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| Tags: contraction, length, testing |
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Tom Roberts wrote in message . com...
Harry wrote: I still wonder how real and unreal these things are in the Einsteinian interpretation. In SR, no rod "contracts" in any way due to its velocity relative to any inertial frame; similarly no clock "dilates" in any way due to its velocity relative to any inertial frame. Just think about it -- since all inertial frames have equal standing, and there are an infinite number of them moving with different velocitites, how could a rod or clock possible "change" due to any such relative velocity? In SR what changes is the relationship between the rod or clock and the various inertial frames. Measurements in each inertial frame, of course, depend on that relationship, and this leads to "length contraction" and "time dilation". As the observer in S measures the rod belonging to S' short, he may also decide to catch it by projecting, simultaneously in S, two barriers just in front and behind the rod. The distance between the barriers in S is shorter than the length of the rod in S' but catching must be successful - otherwise it would be a lie that the observer in S measures the rod short. On the other hand, catching cannot be successful for obvious reasons. The conclusion is that it is a lie that the observer in S measures the rod short. Pentcho Valev |
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"Pentcho Valev" wrote in message om... Tom Roberts wrote in message . com... Harry wrote: I still wonder how real and unreal these things are in the Einsteinian interpretation. In SR, no rod "contracts" in any way due to its velocity relative to any inertial frame; similarly no clock "dilates" in any way due to its velocity relative to any inertial frame. Just think about it -- since all inertial frames have equal standing, and there are an infinite number of them moving with different velocitites, how could a rod or clock possible "change" due to any such relative velocity? In SR what changes is the relationship between the rod or clock and the various inertial frames. Measurements in each inertial frame, of course, depend on that relationship, and this leads to "length contraction" and "time dilation". As the observer in S measures the rod belonging to S' short, he may also decide to catch it by projecting, simultaneously in S, two barriers just in front and behind the rod. The distance between the barriers in S is shorter than the length of the rod in S' but catching must be successful - otherwise it would be a lie that the observer in S measures the rod short. On the other hand, catching cannot be successful for obvious reasons. The conclusion is that it is a lie that the observer in S measures the rod short. Pentcho Valev We only have to show one possible way that it can work, to invalidate your claim. I'll leave it to Tom Roberts or someone else to give you the Einstein-Minkowski explanation. Here is the explanation of Lorentz-Poincare, who assumed length contraction and time dilation, and that matter is a kind of wave phenomenon: - If S is at rest in the ether, S will correctly measure the contracted rod short and "catch" it. *In reality it's not "catching" but _crashing_ into the front barrier, with the rear barrier only used for measurement confirmation. - If S is moving with respect to the ether, "simultaneous" in S is erroneous (due to the mistake made about the light speed) in such a way that S measures the rod short - just as if S was not moving at all. The catching will be done asynchronous, so that the front crashes into the front barrier before the rear barrier is activated (the undeformable things that you have in your mind don't exist and can't exist). - Simple math shows that the same will be true for all intermediate situations. I hope you now _finally_ "got" it! Harald |
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#3
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Pentcho Valev wrote:
As the observer in S measures the rod belonging to S' short, he may also decide to catch it by projecting, simultaneously in S, two barriers just in front and behind the rod. The distance between the barriers in S is shorter than the length of the rod in S' but catching must be successful - otherwise it would be a lie that the observer in S measures the rod short. On the other hand, catching cannot be successful for obvious reasons. The conclusion is that it is a lie that the observer in S measures the rod short. That is too ambiguous -- the rod crashes into the barriers, and you have no way of understanding details. Let me modify it for clarity: In frame S, construct two doors in advance of the moving rod, set apart by the length of the rod measured in S; start with the front door closed and the rear door open. Just as the rod would crash into the closed front door, close the rear door and open the front door, simultaneously in S. This can only happen without either door smashing the rod if the rod "really has "its "contracted length" in frame S. The rod sails through without crashing into either door; at any time in S one of the doors is closed. An observer moving with the rod, of course, has a completely different view of this: the doors are closer together than the rod is long, but the front door opens before the rear door closes, so there is no collision between rod and either door -- the front door opens just as the front of the rod reaches it, both doors remain open for a period while the rod passes through both of them, and the rear door closes just as the rear end of the rod passes through. Tom Roberts |
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"Tom Roberts" wrote in message ... | Pentcho Valev wrote: | As the observer in S measures the rod belonging to S' short, he may | also decide to catch it by projecting, simultaneously in S, two | barriers just in front and behind the rod. The distance between the | barriers in S is shorter than the length of the rod in S' but catching | must be successful - otherwise it would be a lie that the observer in | S measures the rod short. On the other hand, catching cannot be | successful for obvious reasons. The conclusion is that it is a lie | that the observer in S measures the rod short. | | That is too ambiguous -- the rod crashes into the barriers, and you have | no way of understanding details. Let me modify it for clarity: | | In frame S, construct two doors in advance of the moving rod, set apart | by the length of the rod measured in S; start with the front door closed | and the rear door open. Just as the rod would crash into the closed | front door, close the rear door and open the front door, simultaneously | in S. This can only happen without either door smashing the rod if the | rod "really has "its "contracted length" in frame S. The rod sails | through without crashing into either door; at any time in S one of the | doors is closed. | | An observer moving with the rod, of course, has a completely different | view of this: "They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good". - Einstein. This same law of optics suggests that the moving observer has a completely different view the that of the stationary observer, according to Roberts (of course). The question is whether Roberts is giving us relativity according to Einstein or relativity acording to Roberts. Some of us are not as susceptible to Einstein's suggestions as Roberts is. Androcles. the doors are closer together than the rod is long, but | the front door opens before the rear door closes, so there is no | collision between rod and either door -- the front door opens just as | the front of the rod reaches it, both doors remain open for a period | while the rod passes through both of them, and the rear door closes just | as the rear end of the rod passes through. | | | Tom Roberts |
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#5
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Tom Roberts wrote in message ...
