• MTK@lemmy.world
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    37 minutes ago

    Being sci-fi it can be explained with Q u a n t u m E n t a n g l e m e n t

  • Fetus@lemmy.world
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    6 hours ago

    I get that people just refer to them as time machines, but they’re actually space-time vehicles.

    Before your first journey, you calibrate it to a reference point (mine already had Earth mapped out, with a gravity well depth monitor as a fail-safe) so that you lock your target coordinates in space and time.

    But no, it’s not teleportation. You’re still just travelling to your destination, you just get there as quick as you want and without the need to be disintegrated.

  • TheLeadenSea@sh.itjust.works
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    8 hours ago

    What sort of universal reference frame do you seem to be assuming? All location is relative to other things, and keeping your location relative to, say, the Earth would be a lot more convenient that making it relative to some arbitrary star or something.

    • TrickDacy@lemmy.world
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      2 hours ago

      Op thinks the universe is built with some inherently absolute positioning method. Thanks for writing this

    • half_built_pyramids@lemmy.world
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      1 hour ago

      Use the time and space machine on a ruler and send it back in time a pico second, then a millisecond, then a thousand, then a second, then a minute. You just have to calibrate with measurements first.

    • TommySoda@lemmy.world
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      7 hours ago

      But if you’re in a moving car and “pop” back a few seconds while the car doesn’t you won’t be in the car anymore. If it worked more like rewinding a video you wouldn’t need to do much, but I’m assuming OP means literally going “poof” and now you’re back in time. If that’s the case, you would still need to know how Earth is moving through spacetime. If you don’t know your relativistic relationship to the Earth and every other object in the universe then how would you know where you are or your own relativity compared to the Earth?

      • Dave@lemmy.nz
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        6 hours ago

        Their point is that (as per relatively), all movement is relative to something. So if the earth moved away then you must be measuring in relation to some other reference point. There is no absolute positioning system. So when you say the earth is moving, what is it moving in relation to? And why did you pick that reference point instead of having a time machine that uses earth itself as a reference point?

        • TommySoda@lemmy.world
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          5 hours ago

          But that’s the thing though. How can you determine the Earth as a reference point without knowing how it relates to other objects in space? “Here” is as useful a coordinated system as a fake absolute positioning system. “Here” is just your relation to other objects. If you don’t know what your relation to those objects is you can’t determine where “here” is, or the Earth for that matter. Whether it’s the machine or the person operating it, something or someone has to calculate where the Earth is in order to use it as a reference point.

          If you are driving away from your friend at 20 mph, from your perspective they are moving away from you at 20 mph while you are the one that’s stationary. The only thing determining your location, or reference point, is your relation to each other.

          • ByteJunk@lemmy.world
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            3 hours ago

            You’re still thinking in a context where the earth is travelling around the sun, etc etc.

            If you assume the Earth as the reference point, then that is fixed, absolutely frozen, doesn’t move at all. That’s point zero.

            You cannot calculate where the earth is. What you do is calculate where everything else, the universe itself and even other dimensions, are with regards to your fixed point.

            This can feel counterintuitive, but here’s a random visualization: https://youtube.com/shorts/UZyuZVvCE78

            Note that, in that video, only the perspective has changed. The solar system is moving as usual.

            • LilB0kChoy@midwest.social
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              2 hours ago

              This is also demonstrated well in the show Travelers with T.E.L.L.

              Basically, a quantum AI from the future uses historical records to determine the time, elevation, latitude and longitude to send people back. Obviously the Earth itself is the reference point being used.

  • I think it might depend on how the time travel is achieved. We all assume you’re just instantly pooped out in your destination time but if you have to actually travel through time, it might be like just putting everything in reverse, and so you’d move alog with the earth as you move backwards through some kind of time tunnel.

    Think Donnie Darko and not Looper.

    • gedaliyah@lemmy.world
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      4 hours ago

      This was the thing in the HG Wells version that always got me. The machine always exists for the intervening time. I feel like that would be very disruptive to the civilizations that encounter it.

      • Death_Equity@lemmy.world
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        3 hours ago

        I think the distortion field sort of addresses that.

