Joao Magueijo suggests that, if the speed of light is variable, modern physics is dead:
"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
"But the researchers said they spent a lot of time working on a theory that wouldn't destabilise our understanding of physics. "The whole of physics is predicated on the constancy of the speed of light," Joao Magueijo told Motherboard. "So we had to find ways to change the speed of light without wrecking the whole thing too much." http://www.telegraph.co.uk/technology/2016/12/06/speed-light-discovered/
The fact that the speed of light VARIES with the speed of the observer is as obvious as 2+2=4 (Einstein's nonsensical conclusion that it doesn't is equivalent to Big Brother's 2+2=5):
http://www.einstein-online.info/spotlights/doppler Albert Einstein Institute: "The frequency of a wave-like signal - such as sound or light - depends on the movement of the sender and of the receiver. This is known as the Doppler effect. [...] Here is an animation of the receiver moving towards the source:
By observing the two indicator lights, you can see for yourself that, once more, there is a blue-shift - the pulse frequency measured at the receiver is somewhat higher than the frequency with which the pulses are sent out. This time, the distances between subsequent pulses are not affected, but still there is a frequency shift: As the receiver moves towards each pulse, the time until pulse and receiver meet up is shortened. In this particular animation, which has the receiver moving towards the source at one third the speed of the pulses themselves, four pulses are received in the time it takes the source to emit three pulses." [END OF QUOTATION]
"Four pulses are received in the time it takes the source to emit three pulses" means that the speed of the pulses relative to the moving receiver is greater than their speed relative to the source, in violation of Einstein's relativity.