Astronomers can put starlight through a prism to get a light spectrum. If there are black lines in the spectrum, it's due to an electron in an atom absorbing that wavelength of light. There are four black lines in the hydrogen spectrum at four different wavelengths in the red, bluegreen, blue and purple, I think. (Hydrogen is the most common element in space.) If the source of the starlight is electrically ionized or if it's moving away rapidly, the hydrogen black lines are shifted toward the red side of the spectrum. If the source is moving rapidly toward the viewer, the hydrogen black lines are shifted toward the purple side of the spectrum. If ionization causes a redshift, it's called the Compton Effect. If velocity causes the redshift, it's called the Doppler Effect. In either case, the electron lost energy. I don't know if the Compton Effect can cause a blue shift of hydrogen black lines. I think there are about 3,000 galaxies that have blue shift, which means they are likely moving toward us. The large majority of galaxies have redshift, but most of those are likely due to the Compton Effect of ionization, not the Doppler effect of rapid movement away from us. Some redshifts are likely due to a combination of Compton and Doppler Effects.
This video seems pretty good at explaining a little on Emission & Absorption Spectra:
Quasars have large redshifts, while galaxies usually have smaller redshifts or sometimes blueshifts. Astronomers mostly assume wrongly that large redshift correlates to greater velocity and greater distance. However, some quasars are seen to have bridges of matter connecting them to galaxies near them, so such quasars obviously must be at the same distance and same velocity as their companion galaxies. There's one large-redshift quasar in front of a low-redshift galaxy, which obviously disproves that redshift indicates distance and velocity in many or most cases, as shown in this article: https://www.thunderbolts.info/tpod/2004/arch/041001quasar-galaxy.htm .
Plotting the distances to quasars and galaxies under the wrong assumption of the Doppler Effect results in them forming lines in all directions that point toward the Earth, which would mean that the Earth is the center of the universe or of the "Big Bang". So that helps prove that the Doppler assumption is wrong, since the Earth is surely not the center of the universe. Plotting the distances based on the Compton Effect assumption does not give this illusory result, called the Fingers of God illusion, as explained in this article: https://www.thunderbolts.info/tpod/2004/arch/041018fingers-god.htm
Here's the abstract of a paper by John Kierein and his co-author. He developed the Compton Effect model. I had email correspondence with John a couple years ago.
https://www.researchgate.net/publication/241348093_The_Compton_Effect_Red_Shift
In 1923 (Phil Mag. 46, 897.) A. H. Compton noted that the Compton effect produces a red shift for all wavelengths when the scattered electron is free and not bound to an atom or molecule. He suggested that the red shift in the visible spectrum at the limb of the sun is larger than that at the center due to the Compton effect from the greater number of free electrons in the sun's atmosphere along the line of sight. Kierein and Sharp (1968, Solar Physics 3, 450) quantified this and showed a good correlation of red shift observations with the variation in the number of these electrons along the line of sight from center to limb and suggested that the quasar red shift and cosmological red shift could be similarly explained. Grote Reber mapped and measured the background hectometric radiation and found it to be unexpectedly bright. In 1968 (J. Franklin Inst. 285,1), while describing these measurements and maps he explained this brightness as being due to the Compton effect causing the cosmological red shift and accelerating intergalactic electrons. The resulting universe is static. The predicted red shift from the Compton effect deviates from Hubble's law only at large red shifts.
Galaxies are moving in various directions and form somewhat linearly into filaments which kind of resemble spider webs or cobwebs. Here's an image: https://www.technologyreview.com/2020/07/13/1005090/astronomers-found-giant-intergalactic-wall-south-pole-wall/ But it's not entirely accurate because it's based on the Doppler redshift assumption.
There was no Big Bang, but Charles Chandler figured out that galaxies likely originate as unorganized stars, which reach a certain density that causes them to explode. After going through a few cycles of explosions, they then form elliptical galaxies, then explode some more to form spiral galaxies, like our own galaxy, and finally form ring galaxies. Charles has a good paper about that at http://qdl.scs-inc.us/?top=5941.
John Kierein had some old videos here: