All the galaxies in space moves at different speeds and are all moving away from our local group of galaxies. See inflation theory. They take the current theories and incorporate them into what observations have shown. If the universe began as a big bang from one location and then inflated outward from that one location galaxies would not appear to be moving away from in all directions, as observed. We observe those galaxies moving away from us in every direction. And the furthest galaxies are observed to be the same age and size as our own Milky Way galaxy.
I imagine that we are not the center of the universe. I do not know where the center is and it cannot ever be determined because observations show that we are at the center and all distant objects are moving away from our perspective. On top of that it is observed that the furthest objects that are visible are shifted in the red spectrum. Theoretically this means the furthest galaxies are moving away from us at a much faster speed than the galaxies near us and now leads to the Inflation theory.
The universe is inflating but in reality it is not. I can explain the mysterious gamma ray bursts and explain why they contain so much energy at such a far distance forcing old formulas to be rewritten.
We can only reference point the Earth. From this location we can then reference the solar system, the Sun and the Suns path of travel, or solar apex. From there we can reference the Milky Way, it’s center. From there we find that the Milky Way connected to the Andromeda galaxy in a dumbbell like shape with a center of gravity somewhere in between & is called the Local Group. This group is part of a larger group the Virgo cluster which is part of a larger group called the Virgo Supercluster. From there all the other galaxies appear to move away from us. We can then imagine what is happening.
Energy is created at the cores of planets and stars. Then for every galaxy the output of energy is equal to the input of gravity otherwise the galaxy would consume itself and after 13.7 billion years we would not be here. This same energy is then filling up the physical area around the star, Heliosphere, and forces other stars away.
This accounts for the movement of matter in all galaxies away from the central black hole. Gravity keeps each local system containing matter in place while the production of energy causes each body in that system to move away. This movement can be seen with the moon, it moves away from the Earth at almost 2 inches per year.
There is no reason to come up with a separate theory for every observation if this one idea explains so many observations. If the matter in our solar system is found to be oldest nearest the Sun and youngest further away it will prove this hypothesis correct and that new energy is produced as a direct result of gravity.