The newborn universe may have glowed with light beams moving much faster than they do today, according to a theory that overturns Einstein’s century-old claim that the speed of light is a constant.
João Magueijo, of Imperial College London, and Niayesh Afshordi, of the University of Waterloo in Canada, propose that light tore along at infinite speed at the birth of the universe when the temperature of the cosmos was a staggering ten thousand trillion trillion celsius.
It is a theory Magueijo has being developing since the late 1990s, but in a paper published on Monday he and Afshordi describe for the first time how scientists can finally test the controversial idea. If right, the theory would leave a signature on the ancient radiation left over from the big bang, the so-called cosmic microwave background that cosmologists have observed with satellites.
“We can say what the fluctuations in the early universe would have looked like, and these are the fluctuations that grow to form planets, stars and galaxies,” Afshordi told the Guardian.
The speed of light in a vacuum is considered to be one of the fundamental constants of nature. Thanks to Einstein’s theory of general relativity, it was stamped in the annals of physics more than a century ago at about 1bn km/h. But while general relativity is one of the cornerstones of modern physics, scientists know that the rules of today did not hold at the birth of the universe.