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http://cosmo.fis.fc.ul.pt/~crawford/...relativity.pdf
John Stachel: "But here he ran into the most blatant-seeming contradiction, which I mentioned earlier when first discussing the two principles. As noted then, the Maxwell-Lorentz equations imply that there exists (at least) one inertial frame in which the speed of light is a constant regardless of the motion of the light source. Einstein's version of the relativity principle (minus the ether) requires that, if this is true for one inertial frame, it must be true for all inertial frames. But this seems to be nonsense. How can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam? Einstein states that he wrestled with this problem over a lengthy period of time, to the point of despair. We have no details of this struggle, unfortunately. Finally, after a day spent wrestling once more with the problem in the company of his friend and patent office colleague Michele Besso, the only person thanked in the 1905 SRT paper, there came a moment of crucial insight. (...) I shall not rehearse Einstein's arguments here, but it led to the radically novel idea that, once one physically defines simultaneity of two distant events relative to one inertial frame of reference, it by no means follows that these two events will be simultaneous when the same definition is used relative to another inertial frame moving with respect to the first. It is not logically excluded that they are simultaneous relative to all inertial frames. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while simultaneity is different with respect to different inertial frames; this is also logically quite consistent." In 1905 Einstein still did not know that a 80m long pole can be trapped inside a 40m long barn when individuals similar to Einstein forget to reopen the doors of the barn "pretty quickly": http://www.math.ucr.edu/home/baez/ph...barn_pole.html "These are the props. You own a barn, 40m long, with automatic doors at either end, that can be opened and closed simultaneously by a switch. You also have a pole, 80m long, which of course won't fit in the barn....So, as the pole passes through the barn, there is an instant when it is completely within the barn. At that instant, you close both doors simultaneously, with your switch. Of course, you open them again pretty quickly, but at least momentarily you had the contracted pole shut up in your barn." If Einstein had known this breathtaking story, he could have used it to vindicate the outcome of his painful wrestling (instead of referring to the relativity of simultaneity) so much later John Stachel would have written: John Stachel: "It is not logically excluded that the 80m long pole cannot be trapped inside the 40m long barn, even if Einsteinians forget to reopen the doors of the barn pretty quickly. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while any time Einsteinians forget to reopen the doors of the barn pretty quickly, the 80m long pole remains safely trapped inside the 40m long barn; this is also logically quite consistent." Pentcho Valev |
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On Aug 6, 3:11*pm, Pentcho Valev wrote:
http://cosmo.fis.fc.ul.pt/~crawford/...ein-relativity... John Stachel: "But here he ran into the most blatant-seeming contradiction, which I mentioned earlier when first discussing the two principles. As noted then, the Maxwell-Lorentz equations imply that there exists (at least) one inertial frame in which the speed of light is a constant regardless of the motion of the light source. Einstein's version of the relativity principle (minus the ether) requires that, if this is true for one inertial frame, it must be true for all inertial frames. But this seems to be nonsense. How can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam? Einstein states that he wrestled with this problem over a lengthy period of time, to the point of despair. We have no details of this struggle, unfortunately. Finally, after a day spent wrestling once more with the problem in the company of his friend and patent office colleague Michele Besso, the only person thanked in the 1905 SRT paper, there came a moment of crucial insight. (...) I shall not rehearse Einstein's arguments here, but it led to the radically novel idea that, once one physically defines simultaneity of two distant events relative to one inertial frame of reference, it by no means follows that these two events will be simultaneous when the same definition is used relative to another inertial frame moving with respect to the first. It is not logically excluded that they are simultaneous relative to all inertial frames. