnless idiot if you believe that science progresses on a disinteressted-party basis. |
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"The Ghost" wrote in message
om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! |
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Jim Carr wrote: "The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! What would even be better for that particular experimenter is to make sure he doesn't know the answer first. OTOH, if the results match well a theory that can be falsified then all that need be known about the experimenter has been said. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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"Jim Carr" writes:
"The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! This is pun, right? An experiment's results are, by definition, correct. You can't drop a ball from a roof and say, "That's incorrect - the ball fell to the ground. It shouldn't have done that - it should have floated to the sky. I must have the experiment wrong." It may perhaps be the case that the experiment you perform tells you little or nothing about the question(s) you are seeking to answer, but the experiment's outcome is nevertheless never "incorrect." -- % Randy Yates % "And all that I can do %% Fuquay-Varina, NC % is say I'm sorry, %%% 919-577-9882 % that's the way it goes..." %%%% % Getting To The Point', *Balance of Power*, ELO http://home.earthlink.net/~yatescr |
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"Randy Yates" wrote in message
... "Jim Carr" writes: "The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! This is pun, right? Actually, I was shooting for sarcasm. |
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(The Ghost) wrote in message . com...
(Mark) wrote in message . com... Ghost, I think we agree on most points, but I disagree with you on this particualr spcial case. I belive Doppler exists whenever the distance between Rx and Tx is changing. But if the two cones are vibrating in phase (with zero phase shift) at 50 Hz, but not with zero time delay becasue they are seperated by a fixed idstance, ( I do understand the distinction betwen zero time delay and zero phast shift) then I belive in this special case, no Doppler occurs because the distance form Tx to Rx is a constant even though both are moving relative to the medium. As an analogy, if there are two trains on the same track both moving at 60 MPH in the same direction, does Doppler occur when one hears the whistle of the other train. I don't think so. Mark Zero time delay means just that.....zero time delay and zero phase shift. On the other hand zero phase shift occurs for finite time delays each time the distance of the propagating wave increases by one wavelength. For example, consider a loudspeaker radiating 1KHz in a free field. If at some particular distance from the loudspeaker, the phase shift is zero degrees relative to the electrical signal. The phase shift will also be zero degrees for increased distances from the loudspeaker of 1, 2, 3,..... wavelengths. So, even though you move farther and farther away from the loudspeaker and increase the time delay between transmitter and receiver, you can still find points in space where the phase difference relative to the electrical signal is zero degrees. Yes I agree, and it is at these particular points of 0 phase shift that you just described that the Tx cone and Rx cone are moving in phase at 50Hz and therefore the distance between them is constant so there is no Doppler effect. Mark |
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Mark wrote:
Yes I agree, and it is at these particular points of 0 phase shift etc. PLEASE DO NOT CROSS POST INTO THIS ACOUSTICS GROUP, NOR CROSS POST FROM THIS ACOUSTICS GROUP INTO OTHERS. LET'S KEEP FOCUSED ONLY ON ACOUSTICS. ANGELO CAMPANELLA |
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Mark wrote: Yes I agree, and it is at these particular points of 0 phase shift that you just described that the Tx cone and Rx cone are moving in phase at 50Hz and therefore the distance between them is constant so there is no Doppler effect. Bingo. It can hardly be put more succinctly. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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Angelo Campanella wrote: Mark wrote: Yes I agree, and it is at these particular points of 0 phase shift etc. PLEASE DO NOT CROSS POST INTO THIS ACOUSTICS GROUP, NOR CROSS POST FROM THIS ACOUSTICS GROUP INTO OTHERS. LET'S KEEP FOCUSED ONLY ON ACOUSTICS. I DON'T UNDERSTAND WHY YOU DON'T CONSIDER THIS A MATTER OF ACOUSTIC THEORY. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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Randy, in case you use it as a bit bucket and wouldn't know this, I've sent you a brief email at the address you use for these posts. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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Bob Cain writes:
Mark wrote: Yes I agree, and it is at these particular points of 0 phase shift that you just described that the Tx cone and Rx cone are moving in phase at 50Hz and therefore the distance between them is constant so there is no Doppler effect. Bingo. It can hardly be put more succinctly. Bob, Is this the essence of what you've been trying to say all along? I.e., that, when the frequency is low enough, no energy is coupled into the wave, so that the low frequency movement occurs in the transmitter but not the receiver, but then when the frequency is high enough for energy to transfer, the receiver cone moves with the transmitter? I kinda sorta see what you're saying, but something sounds funny about this. Can't put my finger on it right now. -- % Randy Yates % "Remember the good old 1980's, when %% Fuquay-Varina, NC % things were so uncomplicated?" %%% 919-577-9882 % 'Ticket To The Moon' %%%% % *Time*, Electric Light Orchestra http://home.earthlink.net/~yatescr |
