Then you'd have to go back in time and kill your grandfather, who is you, so you don't become your own grandfather so that you aren't alive to go back in time and become your own grandfather so that you don't give birth to Hitler.Lionsfan said:
A question about time travel
- Thread starter Sean Hollyman
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There isn't anything prohibiting time travel in physics though, and some particles (antimatter) are represented mathematically as travelling backwards in time. This can be seen on any Feynman diagram involving anti-matter.Fappy said:
OT; I honestly don't think you could not go back. By observing your future self you collapse the probability function into a single state in which you do go back.
I believe that is why you are generally advised against encounters with yourself, even when you don't plan to kill you. Alternatively, if you subscribe to the many worlds theory, then by not going back you prove that the other you is from a different universe in which you did go back, and is not the same as you, although he may be the same as the you who got visited if you think of it as diverging paths (or trousers of time, to steal from Terry Pratchett) rather than as distinct none interacting universes.
I've just realised that I have given this way too much thought.
Nothing happens.
When the other you came back in time, by talking to you he created an alternate time-line. In which he has YET to go back. It's still an option. He came from a different time-line, so you aren't relaying on the you of THIS time-line to go back and talk to yourself...
Basically, nothing, hard to explain.
When the other you came back in time, by talking to you he created an alternate time-line. In which he has YET to go back. It's still an option. He came from a different time-line, so you aren't relaying on the you of THIS time-line to go back and talk to yourself...
Basically, nothing, hard to explain.
People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff.
OT: It depends what universe laws are in play. Does affecting your own future change your single future or does it create a parallel universe where you have changed your future through a choice made at a single point. Or there's Back to the Future logic where changing your past erases your direct future OR creates a new time line from the point of interaction [footnote]BttF and BttF2 have two conflicting ideas about time travel and that pisses me off but that's for another time[/footnote]. Therefore in reality one (BttF1 rules) going back in time to greet yourself directly alters your past self as you know that in 10 years time you have to go back and greet yourself 10 years in the past. However in reality two (BttF2 rules) going back in time creates an alternate time line where you don't go back but in the alternate time line of the second reality you do have to go back.
Poor example is poor as simply greeting yourself changes nothing except your own expectations of the future. Directly altering the past by either revealing the future or killing someone/yourself in the past would be a better example of the Back to the Future thing I talked about above. However the given example is good to describe Terminator logic.
Terminator/Red Dwarf/MLP (yeah I went there) logic says that the future is set (no matter what John Connor spouts about "There is no fate..."). You will always go back in time to greet yourself and your past self will always wait 10 years until they travel back in time to greet their past self. RD/MLP: It's an endless circle that has no beginning and no end. Terminator: Destined to always go back in time. Either way it will happen and is impossible to escape.
In the end it doesn't matter because the universe we live in hasn't invented time travel so we don't know whose rules are in play
Terminator/MLP/Red Dwarf rules state that if your future self at some point traveled back to meet you, it will happen again and you can't prevent that. Somehow your own death will be foiled by the laws of fate.
Or Back to the Future logic where killing yourself erases your future self or Back to the Future 2 where it creates an alternate timeline
OT: It depends what universe laws are in play. Does affecting your own future change your single future or does it create a parallel universe where you have changed your future through a choice made at a single point. Or there's Back to the Future logic where changing your past erases your direct future OR creates a new time line from the point of interaction [footnote]BttF and BttF2 have two conflicting ideas about time travel and that pisses me off but that's for another time[/footnote]. Therefore in reality one (BttF1 rules) going back in time to greet yourself directly alters your past self as you know that in 10 years time you have to go back and greet yourself 10 years in the past. However in reality two (BttF2 rules) going back in time creates an alternate time line where you don't go back but in the alternate time line of the second reality you do have to go back.
Poor example is poor as simply greeting yourself changes nothing except your own expectations of the future. Directly altering the past by either revealing the future or killing someone/yourself in the past would be a better example of the Back to the Future thing I talked about above. However the given example is good to describe Terminator logic.
Terminator/Red Dwarf/MLP (yeah I went there) logic says that the future is set (no matter what John Connor spouts about "There is no fate..."). You will always go back in time to greet yourself and your past self will always wait 10 years until they travel back in time to greet their past self. RD/MLP: It's an endless circle that has no beginning and no end. Terminator: Destined to always go back in time. Either way it will happen and is impossible to escape.
In the end it doesn't matter because the universe we live in hasn't invented time travel so we don't know whose rules are in play
Actually the way I understand it is that it's impossible to accelerate to the speed of light. Once you're there then you're fine. Somehow.sextus the crazy said:
Interesting question. Do you know this as your past self or is your future self warning your past self to end their life before the point where you travel back in time. Again, whose rules are in play?Aylaine said:What if you don't expect to be alive in 10 years? Would that force some quantum collapse or something?Sean Hollyman said:
Terminator/MLP/Red Dwarf rules state that if your future self at some point traveled back to meet you, it will happen again and you can't prevent that. Somehow your own death will be foiled by the laws of fate.