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while simultaneity is different with respect to different inertial frames; this is also logically quite consistent." In 1905 Einstein still did not know that a 80m long pole can be trapped inside a 40m long barn when individuals similar to Einstein forget to reopen the doors of the barn "pretty quickly": http://www.math.ucr.edu/home/baez/ph...barn_pole.html "These are the props. You own a barn, 40m long, with automatic doors at either end, that can be opened and closed simultaneously by a switch. You also have a pole, 80m long, which of course won't fit in the barn....So, as the pole passes through the barn, there is an instant when it is completely within the barn. At that instant, you close both doors simultaneously, with your switch. Of course, you open them again pretty quickly, but at least momentarily you had the contracted pole shut up in your barn." If Einstein had known this breathtaking story, he could have used it to vindicate the outcome of his painful wrestling (instead of referring to the relativity of simultaneity) so much later John Stachel would have written: John Stachel: "It is not logically excluded that the 80m long pole cannot be trapped inside the 40m long barn, even if Einsteinians forget to reopen the doors of the barn pretty quickly. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while any time Einsteinians forget to reopen the doors of the barn pretty quickly, the 80m long pole remains safely trapped inside the 40m long barn; this is also logically quite consistent." Pentcho Valev Your problem is that you don't have any historical context in which to place the development of the relativity of simultaneity. If you did, you would know what the problem is with it. Instead, having read your papers over the years, I can tell you that you go over the same ground over and over again, never understanding the issues with which you are dealing. It's really sad. Neither does Stachel (or Howard) have any understanding of the history of constructivist math. So it's like listening to two madmen talking to each other, you and your opponents. You don't know what you're talking about, and they don't know what they are talking about. But I do. Here it is: We are in the midst of a renaissance in the historiography of set theory. Above all, I recommend A. Garciadiego, BERTRAND RUSSELL AND THE ORIGINS OF THE SET-THEORETIC 'PARADOXES,' but there's also Grattan-Guinness and Ferreiros, discussed in the paper linked below. Here is the central issue in the understanding of the relativity of simultaneity: Einstein used a mathematical approach which he called "practical geometry." He thought the formulation of this point of view was his crowning achievement, and thought very highly of the lecture in which you can read his discussion of it, "Geometry and Experience." I recommend it. Today this mathematical point of view is called constructivism or natural mathematics, and in his day it had three branches: intuitionism, logicism and formalism. So you have to understand, first, that Einstein expressed the relativity of simultaneity in practical geometry. I don't see any acknowledgment of that in this chain of remarks. If you want to understand what he said, you have to understand the issues which were important to him. From Poincare (SCIENCE AND HYPOTHESIS), but also from the long tradition of natural mathematics stretching back to Aristotle's concern over the "paradox" of Zeno, he adopted the idea that all argumentation leads inevitably to paradox. This is certainly the gist of the response to Cantorian set theory, hence the fame of the supposed set-theoretic 'paradoxes.' The most important result of this concern was the idea that there is no such thing as logical content: arguments, if expressed in a certain way, can approach logical content but can never actually contain it, because, again, argumentation necessarily leads to paradox. So, for practitioners of constructivism or practical geometry, the only way out was a compromise: construct an argument, but make it contain the constructivist idea. That idea is that mathematics is an inherent human function. For those interested in logical content, this is already so far afield that eyes glaze over. And it was never seen to be relevant to relativity, because no one was able to say how Einstein used practical geometry as a technique in constructing an argument. "Geometry and Experience" was seen to be a bunch of genial generalities with no relevance to relativity. Why were people unable to understand where Einstein used "practical geometry"? Because, I think, we share so much of constructivist mathematical thinking that we are blind to its presence in arguments. In any event, you ought to know that Einstein DID use practical geometry in developing the relativity of simultaneity. Whatever else you may now argue regarding the relativity of simultaneity, you can no longer ignore the constructivist mathematics in it--that, now, HAS to be taken into account. There is an historical sidetrack to this: Einstein's use of constructivist math is in "disguised" form in the 1905 