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What could a time machine plausibly look like?

  1. Jul 28, 2017 #1
    So, I've been doing some research for a novel I'm working on that's based around time travel, but seeing as I'm definitely no expert on the theories concerning it, thought it might help to have someone a little more knowledgeable on the subject review my ideas.

    Thus far, I've done some reading up on it, and know the basics. From what I've gathered, time travel is possible, but not to any point in time before the hypothetical date when it's invented (however, one reputable source I found seems to dispute this, commenting on a traveler being able to encounter dinosours, but I'm assuming that's generally not the consensus, right?). There seem to be three methods of travel that are widely discussed as possible: orbiting a black hole, traveling at near-light speeds, and wormholes, though out of these three, only the wormhole option works for what I'm attempting to envision - a method of time travel that could transport people to the future, and then back to the time they left. If all that's correct, great, but if not, do let me know. :)

    Now, onto my question... well, questions. :p Could there - hypothetically - be a way to either create a wormhole or locate and use a preexisting one on Earth, not in space? If so, what might that look like, how might it be accomplished, and what materials/components would be involved? If someone were to go through it, what might they experience? And, finally, once they get to the the other side, assuming any components needed to use/operate such a wormhole were maintained over the years by future generations, could the traveler go back to their own time?

    Oh, and I'm also curious whether having a traveler be able to change their future - but the past of the time they travel to - would be realistic based on what we know now. From what I've found, this seems to be quite the subject of debate, so to clarify, I'm not looking for personal opinions or reasoning, but rather checking that there isn't any evidence to dispute this idea as of yet.
     
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  3. Jul 28, 2017 #2

    russ_watters

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    Welcome to PF! Thread moved to science fiction:
    I don't think I've ever seen a time machine so constrained. Do you have any examples? The closest I can think of was the "Quantum Leap" model, which IIRC could take him back as far as the date he was born...which always struck me as a little contrived and was probably done for budgetary reasons.
     
  4. Jul 28, 2017 #3
    Consensus in physics is that time travel is as impossible as it can be, period. That doesn't mean that it's totally impossible, but anything else is more likely to happen.

    Some people still research this stuff, but I don't think there is anything close to a consensus on the grandfathers paradox.
     
  5. Jul 28, 2017 #4
    Whoops, sorry... I actually didn't see there was a forum for sci-fi here. Thanks, and my bad!

    I'm not familliar with Quantum Leap, but, yeah, that sounds pretty unrealistic. Not quite sure what you're asking, though - examples for what, specifically?
     
  6. Jul 28, 2017 #5
    Yep, that was the impression I got as well. :) From closed timelike curves to alternate universes, it definitely seems like there's a lot of disagreement on what would happen in such a scenario.
     
  7. Jul 28, 2017 #6
    I think there are three major plausible scenarios.
    First, time travel is impossible.
    Second, time travel is possible, but you need continuity of the wave function and therefore, paths with a paradoxon are simply forbidden. You could try to murder your own grandfather, but you would necessarily fail for some reason.
    Third, you get some sort of realization within many worlds interpretation such that any time travel branches of a new universe and you could never go back to the future from which you started.
     
  8. Jul 28, 2017 #7

    anorlunda

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    If you write like Douglas Adams, the time machine might be just an app for your iPhone, or look like a city bus, and you book time trips with T-uber. :woot:
     
  9. Jul 28, 2017 #8
    Thanks, Gigaz (for some reason it's not letting me quote your post, and tagging members doesn't seem to be a thing here, so just going to adress ya by name and hope that clears up any confusion XP ). The third one's the one I'd be going with, then; it's good to know alternate universes are an option. :)
     
  10. Jul 28, 2017 #9
    I don't think anyone can write quite like Douglas Adams... :woot:

    But, yeah, think I'm going to keep my time travel a little less common. :)
     
  11. Jul 28, 2017 #10

    phinds

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    Orbiting a black hole and traveling at near light speed will get you to the future more quickly than just waiting around for it, but neither one will get you to the past. Wormholes I'm not sure about but probably since they could amount to faster than light travel
     
  12. Jul 28, 2017 #11
    Yep, hence why I chose the wormhole option. :)
     
  13. Jul 28, 2017 #12
    Check the Ally Oop comic strip for a well known time machine.
     
  14. Jul 28, 2017 #13

    russ_watters

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    Examples from where you have seen/heard about time travel constrained by the date of its invention.
     
  15. Jul 28, 2017 #14
    My guess is it would look something like a police telephone box in London, around 1960.
     
  16. Jul 28, 2017 #15
    Thanks! Could be a good source of inspiration.

    Well, as awesome as the TARDIS is, I think it's about the farthest from 'plausible' you can get concerning realistic time machines. :-p
     
  17. Jul 29, 2017 #16
    I think one the doctor's incarnations (Tom Baker?), had figured out that the chameleon circuit had a problem with the fluid link.
    Then suddenly Neanderthals started poking on the TARDIS with spears.
     
  18. Jul 29, 2017 #17
    I'll take your word for that; I've seen both the old and the new Who, but still have some catching up to do with some of the earlier incarnations of the Doctor, and haven't seen any of Four (Baker) yet. :)
     
  19. Jul 29, 2017 #18
    As far as I remember the doc's assistant, a mere earthling, confused those guys by wearing a miniskirt and big ear rings.
    But then then the daleks, that trick would not work on them
     
  20. Jul 31, 2017 #19
    According to general relativity, wormholes can only exist if they have always existed. You can not create or destroy them because that would require seaming or tearing the fabric of spacetime. So in order to have a time machine, it would have to somehow contain one end of the Einstein-Rosen bridge as well as being able to manipulate the other end of it. Whatever the technology is to do that, would require insane amounts of power, so the bulk of your time machine would probably be an antimatter powered generator or something.
     
  21. Jul 31, 2017 #20
    A gravitational wormhole would look sort of like a black hole. It would strongly bend light, creating an Einstein ring around it. Let us suppose for fictional sake that it can be made stable and stored on Earth. It would be hard to confine on Earth since there's no way to attach harnesses to it and it tends to destroy everything around it with extreme tidal forces. It's likely that if technology exists to maintain this sort of thing, people have discovered some sort of antigravity which is needed to hold this thing open and keep it from falling toward the center of the Earth and spaghettifying the Earth.
     
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