The 'expanding universe' is an unproven theory, which is based upon the belief that red shift is an indicator of motion and velocity.
Noted astronomer, Halton Arp, proved in the 1960s, that red shift is actually an indicator of age. In his book, "Atlas of Peculiar Galaxies", Arp presented high definition photos of 388 galaxies that are conjoined to companion quasars whose red shifts differ dramatically from their parent galaxies.
These quasars are clearly connected to their companion galaxies by visible filaments, so how can that be? Well, it can't be, if red shift is an indicator of motion and velocity. This observation led Arp to conclude (correctly, in my estimation) that red shift is an indicator of age, not motion or velocity.
Naturally, the astronomical community, which had already accepted the Big Bang theory as gospel, thoroughly rejected Arp's findings out of hand, and labeled him a kook heretic. They did so (and continue to do so) despite the clear associations between these objects and the wild variances in their red shifts.
In subsequent decades, thousands of such objects have been added to Arp's original catalog.
The ramifications of these observations can't be overstated. Arp essentially disproved the Big Bang theory.
They define 3 different types of redshift.
1) Doppler, due to actual movement of light source through space
2) Gravitational, due to strong gravity field “stretching” space-time
3) Cosmological, due to universal expansion