paper. So, I think intentionally, he made it explicit in the "train experiment." If you notice, the train experiment and the clock experiments are the same experiment: they can be translated mechanically, one into the other. Thus, the constructivist term Einstein inserted into the train experiment is also present in the clock experiment. Remember, that in doing this, he intentionally deprived the argument of logical content, because he felt he had to do so. If YOU feel that one must do so, this will not bother you. If you insist on logical content in your argument, it will bother you A LOT. So it's really a matter of taste, and not one for debate. As the paper below says, at one stage of the argument, point M is said to "naturally" (fallt zwar...zusammen" in the original German) coincide with point M'. (By the way, close readers of this text--translators--have realized that this was a conceptual anomaly: they treat it differently in the French and Italian translations of RELATIVITY). The logical problem with this notion is as follows: 1. if you drop the term, and M and M' coincide in traditional Euclidean fashion, you are led to the contradiction of assuming two Cartesian coordinate systems and deducing one such system (I leave the proof of this to you). So M and M' cannot coincide in a Euclidean way: that much cannot, I think, be contested and no one has ever argued that they could so coincide and that Einstein was saying that they did so coincide. At least, I haven't seen any such contentions. 2. if you retain the term, you find that it is not part of the formulation of the relativity of simultaneity. It is not a definition, an assumption, a principle, a deduction or anything else. You will look in vain for the logical role it plays in the argument. It doesn't play any at all. It simply rattles around in the argument--a loose cannon on deck. So what is it? It is what Einstein always meant it to be: it is an arbitrary insertion into the argument, made necessary--according to his approach of "practical geometry"--in order for the argument to avoid paradox. So Einstein did exactly what he wanted to do. However, I think we have had an unconscious prejudice against the lack of logical content, so we never wanted to think that that's what he wanted to do, or did do. But that's not taking Einstein seriously. I suggest you take him seriously--at least do him that courtesy, if you are going to pay any attention to what he says. By the way, are there any paradoxes? That is, was there anything for Einstein to worry about? No. Not even Zeno's paradox has stood up to analysis. The "logical" compulsion we feel with respect to the paradoxes so far proposed, is an artifact of their construction--it's their rhetoric--it is not a result of logical content in these arguments. They have none. Too bad, because they are very seductive. But that's the way it is. This is where the new set theory history is making all kinds of contributions. Particularly Garciadiego is devastating with his care with respect to the history and the terms, showing that Richard didn't even consider his argument a paradox, that there is no Cantor paradox, no Russell paradox, and so on. They are glib sleights of hand which do not stand up historically or logically. So you really have to do some more work understanding the history of math. Another thing which is being revealed by new work into Einstein, is how little he probed into contemporary set theory debates. He never criticized anything Poincare said about those debates, although particularly Grattan- Guinness is scathing in his discussion of Poincare. Einstein didn't really know anything about the set theory which set him off on his mathematical approach. Very remarkable, I think--very eye-opening. Einstein is not alone in the sloppiness with which he approached the mathematical foundation of his argument. The Fefermans and other commentators are amazingly critical of Godel in their remarks in the collected works, regarding his understanding of set theory debates. We tend to think of these twentieth-century mandarins as close students, as scrupulous thinkers. It turns out that they were slobs. And of course, Cantor has been subjected to recent research which is even more embarrassing for his work than the many longstanding critiques. Again, there's more to the background of constructivism than the set theory debates. And it has had an influence far beyond Einstein. You find it in Darwin, Godel, Sraffa, really everywhere. It has stood in the way of logic for a long long time. Finally, you should consider where "natural" coincidence leaves us. If we can't get to general relativity because of "natural" coincidence, then that means that once again the Pythagorean theorem is at issue (it was a resolved issue under general relativity, for reasons you know). Does the Pythagorean theorem have logical content? My feeling is, no. I think it also has a "natural" coincidence in it. But where? Ryskamp, John Henry, "Paradox, Natural Mathematics, Relativity and Twentieth- Century Ideas" (June 17, 2008). Available at SSRN: http://ssrn.com/abstract=897085 |
