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EINSTEIN'S POSTULATES AND THEIR CONSEQUENCES
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Pentcho Valev
May 30, 2014, 9:29:08 AM5/30/14
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http://motls.blogspot.com/2006/12/lorentz-violation-and-deformed-special.html
Lubos Motl: "The second postulate of special relativity morally follows from the first one once you promote the value of the speed of light to a law of physics which is what Einstein did."
http://webs.morningside.edu/slaven/Physics/relativity/relativity3.html
Dave Slaven: "Einstein's first postulate seems perfectly reasonable. And his second postulate follows very reasonably from his first. How strange that the consequences will seem so unreasonable."
Does the second postulate follow "morally" or "very reasonably" from the first one? Why do the consequences "seem so unreasonable"?
Pentcho Valev
Lubos Motl: "The second postulate of special relativity morally follows from the first one once you promote the value of the speed of light to a law of physics which is what Einstein did."
http://webs.morningside.edu/slaven/Physics/relativity/relativity3.html
Dave Slaven: "Einstein's first postulate seems perfectly reasonable. And his second postulate follows very reasonably from his first. How strange that the consequences will seem so unreasonable."
Does the second postulate follow "morally" or "very reasonably" from the first one? Why do the consequences "seem so unreasonable"?
Pentcho Valev
Pentcho Valev
May 30, 2014, 10:01:11 AM5/30/14
to
One of the consequences that "seem so unreasonable" is length contraction. Originally it was interpreted in terms of deformation of rigid bodies in motion resulting from possible effects of the motion on intermolecular forces:
http://en.wikipedia.org/wiki/Lorentz_ether_theory
"Based on that result and to bring the hypothesis of an immobile ether in accordance with the Michelson-Morley experiment, George FitzGerald in 1889 (qualitatively) and independently of him Lorentz in 1892 (already quantitatively) suggested that not only the electrostatic fields, but also the molecular forces are affected in such a way that the dimension of a body in the line of motion is less by the value v^2/(2c^2) than the dimension perpendicularly to the line of motion. However, an observer co-moving with the earth would not notice this contraction, because all other instruments contract at the same ratio."
http://arxiv.org/pdf/gr-qc/0104032
"Both FitzGerald and Lorentz were clearly aware that the deformation hypothesis required some degree of theoretical underpinning if it were not to be dismissed as blatant trickery, or at least entirely ad hoc. Independently, they appealed to the possible effects of motion (relative to the ether) on the forces holding the molecules of rigid bodies in equilibrium, in analogy with the corresponding effect on 'electric' forces."
In Einstein's special relativity "bodies" are not the only ones that contract; distances between them contract as well. This leads to a blatant absurdity which is absent if length contraction is explained in terms of intermolecular forces. Let us imagine that the ants scattered on the rectangular line are initially at rest but then start travelling along the line at 87% the speed of light:
http://www.wpclipart.com/page_frames/animal/ant/ant_border_rectangle_portrait.png
According to special relativity, lengths of travelling ants and distances between them decrease twice (as judged from the system at rest). Therefore, insofar as the length of the sides of the rectangle is fixed in the system at rest, the number of travelling ants on the whole rectangular line must be twice as great as that of ants at rest. Needless to say, this last conclusion is absurd. Since it is a logical consequence of Einstein's 1905 constant-speed-of-light postulate, we have reductio ad absurdum: the postulate is false. The speed of light (relative to the observer) does vary with the speed of the emitter, as established by Newton's emission theory of light.
Pentcho Valev
http://en.wikipedia.org/wiki/Lorentz_ether_theory
"Based on that result and to bring the hypothesis of an immobile ether in accordance with the Michelson-Morley experiment, George FitzGerald in 1889 (qualitatively) and independently of him Lorentz in 1892 (already quantitatively) suggested that not only the electrostatic fields, but also the molecular forces are affected in such a way that the dimension of a body in the line of motion is less by the value v^2/(2c^2) than the dimension perpendicularly to the line of motion. However, an observer co-moving with the earth would not notice this contraction, because all other instruments contract at the same ratio."
http://arxiv.org/pdf/gr-qc/0104032
"Both FitzGerald and Lorentz were clearly aware that the deformation hypothesis required some degree of theoretical underpinning if it were not to be dismissed as blatant trickery, or at least entirely ad hoc. Independently, they appealed to the possible effects of motion (relative to the ether) on the forces holding the molecules of rigid bodies in equilibrium, in analogy with the corresponding effect on 'electric' forces."
In Einstein's special relativity "bodies" are not the only ones that contract; distances between them contract as well. This leads to a blatant absurdity which is absent if length contraction is explained in terms of intermolecular forces. Let us imagine that the ants scattered on the rectangular line are initially at rest but then start travelling along the line at 87% the speed of light:
http://www.wpclipart.com/page_frames/animal/ant/ant_border_rectangle_portrait.png
According to special relativity, lengths of travelling ants and distances between them decrease twice (as judged from the system at rest). Therefore, insofar as the length of the sides of the rectangle is fixed in the system at rest, the number of travelling ants on the whole rectangular line must be twice as great as that of ants at rest. Needless to say, this last conclusion is absurd. Since it is a logical consequence of Einstein's 1905 constant-speed-of-light postulate, we have reductio ad absurdum: the postulate is false. The speed of light (relative to the observer) does vary with the speed of the emitter, as established by Newton's emission theory of light.
