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In 1+1 Minkowski space the distance between two points is given by$$ (x_1 -x_2)^2 -(t_1 - t_2)^2.$$

This is different from the Euclidean distance. But is it possible to come up with a 2D surface embedded in 3D Euclidean space such that the geodesic distance between two points on the surface is like that in Minkowski space?

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  • $\begingroup$ How could you hope to reproduce a negative distance square in a Euclidean space? $\endgroup$
    – Qmechanic
    Commented Feb 22, 2016 at 10:36
  • $\begingroup$ What about just the positive part? Or as two different surface one for inside the light-cone and one for outside it. (disregarding the negative sign in one case) $\endgroup$
    – biryani
    Commented Feb 22, 2016 at 10:39
  • $\begingroup$ Interesting question. I have no idea. If negatives are forbidden, how about$ ((x_1 - x_2)^2 - (t_1 - t_2)^2)^2$. Also, is en.wikipedia.org/wiki/Nash_embedding_theorem related in any sense? $\endgroup$ Commented Feb 22, 2016 at 12:24

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No, it is not possible because the induced metric on any submanifold $N$ of the Euclidean space $E^3$ is necessarily positively defined, whereas the metric on $1+1$ Minkowski space is indefinite.

The reason is trivial: The scalar product $\langle u,v\rangle $ of two vectors $u,v$ in $N$ is, by definition, the scalar product in $E^3$ of these vectors viewed as vectors in $E^3$, so that $\langle u,u\rangle \geq 0$ -- where $\langle u,u\rangle=0$ implies $u=0$ -- in any cases, contrarily to what may happen in Lorentzian manifolds.

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