Redshift Explained Dec. 5, 2017 CAASTRO has produced an astrophysics animation that explains the phenomenon of redshift of distant galaxies. This redshift indicates that most galaxies in the universe are moving away from us (and from each other), and that the universe must be expanding. This cosmological redshift fits in with the Big Bang theory: that our universe began in a tremendous explosion and that space has been expanding ever since. Redshift means that light or other electromagnetic radi