Isn't the question of redshift also connected with true relative motion? And actual relative distance? Cosmological redshift seems to be a theoretical interpretation of observations. I have not heard of or seen observational data that proves it is possible.

If you assume that space cannot physically expand or that space is not physically expanding then another explanation must be found for the observations. Same comment for lets say dark matter or dark energy. If redshift is different than standard theory, a number of observations also change. The observations are not independent of theory.

This paper is a reasonable neutral discussion of redshift along with other cosmological subjects. Leopez-Corredoira, presents data and logic that challenges and supports both standard theory and alternative theories. He tries to be impartial.

“Observational Cosmology: caveats and open questions in the standard model” by Martiın Leopez-Corredoira


http://arxiv.org/PS_cache/astro-ph/p.../0310214v2.pdf