The macrocosm began with the Big Bang, an explosive event that set in stir the expansion of space and the conformation of everything we know moment — matter, energy, stars, worlds, and eventually life itself. But for the first many hundred million times, the macrocosm was a extensively different place dark, cold, and filled with a nearly invariant ocean of hydrogen and helium gas. This time is frequently called the Cosmic Dark periods, a time before the first stars and worlds had burned the macrocosm with light.