Einstein "borrowed" the constant-speed-of-light falsehood from the nonexistent ether and convinced the world that it is a non-negotiable truth. The falsehood became a Procrustean bed to which physics was made to fit:

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

"At a time when other scientists believed that the speed of light was variable, Einstein took it as a fixed limit of nature and made it the absolute non-negotiable around which all other variables and parameters enfolded."
https://www.brainpickings.org/2019/0...ng-relativity/

The texts below suggest that, if the speed of light is variable (it is!), fundamental physics, entirely predicated on Einstein's constant-speed-of-light falsehood, is long dead (exists as a farce or ideology):

"The speaker Joao Magueijo, is a Reader in Theoretical Physics at Imperial College, London and author of Faster Than the Speed of Light: The Story of a Scientific Speculation. He opened by explaining how Einstein's theory of relativity is the foundation of every other theory in modern physics and that the assumption that the speed of light is constant is the foundation of that theory. Thus a constant speed of light is embedded in all of modern physics and to propose a varying speed of light (VSL) is worse than swearing! It is like proposing a language without vowels." http://www.thegreatdebate.org.uk/VSLRevPrnt.html

"The whole of physics is predicated on the constancy of the speed of light," Joao Magueijo, a cosmologist at Imperial College London and pioneer of the theory of variable light speed, told Motherboard. "So we had to find ways to change the speed of light without wrecking the whole thing too much." https://motherboard.vice.com/en_us/a...t-speed-slowed

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