A radical idea can finally be tested

Scientists from the Imperial College in London and the Perimeter Institute in Canada have come up with a radical new theory that suggests that the speed of light is not constant as Einstein suggested. The assumption that the speed of light is constant, and has ever been so, underpins much of our understanding of physics. But researchers have suggested that the speed of light may have been much higher in the early universe. Now they have put forward a prediction that will allow this radical idea to be tested. "The idea that the speed of light could be variable was radical when first proposed, but with a numerical prediction, it becomes something physicists can actually test. If true, it would mean that the laws of nature were not always the same as they are today." Professor João Magueijo from Imperial College London, and one of the theory’s originators, has said.