A collider the size of a galaxy

NewScientist has an article on The limits of knowledge: Things we'll never understand. It mentions quantum mechanics, black holes, origin of life, consciousness, Goedel, cosmic horizon, etc. Also:

Proof of string theory faces other, even bigger obstacles. Even with the extra dimensions in place, there remains the problem of getting to the energies at which string theory could be tested. Probing things on such small scales requires working at extremely high energies - to smash them into ever-smaller pieces takes ever more energy. That is why particle accelerators need to get more powerful to delve deeper into the nature of matter. "To test string theory you'd need a collider the size of a galaxy," Stannard says. The chances of building such a machine are slim.

Slim? It is worse than that. String theory does not make any testable hypotheses even if we had a galaxy-sized collider.