“Es ist immer angenehm, über strenge Lösungen einfacher Form zu verfügen.” (It is always pleasant to have exact solutions in simple form at your disposal.) –Karl Schwarzschild
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?