I hope I should not have posted this in sci-fi channel if this is too stupid I give moderator permission to delete it just send me notification. Based on little bit I picked up about Heisenberg Uncertainty Principle and the fact that the reality of an event is not established until is observed. I don't think you can alter the future through time travel. I say this because I am thinking that to the time traveler events he encounter on his voyage are just that Events. Therefore, I am thinking that he will create his own reality events being realized as he is there to view them. However, he could not change my reality because they happened to me already I myself collapsed the wave function too and perhaps this can not be undone. He however, interact with me via time travel will collapse these time Events wave functions and create a outcome. It's almost as if events on timeline are result of everyone and thing on it collapsing each and every event. If he suddenly appears somewhere time his mere being there changes events, thus even using time travel to predict future may not even work. Because he put himself into another causality loop, for lack of better word. Well that is my take on time travel I know there is no math or advanced technical terms but could someone comment on it? I'm curious what the professionals think about it. PS: I write this before bed and i'm tired so excuse bad english or any pourly assembled thoughts.