Well established on the unfounded foundation that there was a beginning.
Again, you state something without evidence. The evidence shows the "big bang" back to a specific point. If you wish to disingeniously try to argue that the point before that is not the beginning, and then use that to argue for no big bang, you're simply ignoring all the evidence in favor of a deceptive, obviously malicious rhetorical argument.
The evidence back to the "big bag" is fine. It's established, and unless you have extraordinary evidence to counter it, that part we need to accept.
Since we can accept that, then, whatever happened before is the beginning, be whatever it may be.
We don't have to know, or care, what it was, since we have the evidence for what comes after.
If you wish to call it a razziframizibledingdong rather than a "beginning" that has no effect on the part we have evidence for.
You would dismiss the hard, cold evidence in favor of a semantic folly. It is clear, at least to me, that your folly is intentional, as well.
I am sure we need no analogies of houses being built of foundations of sawdust; opps, I guess I just did. Where is the science that evidences a beginning?
The quote directly above is a classical example of assuming something not in evidence.
Show your evidence for both your hypotheses, that there is no "science that evidences a beginning", and for your folly that a lack of same overcomes all the cold, hard evidence for what happened later.
What is your position, in any case? How did we get here? Why?