quote:
I got lazy and didn't want to continue repeating 'all of the cosmological gases and matter produced at the Big Bang', and simply summarized it with the word 'stars'.
But even that doesn't work because matter itself only appears after the Big Bang. And who says that the thermal energy of the particles of matter (their speed) will take them in the same direction as the general expansion ? I don't see any reason why it would have to.
And later stars - practically all the stars we can see (we need very sensitive instruments to see the earliest, "Population III" stars) - incorporate matter thrown out of supernovas. A major part of the velocity of that matter will be due to the supernova (a real explosion), not the Big Bang (not really an explosion).
Edited by PaulK, : No reason given.