Is The Speed Of Light Variable? Scientists Challenge Albert Einstein's Theory Of Relativity

Albert Einstein had suggested way back that light travels at a constant pace. But two scientists are hoping to challenge that theory with one of their own – the idea that the speed of light may be, in fact, variable.

As Quartz reiterated in a report Sunday, most physicists had measured the speed of light as being 299,792,458 meters per second. But it wasn't until Albert Einstein and his theory of relativity that people finally found out why light travels at such a pace in all occasions. According to Einstein, it would be impossible for anything to travel faster than light, as it would be a violation of the rules of physics. That's why he came up with the idea that the speed of light is not variable, but rather stable all throughout.

In the years since the theory of relativity, no one had really stepped up to seriously challenge Einstein and the convention that light always travels at the same speed. But in 1998, Imperial College London scientist Joao Magueijo began to question whether Albert Einstein was spot-on with his theory, or if there were some flaws to his ideas on the speed of light. Magueijo theorized that solving the physics conundrum known as the "horizon problem" may require debunking Einstein's theory – this conundrum suggests that the universe had hit a constant temperature well before photons moving at a constant speed had a chance to cover the universe as it expanded.

The horizon problem is generally explained by inflation, which means the universe's temperature had become more consistent after the Big Bang, but before it had substantially and quickly expanded. But since scientists are often confounded by the how-and-why of inflation, and why it eventually stopped, many physicists question whether inflation serves as a valid solution to the aforementioned conundrum.

That's where Magueijo had begun wondering whether the speed of light is variable – he was looking for another way to solve the horizon problem. But it's only now that his alternate theory is going to be tested in earnest. According to Quartz, Magueijo and fellow researcher Niayesh Afshordi of the Perimeter Institute have worked on a study set to be published Monday in the journal Physical Review that includes a "testable hypothesis" on the speed of light.

Magueijo, who believes his original theory has finally "reached a maturity point," was quoted by the Daily Galaxy as saying the new study could force some changes to Albert Einstein's original theories.

"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."
The hypothesis proposed in the study suggests that light and gravity were moving at different speeds when the universe was still young. And if photons were indeed faster-moving than gravity, that would have allowed them to cover the universe in its entirety, and help it reach a balanced, uniform temperature.

Albert Einstein. [Image by Hulton Archives/Getty Images]
[Image by Hulton Archives/Getty Images]

This can be tested by measuring cosmic microwave background radiation, or a mock-up of the early universe that can still be measured in present-day. The Register noted that CMB radiation is thought to be the residual energy from the Big Bang, containing some "small pockets" with varying levels of energy, but mostly being uniform due to the universe's eventual expansion.

Magueijo and Ashfordi have a predicted CMB value of 0.96478, which is a similar, but not identical figure to the recent reading of 0.968. The above reading comes from a satellite tracking CMB radiation, and if future readings do not match up with the scientists' prediction, that would simply mean that the speed of light is not variable and that Albert Einstein was right all along.

[Featured Image by NanayaViktoria/Shutterstock]