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WHY THE SPEED OF LIGHT IS NOT CONSTANT



 
 
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  #1  
Old October 10th 15, 07:51 PM posted to sci.astro
Pentcho Valev
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Default WHY THE SPEED OF LIGHT IS NOT CONSTANT

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Ethan Siegel: "In 1905, Einstein put forth his theory of special relativity, noting that the failed Michelson-Morley experiment and the phenomena of length contraction and time dilation would all be explained if the speed of light in a vacuum were a universal constant, c."

There were no "phenomena of length contraction and time dilation" that needed explanation. The pre-1905 versions of length contraction and time dilation were just absurdly-sounding ad hoc fabrications introduced to save the ether theory. The null result of the Michelson-Morley experiment did need to be explained, and the only reasonable explanation had been provided by Newton's emission theory of light predicting that the speed of light DEPENDS on the speed of the light source:

http://www.pitt.edu/~jdnorton/papers...nion_final.pdf
"These efforts were long misled by an exaggeration of the importance of one experiment, the Michelson-Morley experiment, even though Einstein later had trouble recalling if he even knew of the experiment prior to his 1905 paper. This one experiment, in isolation, has little force. Its null result happened to be fully compatible with Newton's own emission theory of light. Located in the context of late 19th century electrodynamics when ether-based, wave theories of light predominated, however, it presented a serious problem that exercised the greatest theoretician of the day."

http://www.amazon.ca/Introduction-re.../dp/B003YEIA3S
James H. Smith, "Introduction à la relativité", édition française dirigée par Jean-Marc Lévy-Leblond, pp. 39-41: "Si la lumière était un flot de particules mécaniques obéissant aux lois de la mécanique, il n'y aurait aucune difficulté à comprendre les résultats de l'expérience de Michelson-Morley.... Supposons, par exemple, qu'une fusée se déplace avec une vitesse (1/2)c par rapport à un observateur et qu'un rayon de lumière parte de son nez. Si la vitesse de la lumière signifiait vitesse des "particules" de la lumière par rapport à leur source, alors ces "particules" de lumière se déplaceraient à la vitesse c/2+c=(3/2)c par rapport à l'observateur. Mais ce comportement ne ressemble pas du tout à celui d'une onde, car les ondes se propagent à une certaine vitesse par rapport au milieu dans lequel elles se développent et non pas à une certaine vitesse par rapport à leur source. (...) Il nous faut insister sur le fait suivant: QUAND EINSTEIN PROPOSA QUE LA VITESSE DE LA LUMIÈRE SOIT INDÉPENDANTE DE CELLE DE LA SOURCE, IL N'EN EXISTAIT AUCUNE PREUVE EXPÉRIMENTALE."

https://fr.wikisource.org/wiki/Le_te..._contemporaine
Séance du 19 Octobre 1911, LE TEMPS, L'ESPACE ET LA CAUSALITÉ DANS LA PHYSIQUE MODERNE, Jean Perrin: "Il est remarquable qu'un retour à l'hypothèse de l'émission, en admettant que les particules lumineuses sont émises par chaque source avec une même vitesse par rapport à elle dans toutes les directions expliquerait, dans les conceptions de la Mécanique classique, le résultat négatif de l'expérience de Michelson et Morley quel que soit le mouvement d'ensemble du système. D'autre part les physiciens, en développant la théorie des ondulations au point de vue du principe de relativité, sont amenés à conclure que la lumière est inerte et probablement pesante. N'est-ce pas un retour vers l'ancienne théorie de l'émission ?"

http://philsci-archive.pitt.edu/1743/2/Norton.pdf
"In addition to his work as editor of the Einstein papers in finding source material, Stachel assembled the many small clues that reveal Einstein's serious consideration of an emission theory of light; and he gave us the crucial insight that Einstein regarded the Michelson-Morley experiment as evidence for the principle of relativity, whereas later writers almost universally use it as support for the light postulate of special relativity. Even today, this point needs emphasis. The Michelson-Morley experiment is fully compatible with an emission theory of light that CONTRADICTS THE LIGHT POSTULATE."

http://books.google.com/books?id=JokgnS1JtmMC
Relativity and Its Roots, Banesh Hoffmann, p.92: "There are various remarks to be made about this second principle. For instance, if it is so obvious, how could it turn out to be part of a revolution - especially when the first principle is also a natural one? Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether. If it was so obvious, though, why did he need to state it as a principle? Because, having taken from the idea of light waves in the ether the one aspect that he needed, he declared early in his paper, to quote his own words, that "the introduction of a 'luminiferous ether' will prove to be superfluous."

Pentcho Valev
  #2  
Old October 14th 15, 10:56 AM posted to sci.astro
Pentcho Valev
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Posts: 8,078
Default WHY THE SPEED OF LIGHT IS NOT CONSTANT

The Open University blatantly lying:

http://www.open.edu/openlearn/scienc...ory-relativity
The Open University: "In 1905, Einstein based a new theory on two principles. First, the law of physics appear the same to all observers. Second, he calculated that the speed of light - 186.000 miles per second ( 299,338 kilometers ) - is unchanging. Prior to Einstein, scientists believed that space was filled with luminiferous aether that would cause the speed of light to change depending on the relative motion of the source and the observer."

Lie 1: Einstein did not "calculate" that the speed of light is unchanging - rather, he borrowed his constant-speed-of-light postulate from the ether theory:

http://books.google.com/books?id=JokgnS1JtmMC
Relativity and Its Roots, Banesh Hoffmann, p.92: "There are various remarks to be made about this second principle. For instance, if it is so obvious, how could it turn out to be part of a revolution - especially when the first principle is also a natural one? Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether. If it was so obvious, though, why did he need to state it as a principle? Because, having taken from the idea of light waves in the ether the one aspect that he needed, he declared early in his paper, to quote his own words, that "the introduction of a 'luminiferous ether' will prove to be superfluous."

https://en.wikipedia.org/wiki/Lorentz_ether_theory
Albert Einstein: "...it is impossible to base a theory of the transformation laws of space and time on the principle of relativity alone. As we know, this is connected with the relativity of the concepts of "simultaneity" and "shape of moving bodies." To fill this gap, I introduced the principle of the constancy of the velocity of light, which I borrowed from H. A. Lorentz's theory of the stationary luminiferous ether..."

Lie 2: The luminiferous aether would NOT cause the speed of light to change depending on the relative motion of the source and the observer. It would cause the speed of light to vary only with the speed of the observer, NOT with the speed of the source.

Pentcho Valev
 




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