Pentcho Valev wrote: As the observer in S measures the rod belonging to S' short, he may also decide to catch it by projecting, simultaneously in S, two barriers just in front and behind the rod. The distance between the barriers in S is shorter than the length of the rod in S' but catching must be successful - otherwise it would be a lie that the observer in S measures the rod short. On the other hand, catching cannot be successful for obvious reasons. The conclusion is that it is a lie that the observer in S measures the rod short. That is too ambiguous -- the rod crashes into the barriers, and you have no way of understanding details. Let me modify it for clarity: In frame S, construct two doors in advance of the moving rod, set apart by the length of the rod measured in S; start with the front door closed and the rear door open. Just as the rod would crash into the closed front door, close the rear door and open the front door, simultaneously in S. This can only happen without either door smashing the rod if the rod "really has "its "contracted length" in frame S. The rod sails through without crashing into either door; at any time in S one of the doors is closed. You seem to have discovered the perfect strategy: any argument that demonstrates the contradictory nature of relativity is either "inherently" or "too" ambiguous. So, after your intervention, the theory's ambiguity goes to particular arguments whereas its essence remains unambiguous. However in this case the strategy does not work. There are two LEGITIMATE types of arguments in SR: ones presupposing a crash and ones not presupposing a crash. The former allow one to PROVE a contradiction in SR whereas the latter don't. If relativity priests had known how dangerous "crash" arguments are, they would have removed them from textbooks and confused everything so that now nobody would even suspect that such a problem might exist. Fortunately priests were not so clever. The contradiction described above is the result of reductio ad absurdum and in such cases the theory must be rejected. Pentcho Valev |
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#6
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"Pentcho Valev" wrote in message om... | Tom Roberts wrote in message ... | Pentcho Valev wrote: | As the observer in S measures the rod belonging to S' short, he may | also decide to catch it by projecting, simultaneously in S, two | barriers just in front and behind the rod. The distance between the | barriers in S is shorter than the length of the rod in S' but catching | must be successful - otherwise it would be a lie that the observer in | S measures the rod short. On the other hand, catching cannot be | successful for obvious reasons. The conclusion is that it is a lie | that the observer in S measures the rod short. | | That is too ambiguous -- the rod crashes into the barriers, and you have | no way of understanding details. Let me modify it for clarity: | | In frame S, construct two doors in advance of the moving rod, set apart | by the length of the rod measured in S; start with the front door closed | and the rear door open. Just as the rod would crash into the closed | front door, close the rear door and open the front door, simultaneously | in S. This can only happen without either door smashing the rod if the | rod "really has "its "contracted length" in frame S. The rod sails | through without crashing into either door; at any time in S one of the | doors is closed. | | You seem to have discovered the perfect strategy: any argument that | demonstrates the contradictory nature of relativity is either | "inherently" or "too" ambiguous. So, after your intervention, the | theory's ambiguity goes to particular arguments whereas its essence | remains unambiguous. However in this case the strategy does not work. | There are two LEGITIMATE types of arguments in SR: ones presupposing a | crash and ones not presupposing a crash. The former allow one to PROVE | a contradiction in SR whereas the latter don't. If relativity priests | had known how dangerous "crash" arguments are, they would have removed | them from textbooks and confused everything so that now nobody would | even suspect that such a problem might exist. Fortunately priests were | not so clever. The contradiction described above is the result of | reductio ad absurdum and in such cases the theory must be rejected. | | Pentcho Valev Almost perfect, Pentcho. His backup tactic is to ignore anything he doesn't like and then claim experiments 'prove' his assumptions. The Seven Deadly Sins of Special Relativity. For quotations following, reference: http://www.fourmilab.ch/etexts/einstein/specrel/www/ ("On the Electrodynamics of Moving Bodies" by Albert Einstein) 1) "light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body", a totally unproven assumption without any evidence to support it, and a great deal of evidence against it. 2) "In agreement with experience we further assume the quantity 2AB/(t'A-tA) = c to be a universal constant- the velocity of light in empty space.", an admitted assumption that is quite worthless when there is any relative motion between A and B, yet essential to the derivation of the remainder of Einstein's nonsense. 3) The equation ½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)) , the ½ of which is derived from 2) above and is tantamount to saying (1/3 + 2/3)/2 = 1/3. 4) The missing 0' from that equation, since x' = x-vt, hence 0' = 0-vt, and the equation should be ½[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)) at the very least. 5) The further assumption "IF we place x' = x-vt ... " without considering IF we place x' = x+vt, from which we derive (using Einstein's method) tau = (t+xv/c^2)/sqrt(1-v^2/c^2) xi = (x + vt)/sqrt(1-v^2/c^2)" -Paul B. Andersen 6) The statements "But the ray moves relatively to the initial point of k, when measured in the stationary system, with the velocity c-v..." and "It follows, further, that the velocity of light c cannot be altered by composition with a velocity less than that of light. For this case we obtain V = (c+w)/(1+w/c) = c." which are contradictory, the first being Galilean, the second being contrary to the vector addition of velocities, an axiom of a vector space. 7) The lack of a check to verify the theory is self-consistent by feeding the new PoR given in 6) into the equation given in 3) and finding a total failure. Check: (t1-t)/(t2-t)*[tau(-vt,0,0,t)+tau(-vt,0,0,t+x'/V+x'/V)] = tau(x',0,0,t+x'/V) The so-called "Lorentz transforms", which were aether dependent anyway, cannot be derived. Androcles. |
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