Time Travel

It is physically impossible to travel back in time because how time actually works, let me try to explain why.

In the 19th century, scientists realized the speed of light is always constant to everyone. A few decades after that discovery, Einstein came up with a theory explaining just how come. Time is relative, in a way the closer you get to the speed of light, the faster the outside world seems to run. We know that is true because satellites and some other things we use daily are based on the principle time is relative. So, if you want to reverse time, you will have to accelerate past the speed of light. That's impossible because, when you reach the speed of light, the Universe will have already ended, as, from the perspective of something at light speed, the Universe starts, happens and ends in one single instant.

>>9127470
Time travel to the future and past is not possible.

Call this moment youre in right now reading this t0. At t0 the entire universe is in some state relative to you. As time goes on, the state of the universe changes. Travel back in time implies you can completely reverse the entire universe to a previous state. This is obviously not possible because the very fact that you'd be in the past creates a different past state. Time travel to the future is the same. If you do nothing and move through states of the universe as you currently are, at tx, you'll find some state x. If you travel to the future you'd travel to some new state x'. In this new state, everything you would have done didn't happen.

>inb4 no free will

>>9127525
Time travel to the future is possible though.
Just not to the past.

>>9127525
"time travel" to the future is feasible if we can get up to the speeds. Is it true time travel? Nah, but you can still get there.

We are moving forward in time, we can change rate at which time happens (dt(observer)/dt(you)) by moving faster, or by getting closer to a gravity well stronger to earth's.
For the observer, you are moving slower, for you everything around you is happening faster.

We can even slow it to a halt in a black hole (from the observers perspective, you are static. From your own perspective, you'd be falling in the black hole forever.

But we don't know if we can somehow reverse it...

If string theory is right, it could be possible to tear a hole in the 5th dimension and move to an earlier point in the forth dimension, but this is little more than sci-fi...

Titor is likely just a larper selling his hoax.

Cause THEN Effect.
So hypothetically it's possible to travel to the future but not the past.
After quantum probability fields collapse, then that's that.
It's really that simple.

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>>9127470
>What do you think about the John Titor story?
I think it was a hoax.

>what do you think about time travels?
Who knows. If we knew everything there is to know about the universe then science would no longer be a thing.

>>9127571
how do we explain the gap between the existence of quantum retrocausality when no such thing exists on non-quantum scales?

It's possible but it won't be done using relativity, because there's better explanations for eg Michelson-Morley etc without time dilation and length contraction

OP here

personally, and in a very idealist way, i think that in the future it could be possible, just like we overcome gravity and went to the moon, many things that seem impossible in the past became possible, i just love to see all the theories that people have