What was it Einstein said to Georges Lemaître (father of the Big Bang Theory)? "Vos calculs sont corrects, mais votre physique est abominable" ("Your calculations are correct, but your physics is atrocious.")
Mathematics and physics are distinct. Nothing is ever "proven" in physics, hypotheses are confirmed to model the real world accurately, or not.
Arrogant scientists probably know less than 1/100th of 1% of all there is to be known......and the very essence of science is that it is almost daily discovering ——— hold on for this ————
IT WAS WRONG!
You’d think this process, after a few thousand years, would produce some humility in scientists..........
But boy - is that rare...........
and one cannot experimentally ‘prove’ the big bang