Briefly into the big bang, matter anti-matter annihilation which lead to an excess of matter that is what is our current universe, left us with roughly 20 billion photon for each proton. From what I understand, the rough scenario is that CP violation meant that for every 10 billion matter anti-matter pair, we got an extra proton, which is the left over. The 10 billion matter, and 10 billion anti-matter proton then annihilated and produced the 20 billion photon of gamma energy that is now the micro-wave background radiation. So, my question is, does this process mean that in theory, had the big bang created 20 billion normal matter proton instead of 10 billion matter and 10 billion anti-matter proton, that the current universe would be 20 billion time more massive, and have 20 billion time more matter? I mean where am I wrong? Because it seems that a proton anti-proton annihilation simply makes the mass of the both of them convert into a massless gamma ray, that then cools off for billions of years... Which sounds as a weird way to get rid of mass. That also begs the question, how does a gamma ray cool down and loses all that energy?