The observed redshifts of galaxies are evidence for the big bang theory of the origin of the universe because they indicate that

Are moving rapidly away in all directions

Explanation:

Edwin Hubble discovered in 1929 that the distance to far away galaxies were generally proportional to their red shifts astronomers viewing distant stars see evidence of this expansion evidence of red shift

I hope this helps Mate :) Sorry im late

there's the proffessional site that will you.

when it is at an intermediate population density