Newest Speed Of Light Theory Could Put Albert Einstein's Theory To Test
Albert Einstein has been known for his theory on the speed of light. However, a recent study suggesting that the speed of light is variable may put Einstein's suggestion in hot water. Researchers have come up with a numerical prediction that will allow their theory to be tested.
According to an article published in Tech Times, Einstein observed that the speed of light stays the same in any given situation. This meant that space and time could be different in different situations.
This assumption has always underpinned many theories in physics, like Einstein's theory of general relativity. In particular, it plays a role in models of what happened in the very early universe, seconds after the Big Bang.
However, there have been some researchers suggesting that the speed of light could have been much higher in this early universe. One of this theory's originators, Professor João Magueijo from Imperial College London, working with Dr. Niayesh Afshordi at the Perimeter Institute in Canada, has made a prediction that could be used to test the theory's validity.
The report also says that structures in the universe, such as galaxies, were all formed from fluctuations in the early universe, tiny differences in density from one region to another. A record of these early fluctuations is imprinted on the cosmic microwave background, a map of the oldest light in the universe, in the form of a 'spectral index.'
With the use of their theory that the fluctuations were caused by a different speed of light in the early universe, Professor Magueijo and Dr. Afshordi have now used a model to come up with an exact figure on the spectral index. The predicted figure and the model it is based on are published in the journal Physical Review D.
Experts are currently getting ever more precise readings of this figure, so that prediction could soon be tested, either confirming or ruling out the team's model of the early universe. According to Imperial College London, the figure is a very precise 0.96478. This is close to the current estimate of readings of the cosmic microwave background, which puts it around 0.968, with some margin of error.
"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," Professor Magueijo explained.
He added by saying, "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."
Researchers claim that the testability of the varying speed of light theory sets it apart from other rival theory: inflation. According to inflation, the early universe went through an extremely rapid expansion phase, much faster than the current rate of expansion of the universe.
It is also important to note that the varying speed of light theory suggests that the speed of light was much higher in the early universe, allowing the distant edges to be connected as the universe expanded. The speed of light would have then dropped in a predictable way as the density of the universe changed. This variability led the team to the prediction published today.