In case of deletion ...
"Of course, at some point your ability to build ever bigger particle colliders will fail, so you can never verify that you have The Final Theory of Everything."
While true of purpose-built accelerators, there are other ways to access higher energies -- the universe itself is a low luminosity 10^10 GeV accelerator accessible by data-mining cosmic ray events. That gets us most of the way (logarithmically) to the Planck scale. We'd just have to change our idea of experiments from contemporaneous groups to a "generation ship" model.
And that could be a good way to think about empirical economics -- we've only had a few decades of decent macro data. Maybe we need to wait it out a few more decades before we can draw any macro conclusions ...
[And now it's gone ... and I have no idea why ...]