Well, I do tend to think there are other universes out there most likely. But as for everything else, it's a bit too complicated, I think, for humans to fully understand. The black hole thing is interesting, though, because if there was an observer who saw another person get sucked into a black hole, they would basically see them explode into tiny little particles before they even got to the singularity. However, the other person's perspective would be completely different. They would actually be totally fine, just stuck inside an abyss of nothingness. At least, that's the theory, since no one's actually seen anyone get sucked into a black hole. So two different realities would exist at one time, one in which the person was dead and one in which they were still alive. Kind of like Shroedinger's cat.