Thanks for the reponse.
What evidence would disprove the big bang? What experiment could we run that would that, if successful, disprove the big bang?
The Big Bang theory depends on the support of mathematical models, known laws of physics, observations of astrophysical phenomena, and a LOT of interpretations of things that could have multiple interpretations.
The Big Bang itself could be challenged to the point of unusability if a few of its key support items were shown to be false or to not support the theory as originally posited. To disprove the entire theory would be pretty tough, but possible if some new set of observations showed massive flaws in the existing descriptions. Every year, new observations flood in as our tools and telescopes and satellites get better and more refined.
I do not doubt for a moment that some of what makes up the current theory is going to be thrown out in the coming years, and replaced with a better description of what we think went on at The Start.
That's what (to me) shows the power and beauty of the scientific method. The very process of challenging the weak parts of a theory, will often also strengthen its correct parts by providing corroboration, such as confirming predictions.
> What experiment could we run that would that, if successful, disprove the big bang?
Well, suppose someone says, "I think there's a flaw in the description, here, and it's not 'A', it's 'B', and I propose the following experiment to test which is correct." Suppose that 'A' is critical to support of the theory. So somebody funds the experiment, and it is run, and ... it turns out 'B' is a better model for the observed data. That would shake the theory a bit. Now suppose that the theory gets modified/corrected to incorporate an explanation for the 'B' observations -- without breaking the explanations for all the other observations to date. It's a better model for the challenge.
But what if it could not explain them, even when modified? That could show that some fundamental aspect of the theory is incomplete or flawed.
If that challenge could not be met, then the theory falls. Many long-standing theories have thus fallen over the course of scientific study. The Big Bang is a good theory, but it's not invincible.