> if the contradictory data were to mount, and be confirmed and reconfirmed by multiple researchers over time, well, I'd like to think that we'd have the intellectual courage to admit that this explanation doesn't seem right, even though we don't have a better one.If we don't have a better one, and if our current model makes reasonably good predictions about many things, even if its predictions aren't as good about some things, we wouldn't say our current model is wrong because it isn't wrong. What we would do is to start having more conversations about our current model's domain of validity.
Perhaps some historical observations will help. Consider the history of physics, or more specifically mechanics. Before Galileo and Newton the best model of mechanics we had was Aristotelian physics. When Galileo and Newton came along and gave us a better model, we dropped Aristotelian physics, and now if you asked most physicists they would probably say Aristotelian physics was wrong, period, without feeling the need to add qualifiers or explanations. This is the kind of case I think most people are thinking of when they talk about falsifying a theory with contradictory data.
But since that transition, there have been no theories of mechanics that have been falsified by contradictory data. When special relativity came along, we didn't drop Newtonian mechanics, and physicists now don't say Newtonian mechanics is wrong. They just say it has a limited domain of validity: it's an approximation to relativity that works reasonably well for relative speeds much smaller than the speed of light.
Similarly, when general relativity came along, we didn't drop Newtonian gravity and say it was wrong; we just clarified that the domain of validity of Newtonian mechanics is also limited to weak gravitational fields. And even if GR hadn't been discovered, physicists would still have continued using Newtonian mechanics even though there was data known in the 19th century, like the extra precession of Mercury's perihelion, that was not consistent with Newtonian mechanics. Newtonian mechanics still gets taught to physics students today, and is still used for practical computations in all kinds of contexts.
When Eric Lerner claims that "the Big Bang didn't happen", he is claiming that the Big Bang theory is destined to go the way of Aristotelian physics. But none of the data he cites justifies that claim. At best the data justifies a claim that the standard Big Bang model that assumes homogeneity and isotropy is an approximation with a limited domain of validity--which cosmologists all already agree on anyway! What we are still working out are the exact limits of its domain of validity. In other words, cosmologists in general expect our current Big Bang theory to work like Newtonian mechanics: we might discover models in the future that are more comprehensive and to which our current model is an approximation in some limited domain, but that's very, very different from it being falsified.