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?
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.