Physicists Challenge What Einstein’s Theory Said About the Speed of Light
One of the odd things about our universe is that there are some universal constants. Like masses of subatomic particles, speed of light in vacuum and some others. These constants do not change no matter what the conditions are.
Speed on light is a famous constant, and in vacuum, it has a value of 299,792,458 meters per second. This value was confirmed by numerous scientists in the 19th century. Later, Albert Einstein developed the theory of relativity to understand why it was so.
Now, from high school physics, you must be knowing the light has both a particle and wave nature. Now, Einstein hypothesized that if anything can travel faster than light, then it would break the fundamental laws of physics. Then it – or the thing travelling as fast as light – can observe a stationary electromagnetic wave (hypothetically speaking). Therefore, Einstein said that the speed of light is constant.
The Horizon Problem
Now, the horizon problem, one of the biggest unsolved problems in physics say that
different regions of the universe have not “contacted” each other because of the great distances between them, but nevertheless they have the same temperature and other physical properties. This should not be possible, given that the transfer of information (or energy, heat, etc.) can occur, at most, at the speed of light.
In 1998, João Magueijo of Imperial College London asked if this value of speed of light was faulty from the very beginning, because the only thing other than variable speed of light is cosmic inflation that can explain the horizon problem.
The theory of Inflation states that after the Big Bang, the temperature evened out before the universe expanded rapidly. The inflation theory works with many scientists, but nobody can say why it started or why it stopped.
Speed of Light and Speed of Gravity
Now, according to a journal published in the Physical Review by Magueijo and Niayesh Afshordi of Perimeter Institute, if at the very beginning of the Universe, if photons moved faster than gravity, it would have given them enough time to travel to all parts of the universe and thus help reach temperature equilibrium.
The hypothesis can be tested using cosmic microwave background (CMB) radiation. The value they predict, called the spectral index, which describes the density ripples in the universe, is 0.96478 and the satellite based data is 0.968, which is very close.
In near future, a match would mean that the speed of light is constant, but however, a mismatch would mean that all that we know about the fundamental laws of physics is wrong.