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On Aug 6, 6:40*pm, jrysk wrote:
On Aug 6, 3:11*pm, Pentcho Valev wrote: http://cosmo.fis.fc.ul.pt/~crawford/...ein-relativity... John Stachel: "But here he ran into the most blatant-seeming contradiction, which I mentioned earlier when first discussing the two principles. As noted then, the Maxwell-Lorentz equations imply that there exists (at least) one inertial frame in which the speed of light is a constant regardless of the motion of the light source. Einstein's version of the relativity principle (minus the ether) requires that, if this is true for one inertial frame, it must be true for all inertial frames. But this seems to be nonsense. How can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam? Einstein states that he wrestled with this problem over a lengthy period of time, to the point of despair. We have no details of this struggle, unfortunately. Finally, after a day spent wrestling once more with the problem in the company of his friend and patent office colleague Michele Besso, the only person thanked in the 1905 SRT paper, there came a moment of crucial insight. (...) I shall not rehearse Einstein's arguments here, but it led to the radically novel idea that, once one physically defines simultaneity of two distant events relative to one inertial frame of reference, it by no means follows that these two events will be simultaneous when the same definition is used relative to another inertial frame moving with respect to the first. It is not logically excluded that they are simultaneous relative to all inertial frames. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while simultaneity is different with respect to different inertial frames; this is also logically quite consistent." In 1905 Einstein still did not know that a 80m long pole can be trapped inside a 40m long barn when individuals similar to Einstein forget to reopen the doors of the barn "pretty quickly": http://www.math.ucr.edu/home/baez/ph...barn_pole.html "These are the props. You own a barn, 40m long, with automatic doors at either end, that can be opened and closed simultaneously by a switch. You also have a pole, 80m long, which of course won't fit in the barn....So, as the pole passes through the barn, there is an instant when it is completely within the barn. At that instant, you close both doors simultaneously, with your switch. Of course, you open them again pretty quickly, but at least momentarily you had the contracted pole shut up in your barn." If Einstein had known this breathtaking story, he could have used it to vindicate the outcome of his painful wrestling (instead of referring to the relativity of simultaneity) so much later John Stachel would have written: John Stachel: "It is not logically excluded that the 80m long pole cannot be trapped inside the 40m long barn, even if Einsteinians forget to reopen the doors of the barn pretty quickly. If we make that assumption, we are led back to Newtonian kinematics and the usual velocity addition law, which is logically quite consistent. However, if we adopt the two Einstein principles, then we are led to a new kinematics of time and space, in which the velocity of light is a universal constant, while any time Einsteinians forget to reopen the doors of the barn pretty quickly, the 80m long pole remains safely trapped inside the 40m long barn; this is also logically quite consistent." Pentcho Valev Your problem is that you don't have any historical context in which to place the development of the relativity of simultaneity. *If you did, you would know what the problem is with it. *Instead, having read your papers over the years, I can tell you that you go over the same ground over and over again, never understanding the issues with which you are dealing. *It's really sad. *Neither does Stachel (or Howard) have any understanding of the history of constructivist math. So it's like listening to two madmen talking to each other, you and your opponents. *You don't know what you're talking about, and they don't know what they are talking about. But I do. *Here it is: We are in the midst of a renaissance in the historiography of set theory. Above all, I recommend A. Garciadiego, BERTRAND RUSSELL AND THE ORIGINS OF THE SET-THEORETIC 'PARADOXES,' but there's also Grattan-Guinness and Ferreiros, discussed in the paper linked below. Here is the central issue in the understanding of the relativity of simultaneity: Einstein used a mathematical approach which he called "practical geometry." He thought the formulation of this point of view was his crowning achievement, and thought very highly of the lecture in which you can read his discussion of it, "Geometry and