Those are all evidence for the universe being hotter and denser in the past. None of them are evidence for the universe at some point being non-existent, nor that it has an actual beginning of time.
What they all have in common is that they are just evidence for the universe being smaller, hotter, and denser, than it is now, and that the universe we see today expanded from that hotter, smaller, and denser state. That’s it. The changes in redshit with distance implies an expanding universe, so extrapolating backwards we infer that everything used to be closer together. How much closer together? Well if it was really close together, we would have been in some sort of plasma state, which predicts the existence of the CMBR once the universe cooled down as it expanded. Same goes for the distribution of light elements during the period of so-called big bang nucleosynthesis(which also implies a particular spectral type for the first generations of stars to form). Again, that does not logically imply an ultimate beginning to time, nor a coming into existence from nothing.
The inference of an ultimate beginning(both in the sense of a first moment of time, and for a coming into being by transitioning from a state of absolutely nothing) is, and always were, completely hypothetical extrapolations. We don’t have to assume such states of affairs to explain what we see.
You’ve got it the wrong way around. There is no evidence that the universe actually had a beginning, that’s an extrapolation. There are other models, such as cyclic universes, eternal universes, multiverses and what have you. It’s not really important for my argument though, because even if our universe has a finite age and thus a “beginning” in a first moment of time, it still doesn’t mean it was at some point non-existant.
The only thing implied by the above lines of evidence is that the universe was smaller in the past. None of them logically imply a beginning, nor even a first moment of time. It is some times extrapolated backwards, from the inferred rate of expansion, that the universe had a first moment of time at some point where it might have been compressed into a singularity.
But a first moment of time is not the same thing as not existing. Neither is a singularity. The singularity is also a completely hypothetical extrapolation, which is also not actually logically implied by an expanding universe giving rise to the CMBR and the distribution of light elements in the early universe.
Yeah that has been argued, though those arguments fail for all sorts of reasons. It doesn’t even matter though, because those arguments merely conclude that there must have been a first moment of time(a universe with a finite past). None of them entail the non-existence of the universe. Hence there is still no need to invent causes to explain some sort of coming into being from nothing.
There are, but they’re irrelevant to my arguments. All we need to do is look at the evidence we currently have, and understand that we have no good scientific justification for thinking that there was at some point nothing in existence. Even if we assume the universe has a finite age in the past, it still doesn’t follow it was once not even in existence.
I agree. The brute fact assertion has no explanatory power, and seems to just be an assertion.
If you want an answer to the question “why is there something rather than nothing?” then you’re out of luck, because nobody knows. Some people want various answers to be true, like “God made something”, but then that just raises the question why God exists rather than nothing.
The fact is, we just don’t know. Too bad. We just have to live with it. There are things we don’t know.