Theory trumps reality in this example, since the assumption is that the timeline would center around humanity, which it might or might not. For example, say a

Theory trumps reality in this example, since the assumption is that the timeline would center around humanity, which it might or might not. For example, say a time machine was created on a planet for which interplanetary travel was impossible. Time would be in constrained to that planet and would likely appear as a black hole to any observer outside its sphere of influence; meaning any matter entering that space would be transformed to such a degree it would be relatively speaking unreconizable and unobservable due to the constant flux of time relative to the speed of light.