> "nothing happened before because that's when time started" feels like an acknowledgement of the limitations of our human understanding.
"Nothing happened" is not the correct answer. The correct answer is that we don't know what happened because before you get to the big bang, our current theories of physics stop working. If you run the equations of general relativity backwards from current conditions you get to a singularity and at that point you can't go back any further. That singularity is called the "big bang". But we know that this is (almost certainly) not an accurate model of what actually happened because we know that GR is (almost certainly) just an approximation of some as-yet-undiscovered theory of quantum gravity, just as Newtonian mechanics is an approximation of GR (in the case of weak gravitational fields).
> So here's my follow-up question: Obviously we build an understanding of the universe based on observations of the data. And sometimes the data doesn't match and we have to upgrade Newtonian Physics to Einsteinian, or introduce Quantum Mechanics, etc. So are there comparable/equivalent investigations/experiments going on today that reveal numbers/observations that are basically fundamentally unexplainable without looking beyond the realms of our understanding of the limitations of our universe?
They're trying. The big problem is that all of the low-lying experimental and theoretical fruit has been picked, and doing experiments that will actually advance fundamental physics (i.e. whose outcomes cannot be predicted accurately by GR and QFT) is fantastically difficult. The math turns out to be really hairy too. No one has been able to figure out out to quantize gravity so that GR and QFT can be combined into a single theory, let alone propose an experiment that could test such a theory. It's a major problem, almost at the level of a crisis. Fundamental physics essentially has made no progress since the standard model was finished 50 years ago.
> "nothing happened before because that's when time started" feels like an acknowledgement of the limitations of our human understanding.
"Nothing happened" is not the correct answer. The correct answer is that we don't know what happened because before you get to the big bang, our current theories of physics stop working. If you run the equations of general relativity backwards from current conditions you get to a singularity and at that point you can't go back any further. That singularity is called the "big bang". But we know that this is (almost certainly) not an accurate model of what actually happened because we know that GR is (almost certainly) just an approximation of some as-yet-undiscovered theory of quantum gravity, just as Newtonian mechanics is an approximation of GR (in the case of weak gravitational fields).
> So here's my follow-up question: Obviously we build an understanding of the universe based on observations of the data. And sometimes the data doesn't match and we have to upgrade Newtonian Physics to Einsteinian, or introduce Quantum Mechanics, etc. So are there comparable/equivalent investigations/experiments going on today that reveal numbers/observations that are basically fundamentally unexplainable without looking beyond the realms of our understanding of the limitations of our universe?
They're trying. The big problem is that all of the low-lying experimental and theoretical fruit has been picked, and doing experiments that will actually advance fundamental physics (i.e. whose outcomes cannot be predicted accurately by GR and QFT) is fantastically difficult. The math turns out to be really hairy too. No one has been able to figure out out to quantize gravity so that GR and QFT can be combined into a single theory, let alone propose an experiment that could test such a theory. It's a major problem, almost at the level of a crisis. Fundamental physics essentially has made no progress since the standard model was finished 50 years ago.