        The machine would be hidden within the field and invisible and intangible. That of course presents the problem of ending up in a wall and also would likely mean that you would end up in the air if the ground erodes or in the ground if sediment is deposited.

        The alternative is either there is a mysterious bubble that becomes a scientific curiosity or there is the machine with someone frozen inside it that is destroyed by people being people. Both have their own fun little narratives to explore.

        That is all based on the assumption that the machine travels forward in time through localized dilation instead of folding spacetime, which would mean it has two methods to travel depending on it going forwards or backwards in time.

  • otacon239@lemmy.world
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    7 hours ago

    That’s why I always liked approaches that use a physical machine that has to stay in one place for an extended period of time. Quantum Break’s hard sci-fi approach to this was fascinating and kept making me reconsider how the time loop worked. Highly recommended for time loop nerds like me.

  • troed@fedia.io
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    8 hours ago

    You’re obviously the main character in this simulation so it’s much more likely that all other coordinates are derived from your position in the simulation engine.

  • jordanlund@lemmy.world
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    7 hours ago

    Forget the orbit… remember the song…

    https://genius.com/Monty-python-the-galaxy-song-lyrics

    “Just remember that you’re standing on a planet that’s evolving
    And revolving
    at 900 miles an hour.
    It’s orbiting at 19 miles a second,
    so it’s reckoned,
    The sun that is the source of all our power.
    Now the sun, and you and me,
    and all the stars that we can see,
    Are moving at a million miles a day,
    In the outer spiral arm,
    at 40,000 miles an hour,
    Of a galaxy we call the Milky Way.”

  • TabbsTheBat@pawb.social
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    8 hours ago

    What if it works by reversing/fastforwarding time outside while preserving things within the time machine? Then as long as the time machine is grounded to the earth it would move with it

    • KoboldCoterie@pawb.social
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      7 hours ago

      So, Primer, then? Where you can’t return to a point in time before the time machine was constructed?

  • VicksVaporBBQrub@sh.itjust.works
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    7 hours ago

    A wormhole type time machine would leave the travel points A and B physically independent of each other. This opens up the option to change destinations… step in at New York, exit in San Francisco.

    • r00ty@kbin.life
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      7 hours ago

      No, he used a Delorean because of the style, and something about the stainless steel construction that we’ll never know the rest of. :P

  • rowinxavier@lemmy.world
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    8 hours ago

    Yep, and not to mention the position of our solar system in the Milky Way or our galaxy in the local cluster. In fact, without a specific reference frame you would have to make corrections very rapidly for even a tiny jump in time.

    • Hugin@lemmy.world
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      24 minutes ago

      There was a not very good TV show Seven Days that used this well. They had a time machine that could go back in time seven days. The pilot had to fly the machine chasing the earth as he traveled back in time.

      He would usually end up crashing it somewhere and have to find a phone to call for pickup.

    • toast@retrolemmy.com
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      5 hours ago

      Depends on how time travel works. I mean, within the next 24 hours I plan to travel to tomorrow. I’m not going to be taking any of that into account.

  • r00ty@kbin.life
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    7 hours ago

    Well, it depends. I mean the original story “The Time machine” I think very deliberately had a machine that was on the ground. I guess if you’re “travelling” through time then you could follow your local location in the same way you do when it is moving forward at the normal rate.

    The argument is more true for time machines that instantly move through time, like back to the future. Since yes it would need some way to account for planetary movement.

  • ns1@feddit.uk
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    7 hours ago

    This is interesting because the most “realistic” (i.e. still not realistic) depictions of time travel in fiction involve travelling through a singularity or wormhole. So you probably have to be in space to start with, but also both ends of the wormhole have mass so they can be orbiting a planet or star and stay within a stable distance of it. It solves this particular problem (just leaving the other usual problem of causality!) It also proves your point since it does allow travelling in space, in fact it allows travelling faster than light.

    I think the converse is true as well, that if faster than light travel is possible then time travel must be possible, at least if you take relativity at face value. As others have pointed out there’s no universal reference frame, and for any journey that is faster than light in one reference frame, there is another frame in which the journey goes backwards in time.