Has the speed of light in the universe been slowing down?

This problem is called variable speed theory. In classical physics, the speed of light in vacuum is considered to be constant. According to the variable light speed, the light speed is a function of time and space, so it is uncertain. Albert Einstein once studied this theory. 19 12 years, he thinks that the speed of light is constant only in some space-time regions where the gravitational potential energy is constant. But Einstein later gave up this research, and variable speed of light caused controversy because of his conflict with widely accepted wisdom. At least two specialized scientists are still studying it and published a research paper at the end of 20 16.

These scientists are Joao Maggiu, an astrophysicist in Imperial College London, London, and Niaye, an astrophysicist at Perimeter Institute of Theoretical Physics, Canada. On February 20 16, 16, Ashdy published a paper in Physical Review D, suggesting that the speed of light in the early universe was faster than it is now, and put forward a method to test this prediction.

They pointed out that the violent events after the Big Bang led to the formation of density fluctuation regions driven by different light speeds in the universe, that is, instability, and these early fluctuations would leave traces in the cosmic microwave background (CMB) radiation. According to their computer model, they predicted that the exact number of the original light speed in CMB spectral index was 0.96478. If future observations are correct, then the speed of light is slowing down and Einstein's theory of gravity may have to be revised.

Ma and Ashodi are staunch supporters of this theory, which was first put forward by Canadian scientist John Moffet in 1990s, and is an alternative theory of the expansion of the universe. According to this theory, the speed of light in the early universe was much faster than it is now. According to one theory, the speed of light is 65,438+0035 km/s, which is 65,438+0060 times that of today, so the distant regions in the expanding universe have time to interact at the beginning of the universe.