Is time travel really possible?
I think science says time travel to future is possible but to past is more likely not possible.
I think traveling to past would break causality (which seems one of foundations of reality around us)
because of the Grandfather Paradox (which should be true even for subatomic particles; not just humans).
I think this is also called Cosmic Censorship (preventing events out of causality from happening).
But I also had read about some quantum particle experiments which could be interpreted as future events can have an effect in the past.
I don't know enough about quantum mechanics to fully support that interpretation but I think it is possible.
I had also read that anti-particles could be interpreted as particles moving backwards in time.
I have the same thought on that interpretation also.
We could also consider what would happen if we traveled to the past anyway.
I think first of all we could be creating a Butterfly Effect on the weather which would change all future weather of our world, over time.
Think about how many wars in history won by weaker side because of the bad weather.
(I had read Mongols who conquered China tried twice to conquer Japan but failed because of the bad weather (a typhoon?).
Napoleon failed at conquering Russia because of the bad winter?)
Also think about how different weather would change history of traffic accidents and/or crimes, even daily routine of countless people.
I had read a counter argument against Butterfly Effect which was saying most (small scale) atmospheric disturbances actually would get dumped down.
If true then what scale disturbances do not cause Butterfly Effect must be determined, to know how we could preserve to future history, if we traveled to past.
Also I think there maybe psychological and/or sociological counterparts to Butterfly Effect (on weather).
Can we see daily thought history of each person like a dynamical system similar to an atmospherical system?
If we change daily thought history of a person in the past, would that can change whole future daily thought histories of that person?
If so, can that change propagate to other people and eventually to all humans of the future?
How about creating sociological disturbances like starting a new fashion, new words/expressions of language?
How about creating scientific and/or technological disturbances like bringing advanced knowledge/tech from the future?
I think Butterfly Effect is much more general than most people would estimate.
Which means traveling to the past would be very risky if we want to preserve our own history.
Time travel to the future on the other hand seems okay for causality.
Relativity says if a spaceship can approach speed of light then time would slowdown for the ship and anyone inside of it.
That means anybody inside of the ship would age slower.
But I think by far the most practical way to travel to future would be suspended animation.
When all biological processes inside an organism slowdown that organism would age slower naturally.
It seems there are many organisms on earth already can do it.
I think it is also interesting that there are even religious stories about time travel to the future.
One of them is "Seven Sleepers" in Christianity and Islam.
Another is the story of a prophet(?) in Judaism/Islam(/Christianity?) who "slept" for decades and came back to his town/city.