The term "red shift" is used so loosely, most think of it as just a simple number having a consistent meaning, like a temperature.
A red shift is not that simple and anyone using the term so loosely is showing they consider it as just a simple number.
It is crucial to recognize there are 4 different red shifts. Each is a measurement of a distinct behavior.
Galaxies are totally different entities than quasars. A galaxy has billions of stars while a quasar is a quasi-stellar object having no stars.
A metallic element is one which is not hydrogen or helium.
The 4 distinct red shifts:
1) galaxy – hydrogen
2) galaxy – metal
3) quasar – hydrogen
4) quasar – metal
(1) the hydrogen absorption line is driven by hydrogen in the inter-galactic medium. This line is not from the galaxy.
(2) the calcium ion absorption line is driven by calcium ions near the galactic corona, as in the case of M31 and others. Calcium is a metal. The metallic line is not from the galaxy.
(3) The quasar high red shift comes from the hydrogen Lyman-alpha emission line.
(4) The quasar low red shift comes from the metallic ion emission lines.
(1) can never be a galaxy velocity. However, when used in conjunction with Cepheids, this value enables a distance calculation, with Cepheids providing a distance metric for the hydrogen density within the IGM in the line of sight to its galaxy.
(2) there are galaxies with either a red or blue shift of the metallic ion absorption lines. M31 has a calcium line blue shifted. This can never be a galaxy velocity, nor can it be related to a alaxy distance. Only a Cepheid provides a distance metric.
LINER galaxies, which include Seyferts, exhibit several metallic elements when taking the spectrum of only the AGN. None of these metallic lines in a LINER galaxy spectrum are related to the galaxy motion.
(3) this hydrogen emission line is found in a "typical" quasar. This can never be a quasar velocity, nor can it be related to a quasar distance.
(4) these metallic lines are found in the quasars used by Halton Arp, in his book Seeing Red. This can never be a quasar velocity, nor can it be related to a quasar distance, nor can it be related to the age of matter. These ions just slow down in apparent incremental changes in their velocity.
The z value for (3) has exceeded 7, while the z value for (4) is < 1.
It is crucial to note that none of the 4 types of a red shift is an indicator of the object's real velocity.
When one accepts that simple fact about the false velocities, then there is no "Hubble Flow." That was the term Edwin Hubble used initially for the red shift trend, but later in 1936, he noticed (1) is observed with only galaxies beyond our Local Group.
Hubble recognized the "Hubble Flow" was not consistent. Dark energy arose from the wrong assumption that the false expansion is consistent.
There is also no expansion, no dark energy, no big bang.