Let's talk about time(physics). You go back in time and

Your premise is wrong because time travel is impossible.

>>7976911
Assuming it's possible, mann

>>7976917
uhh.. It's not a legitimate hypothetical question. It's like me asking you to assume something exists and doesn't at the same time.

>>7976905
this >>7976911
Temporal paradox is the result if you just assume it's possible
https://en.wikipedia.org/wiki/Temporal_paradox

>>7976917
Assuming OP is not a fag...
Wait, I think I went too far.

>>7976905
If your model of time travel permits temporal paradoxes, then it's retarded.

Obviously, the Novikov Self Consistency Principle is the best model, and all other models are worse than it.
https://en.wikipedia.org/wiki/Novikov_self-consistency_principle
http://authors.library.caltech.edu/6469/1/ECHprd91.pdf

>>7976905
The short answer is we don't know, there's no way to test how time reacts in those situations because we cannot create them and therefore cannot test them

>>7976905
According to your perception of time travel, there is a unique timeline and a unique universe, therefore creating this paradox. But if we were to follow the rules of your time travel, then it's already a paradox that the event of you arriving in the past didn't already occur.
Therefore the obvious possibilities are:
>You come back to the past but don't / can't alter any event.
>You come back and do things that were never supposed to happen and thus modify your present.
This is weird because some of your actions may have "already" been done by yourself and you're just perpetuating the circle.
But we're imagining a paradox situation in which you modify your own present, for example by killing your grandfather.
In this case, the only way that a paradox would not occur is by having two separate timelines/universes.
You're still alive in the universe you came from but never existed in the one you went. You would have then created an event which modified the destination timeline but never affected the origine one.

>>7976905
>therefore you don't exist
No, the sequence of events by which you exist is suddenly isolated from a singular chronology. That isn't even true for the time line you came from so it can't be said that you just "don't exist."

>>7977221
>In this case, the only way that a paradox would not occur is by having two separate timelines/universes.
A much less messy model is one on which your changes were always a part of the past. So there''s a single, unchanging, self-consistent timeline.

For example: if in ten years you'll invent a time machine and go back to kill your grandfather, you might open a photoalbum tomorrow and find the picture of yourself fucking up and dropping the knife.

>>7976905
How and why would there be a past instance of time in existence? Where is it? How would it be created just by stepping into a machine? The only way to travel to the past is to physically create the past and move there. And if you do that, your hypothetical and its implications become non-existent.

>>7977259
>How and why would there be a past instance of time in existence?
Because it's where we came from.

>Where is it?
Behind us.

>The only way to travel to the past is to physically create the past and move there.
Why would you assume that?

>>7977266
Please go and find me a past instance of time. I'll wait.

>>7977244
And then what? You go back in time fully aware that you'll fuck up and still end up fucking up anyway? Seems like the dumbest attempt at a paradox ever conceived.

File: Causal_loop_billiard_ball.svg.png (37KB, 498x599px) Image search: [Google]

37KB, 498x599px

>>7977279
>Please go and find me a past instance of time.
I don't need to. You just came from it.

>I'll wait.
Yes, exactly.

>>7977282
>And then what? You go back in time fully aware that you'll fuck up and still end up fucking up anyway?
Well, maybe. That was just an example picked to be obvious.
Anyway, trying to kill your own ancestors (or yourself, I guess) is a particularly stupid use of a time machine, so it shouldn't be too strange that it's doomed to failure.

The really interesting shit comes up around the reverse - jinn - which are items or information that cause their own origin.
http://thelifeofpsi.com/wp-content/uploads/2015/01/Lossev-Novikov-1992.pdf

>>7977312
There was one of those in LOST. I call them time wraiths.

File: X on SCI.png (31KB, 694x968px) Image search: [Google]

31KB, 694x968px

This has nothing to do with /sci/.

>>7977329
>There was one of those in LOST.
I've never seen that show, but from what I've heard that sounds fairly likely.

>>7977338
How is this /x/ material?
No-one is asserting that time machines exist, or that lizard-men from orion are building them. We're just talking about the physics involved.

>>7977338
N3

>>7977282
Because you are totally unaware of how you fuck up, you still end up doing it despite your best attempts otherwise. Perhaps the reason you fuck up in the first place is you trying so hard NOT to.

Personally I prefer the branching timeline theories, but that is just me.

How did you go back to a time before your time travel vehicle was created?

>>7977410
Why would you assume there's anything special about the time the machine was created?