
Way back in the earliest epochs of the Universe, the Big Bang was followed by a period called the Cosmic Dark Ages. It was a time when the cosmic soup of primordial particles was so thick that light couldn't propagate. Hence the term "dark"; also, because, even with our best telescopes, we can't see "into" that epoch. Although we don't have a definite "century by century" timeline of activity, that doesn't mean that period of history didn't lead to something interesting.

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