Hydrogen, while being the simplest element, is near a peak of the binding potential curve. Presumably in the first 1 second or less of the Big Bang timeline, densities and temperatures were such to enable the formation of helium, which is more stable, or iron, which is the most stable. Why didn't most matter settle into one of these stable states?
Furthermore, it is posited that strange quark matter is the most stable form of matter possible, and may exist in the cores of some neutron stars. Why didn't most matter form as strange matter even earlier in the timeline, precluding the formation of any less stable form?
This answer addresses many aspects of my question, but not all. Is it accurate to say that, by the time expansion reached a state that with low enough temperature and density for any baryons to form, it was already too diluted to form any but single protons (except for the rare dense patch)? And the question about strange matter still remains. Thank you.
