Consider this hypothesis:
Two objects A and B, are able to maintain their spatial distance. Object A is near a neutron star, and thus it clock is running at a different speed than object B, and both objects would see red shift. Due to Einstein shift countering that effect, there would be no red shift.
However, if the two objects were running at a different clock, due to an unknown reason that is not nearby gravity - we WOULD see red shift. There would not be Einstein shift to counter that effect. This obviously seems impossible, without those objects having a relative velocity.
The hypothesis is:
All matter was given an initial four-velocity c at The Big Bang, relative to where that matter originated. This velocity was distributed in all four dimensions, space and time. Distant regions of the universe is running at a different clock rate than our local clock rate, and this causes us to observe universal red shift.
A couple of thoughts:
Particles that are nearby each other today, would more likely have been given a similar initial space-time direction in The Big Bang.
However, integrating the particle velocity in the time dimension since The Big Bang, could yield vastly different ages for different particles.
A particle with a vastly different "age", would seem to be be less affected by gravity. This is merely a consequence of the particle having a great distance in the time dimension. Such a particle would be able to pass straight through earth without stopping.
Gravity causes particles clock rate to align, in exactly the same way that their spatial velocity aligns.
Even though particles are local to each other and following a somewhat synchronized clock, over time their four dimensional distance will increase little by little - while their three dimensional distance might be stable.
Gravity depends on particles four dimensional distance, including their "time distance", this predicts a Big Freeze end to the universe.
Is this a hypothesis to pursue? If so, any ideas for how it could be tested?
Particles position in X, Y and Z is the integral of their velocity in X, Y and Z over the course of the universe. I merely claim that particles have a "time position" as well, and that this "time position" is important when calculating gravity over vast distances. Over small distances, the relative "time position" is negligible.