What Was It Like When There Were No Stars In The Universe?
“It takes just half a million years to take all the normal matter in the Universe and have it be completely neutral, but 100-to-200 times as long before that neutral matter can collapse down enough to form the very first star in the Universe. Until that happens, the only light to see will be the leftover glow from the Big Bang, which falls to low enough energies to make it invisible after just 3 million years. For 47-to-97 million years, the entire Universe is truly dark. But as the first star ignites, “let there be light” is finally, once again, a part of our cosmic history.”
When you hear the term dark ages, you generally think about a time where whatever illuminated humanity’s existence ceased to do so. Well, the Universe itself had a dark ages. After neutral atoms first formed, there was still a hefty, visible glow of leftover radiation from the Big Bang, but the expansion of the Universe finally makes it invisible after about 3 million years. Yet the first stars in our cosmic history, emerging from the largest, rarest density fluctuations of all, won’t arrive until the Universe is 50-to-100 million years old. These cosmic dark ages are real, and vital to our existence. There’s an incredible story to them, and a reason why no visible, energetic light could have existed during this time.