Could the known universe be inside a black hole and it's curvature really be the event horizon of the black hole?

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    $\begingroup$ What curvature? Measurements indicate the large scale curvature is very close to zero. $\endgroup$
    – Jens
    May 2, 2019 at 16:39
  • $\begingroup$ If the universe was inside a black hole, the universe would be self-replicating, like a mother giving birth to many children, who in turn birth many, etc etc. The consequences of a cosmic self replication are nebulous and less important than tomato sauce recipes and resource management. $\endgroup$ May 4, 2019 at 9:42
  • $\begingroup$ The wiki pages for the topic are "white hole" and "black hole cosmology"... the latter article implies that: The Hubble radius of the observable universe must be equal to its Schwarzschild radius, that is, the product of its mass and the Schwarzschild proportionality constant. This is indeed known to be nearly the case; however, most cosmologists consider this close match a coincidence.[3] $\endgroup$ May 4, 2019 at 15:13

1 Answer 1


No. The metrics look very differently.

  • The metrics of the the Universe is determined by the FLRW metrics. Its spacelike sections are planar.
  • The spacelike sections of the spacetime around a Schwarzschild (non-rotating) BH is spherical.

More elementarily formulated: the black hole is like a static sphere. The Universe is like an expanding sheet. However, this is what we currently see, matched by our current models. These are not so strong facts, like the density of the iron, what anybody could measure on his desk. I think the correct explanation is roughly this: "it doesn't really looks so, but no one knows".

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage
    May 4, 2019 at 16:15

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