Stick to the facts …

… Physicists and Philosophers Debate the Boundaries of Science | Quanta Magazine. (Hat tip, Dave Lull.)

Whether the fault lies with theorists for getting carried away, or with nature, for burying its best secrets, the conclusion is the same: Theory has detached itself from experiment. The objects of theoretical speculation are now too far away, too small, too energetic or too far in the past to reach or rule out with our earthly instruments. So, what is to be done? As Ellis and Silk wrote, “Physicists, philosophers and other scientists should hammer out a new narrative for the scientific method that can deal with the scope of modern physics.”

But if the "scope of modern physics" falls outside the realm of possible experience, it would seem that it is no longer science, but science fiction. Every now and then it useful to employ the words "I don't know."