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I'm finding a lot of popular articles about the "exciting" possibility that the speed of light might be changing. However, I'm having no luck finding a good rebuttal. My general understanding is that variable speed of light theories aren't widely accepted, or worse, fringe theories. Can someone offer a rebuttal or point to a good reference?


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marked as duplicate by sammy gerbil, stafusa, Kyle Kanos, Chris, Jon Custer Feb 7 '18 at 3:09

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  • $\begingroup$ Variable speed of light - Criticism. $\endgroup$ – AccidentalFourierTransform Feb 5 '18 at 15:47
  • $\begingroup$ -1 Not clear. What articles? For what arguments are you asking for a rebuttal? $\endgroup$ – sammy gerbil Feb 5 '18 at 17:04
  • $\begingroup$ My vague understanding is that the scientific community largely thinks variable speed of light theories don't hold water. Niels Nielsen's answer is along these lines (thank you, Niels). I'm looking for a reputable article or commentary presenting the reasons why most scientists don't buy into variable speed of light theories... $\endgroup$ – andtomorrow Feb 5 '18 at 19:33
  • $\begingroup$ Hi andtomorrow, wikipedia is a good place to start, try also a search on "VSL Smolin" as Lee Smolin has written some good stuff about this. $\endgroup$ – niels nielsen Feb 6 '18 at 1:18
  • $\begingroup$ Thanks -- Following up on your leads I found a paper by George Ellis that was helpful, too. $\endgroup$ – andtomorrow Feb 7 '18 at 14:38

Noether's Theorem explicitly links energy conservation with the time invariance of physical laws, as for example those responsible for the measured value of c. This means the immediate consequence of variable-speed-of-light cosmologies is the nonconservation of energy in the universe. The experimental and observational fact that as near as we can tell, energy is indeed conserved in our universe (experts invited to weigh in here) is a powerful counterargument to variable-speed-of-light.


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