Comment on Maybe ghosts are real, but since they're incorporeal they're unaffected by gravity and get left behind in the void of space

• Masimatutu@lemm.ee ⁨8⁩ ⁨months⁩ ago

  It is straight in reference to the distorted spacetime.

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  • Rodeo@lemmy.ca ⁨8⁩ ⁨months⁩ ago

    Is this 2D-3D comparison supposed to be like a human-understandable analogy for a 3D-4D relationship?

    I saw an explanation once about how time is the 4th dimension. They drew a line on the edge of a book. From the perspective of a single page (2D) it just looks like a dot, but because we can see many instances of that 2D representation it appears to us as a line. An individual page represents how we experience time.

    Is your ball example supposed to be kind of like that because I just can’t imagine how spacetime could be a 2D thing in a 3D universe.

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    • Masimatutu@lemm.ee ⁨8⁩ ⁨months⁩ ago

      Well, kind of. The time dimension is a bit tricky, though – in Minkowsky space, a common way to think about spacetime, it is hyperbolic in relation to the other dimensions. In a nutshell, this means that distance is not the square root of the sum of the squares of the distances in specific dimensions, but rather of the difference. This makes it especially tricky to visualise. (I do recommend you check out this series by minutephysics)

      My analogy, therefore, doesn’t translate directly to spacetime, but it does provide an explanation for why straight things can act curved.

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• ssboomman@lemm.ee ⁨8⁩ ⁨months⁩ ago

  I think a better way of explaining it is with the idea of a shortest path, and not nessesarily a straight line. With two points in space the shortest path between them will be a straight line. If there’s a large amount of gravity tugging on space time the shortest path will be curved.

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• RojoSanIchiban@lemmy.world ⁨8⁩ ⁨months⁩ ago

  That’s called General Relativity and Reference Frames.

  Start watching PBS Spacetime if you actually want to get into it.

  You’re also entirely missing the point of the comment that was a joke entirely re-explaining the “reason” for ghosts ending up at the center of the Earth, which is implied by the original comment.

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