According to the theory of relativity, there exists no “past”, “present”, nor “future”. Based on the speed at which you move, your assumption of time is relative to a continuum we define as space-time. This means that the amount of years that have passed since an event is relative to your position in the universe, kind of like a time zone. If you travel far enough into space, you will exist 100 billion years ago. You theoretically could manage watching the entire universe unravel the further you travel. Our world is not three dimensional but four dimensional, with the fourth dimension being time, and the past, present, and future all occur at once.