Did Einstein Know That the Speed of Light Is Variable?

[Pentcho Valev]

Yes, Einstein did know that the speed of light is variable. He knew that the Michelson-Morley experiment had proved variability as per Newton, but "resisted the temptation" to obey the truth. Then, in 1921, already a deity, Einstein proclaimed that the experiment had proved constancy of the speed of light.

"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." Banesh Hoffmann, Relativity and Its Roots, p.92 https://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768

"Emission theory, also called emitter theory or ballistic theory of light, was a competing theory for the special theory of relativity, explaining the results of the Michelson–Morley experiment of 1887...The name most often associated with emission theory is Isaac Newton. In his corpuscular theory Newton visualized light "corpuscles" being thrown off from hot bodies at a nominal speed of c with respect to the emitting object, and obeying the usual laws of Newtonian mechanics, and we then expect light to be moving towards us with a speed that is offset by the speed of the distant emitter (c ± v)." https://en.wikipedia.org/wiki/Emission_theory

The New York Times, April 19, 1921: "The special relativity arose from the question of whether light had an invariable velocity in free space, he [Einstein] said. The velocity of light could only be measured relative to a body or a co-ordinate system. He sketched a co-ordinate system K to which light had a velocity C. Whether the system was in motion or not was the fundamental principle. This has been developed through the researches of Maxwell and Lorentz, the principle of the constancy of the velocity of light having been based on many of their experiments. But did it hold for only one system? he asked. He gave the example of a street and a vehicle moving on that street. If the velocity of light was C for the street was it also C for the vehicle? If a second co-ordinate system K was introduced, moving with the velocity V, did light have the velocity of C here? When the light traveled the system moved with it, so it would appear that light moved slower and the principle apparently did not hold. Many famous experiments had been made on this point. Michelson showed that relative to the moving co-ordinate system K1, the light traveled with the same velocity as relative to K, which is contrary to the above observation. How could this be reconciled? Professor Einstein asked." https://ebay.com/itm/ALBERT-EINSTEIN-Lecture-on-SPEED-OF-LIGHT-Time-1st-Visit-to-US-1921-Newspaper/373400655156

Pentcho Valev https://twitter.com/pentcho_valev

[Pentcho Valev]

Einstein not only knew that the speed of light is variable - he was trying to base his theory on this fact:

John Norton: "Einstein could not see how to formulate a fully relativistic electrodynamics merely using his new device of field transformations. So he considered the possibility of modifying Maxwell's electrodynamics in order to bring it into accord with an emission theory of light, such as Newton had originally conceived. There was some inevitability in these attempts, as long as he held to classical (Galilean) kinematics. Imagine that some emitter sends out a light beam at c. According to this kinematics, an observer who moves past at v in the opposite direction, will see the emitter moving at v and the light emitted at c+v. This last fact is the defining characteristic of an emission theory of light: the velocity of the emitter is added vectorially to the velocity of light emitted...If an emission theory can be formulated as a field theory, it would seem to be unable to determine the future course of processes from their state in the present. As long as Einstein expected a viable theory of light, electricity and magnetism to be a field theory, these sorts of objections would render an emission theory of light inadmissible." http://www.pitt.edu/~jdnorton/papers/companion.pdf

As John Norton explains, c'=c+v is incompatible with the continuous-field model of light - the all-powerful supporters of the ether theory would have destroyed Einstein if he had adopted c'=c+v. So Einstein decided to betray the truth in order to have etherists on his side:

Albert Einstein: "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." https://en.wikipedia.org/wiki/Lorentz_ether_theory

A year before his death Einstein became honest and made a confession: It is "entirely possible" that the continuous-field model of light, with its false tenet, the constancy of the speed of light, has actually ruined physics:

Albert Einstein (1954): "I consider it entirely possible that physics cannot be based upon the field concept, that is on continuous structures. Then nothing will remain of my whole castle in the air, including the theory of gravitation, but also nothing of the rest of contemporary physics." John Stachel, Einstein from 'B' to 'Z', p. 151 https://www.amazon.com/Einstein-B-Z-John-Stachel/dp/0817641432

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