Hi all Maybe a quick question! After the big bang and inflation, a little while later there is the mass annihilation event where 10 billion matter particles and 10 billion anti matter particles annihilate, sending out energetic photons. For each 10 billion annihilation events there is one remaining matter particle (or 2? whatever.. :) So the contribution to the energy content of the universe from photons should be 10 (or is it 20) billion times more than that of matter. But as we're told, by like wikipedia and books and stuff, the radiation content of the universe is negligible.... What's going on there? Where have all those photons gone? Or where has their energy gone, I don't think the expanding universe/photons can cover all that! Thanks!