Big Bang Theory is a bunch of really solid observations and hypotheses mixed with a bunch of open questions, even about the fundamental nature of forces. It wa

Big Bang Theory is a bunch of really solid observations and hypotheses mixed with a bunch of open questions, even about the fundamental nature of forces. It was only 30 years ago that we discovered what we call now dark energy. And it turns out that within that short time frame we have multiple ways of measuring the amount of it, and those methods agree. There is more dark energy than dark matter, and that the visible matter is even a small fraction of the dark matter. But even with this discovery of the acceleration of expansion of the universe, the core big bang theory holds. There are many alternatives to the predominant and not-yet-accepted-as-true Lambda-Cold Dark Matter model of physics, such as Timescapes, but none of them have enough evidence behind them to be considered serious alternatives at the moment. Things like the Baryonic Acoustic Oscillation theoretical predictions, that are visualized in the spacing of galaxies, are literally mind blowing to me. Theoretical physics predicted how matter would behave when it's so hot and dense that none of it can even form atoms, and it predicts the structure of all sorts of things, even the variability we observe in the cosmic microwave background. TL;DR The depth and consistency of observation that point to a big bang are stunning. But we still have so much we don't know about the particulars, and the fundamental forces.