Remember your high school science where C= speed of light and is always constant in equations? What if that figure may have changed over time with changes in the universe? That’s the question some researchers at the Imperial College London have tried to answer. Professors João Magueijo and Niayesh Afshordi have developed a model that should be able to test for such changes with respect to the speed of light.
Given fluctuations in the density of the universe detectable through cosmic background radiations, the figure is exactly 0.96478 for the speed of light in the first seconds following the Big Bang. This figure is close to current estimate of readings of the cosmic microwave background, which puts it around 0.968, with some margin of error.
Professor Magueijo said: “The theory, which we first proposed in the late-1990s, has now reached a maturity point – it has produced a testable prediction. If observations in the near future do find this number to be accurate, it could lead to a modification of Einstein’s theory of gravity.
“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.”
So if future measurements stack up to 0.96478 for example, it could be a win for those who have held the notion that the speed of light has indeed changed with changes in the universe and could alter a lot of laws of physics as we know it. The big challenge is getting data with such high accuracy that would support the idea because as the report notes, the very early universe evened out while incredibly small, and then suddenly expanded, with the uniformity already imprinted on it.
Those who support the theory that the speed of light has changed over time base this on the premise that the speed of light was much higher in the early universe, allowing the distant edges to be connected as the universe expanded.
Whichever theory works for you, the constant speed theory does not provide for enough time for light to have traveled to where it is in the cosmos which means super-fast light would have filled that lapse in time. This gives credence to the theory that the universe expanded rapidly at some point in time.
In any case, the speed of light change is not about to change anytime soon. So carry on with you were taught in school.