Physicists and science enthusiasts all agree that the speed of light is a constant thing in the universe. This is where the bulk of science fiction stories are based on. However, it appears the speed of light may not have always been the same -- and it's gravity's fault.

Niayesh Afshordi at the Perimeter Institute in Canada said that light and gravity had different speeds in the early universe. According to New Scientist, his team said if photons traveled faster than gravity after the Big Bang, then they may have reached the universe quicker, therefore achieving equilibrium temperature quickly. 

The problem first surfaced in 1998 when Joao Magueijo at Imperial College said that the speed of light may vary in order to solve the horizon problem. This states that the universe has reached a uniform temperature way before heat-carrying photons had time to reach all corners of the universe.

The phenomenon can be explained with an idea called "inflation" where the universe may have gone a short period of expansion - meaning the temperature evened out while the universe was small. It was then after some time that the rate of expansion grew. However, no one can explain why such a phenomenon happened in the first place.

Afshordi and his peers' idea also made a specific prediction about the cosmic microwave background (CMB) or radiation that filled the universe after the Big Bang. They said there may have been an "abrupt" change at a certain point in time when the speeds of light and gravity went to "infinity."

A lot of experts in the field are excited to work on this idea because it can be tested. The idea revolves around a "spectral index" that describes the initial density ripples in the universe. Their theory gave the number at 0.96478, terrifying close to the CMB-mapping Plack satellite's 2015 data of 0.968. 

Maguiejo said that if more data reveals mismatches, then the theory could be easily discarded. However, the mere fact that there are a lot of inflation theories meant it had to be explored. 

Not to mention, being able to observe more on phenomena like inflation could give a better understanding of life in the early universe.