João Magueijo and Niayesh Afshordi have developed a theory that might replace the advances made in the physics field by Albert Einstein. The new hypothesis states that the speed of light is not a constant in the universe, which in the case of successfully passing the tests, will prove Einstein wrong.

Magueijo first said that the speed of light was variable in 1998, and now these researchers have come with a numerical prediction that will allow their theory to be tested. If their theory is tested, it would mean that basically everything that has been achieved or assumed in the physics field could be doubted hereafter.

Under a constant speed of light, every hypothesis and theory Einstein made were proven correct. Image Credit: Youtube

“The theory…has now reached a maturity point…If true, it would mean that the laws of nature were not always the same as they are today,” said Magueijo.

Is the speed of light an unequivocal constant? 

One of the things humans have assumed about the universe is that it has fundamental constants. One of them is the speed of light, which have a numerical value no matter what conditions it is tested under. It has been measured by many scientists as 299,792,458 meters per second since the 19th century.

However, it was Albert Einstein with his theory of relativity to show why it was like that: light travels as electromagnetic waves and as particles of photons. Einstein made a hypothesis that if something was able to travel faster than the speed of light it would break fundamental physical laws, creating a visible stationary electromagnetic wave.

But, what if the assumption of a constant speed of light was somehow wrong from the very beginning? This is something that has been suggested by Joao Magueijo from Imperial College London since 1998. It has a strong theory to believe, given the success of Einstein. However, it has taken more power, and now the physics work is keeping track on everything that Magueijo –alongside Niayesh Afshordi at the Perimeter Institute in Canada – is ready to prove.

“The theory, which we first proposed in the late-1990s, has now reached a maturity point – it has produced a testable prediction,” said Magueijo.

The ‘Horizon Problem’

Magueijo said that to solve one of the main problems of the universe, called the horizon problem, we need to challenge the conception of a constant speed of light. The researchers suggest that the speed of light could have been faster in the early universe. He says that the problem is that the universe reached a uniform temperature long before the photons (charged with energy) traveling at a constant speed could have reached all the corners of the expanding universe.

The most accepted explanation is the “inflation” suggesting that after the Big Bang, the temperatures stabilized before the universe started a rapid phase of expansion. However, it is unclear why the inflation started and why it stopped. As well, the inflation theory suggests a universal expansion rate that is way faster than the actual expansion in the universe today.

That is why, Magueijo tried to find an alternative for the inflation, focusing on the speed of light.

He is publishing alongside Afshordi a study that will be published by the Physical Review on November 28th. It includes a testable mechanism to his hypothesis. Their theory is that light and gravity were traveling at a different speed in the early moments of the universe, given the fact that if photons were moving faster that gravity that would have given them enough time to travel to through all the universe and help it reach an even temperature.

Magueijo said that the idea of a variable speed of light was seen as radical when it was proposed, but he said that a numerical prediction it can become something testable for the physicists.

Physicists can test the hypothesis by measuring the Cosmic Microwavable Background (CMB) radiation, a fossilized impression the early universe that we can test today. The theory is that the CMB should show if the speed of light and the speed of gravity is modified as the temperature of the universe change.

The Spectral Index

The value they predict or the spectral index, which describes the density ripples in the universe, is of 0.96478. The most recent value, which is based on a satellite measuring the CMB, is 0.968, which is pretty close to their predictions. If a future CMB measurement shows a disparity, it would mean that the Magueijo-Afshordi theory could be thrown away.

If a future CMB measurement shows a disparity, it would mean that the Magueijo-Afshordi theory could be thrown away.
What if measurements of the spectral index don’t match Magueijo’s and Afshordi’s prediction? “That would be great—I won’t have to think about these theories again,” Magueijo said.

Scientists are slowly opening up to new theories, such as Magueijo and Afshordi’s. However, it still has to endure the tests. We have to understand that the most commonly accepted theories of physics may help us understand a lot of things, but they can’t explain quite everything

Source: Deccan Herald