Roy,
I understand redshift as a function of recessional velocity. It's the Doppler effect. The problem is that it is based on recession within a stable frame of reference. As in the train is moving away on the tracks, the tracks are not being stretched. Originally the proposed expansion of the universe was based on this concept, that other galaxies are simply flying away from us, the problem is that they are all redshifted directly away from us, as though we were at the center point of this expansion. The idea was then changed to that it was actually space itself which expands and everything is being carried along with it. The rising loaf of raisin bread analogy.
The Big Bang model first started to bother me when I read that for the universe to be as stable as it is, this expansion is balanced by the force of gravity, effectively contracting space at an equal rate. So if space is essentially falling into gravity wells at the same rate it is expanding between them, it would seem there would be no additional expansion of the overall universe. There seemed to be some form of convection cycle of expanding space/radiation, balanced by a contraction of gravity/mass. Now when gravity collapses mass to sufficient pressure and heat, it ignites and the constituent energy is radiated back out.
So the question would be; What might be the other transition? Obviously any radiation actually contacting mass is absorbed, but is there some mechanism by which energy that has sufficiently cooled, starts to condense out as any form of quantum particulate structure, say the black body radiation of the cosmic background, as it is said to have originated at the edge of the visible universe and so has traveled the furtherest.
The Hubble constant of redshift is that the further away a source is, the faster it (presumably) recedes, until at about 13 billion years out, it is receding at the speed of light and this creates a horizon line over which visible light can't travel. So the question is; hypothetically of course, what if there is some effect of distance, other than actual progressive recession, which causes the spectrum of light to be redshifted? For one thing, it would be a cumulative effect, so that the further away it is, the more the redshift is compounded, so it appears to be receding faster, thus the Hubble constant. It is isomorphic, in that every point would have other light sources redshifted directly away. It would be a consistent counter to gravity, effectively a cosmological constant, so the fact they counteract wouldn't simply be coincidental.
It would do away with having to accept the very large questions raised by the Singularity and Inflation. Dark energy wouldn't be necessary, as the galaxies are not actually moving apart over time, because the "space" is falling back into gravity/mass. Possibly it would exert additional pressure on gravitational systems, since the entire universe isn't being pushed apart and this would explain the excess rotational velocity of galaxies which is ascribed to dark matter.
So this is the basis of my observation: If space is expanding, than when it doubles in size, would two galaxies, which had been a billion light years apart, now be two billion light years apart? If so, that is not expanding space, but an increasing amount of constant space and you are back to the question of why we appear to be at the center of the universe. Otherwise, if the speed of light increases as space expands, so that the distance always appears to be one billion lightyears apart, what is the point of the theory, since there is no apparent recessional velocity?