• nucleative@lemmy.world
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    12 hours ago

    I know we’re in a meme community but this did get me thinking… Not only is the Earth spinning but it’s also in an orbit around the Sun which is also orbiting around the center of the Milky Way which is moving through space relative to other galaxies and so on.

    Do we have enough information to calculate a position in space in the future for Earth without a fixed reference other than current point?

    • mexicancartel@lemmy.dbzer0.com
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      43 minutes ago

      That’s what einstein said. There is no fixed reference frame, but only relative ones. Every “inertial”(meaning, motion without any external force) frame of reference is equally valid as any other inertial frame movibg with respect to it.

      But for sure we can tell earth’s orbit is not inertial since circular motion occur, which is due to external force of gravity.

      Edit:typo

      • Ymer@feddit.dk
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        4 hours ago

        Shouldn’t it be (at least theoretically) possible to find some sort of geometric center where - on average - the rest of the universe is expanding away from?

        • BrainInABox@lemmy.ml
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          1 hour ago

          Turns out, no; every point is expanding away from every other point, so every point sees itself as the center of expansion.

          • Ymer@feddit.dk
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            12 minutes ago

            That could sort of explain why it’s inherently impossible to determine the center - but that doesn’t rule out the existence of a geometric center of the universe, right?

        • Klear@sh.itjust.works
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          4 hours ago

          No, for the same reason you can’t find a point a balloon is expanding from on its surface. Everything is expanding everywhere.

          • Ymer@feddit.dk
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            15 minutes ago

            I’m not sure if I follow the balloon analogy. Sure, you can’t find the center on it’s surface. But somewhere within the balloon, there is a center. It might be virtually impossible to determine the center while actively inflating the balloon, but that doesn’t mean there isn’t any center? What makes the rest of the universe fundamentally different from an inflating balloon? I’m genuinely curious.

    • ssnoer@feddit.dk
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      7 hours ago

      There is not central point in the universe, and no way to calculate a position. Everything is relatove

    • NigelFrobisher@aussie.zone
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      11 hours ago

      This is why Doctor Who has a time and space machine. Also because the BBC didn’t have the effects budget to show him flying around.

      • JustAnotherKay@lemmy.world
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        9 hours ago

        We also get a few glances of the coordinate system that the time machines use in doctor who. It appears to have enough digits for a date/time as well as an X/Y/Z grid coordinate.

    • comrade19@lemmy.world
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      9 hours ago

      I don’t think we have a relative fixed point to go off unless you choose the centre of the big bang. It’s all relative to other things around us which are also moving lol