swansont Posted May 14, 2005 Posted May 14, 2005 [indent']It would be a neat trick to have the beam reflact back to the laser source.[/indent] It is a neat trick. The opposite has been done with corner reflector cubes on the moon, but over such a large distance the laser spot gets pretty big.
geistkiesel Posted May 14, 2005 Posted May 14, 2005 You accept the consistency of the math' date=' but not the experimental results? Or not the physical interpretation?[/quote'] I will assume the math is as you say, but I see no real physical connection. In fact I see that the statement effectively negates the concept of motion. In the sense that if you are on a train that accelerated and therefore was in a state of motion wrt the embankment, thagtdid not accelerate and you assume yourself in a state of rest (using the equivalence of inertial frames postulate) and the embankment moving at your initial speed, you have effectively negated your own speed. And more, you have created two impiossibile physical conditions that can never be produced (and therefore cannot be used to verify SRT assumptiosn): You have generated speed in the embankment, and you have negated the motion of the train. My objections to SRT are nmore than philosophical. Is it not true that all observed relative motion with earthbound objects and the earth are generated by the acceleration of the object only, and that never is the earth accelerated to generate realtive motion of earthframe anad earthbound object? The acceleration of one of the "twins" in the twin paradox was used to rationalize the lack of reciprocity in that using SRT and the equivalence postutlate one may equally say that either twin aged faster than the other. To me that was an admission of of the weakness of SRT. The equivalence postulate flows from the claim that the relative speed of light is the same when measured from all inertial frames, which effectivley negates the speed of all inertial frames. It may not seem like that mathematically, but physically this is what SRT is doing. One never sees much discussion that the the speed of light stratement is directed at the relative speed of light wrt frame and photon. When mweasuring the sopeed of light firectly wrt v = 0, the constancy of the speed of light will alwaqyas measure c, which is what the mathematics does in describing the measure of the relative motion of frrame and photon.
swansont Posted May 14, 2005 Posted May 14, 2005 I will assume the math is as you say' date=' but I see no real physical connection. In fact I see that the statement effectively negates the concept of motion. In the sense that if you are on a train that accelerated and therefore was in a state of motion wrt the embankment, thagtdid not accelerate and you assume yourself in a state of rest (using the equivalence of inertial frames postulate) and the embankment moving at your initial speed, you have effectively negated your own speed. And more, you have created two impiossibile physical conditions that can never be produced (and therefore cannot be used to verify SRT assumptiosn): You have generated speed in the embankment, and you have negated the motion of the train. My objections to SRT are nmore than philosophical. Is it not true that all observed relative motion with earthbound objects and the earth are generated by the acceleration of the object only, and that never is the earth accelerated to generate realtive motion of earthframe anad earthbound object? The acceleration of one of the "twins" in the twin paradox was used to rationalize the lack of reciprocity in that using SRT and the equivalence postutlate one may equally say that either twin aged faster than the other. To me that was an admission of of the weakness of SRT. The equivalence postulate flows from the claim that the relative speed of light is the same when measured from all inertial frames, which effectivley negates the speed of all inertial frames. It may not seem like that mathematically, but physically this is what SRT is doing. [/quote'] Yes, it's a limitation of SRT - it doesn't account for acceleration. It explicity says that it's for inertial frames. Get over it already. That's why Einstein went ahead and developed the general theory.
J.C.MacSwell Posted May 15, 2005 Posted May 15, 2005 I will assume the math is as you say' date=' but I see no real physical connection. In fact I see that the statement effectively negates the concept of motion. In the sense that if you are on a train that accelerated and therefore was in a state of motion wrt the embankment, thagtdid not accelerate and you assume yourself in a state of rest (using the equivalence of inertial frames postulate) and the embankment moving at your initial speed, you have effectively negated your own speed. And more, you have created two impiossibile physical conditions that can never be produced (and therefore cannot be used to verify SRT assumptiosn): You have generated speed in the embankment, and you have negated the motion of the train..[/quote'] How is any of this different in principle from Galilean transformations? (or any other frames of reference) When I switch reference frames I am not physically changing anything. If I look at a closed system, that does not include you, do you disappear? Have I physically negated you?
geistkiesel Posted May 15, 2005 Posted May 15, 2005 It is a neat trick. The opposite has been done with corner reflector cubes on the moon, but over such a large distance the laser spot gets pretty big. Yes, as I remember 15 km sounds like the order of magnitude of the beam width, striking the moon, still a neat trick to hit the targets approxiinmately 1 square meter.
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