Wormholes and causality

[bascule]

Okay, suppose we can create a stable wormhole with exotic matter.

 

Wouldn't both ends of the wormhole remain in more or less the same reference frame? So if someone were to grab one end of the wormhole and start going 0.999cish for awhile, thousands of years could elapse on the planet he left from (where the other mouth of the wormhole lies) yet time relative to those on either side of the wormhole would appear to be going at more or less the same rate, correct?

 

Yet because both ends of the wormhole remain are in the same reference frame, wouldn't it be possible for our traveller to send information about the future (as he observes it) back to his planet? Or if the wormhole were large enough, couldn't he simply travel back to the past through it?

 

Do these kind of causality violations really crop up with wormholes?

[Xyph]

If time was dilated on the trip to the extent that it took only, say, a hundred years from the perspective of those travelling with the wormhole, people from the planet would be able to step through the wormhole and come out at the destination after only a hundred years, I think - when, ordinarily, it would take thousands of years.

 

This would probably allow causality violations in some cases, such as if he looped back on himself with the wormhole at 0.999c so the light from his home planet thousands of years in the future would be reaching the wormhole, which was linked back to a planet only a hundred years from when he left.

 

Problems like that could probably be avoided, though... I'm pretty sure if he left in a straight line and didn't try to go back, there wouldn't be any problem with having a wormhole linking his home planet to another one thousands of years in the future and thousands of light years away, especially since it would only take a hundred years from the perspective of the travellers and those who stayed on the planet.

[CanadaAotS]

But there could be problems with it, right?

Would the universe come to an end because of these violations??

 

lol, sounds interesting

[Xyph]

More likely the wormhole would just collapse in some way, I'd think - into a non-traversible black hole, perhaps, if causality is to be preserved. Or the universe could just turn out to be acausal.

[bascule]

Wow, I was really hoping one of the physics experts would chime in here, but...

 

My gut instinct would be that stable wormholes can't exist because they'd allow for causality violations.