Just to (hopefully) clarify, the CMB that we detect are microwave photons that were finally released from the very hot, dense "fog" of electrons and hydrogen and helium nuclei roughly 300,000 years after the "big bang." At this time the rapidly expanding universe had finally cooled enough for the nuclei to hold onto the electrons without them being blasted off again by the (then) very high-energy radiation. Electrons joined with nuclei are electromagnetically NEUTRAL, so the radiation (photons) could then travel freely without being scattered or absorbed/re-emitted in the dense fog of charged particles. This cooling and electron capture is the "event" referred to above.
Originally Posted by forrest noble
Everyone is entitled to his own opinion, but not his own facts.