Loop quantum gravity actually does have at least one testable conclusion: non-constancy the speed of light at high energies. There's even some support for this as of a couple of weeks ago, with measurements from the Fermi telescope.
A quick Internet search reveals that there is research being conducted to test this testable conclusion. (Full disclosure: I never understood special relativity very well, much less general relativity; I do not feel qualified to comment on the results described in the link, attractive though they are.)
Another alternative reading is "can theoretically be checked". Obviously, this is strictly weaker, but still covers a large number of logical failures (e.g. creationism).
Loop quantum gravity actually does have at least one testable conclusion: non-constancy the speed of light at high energies. There's even some support for this as of a couple of weeks ago, with measurements from the Fermi telescope.