Experience." *I recommend it. Today this mathematical point of view is called constructivism or natural mathematics, and in his day it had three branches: intuitionism, logicism and formalism. So you have to understand, first, that Einstein expressed the relativity of simultaneity in practical geometry. *I don't see any acknowledgment of that in this chain of remarks. *If you want to understand what he said, you have to understand the issues which were important to him. From Poincare (SCIENCE AND HYPOTHESIS), but also from the long tradition of natural mathematics stretching back to Aristotle's concern over the "paradox" of Zeno, he adopted the idea that all argumentation leads inevitably to paradox. *This is certainly the gist of the response to Cantorian set theory, hence the fame of the supposed set-theoretic 'paradoxes.' The most important result of this concern was the idea that there is no such thing as logical content: arguments, if expressed in a certain way, can approach logical content but can never actually contain it, because, again, argumentation necessarily leads to paradox. So, for practitioners of constructivism or practical geometry, the only way out was a compromise: construct an argument, but make it contain the constructivist idea. *That idea is that mathematics is an inherent human function. For those interested in logical content, this is already so far afield that eyes glaze over. *And it was never seen to be relevant to relativity, because no one was able to say how Einstein used practical geometry as a technique in constructing an argument. *"Geometry and Experience" was seen to be a bunch of genial generalities with no relevance to relativity. *Why were people unable to understand where Einstein used "practical geometry"? Because, I think, we share so much of constructivist mathematical thinking that we are blind to its presence in arguments. In any event, you ought to know that Einstein DID use practical geometry in developing the relativity of simultaneity. *Whatever else you may now argue regarding the relativity of simultaneity, you can no longer ignore the constructivist mathematics in it--that, now, HAS to be taken into account. There is an historical sidetrack to this: Einstein's use of constructivist math is in "disguised" form in the 1905 paper. So, I think intentionally, he made it explicit in the "train experiment." *If you notice, the train experiment and the clock experiments are the same experiment: they can be translated mechanically, one into the other. Thus, the constructivist term Einstein inserted into the train experiment is also present in the clock experiment. Remember, that in doing this, he intentionally deprived the argument of logical content, because he felt he had to do so. *If YOU feel that one must do so, this will not bother you. *If you insist on logical content in your argument, it will bother you A LOT. *So it's really a matter of taste, and not one for debate. As the paper below says, at one stage of the argument, point M is said to "naturally" (fallt zwar...zusammen" in the original German) coincide with point M'. *(By the way, close readers of this text--translators--have realized that this was a conceptual anomaly: they treat it differently in the French and Italian translations of RELATIVITY). The logical problem with this notion is as follows: 1. *if you drop the term, and M and M' coincide in traditional Euclidean fashion, you are led to the contradiction of assuming two Cartesian coordinate systems and deducing one such system (I leave the proof of this to you). So M and M' cannot coincide in a Euclidean way: that much cannot, I think, be contested and no one has ever argued that they could so coincide and that Einstein was saying that they did so coincide. *At least, I haven't seen any such contentions. 2. *if you retain the term, you find that it is not part of the formulation of the relativity of simultaneity. *It is not a definition, an assumption, a principle, a deduction or anything else. *You will look in vain for the logical role it plays in the argument. *It doesn't play any at all. It simply rattles around in the argument--a loose cannon on deck. So what is it? *It is what Einstein always meant it to be: it is an arbitrary insertion into the argument, made necessary--according to his approach of "practical geometry"--in order for the argument to avoid paradox. *So Einstein did exactly what he wanted to do. *However, I think we have had an unconscious prejudice against the lack of logical content, so we never wanted to think that that's what he wanted to do, or did do. *But that's not taking Einstein seriously. *I suggest you take him seriously--at least do him that courtesy, if you are going to pay any attention to what he says. By the way, are there any paradoxes? *That is, was there anything for Einstein to worry about? *No. *Not even Zeno's paradox has stood up to