Pentcho Valev
Pentcho Valev
May 30, 2014, 1:45:40 PM5/30/14
to
According to special relativity, if a single moving clock successively passes multiple synchronized clocks which are stationary, observers in both frames see that the difference between the reading of the stationary clock just being passed and that of the moving clock increases with the number of stationary clocks passed (in this sense the moving clock runs slower than the stationary clocks):
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/Reciprocity/index.html
John Norton: The figure shows the bare essentials of the moving clock and all the other clocks spread out through space. The moving clock agrees with the reading of the leftmost clock--my wristwatch--as it passes by. However when it passes the rightmost, it now reads much less:
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/Reciprocity/clocks.gif
Special relativity also says that the single clock can be regarded as stationary and the multiple synchronized clocks as moving - again, the single (stationary) clock runs slower than the multiple (moving) clocks. This leads to an absurdity:
Let us assume that the ants moving along the rectangular line are travelling at 87% the speed of light:
http://www.wpclipart.com/page_frames/animal/ant/ant_border_rectangle_portrait.png
From what was said above, a single stationary ant watching its brothers go by at 87% the speed of light ages half as fast as them. According to the original twin paradox scenario, however, the single stationary ant must age faster than the moving ants.
Clearly we have reductio ad absurdum which means that the underlying postulate, the principle of constancy of the speed of light, is false. The speed of light (relative to the observer) does vary with the speed of the emitter, as established by Newton's emission theory of light.
Pentcho Valev
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/Reciprocity/index.html
John Norton: The figure shows the bare essentials of the moving clock and all the other clocks spread out through space. The moving clock agrees with the reading of the leftmost clock--my wristwatch--as it passes by. However when it passes the rightmost, it now reads much less:
http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/Reciprocity/clocks.gif
Special relativity also says that the single clock can be regarded as stationary and the multiple synchronized clocks as moving - again, the single (stationary) clock runs slower than the multiple (moving) clocks. This leads to an absurdity:
Let us assume that the ants moving along the rectangular line are travelling at 87% the speed of light:
http://www.wpclipart.com/page_frames/animal/ant/ant_border_rectangle_portrait.png
From what was said above, a single stationary ant watching its brothers go by at 87% the speed of light ages half as fast as them. According to the original twin paradox scenario, however, the single stationary ant must age faster than the moving ants.
Clearly we have reductio ad absurdum which means that the underlying postulate, the principle of constancy of the speed of light, is false. The speed of light (relative to the observer) does vary with the speed of the emitter, as established by Newton's emission theory of light.
Pentcho Valev
Pentcho Valev
Jun 9, 2014, 3:01:11 PM6/9/14
to
http://www.amazon.com/Time-Reborn-Crisis-Physics-Universe/dp/0547511728
"Was Einstein wrong? At least in his understanding of time, Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas..."
http://www.guardian.co.uk/books/2013/jun/10/time-reborn-farewell-reality-review
Philip Ball: "Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says Smolin."
Both Lee Smolin (called "the new Einstein") and Philip Ball know that the special relativistic time is a consequence of Einstein's 1905 two postulates so if the consequence is "dead wrong", at least one of the postulates must be false. Yet, if asked, both Smolin and Ball would declare, and Einsteinians all over the world would wholeheartedly agree, that "the postulates and their consequences are then checked experimentally and, so far, they hold remarkably well":
http://www.independent.com/news/2013/apr/17/time-reborn/
QUESTION: Setting aside any other debates about relativity theory for the moment, why would the speed of light be absolute? No other speeds are absolute, that is, all other speeds do indeed change in relation to the speed of the observer, so it's always seemed a rather strange notion to me.
LEE SMOLIN: Special relativity works extremely well and the postulate of the invariance or universality of the speed of light is extremely well-tested. It might be wrong in the end but it is an extremely good approximation to reality.
QUESTION: So let me pick a bit more on Einstein and ask you this: You write (p. 56) that Einstein showed that simultaneity is relative. But the conclusion of the relativity of simultaneity flows necessarily from Einstein's postulates (that the speed of light is absolute and that the laws of nature are relative). So he didn't really show that simultaneity was relative - he assumed it. What do I have wrong here?
LEE SMOLIN: The relativity of simultaneity is a consequence of the two postulates that Einstein proposed and so it is deduced from the postulates. The postulates and their consequences are then checked experimentally and, so far, they hold remarkably well.
Pentcho Valev
"Was Einstein wrong? At least in his understanding of time, Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas..."
http://www.guardian.co.uk/books/2013/jun/10/time-reborn-farewell-reality-review
Philip Ball: "Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says Smolin."
Both Lee Smolin (called "the new Einstein") and Philip Ball know that the special relativistic time is a consequence of Einstein's 1905 two postulates so if the consequence is "dead wrong", at least one of the postulates must be false. Yet, if asked, both Smolin and Ball would declare, and Einsteinians all over the world would wholeheartedly agree, that "the postulates and their consequences are then checked experimentally and, so far, they hold remarkably well":
http://www.independent.com/news/2013/apr/17/time-reborn/
QUESTION: Setting aside any other debates about relativity theory for the moment, why would the speed of light be absolute? No other speeds are absolute, that is, all other speeds do indeed change in relation to the speed of the observer, so it's always seemed a rather strange notion to me.
LEE SMOLIN: Special relativity works extremely well and the postulate of the invariance or universality of the speed of light is extremely well-tested. It might be wrong in the end but it is an extremely good approximation to reality.
QUESTION: So let me pick a bit more on Einstein and ask you this: You write (p. 56) that Einstein showed that simultaneity is relative. But the conclusion of the relativity of simultaneity flows necessarily from Einstein's postulates (that the speed of light is absolute and that the laws of nature are relative). So he didn't really show that simultaneity was relative - he assumed it. What do I have wrong here?
LEE SMOLIN: The relativity of simultaneity is a consequence of the two postulates that Einstein proposed and so it is deduced from the postulates. The postulates and their consequences are then checked experimentally and, so far, they hold remarkably well.
Pentcho Valev
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