I have a conceptual question about the epistemological status of string theory. According to Popper, a scientific theory has to be falsifiable, meaning it must make predictions that could, in principle, be refuted by observation or experiment.
In the case of string theory, is it considered falsifiable only in principle, since any observable effects would show up at extremely high energies?
Or does it actually fail Popper's criterion in practice, given how hard it is to extract specific, testable predictions, especially with the whole "landscape" issue?