Time Travel paradoxes

[ellymelly]

I don't know, I still think that the universe would prevent time travel because of the obvious problems and paradoxes it presents.

For one, matter bouncing about would essentially break the fundamental 'matter cannot be created or destroyed' rule unless the universe works wholistically (which seems unlikely).

In other words, the moment you arrive 5 000 years in the past, the universe suddenly has however many more particles that make you up. The reverse is true about the timeline you left. As with the events of stargate's Moebius Part I & II, this was a permanent situation.

Theoretically, this could be very problematic for the universe. Consider if a race was actually capable of going back in time and preventing the universe from existing? What about going *past* the creation of the universe? If time is not connected to this particular universe, the doors time travel open up would be highly dangerous.

Skipping between parallel universes is more probable, but still plagued with the same problems. Even if parallel universes exist, it seems unlikely that we would ever be able to venture into them.

In answer to your question, you would not be able to go back and kill your grandfather in the first place, thus, all is right with the universe.

This is not to say that you can't *play* with time. I just don't think you can break its rules. Traveling OUTSIDE of time, is an entirely different beast. I believe the stargate, like subspace, is concerned with the 'outside of time' thing. (which is far more achievable).

Sorry I couldn't be more helpful.

[!!??]

hey people hav u never seen futurama, fry ends up killin his own granddad and in sick twist become his own grandfather by doin his grandma, lovely lol wat a great episode that was!!

I did. He blows up in the nuclear testing.Lol

[gavo2o]

hey people hav u never seen futurama, fry ends up killin his own granddad and in sick twist become his own grandfather by doin his grandma, lovely lol wat a great episode that was!!

I am suprised that Fry didn't get stuck in a time loop where he became infinitly inbread because of it

[Dark Soul]

I am suprised that Fry didn't get stuck in a time loop where he became infinitly inbread because of it

That would suck.
But it would be interesting for him to figure out a way to break the loop.

[Daryl Froggy]

Breaking such a theoretical time loop would be easy, just kill your grandmother and you were never born to set the loop in motion in the first place.

[Jsmith45]

I thought it had something to do with the wormhole going through a solar flare? I could be wrong it has been a while since I saw this episode and I forgot about most of the stuff they talked about.

The solar flare was indeed important in the time travel in that episode.
However, what I was noting was a causality loop. In most episodes of SG-1, traveling back in time and changing things such that is there is no longer a need to travel back in time does not create a paradox, but effectivly creates a separate universe under a multi-universe theory. It would turn out that this separate universe is not entirely self-contained, as the cause of some events in that world (specifically the entrance of the time travelers) would be due to a cause in another universe. However, the show has consistently shown that having a cause in a different universe does not constitute a paradox. (See for example the episodes involving the quantum mirror).

However 1969 was different. In that episode, the characters were predestined to go back in time. Basically, unlike other time travel episodes, where the time travel causes the spawning of a new universe, where in a few effects have causes that occur later in time in a different universe,
the episode 1969 contained exactly one universe. So there were some causes that occurred long after the effect within the same universe. How a universe with an internal causality loop could come into existence at all is unclear.

(Of course time travel under multi-universe theory can be confusing, since the universes are formed at every decisions, so several universes share a single universe back at some specific time. This type of theory actually could prevent all theoretical time paradoxes due to the branching nature. If you go back and kill your grandfather, the effect is basically changing a separate copy of the past. So a new universe without you ever existing would form (actually an infinite number of such universes would form), but that would not cause a problem with your existence anywhere, as you original past would remain unchanged.)

[Aethon]

If you went back in time and killed your grandfather or whatever, I don't think you would die until you travelled back. If you go back kill him you would just have killed the man. If you go to the original time first then would your mother not have given birth to you.

[Dark Soul]

Breaking such a theoretical time loop would be easy, just kill your grandmother and you were never born to set the loop in motion in the first place.

Yes but would he be smart enough to do that? Like if he doesnt remember things from the previous loops?

The solar flare was indeed important in the time travel in that episode.
However, what I was noting was a causality loop. In most episodes of SG-1, traveling back in time and changing things such that is there is no longer a need to travel back in time does not create a paradox, but effectivly creates a separate universe under a multi-universe theory. It would turn out that this separate universe is not entirely self-contained, as the cause of some events in that world (specifically the entrance of the time travelers) would be due to a cause in another universe. However, the show has consistently shown that having a cause in a different universe does not constitute a paradox. (See for example the episodes involving the quantum mirror).

However 1969 was different. In that episode, the characters were predestined to go back in time. Basically, unlike other time travel episodes, where the time travel causes the spawning of a new universe, where in a few effects have causes that occur later in time in a different universe,
the episode 1969 contained exactly one universe. So there were some causes that occurred long after the effect within the same universe. How a universe with an internal causality loop could come into existence at all is unclear.

(Of course time travel under multi-universe theory can be confusing, since the universes are formed at every decisions, so several universes share a single universe back at some specific time. This type of theory actually could prevent all theoretical time paradoxes due to the branching nature. If you go back and kill your grandfather, the effect is basically changing a separate copy of the past. So a new universe without you ever existing would form (actually an infinite number of such universes would form), but that would not cause a problem with your existence anywhere, as you original past would remain unchanged.)

OK, I kind of see where you are coming from now.

[General Burro]

This is a hypothetical question, I know time travel has not been proven yet. But it hasn't been disproven either. I don't know too much about how time travel is used in the Stargate universe. But do they ever talk about the grandfather paradox? For those who do not know what the grandfather paradox is it is this: If you travel back in time and kill one of your ancestors, would you ever have been born to go back and kill him?
My question: If you kill him, then you would never have been born. If you had never been born you would not have killed him, so then if you had not killed him you would have been born and would have been able to go back and kill him. Try not to think about this question too much you might get confused.

What are some other paradoxes about time travel?
What kind if any are used in Stargate?

dbz explained this better than i've seen so far. instead of trunks going back in time of his own timeline he went back in time to another timeline then returned to the future of his. weird but most plausible

[Dark Soul]

dbz explained this better than i've seen so far. instead of trunks going back in time of his own timeline he went back in time to another timeline then returned to the future of his. weird but most plausible

I thought he went back in time in his own timeline, then when he helped Goku he created another timeline. When he goes back to the future he ended up in his own timeline (original one). It has been a long time since i have read the manga or seen the show.