You would need to come up with a way to record past light images of the past which outer space already does. The lights you see in space are sometimes from galaxies, stars, and events from way, way in the past. If you could bounce a signal to a far away galaxy and bounce it back, then find a way to zoom in so to speak, perhaps you could witness the light images of the past like a projected image from somewhere or even here. Then you could use those recorded images, put them in a virtual reality-like simulator, and physically walk around those events in 3 dimensional space, kind of like Halo virtual reality style. You could just witness the events or through simulation actually change the future of those events at least in the simulated version.
Time is a thing that has already happened, that ham you were going to eat tommorow already happened on a different time-line, and these time-lines all lead to different dimensions, it may not be possible to travel back in time, but it is possible to travel interdimensionally... Theoretically at least. I should know I have dream deja vu, I go through this about 13 times a month and dream deja vu is basically a theory about a minority of people who have dreams every now and then about an event that will occur later in life (from hours to years later), only to wake up with no memory of the dream, you then remember the dream seconds before the event occurs, a few times I've been able to change what I did in the dream, theoretically travelling interdimensionally. By the theory of quantum physics, all people travel interdimensionally, but the few like me with dream deja vu (if fast enough and smart enough) can actaully CHOOSE which dimension to go to, unlike everyone else
Many current discoveries seemed impossible in the past. Therefore, there may be a possibility that travelling back in time would be a reality in the future. Science is a never-ending quest of discovery and common theories are proved wrong by different scientists. Thus there is no definite law that states that travelling back in time is possible, but neither does it deny the possibility.
It would be weird and so impossible to travel back to time IN OUR OWN UNIVERSE( since the future objects may interpret the past causes and causing the future objects to disappear, meaning the interpretation has never happened and the causes still exist and the future objects still exist and go back to the past and the same thing keeps happening, (...). I suggest a theory that includes infinite amount of universes that is the same as our universe but are at different times. To do time travel, "simply" create a gate to a universe.
All that is needed to make time travel actually happen, is needing to find something faster than the speed of light. In this case it is possible as now days, we have technology, which could be programmed to bit just even that tiny bit faster than the speed of light. Yes, it is possible.
There's a concept called Time's Arrow. Precisely, physicists don't know why time goes forth, because it is theoretically possible for it to go backwards as well, and that concept makes up for it. The truth is, if you take current _theories_ into account, it is possible. Either way, they cannot be currently proven to be neither true nor false. They're mathematical calculations that may or may not be flawed.
Though I don't know why I'm writing in 'yes' column, because even if it may make sense from the perspective of theoretical physics, it is absolutely pointless logically. Just what would happen if I go back in time and make sure my parents never meet?
I myself am convinced that the theory of time travel, especially the extent to which it’s been applied, will be one of the great jokes in the history books of the future. Posterity will marvel that so very flimsy and dubious an hypothesis could be accepted with the incredible credulity that it has. Any modern scientist would agree.
I doubt it is possible but even if it was, you would could not change the present timeline or worse.
Hypothetically, if you traveled back in time to change historic events, there would be no change to the existing timeline. There would only be a change in the new timeline you caused. For lack of a better example, lets say you went back in time to kill Hitler as a Child. If you did that in the past, you would have no reason to go back and kill him in the present so you would not kill him. The only way two contradictory states can exist is if they exist on different timelines. On the existing timeline, Hitler still exists in our history but in the other, he does not. To people of this timeline, it would seam like you just got disintegrated without any affect on history.
If it did not create a new timeline then things could be much worse. You travel back in time but that means that you will still travel back in time to that exact point and time. This means the moment you arrive, your mass instantly doubles. Problem is, it does not end there. Because the second arrival will have another future self travel back in time, and that one will and so on. Basically at the same moment you arrive back in time, so will an infinite number of you. That means your mass will suddenly become infinite and create an immeasurable black hole that destroys everything.
Think about the time stream like this, it's a fuse that's forever traveling towards the end of time you can't unburn the smoldering ashes of the past; so no you would not be able o see your great x100 gandfather who fought in the revolutionary war and you can't visit the end of the world 300 years after you're dead it is a scientific impossibility.
You would need an infinitely big cylinder filled with dark matter spinning on the opposite axis of the universe. A lot of people are answering this question with how the universe would turn out, and the timelines that would be made within the new realm created by the very act of going back in time and doing things like killing hitler. This is a science question, and it asks whether or not it is physically possible to time travel, and I guess my real answer is yes, but it's not probable. Or fathomable, with the information we've gathered as scientists thus far. You'd need to know how to make dark matter, which is currently unknown to scientists. You'd also need something infinitely big. Which is improbable.