I mean, here we are and we have this thing called energy sort of, which turns into solid matter when it gets cold so we have stuff around us and planets to walk on and as long as it`s feed energy it`ll stay the same and you might wonder is this energy a fixed amount or does it become more over time because it`s a perhaps a living thing, doesn`t that mean it`s really a magical thing? I don`t personally believe in time-travel and stuff because in order to do that you had to somehow change the nature, I mean to for example reverse it and every person with a soul would have resisted the changes also, I also think that since the universe is a positive place to be that it`ll never turn just cold and dead, but the matter would just turn into energy again and theres no bubble I think, it`s just infinite space in every direction, so no black matter or something like that in my opinion, I`m not really into quantum-things ether so much, you can speculate about a particle that gives everything else it`s matter like the god-particle, but I think it`s all just energy anyways