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

It would create a different universe. Also, define time.

It would create a different universe. Also, define time.

_en1gma_

[QUOTE="_en1gma_"]

It would create a different universe. Also, define time.

Elemayo

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!?

You'd exist up until you decided to kill your grandfather. If you're thinking you would've never been there then killing your grandfather would be impossible since you would not be you and he would not be he.

Just don't make that mistake and you won't have to worry about that.

Right when you killed him you'd die. And then the world would just continue on without you.

Its not a paradox, because you did kill him, you would just fade from existence, if time and space were actually traversable on the same plaine(right word?) that is.
There always the chance that it would change nothing in you life and just screw up your future in that time plaine.
Or Am I wrong?

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

*walks into thread, farts, and walks away*

RTUUMM

You polluted the thread.

Then I'd never want to time travel, because you'd never see the same people again.

*walks into thread, farts, and walks away*

RTUUMM

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

[QUOTE="carrot-cake"]

[QUOTE="avatar_genius"]

*walks into thread, farts, and walks away*

avatar_genius

lol, this got bad.

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.

Futurama did it. He became his own grandfather in the end...

you could become immortal because you would no longer be constrained by the limits of time

*walks into thread, farts, and walks away*

RTUUMM

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.

Suddenstriker52

It would create a different universe. Also, define time.

It would create a different universe. Also, define time.

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

Then I'd never want to time travel, because you'd never see the same people again.

Jfisch93

Even just going back in time can cause catostrophic events to happen in the future, and alter your future so much that when you returned (if you even still exist) everything would be completely different.

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

[QUOTE="The_Zoid"]You've obviously haven't watched enough Futurama._en1gma_

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

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."

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

[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."

Im on summer vacation and Im trying not to use my brain, k?

Im on summer vacation and Im trying not to use my brain, k?

ps3wizard45

Im on summer vacation and Im trying not to use my brain, k?

ps3wizard45

Low brain activity leads to weight gain.

Then I'd never want to time travel, because you'd never see the same people again.

Jfisch93

[QUOTE="ps3wizard45"]

Im on summer vacation and Im trying not to use my brain, k?

carrot-cake

This is sorta like the same problem as if you went back in time by 5 minutes, would you meet yourself? If so, couldn't you go back in time another 5 minutes bringing the 2nd you with you. Then you'd have 3 yous. Then what if you killed one or both of the previous yous?

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.