Grandfather paradox

jm1372

Temporal Novice
The grandfather paradox is a paradox of time travel, supposedly first conceived by the science fiction writer René Barjavel in his book "Future times three" ("Le voyageur imprudent", 1943). Suppose you travelled back in time and killed your biological grandfather before he met your grandmother. Then you would never have been conceived, so you could not have travelled back in time after all. In that case, your grandfather would still be alive and you would have been conceived, allowing you to travel back in time and kill your grandfather, and so on.

The above is quoted from wikipedia.

Is this possible? When "X" kills his grandfather "X" causes a baby version of "X" never to be born. If "X" is able to do the act of killing his grandfather it seems it would not be able to be undone because it is a past event. It seems that "X" would be a added part to that timeline and not related to it in anyway and not affected by anything directly that takes place there as long as it does not affect "X" directly. Such as the grandfather shoots "X" in the leg before he dies then "X" will always have a limp no matter where "X" is. The grandfather will die and "X" would be left on that planet to continue on with life.

Now that timeline that the grandfather was shot on will not have a version of "X" called "Y" to come back in a time machine and kill the grandfather in another timeline. Is it possible that such a occurance is a cycle? By that "Y" never existing because "X" killed his grandfather it seems that the timeline where "Y" would have come back to to kill his grandfather would remain just as the original one that "X" came from. I see how the idea that the grandfather paradox presents is possible just not on the same timeline. It seems it would work well on just 2 timelines that cycled.

While it may be possible that there is a infinite amount of timelines that are identical or nearly identical that can be returned to and influenced because they are actually happening at the same time as the original timeline just behind it. I beleive it to be a question if you are actually going back in time or are traveling to a different timeline that is just behind yours. If you were to travel back in time would not those actions already have happened and you would just be actually watching them take place unable to make contact with anything.

The problem with the Grandfather Paradox theory is that when a event takes place it is history. It can't be affected by anything because it has happened before the repercussions take place. While "X" may just evaparote under some reasoning that I can't see, that grandfather is surely dead in that timeline. If by killing the grandfather "X" was to no longer exist what would happen to that time that "X" was on. Would it stop to exist also. Would time be restarted from the begining to give the grandfather back his life because his son was not actually able to come back and do the deed. It seems imposible because it is already based on the idea that the son was able to come back and pull the trigger and kill the grandfather. It seems to suggest that multiple timelines must exist for any of these things to be possible.

If there is just 1 timeline that everything exist on does it exist from start to end or from start to infinite. During the life of "X" the only time that "X" could ever hope to go to and not find 2 of him, either as a child or a old man would be the exact time that he left. Not a thousandth of a second behind or forward or there would be another. It seems that exact time is his timeline and everyother time is anothers.

These are just some of the ideas I had on the Grandfather Paradox, it just does not seem to stand up to logic to me. Perhaps I am looking at it the wrong way. When I read it I surely believe it talks about 1 timeline. How else could it directly effect "X" if it's not 1 timeline and that one of course being "X"s. How can "X" kill his grandfather and not kill his grandfather because he does not exist, he never would have been able to do it the first time. At some time he existed and he killed his grandfather, for him to then unexist and his grandfather to return to life time would have to move backwards to before the time that the grandfather was shot. It would then either continue on until the time a time machine was invented and the son came back, or the son would come back in a time machine and once again kill the grandfather,(unless freewill is such that choices are made and can differ even if all the leading events are 100% the same, which one assumes effects the decision at a 100% accuracy, at least I do). Either way time gets stuck in repeat. Is the world just a video tape God left in the VCR and it is playing through and stoping and rewinding and playing through again?

/ttiforum/images/graemlins/smile.gif Sorry for all the it seems, I don't like saying anything as if it was a certainty for I am sure I am wrong and that at the least someone will be able to point out many ideas that at least cause for multiple possiblities. For if not then this would be no longer a theory and we would not be talking about philosophy but science and I don't do science, j/k.

I am not submitting this for any reason other then to hear people thoughts on the subject and often when I read things that don't add up to me I would like to talk about them. But unfortunatly talking about things such as this with the average person is not possible for one even though these things are not indepth at all it seems to go over their head or over their interest.
 
The idea of cycling timelines holds well when talking of 1 person coming back and doing something to effect his ability to return and do it again in the future. Such as killing his grandfather, or destroying a time machine. As long as one believes that each timeline is the same and that events would unfold just as they had in the other's. If "X" comes back and does not, and never did, kill his grandfather the actions he makes as long as they do not effect the ability for his future self to be born or for the time machine to be invented and to be used in the same way that he used it would result in a repetitive timeline.

Would the timeline that "X" was supposed to go to even exist before he arrived? If it always did exist then the repetitive timeline is reasonable. What would happen if 1000 people all had time machines? Would each appear on the same timeline? Is it possible for a time traveler and his buddy in different machines to both travel back to the exact same timeline. Or would they be on a different one each and every time they traveled in time. Never able to return to the same one they came from or went to before.
 
But the grandfather paradox is surely only a paradox if their is only 1 timeline; X, in killing his grandfather, causes himself not to exist, hence his grandfather lives and so he exists again, yadda, yadda, yadda...

Example of how it could be non-paradoxical:
If you take the set of all realities though, X starts in reality 1 (let's say for ease). He goes back, and kills his grandfather. Now, he returns to the present, but reality has changed - this is reality 2. In reality 2, his father (and hence himself) were not born. Seeing how screwed up this is for him, he goes back again to just before the point of divergence between realities 1 and 2 - when he killed his granddad - and knocks his earlier self unconscious just before earlier X was about to kill his grandfather. He then grabs his earlier self and they both return to the present, now in reality 3.
In reality 3, his granddad was almost killed by a young man, who was knocked unconscious and then vanished. The X who is native to reality 3 exists here, as do the other 2 X's - the first X who was knocked unconscious, and the later one who knocked him out (and incidentally is now not the future of his earlier self...that could cause a small headache).

And yet, no paradox. Voilá! :D
 
the only time that "X" could ever hope to go to and not find 2 of him, either as a child or a old man would be the exact time that he left. Not a thousandth of a second behind or forward or there would be another. It seems that exact time is his timeline and everyother time is anothers.
i used 2 think this as well, but your right for going back, he would find 2 versions, but when u return to ur present, (assuming theres only 1 time line) then all u would have to do would be to arrive any time after you left originally
 
i used 2 think this as well, but your right for going back, he would find 2 versions, but when u return to ur present, (assuming theres only 1 time line) then all u would have to do would be to arrive any time after you left originally

But there's my point - you're assuming the existence of a single timeline. I'm assuming in the possible example that I gave, that every reality is playing out in its' own timeline. So the reality that both X and his later, now disjointed self, return to is not the same one that X originally left, hence why they meet a new X whose grandfather was *nearly* killed.
 
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