The Theory of the Big Bang states that at some "nanoseconds" after the expansion of the "singularity" started, everything was dark (absence of light) and then space became transparent with the formation of "baryons" which are sub-atomic particles. The "protons" and "neutrons" in an atom are baryons. But what constituted these baryons? They are made up from "Quarks" which are of six "flavors" or kinds. All these are "radiations" from the Big Bang.