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Randy Yates wrote: Bob Cain writes: Mark wrote: Yes I agree, and it is at these particular points of 0 phase shift that you just described that the Tx cone and Rx cone are moving in phase at 50Hz and therefore the distance between them is constant so there is no Doppler effect. Bingo. It can hardly be put more succinctly. Bob, Is this the essence of what you've been trying to say all along? I.e., that, when the frequency is low enough, no energy is coupled into the wave, so that the low frequency movement occurs in the transmitter but not the receiver, but then when the frequency is high enough for energy to transfer, the receiver cone moves with the transmitter? No, but rather that for a Piston In A Tube you could substitute any frequency for 50 Hz and Mark's statement would be true. For the PIAT case, as you know, I think I've found what will be a very simple proof that no Doppler mixing will occur and that the Rx gets exactly what the Tx sends based on one axiom that is at Art's site and Fourier theory. You can't get down to many fewer first principles than that. For anyone who wants to anticipate that proof, the axiom is equation (1) at: http://www.silcom.com/~aludwig/Physi...collisions.htm I doubt anyone could find a hole if I were to just verbally state it but I want to do better than that and it shouldn't be very difficult except for one as rusty at proof as I am. What you said is very close for systems other than the PIAT, such as a speaker swinging on a rope or a speaker on a train or ultimately for the speaker in a stationary cabinet. It is the frequency dependant decoupling of motion of the Tx to the Rx that causes Doppler mixing. I kinda sorta see what you're saying, but something sounds funny about this. Can't put my finger on it right now. I know you will be trying. :-) Thanks very much, at the very least, for giving it consideration. Getting just that much for these ideas has proven incredibly difficult. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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Bob Cain wrote: No, but rather that for a Piston In A Tube you could substitute any That should have said, "Yes, and that for a Piston In A Tube...". And when I said you are "very close", I should have said you are "spot on". Sorry, Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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"The Ghost" wrote in message om... (Mark) wrote in message . com... Ghost, I think we agree on most points, but I disagree with you on this particualr spcial case. I belive Doppler exists whenever the distance between Rx and Tx is changing. But if the two cones are vibrating in phase (with zero phase shift) at 50 Hz, but not with zero time delay becasue they are seperated by a fixed idstance, ( I do understand the distinction betwen zero time delay and zero phast shift) then I belive in this special case, no Doppler occurs because the distance form Tx to Rx is a constant even though both are moving relative to the medium. As an analogy, if there are two trains on the same track both moving at 60 MPH in the same direction, does Doppler occur when one hears the whistle of the other train. I don't think so. Mark Zero time delay means just that.....zero time delay and zero phase shift. On the other hand zero phase shift occurs for finite time delays each time the distance of the propagating wave increases by one wavelength. For example, consider a loudspeaker radiating 1KHz in a free field. If at some particular distance from the loudspeaker, the phase shift is zero degrees relative to the electrical signal. The phase shift will also be zero degrees for increased distances from the loudspeaker of 1, 2, 3,..... wavelengths. So, even though you move farther and farther away from the loudspeaker and increase the time delay between transmitter and receiver, you can still find points in space where the phase difference relative to the electrical signal is zero degrees. Quite true, but the time delay will increase by the duration of the particular wave cycle with each wavelength distance from the signal. In the case of a 1 KHz sine wave, this would be an increase of one millisecond in time delay between the electrical wave and the acoustic wave for roughly every foot of distance between the source and the listener. I'm not sure I see any particular relevance in the phase relationship between the electrical and acoustical waves except in the case of sound reinforcement where feedback or source/reinforcement interference might be a problem. |
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"Jim Carr" wrote in message news:ndwYc.62149$yh.14812@fed1read05...
"The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! Who said anything about knowing the correct result in advance, you ****ing moron. Read some science history, asshole! |
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"The Ghost" wrote in message
om... "Jim Carr" wrote in message news:ndwYc.62149$yh.14812@fed1read05... "The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! Who said anything about knowing the correct result in advance, you ****ing moron. Read some science history, asshole! LOL! Do you kiss your mother with a mouth like that? |
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Jim Carr wrote: Who said anything about knowing the correct result in advance, you ****ing moron. Read some science history, asshole! LOL! Do you kiss your mother with a mouth like that? His mother isn't allowed in his room and he's afraid to leave it because of talking **** to so many people and reaching out to touch them in such kind ways as calling the CEO of the company that they work for over personal matters or clipping bits of usenets posts without context to email to someone in order to poison a conversation in progress. He really does have good reason to be paranoid and he keeps multiplying them. A real class act but he knows no acoustics or physics so he can be pretty safely ignored. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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"Jim Carr" wrote in message news:p0Q_c.75103$yh.51210@fed1read05...
"The Ghost" wrote in message om... "Jim Carr" wrote in message news:ndwYc.62149$yh.14812@fed1read05... "The Ghost" wrote in message om... No. A meaningful experiment is one that yields the correct result. Knowing the correct results in advance sounds like good science to me! Who said anything about knowing the correct result in advance, you ****ing moron. Read some science history, asshole! LOL! Do you kiss your mother with a mouth like that? No, but I wouldn't be surprised if I have unknowingly kissed both your wife and your daughter. |
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