If you go back in time and kill your grandfather, (Paradox)

that would eliminate you and your history from existence, and if you never existed, how could you have ever gone back in time and killed your grandfather?Elemayo

that would eliminate you and your history from existence, and if you never existed, how could you have ever gone back in time and killed your grandfather?Elemayo

Simple answer is that you CAN'T go back in time and kill your grandfather, because you were born. Moments do not change. Moments are eternal. When you first met your wife, that moment persists for eternity in the grand totality of spacetime. If your grandmother gave birth to your mother, then your grandmother ALWAYS gives birth to your mother in THAT moment in spacetime.

Moments do not change.

So the simple answer is that you CAN'T kill your grandfather before your parents were conceived. That DIDN'T happen, so it WON'T happen. Not even if you use a time machine to travel to the past and TRY to make it happen. Think The Terminator and 12 Monkeys. Why did the Terminator fail to kill Sarah Connor? Because it COULDN'T kill Sarah Connor. Spacetime will not allow that to happen. And in 12 Monkeys, the time traveller freely admits to the people in the past that he can't change ****, because what happened happened and they are already dead.

Moments do not change. And if your parents were born, it's it's impossible to go back in time and make them not born. That moment already exists, and it is unchangeable.

However, there is the many worlds hypothesis, which supposes that anything that can happen WILL happen in some alternate universe. If a particle has 80% probability of being here, and a 20% probability of being there, then in 80% of worlds it will be here, and in 20% of worlds it will be there. In this framework, if it CAN happen, then it WILL. The only thing is, if you do manage to kill your grandfather, then that happened in a world in which you were never born. This is a different universe from which you came, so there's still no paradox. In this universe, you were born and you went back in time. You emerged in a different universe, at which point you killed THAT version of your father. This is acceptable, because in this new universe, you are never born.

You've obviously haven't watched enough Futurama.The_Zoid

Haven't you seen Roswell that Ends Well? It merely means that you impregnated your grandmother, not your grandfather, who is dead.

Foolz3h

[QUOTE="Suddenstriker52"]

2 things might happen.

1. You create aparalell universe and whatever you do has no effect on the time which you came from.

or

2. Your destined to fail to kill your grandfather because everything you do in the past has already been done. All you are doing is just fulfilling your part in thathistory.

carrot-cake

Well, strictly speaking, if we are talking about parallel universes, then the person that you kill ALSO isn't your grandfather. He's NOBODY'S grandfather, because he is dead.

So...as someone else already said, you CAN'T go back in time and kill your grandfather before your parents are conceived. Technically, in either time travel framework, it's still impossible.

Parallel universes.
I personally think this paradox tells us that time travel is impossible without the creation of parallel universes every time on were to time travel.
For example; if I were to go back in time, I would probably accidentally change something. This changes the future that I know of. Therefore from my perspective, the universe has changed, therefore creating a different time line that which I came from. This would create a parallel universe. Basically the idea the Doc. gives when he explains to Marty when he explains about time branching off into a different direction.
Sure the universe from which you came would still exist, however you would be gone from the time you went back in time, probably never to go back. Ever.
Does time travel exist? Who knows. If it does and my assumption is true, then which is the original universe? Are we a branch of an 'original' universe in which someone went back in time and changed a few things!?

IS JESUS FROM THE FUTURE!?carrot-cake

See, this is where I get confused. I stayed with it until the last sentence. How could Jesus be from the future?

[QUOTE="carrot-cake"]

[QUOTE="Suddenstriker52"]

2 things might happen.

1. You create aparalell universe and whatever you do has no effect on the time which you came from.

or

2. Your destined to fail to kill your grandfather because everything you do in the past has already been done. All you are doing is just fulfilling your part in thathistory.

MrGeezer

Well, strictly speaking, if we are talking about parallel universes, then the person that you kill ALSO isn't your grandfather. He's NOBODY'S grandfather, because he is dead.

So...as someone else already said, you CAN'T go back in time and kill your grandfather before your parents are conceived. Technically, in either time travel framework, it's still impossible.

[QUOTE="carrot-cake"]

Parallel universes.
I personally think this paradox tells us that time travel is impossible without the creation of parallel universes every time on were to time travel.
For example; if I were to go back in time, I would probably accidentally change something. This changes the future that I know of. Therefore from my perspective, the universe has changed, therefore creating a different time line that which I came from. This would create a parallel universe. Basically the idea the Doc. gives when he explains to Marty when he explains about time branching off into a different direction.
Sure the universe from which you came would still exist, however you would be gone from the time you went back in time, probably never to go back. Ever.
Does time travel exist? Who knows. If it does and my assumption is true, then which is the original universe? Are we a branch of an 'original' universe in which someone went back in time and changed a few things!?