Or Back to the Future logic where killing yourself erases your future self or Back to the Future 2 where it creates an alternate timeline
We call that a stable time loop.TimeLord said:
It's essentially the uni(multi?)verse's answer to paradoxes: events are structured such that things will abide by a logical flow.
Homestuck actually has some pretty great casual time-travel shenanigans. In the event you fail to maintain a stable time loop, you and your rendition of events will split into an offshoot "fake" timeline that will eventually unravel and cease to exist. Time travel, however, permits you can go back to before the critical event and set things right, allowing "alternate future" you to exist in the "real" timeline and enabling multiple versions of yourself to exist at one time.
This actually gets exploited more than once for things like Dave's alternate future self becoming his own spirit guide, and having doppelganger armies amass from doomed timelines. Trust me, it makes sense.
But then which one of you goes back 10 years? If you go back 5 minutes then the version of yourself you tell to go back can't wait 5 minutes and go back to tell you to go back 10 years. Unless the one who traveled back 5 minutes then goes back 10 years, the person who you reminded to go back waits 5 minutes, goes back 5 minutes to remind yourself and the travels back 10 years. Circle repeats.Aitur said:
Well, I don't suppose there's a multiversally accepted authority on this matter, so you can call them whatever you want.TimeLord said:I call them hard loopsC F said:
*cough* [http://tvtropes.org/pmwiki/pmwiki.php/Main/StableTimeLoop]
Yeah I know. I just wanted to plug a two year old threadC F said:Well, I don't suppose there's a multiversally accepted authority on this matter, so you can call them whatever you want.TimeLord said:I call them hard loopsC F said:
*cough* [http://tvtropes.org/pmwiki/pmwiki.php/Main/StableTimeLoop]
It's impossible to go the speed of light if you have mass. If you don't, you must travel at the speed of light. Think of mass as subtracting velocity.TimeLord said:
I send the me from 5 minutes ago back and I let the me from 10 years ago worry about all that paradoxical stuff. Then I say screw the universe because I've got a time machine! (and I'm not screwing it sonically either!) Before zooming off to relieve myself in the primordial soup.TimeLord said:
If I met myself from the past, than my personal timeline will change. If I refuse to go back to the past myself then my past self will enjoy his own timeline why my current self who was visited by my future self, will continue to exist in that time line. That's what I would think would happen anyway.
Why does everyone talk about time as if Wednesday is a place you can walk to?
Time is a measurement of change in a system, therefore all time travel would be manipulations of change. If you wish to travel forward in time, stop change in yourself until the rest of existence reaches the state of change you wish to be at. To travel backwards just take apart all existence and reassemble it in the state it was at the point in the past you wish to be at. Since you omitted undoing yourself the previous you won't be there unless you cheat and use some excess space dust to make a spare earlier you (should be easy after dissassembling and reassembling all matter and energy).
Time is a measurement of change in a system, therefore all time travel would be manipulations of change. If you wish to travel forward in time, stop change in yourself until the rest of existence reaches the state of change you wish to be at. To travel backwards just take apart all existence and reassemble it in the state it was at the point in the past you wish to be at. Since you omitted undoing yourself the previous you won't be there unless you cheat and use some excess space dust to make a spare earlier you (should be easy after dissassembling and reassembling all matter and energy).
Well, personally, I subscribe to the "stable time loop" theory. Even if you didn't intend to go back in time, some wacky series of events would have you stuck ten years ago, and oddly complelled to talk to your past self.
Well not planning to and actually doing are two different things. If you don't plan to live till 30 but your 31 year old self travels back in time to meet you. That obviously means that something happened in the future to make you wait till 31 before going back. Causing the loop to endlessly repeat (Red Dwarf/MLP logic) with no chance of breaking the cycle. But if you go by Back to the Future 1 logic and have seen your future self greet you but die before you go back to meet yourself in the past, you would break the loop. But how would it affect your past self having not met her future self? Was it the meeting of her future self that made her decide to not want to grow up to travel back in the first place? If so would she grow up not knowing and then reach a specific age where she has to go back in time for whatever reason?Aylaine said:I'm not nearly as versed on time travel as you, my time traveling companion. However, I can answer that part. My past self knows this without a doubt. For all intensive purposes, I do not plan on being alive past 30.TimeLord said:
So what happens now?
Its a paradox. What happens depends on your own notion of what time travel means. Paradoxes like these are why time travel can never actually exist.