This Is Why Our Universe Didn’t Collapse Into A Black Hole
“The level to which the expansion rate and the overall energy density must balance is insanely precise; a tiny change back then would have led to a Universe vastly different than the one we presently observe. And yet, this finely-tuned situation very much describes the Universe we have, which didn’t collapse immediately and which didn’t expand too rapidly to form complex structures. Instead, it gave rise to all the wondrous diversity of nuclear, atomic, molecular, cellular, geologic, planetary, stellar, galactic and clustering phenomena we have today. We’re lucky enough to be around right now, to have learned all we have about it, and to engage in the enterprise of learning even more: the process of science. The Universe didn’t collapse into a black hole because of the remarkably balanced conditions under which it was born, and that might just be the most remarkable fact of all.”
The Universe is a vast and complex place, full of a diversity of structure from the smallest scales to the largest. And yet, by many accounts, it’s a wonder that it came to be this way at all.
If things were just a little bit different at the very beginning, the Universe could have recollapsed in on itself in a mere fraction-of-a-second after the Big Bang. That very clearly didn’t happen, but why not? And, if it did happen, would we have formed a black hole? There must have been an incredibly perfect, finely-tuned balance between the initial expansion rate and the energy density of everything within the Universe, or this careful balance wouldn’t have existed, and we never would have arisen in this Universe.