bonezelite - From the above lines of evidence, and other evidence involving red shfts showing expansion rate, and evidence from type 1A supernovae (I hope to post on the latter in my Biblical astronomy thread.), comes the standard big bang model.<br /><br />In that model, the temperature after the first millionth of a second from start of expansion calculates out to be (by extrapolating back): 10^12 degrees Kelvin.<br /><br />Then down to about 3,000 K by 100,000 years after Big Bang, at which point matter and energy decoupled and the CMBR was released.<br /><br />Now, the standard model has matter and antimatter all forming from energy within the first millionth of a second! And also mutually annihilating, leaving a slight surplus of matter over antimater surviving.<br /><br />Protons and neutrons would also have been formed in the first millionth of a second.<br /><br />Much earlier, in minute fractions of this first millionth of a second, all the properties of our universe were fine tuned - probably within 10^-43 second. That is, of course, a miracle - and it also involves the establishment of the laws of our universe!<br /><br />Electrons and positrons stopped being formed a few seconds after big bang, at a temperature of a few billion degrees K.<br /><br />About 3 minutes after BB, the universe had cooled to one billion K, and protons and neutrons fused to form Helium, Deuterium, tritium and a small amount of Lithium [i.e. the nuclei only.] {deuterium before tritium before helium}<br /><br />There is new data which I hope other posters will post on, and these shed light on how galaxies may have formed.<br /><br />Note that there is evidence of re-ionization, and the present IGM (intergalactic medium) is both highly ionized and extremely hot.<br /><br />There is a very good Scientific American article on the IGM, and the apparent history of temperature and ionization which is not a steady decrease from BB at all, btw.<br /><br />This evidence may indicate that ionization, and resul