Now let me tell you how I came to the conclusion that the speed of light also has changed over time since the big bang. As I stated before, I believe the permittivity and permeability of the vacuum is directly related to the density of the ether. Gravity attracts the ether in my hypothesis, leading to compression. The compression leads to slower electromagnetic reaction time. Motion throught the ether compresses the ether, also leading to slower electromagnetic reactions. Now, if the ether is compressable by gravity, what happens when the gravity is reduced or almost eliminated? The ether, spacetime itself, will expand. When groups of galaxies separate enough that gravity is almost eliminated, they will begin to separate at increasing rates. But what about when the universe was smaller, in the early universe? The ether would have had to be denser then compared with today in this expanded universe. The universe is a closed system, it has increased in volume, but not matter and energy. So it naturally falls out that intergalactic space would be less dense today than early in the universe's evolution. The permittivity and permeability of interglactic space would be altered, less dense, leading to a change in electromagnetic processes, a faster speed of light when compared to the early universe, faster ticking atomic clocks.
Now back to time itself. There are two kinds of time, proper time kept by a local atomic or photon clock, and universal coordinated time, time kept by such things as pulsars. Proper time deviates from universal time because of local ether density and motion through the ether. Proper time is analogous to 'relative' time in a way because it changes according to conditions, but the universal time kept by the pulsar clock, a clock unaffected by local conditions, is 'true time'. The universe does not change time intervals because of local clock motion, the moving clock changes if it is based on electromagnetic processes.