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Wormholes and time travel

  1. Feb 28, 2004 #1
    I was reading an interview with Carl Sagan, where he described how a wormhole would theoretically work if you travel between 2 points, point A and point B. However, is it possible that we can not only use this to traverse space, but time (assuming wormholes exist)? For instance, if we find a wormhole here on earth the leads to the same exact spot.. but 300 years in the past or the future? Also this leads me to ask, can a wormhole travel to another dimension, given the theory that there are a vast number of other dimensions and ours is just one of that number? Assuming all this in Am I just making up nonsense and is this completely out of the range of current theories, or can it be possible?

    Any comments are appreciated :smile:
  2. jcsd
  3. Feb 28, 2004 #2
    *sigh*, this is the problem with all these subforums.. I have no clue where to put things, and astronomy would be the last place i'd consider putting this
  4. Feb 29, 2004 #3
    Wormholes can only and theoretically exist 'between' 2 singularities. If you can somehow find a way to escape from a singularity and enter a singularity without being destroyed, then you have your wormhole. If not wormholes are impossible and frankly they probably are. Warp is a more likely candidate for ftl travel. Though the creation of thousands of mini black holes, may lend an avenue for the creation of a safe wormhole.
  5. Mar 2, 2004 #4
    Wormholes can exist at the edges of event horizons, or ergospheres. Hawking radiation allows the existance of virtual particles and anti-particles, which wink in and out of existance everywhere. When this balance is upset near a black hole, the vacuum has a chance of having a negative energy density, creating exotic matter. Thus, wormholes can exist.

    The main problem, if you want to make wormholes, is getting to a black hole. Perhaps artificially producing one by utilization of the casimir effect, and opening the other termini near the quantum singularity. When the wormhole reaches there, Hawking radiation will effectively fuel and control the wormholes, and an interstellar hub will be made. The high costs involved would only have relevance to the initial wormhole link, and then the black hole node will automatically let our species expand throughout our galaxy. I'm sure many an astronomer/pioneer would love to see a pulsar, probe a planetary nebula, or journey around the black hole itself.

    It's strange, but has anyone noticed that everything I write usually needs to end up at the Theory Development sub-forum? I guess that's the nerd-eee-ness in me popping up.
  6. Mar 18, 2011 #5
    Yep. This is has been understood since about 1988. See http://prl.aps.org/abstract/PRL/v61/i13/p1446_1"

    Assuming that by "another dimension" that you mean a parallel universe, the answer is also "yes". Basically, allowing wormhole traversals between parallel universes is a way of eliminating the paradoxes that arise when you allow wormholes to function as time machines. See https://www.amazon.com/Physics-Stargates-Parallel-Universes-Wormhole/dp/0984150005".
    Last edited by a moderator: May 5, 2017
  7. Mar 19, 2011 #6
    A theoretical physicist by the name of Kip Thorn has proposed using wormholes for time travel. Anyway, if one could be created that was stable and safe then he proposes having one of the mouths carried away through space at very high speed, and another one to remain stationary, say occupying your living room. Anyway since time would slow down for the mouth being carried away at high speed, say near the speed of light, than time would slow down for this mouth. And if you were to go through this high speed mouth and come out in your living room then you would come out in the past. You could never go back in time before the creation of the wormhole though. That might be why there has not been any evidence of time travel, basically because no real time machines have been created yet.
  8. Mar 19, 2011 #7
    A good video on wormholes and time travel by them

    Last edited by a moderator: Sep 25, 2014
  9. Mar 19, 2011 #8


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    Time travel to the past is implicitly paradoxical. You can try to avoid this dilemma by traveling to a parallel universe, but ... the universe you exited would lose mass and the parallel universe you entered would gain mass. It's hard to imagine the consequences of this action, but, I suspect both universes would be very angry. It would be embarassing were you to discover you were the equivalent of anti matter in the destination universe and promptly returned to your universe of origin in slightly altered form - say like a gamma burst.
  10. Mar 19, 2011 #9


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    The options for time travel into the past are:

    1. You can't alter the past. Attempts to change the timeline will either fail, or go unrecorded/covered up.

    2. Going into the past results in an alternate timeline. If you travel back to the future (pun intended) you will find that things are different. This is the one I usually prefer.
    Some could argue that this violates the conservation of matter/energy, but when both timelines are viewed as a whole their total matter/energy has not changed.

    Some say that attempting to use wormholes for time travel will cause them to collapse, and they can only be used to travel through space.
    Others say that you will not be able to go back before the wormhole was created.

    I personally think time travel is cool. And wormholes. :cool:
  11. Mar 20, 2011 #10


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    1] Agreed, you cannot alter the past without altering the future from which you originated. That is paradoxical.
    2] An alternate time line resulting in a future inconsistent your personal history is, by defintion, a parallel universe.

    I have issues with energy transport between parallel universes. It upsets the natural order. A zero net energy universe arising from 'nothing' cannot afford to lose a single particle to any other universe without becoming unbalanced.
  12. Mar 20, 2011 #11
    We usually use the phrase trouser leg of time.

    In many worlds interpretation I wonder what implication the creation of a new time line would have, would it be one of the worlds that already existed, in which case the "future" would have to exist in order to account for a shift in the past or would it be infinite +1. MWI is pretty much bunkum anyway in the same line as this Sci Fi nonsense.

    Worm holes are interesting consequences of too much time spent wondering what if, breaking equations says nothing more about reality than does going faster than light has to imply retro causality. Maths is not reality necessarily, we could assume that x is a consequence of y but we would be gauche to claim that was in any way true without actually setting up the experiment. By the same token claiming a singularity has infinite anything is also just a consequence of maths, it probably isn't really true that there is infinite spatially infinite masses, that would be absurd. And if you tried to claim it was the case in front of a hall of peers I suspect you would end up in the corner with the dunce hat on.
    Last edited: Mar 20, 2011
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