Wormholes and paradoxes

[Napoléon]

So I've been delving into the whole "will we ever time travel" question, and wormholes.

One of the things I don't buy is this whole idea of shooting yourself from the future to kill yourself in the past.

Now, while reading some of Hawking, he talks about wormholes as though they could be used as a means of FTL travel. And I've heard this idea from other sources too. That if you could pull spacetime back on itself that you'd be able to make a hole from one point to another. It doesn't seem all that illogical (provided you figured out a way to find a hole from one point of space to another, which probably isn't possible realistically).

However watching this video I get rather confused.

http://www.youtube.com/watch?v=UJNhLDwj6kI

This video talks about time travel explicitly. In the sense that, you could view yourself through a wormhole, from a minute in the future.

Now, my understanding of how this would work seems to suggest that this whole idea of wormholes is incompatible with what is suggested by travel with wormholes in the first place. Seeing as everyone has their own account of time, and it depends on where you are in the universe, and not so much when, I don't see how this scenario would ever come to fruition. Logically speaking, if you opened up a wormhole, from one side of the room, to the other, why would that ever mean you would be able to shoot yourself in the past? Now, ofcourse, everything we see is theoretically in the past, but from what I understand of this particular scenario, it wouldn't be like killing yourself from 1 minute ago like the video would suggest, but rather shooting a bullet and having it simply follow its path through the wormhole back at your present self. Where is the need for two versions of yourself in this scenario?


Sorry for the ramble, probably made no sense whatsoever.

Anyways, wormholes being compatible with time travel seems illogical. Thoughts?

[pocaracas]

Yes, wormholes make great sci-fi.

[Rayaan]

I've heard of one idea which argues that when you go into the past and kill yourself (assuming that such a thing is possible in the first place), you physically create two different histories of yourself, which basically means that in one universe you are alive while in another universe (or a multiverse) you are dead.

Then again, the whole time travel thing is just a little too complicated for me to understand.

[KichigaiNeko]

Shit just watched a doco from Brian Greene regarding this.... didn't feel any further enlightened... must have been old hypothesise

http://worldsciencefestival.com/blog/ask..._causality

This is only 10 mins of an hour programme

http://youtu.be/MO_Q_f1WgQI

[Napoléon]

I've heard of one idea which argues that when you go into the past and kill yourself (assuming that such a thing is possible in the first place), you physically create two different histories of yourself,

Yeah this is what I'm having trouble with.

From what I understand, even if you could 'go into the past' with FTL travel, it still wouldn't from what I understand create this need for an alternate history in which there is another version of events.

I just don't buy it.


But yes, it's rather complicated. I was going to start a thread on annoying paradoxes, I guess that might have got more interest, but I needed a rant about this particular one and to have some other insight into it.


And cheers for the vid Kichi!

[John V]

Rent Loopers, should answer all your questions.

[Anomalocaris]

We don't have a good theory for time.

So we can't extrapolate with confidence how things would behave when time is manipulated in a way whose analogue we have not witnessed before.

One notion is the causality relationship that defines time is nothing but an artifact of our cognition conditioned by our perception. If there is no true causality, then there is no causality paradox of shooting your grandfather before your father was born. But since time has never been manipulated by us before in a way that would reveal the nature of the limitations of perception of causality, we assume causality is real and can't be broken.

[Ryantology]

If time travel is possible, it follows that time travelers from the future are here, or have been.

If time is a single causal string, then perhaps my life's memories (not to mention world history) may be fluctuating wildly from one moment to the next as changes are applied and we just don't know it. That'd be trippy.