Sure, experiments will always be the ultimate arbiter of truth. But if you don’t “visit the territory”, you’ll never know that your map is wrong. The map has be

Sure, experiments will always be the ultimate arbiter of truth. But if you don’t “visit the territory”, you’ll never know that your map is wrong. The map has been challenged in many many ways that seemed more impossible than large scale QC, and the map turned out to be right. Backwards time travel isn’t possible in general relativity, though, making very mild and physically plausible assumptions about the spacetime. Same in semiclassical quantum gravity.