General Relativity? Ohw, I’m not going to argue with Einstein’s theory expect for one thing. Its not complete, it does give us many wonderful things but does not explain everything its missing something still. “The red-shift distance relationship” as I understand it has to do with light, not gravity Everything radiates something so CMB can have lots of causes. 1 atom not so much, a lot of atoms like the sun… very much, Black hole …… For all I know the CMB can be a distant second universe “And the proportions of hydrogen and helium in the universe?” don’t see what that has to do with my theory.