IS JESUS FROM THE FUTURE!?Maniacc1

See, this is where I get confused. I stayed with it until the last sentence. How could Jesus be from the future?

[QUOTE="Maniacc1"]

[QUOTE="carrot-cake"]

Parallel universes.
I personally think this paradox tells us that time travel is impossible without the creation of parallel universes every time on were to time travel.
For example; if I were to go back in time, I would probably accidentally change something. This changes the future that I know of. Therefore from my perspective, the universe has changed, therefore creating a different time line that which I came from. This would create a parallel universe. Basically the idea the Doc. gives when he explains to Marty when he explains about time branching off into a different direction.
Sure the universe from which you came would still exist, however you would be gone from the time you went back in time, probably never to go back. Ever.
Does time travel exist? Who knows. If it does and my assumption is true, then which is the original universe? Are we a branch of an 'original' universe in which someone went back in time and changed a few things!?

IS JESUS FROM THE FUTURE!?carrot-cake

See, this is where I get confused. I stayed with it until the last sentence. How could Jesus be from the future?

Oh I'm just saying that Jesus could be a guy from the future who performed "miracles" with technology from the future, thus making our universe the not original version. Just a little joke I made, thats all.

I knew it was joke, just the whole alternate universe thing made my head explode. :P I think I get it now.

[QUOTE="carrot-cake"]

[QUOTE="Maniacc1"]

See, this is where I get confused. I stayed with it until the last sentence. How could Jesus be from the future?Maniacc1

Oh I'm just saying that Jesus could be a guy from the future who performed "miracles" with technology from the future, thus making our universe the not original version. Just a little joke I made, thats all.

I knew it was joke, just the whole alternate universe thing made my head explode. :P I think I get it now.

Ever seen Futurama? just means you have to get with your grandma.

EDIT: damn got beat to it.

Impossible. If you go back in time to kill your grandfather. You would have not existed. Therefore, you will not be able since you have not existed in the first place to kill your grandfather so he will still be alive. But since he is alive now, you can travel back in time to kill him. But thenyouwillnotexisttokillhimtherforeyoucannotkillhimsohewillsurvivemeani........

*Head explodes*

[QUOTE="GabuEx"]

[QUOTE="carrot-cake"]

The second thing is invalid because the TC says you kill your grandfather, its the grandfather paradox. It cannot be explained without using parallel universes.

carrot-cake

It's an answer to the question, just not a direct one: "It can't be done; therefore the question is meaningless."

[QUOTE="carrot-cake"]

[QUOTE="GabuEx"]

It's an answer to the question, just not a direct one: "It can't be done; therefore the question is meaningless."

xaos

futurama says hi, even though someone already mentioned it :(Dante2710

[QUOTE="Dante2710"]futurama says hi, even though someone already mentioned it :(Chutebox

No...haven't you seen that episode of Futurama where Fry turns into his own grandfather?

I just saw this discussed on Back To The Future Part II.

The doc from the movie claims you will disappear and so will your lineage past that point.

Or something about a parellel universe being created..

No no no, If you kill your grandfather then you would NEVER have been born if you were NEVER born then you NEVER could have killed your grandfather ALLOWING your grand father to exist and thus you. Thats why its called paradox.

........

[QUOTE="carrot-cake"]

The second thing is invalid because the TC says you kill your grandfather, its the grandfather paradox. It cannot be explained without using parallel universes.

GabuEx

It's an answer to the question, just not a direct one: "It can't be done; therefore the question is meaningless."

[QUOTE="xaos"][QUOTE="carrot-cake"]Is that really the answer though?

carrot-cake

Time is not two dimensional.

You can only time travel to the future ^^Famiking

ill just have to go back in time even further to kill your grandfather so you don't kill mine

lol. plot twist

[QUOTE="MrGeezer"]

[QUOTE="carrot-cake"]
The second thing is invalid because the TC says you kill your grandfather, its the grandfather paradox. It cannot be explained without using parallel universes.

carrot-cake

Well, strictly speaking, if we are talking about parallel universes, then the person that you kill ALSO isn't your grandfather. He's NOBODY'S grandfather, because he is dead.

So...as someone else already said, you CAN'T go back in time and kill your grandfather before your parents are conceived. Technically, in either time travel framework, it's still impossible.

No, he NEVER would have been your grandfather, because he is simply not the same person as your grandfather from your universe of origin.

The very concept of "would have" is irrelevant anyway. There is no "would have", there's only what is. And he isn't your grandfather, plain and simple.