analysis. *The "logical" compulsion we feel with respect to the paradoxes so far proposed, is an artifact of their construction--it's their rhetoric--it is not a result of logical content in these arguments. *They have none. *Too bad, because they are very seductive. *But that's the way it is. This is where the new set theory history is making all kinds of contributions. Particularly Garciadiego is devastating with his care with respect to the history and the terms, showing that Richard didn't even consider his argument a paradox, that there is no Cantor paradox, no Russell paradox, and so on. They are glib sleights of hand which do not stand up historically or logically. So you really have to do some more work understanding the history of math. Another thing which is being revealed by new work into Einstein, is how little he probed into contemporary set theory debates. *He never criticized anything Poincare said about those debates, although particularly Grattan- Guinness is scathing in his discussion of Poincare. *Einstein didn't really know anything about the set theory which set him off on his mathematical approach. *Very remarkable, I think--very eye-opening. Einstein is not alone in the sloppiness with which he approached the mathematical foundation of his argument. *The Fefermans and other commentators are amazingly critical of Godel in their remarks in the collected works, regarding his understanding of set theory debates. We tend to think of these twentieth-century mandarins as close students, as scrupulous thinkers. *It turns out that they were slobs. And of course, Cantor has been subjected to recent research which is even more embarrassing for his work than the many longstanding critiques. Again, there's more to the background of constructivism than the set theory debates. *And it has had an influence far beyond Einstein. *You find it in Darwin, Godel, Sraffa, really everywhere. *It has stood in the way of logic for a long long time. Finally, you should consider where "natural" coincidence leaves us. If we can't get to general relativity because of "natural" coincidence, then that means that once again the Pythagorean theorem is at issue (it was a resolved issue under general relativity, for reasons you know). *Does the Pythagorean theorem have logical content? My feeling is, no. *I think it also has a "natural" coincidence in it. *But where? *Ryskamp, John Henry, "Paradox, Natural Mathematics, Relativity and Twentieth- Century Ideas" (June 17, 2008). Available at SSRN:http://ssrn.com/abstract=897085 xxein: I didn't order a word salad. Just give me a broiled lobster with butter. Maybe you don't understand --- which is why you are confused with Pathagoras. Euclidean and Minkowski spaces have no real effect on it. Neither does SR. But GR does. All your talking about math, logic, constructivism and all the other terms you think you know about, have no effect on how the physic works. If GR was truly SR compliant in principle there would be no GR. GR cannot be compliant, but that doesn't make it correct either. It is simply a derived math to explain what we see --- NOT a description of the workings of the physic. That is attempted by the other theories though. Notably Q's and Strings. But they have failed in each of their own respects also. OK. You may deem me guilty of word salad if you want, and I am deliberately NOT clear with it. There is a reason for that. All you egg-heads have had a chance to guess what the physic is and you still follow a herd instinct. I've heard of a few coming close but you trodded them down. Well, I can't lay a complete blame for that. After all, they missed. I was already in a position to realize that at the time. I'm certainly no god, but I do know something. Not in a perfect way (I already know that --- no TOE here), but apparently beyond the current genre of how to think about it. Despite all you might imagine about how goofy I sound, it is all just closer to the physic. When I started (about 23 yrs-ago), I was 24-7. That was just for Lorentz-SR. Solved from scratch. GR and gravity required a rethink. Iow, I had the chance of just accepting it or relying on my proven logic to figure it out from scratch. I knew I had to go the latter course. I went dormant for a while and actually gave it up three times until a thought occurred to me. A stupid thought that had no chance of working. But I tested it out, anyway. Test 1 passed. Test 2 passed. Test 3 passed. Test n+1 passed. It passes all known phenomenae that we can measure including BH's and the Pioneer anomaly --- except that it doesn't quite get down to the Q level, but that is primarily because gravity seems to vanish there. I'm working on it though. I don't see anybody else coming close. Did I just have a lucky guess? If I did, it works extremely well. Try guessing some more, rather than running with the herd. |
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