Comment by pdonis

Comment by pdonis 3 days ago

> between two singularities merging

Two black holes merging does not mean two singularities merging. The singularity (singular, not plural) is a moment of time that is to the future of all other moments inside the hole. If two black holes merge, there is just one singularity inside the merged hole.

Remember that GR is a model of spacetime, not space. In spacetime, a single black hole looks, heuristically, like a cylinder, and the singularity inside is at the future end of the cylinder. Two black holes merging look, heuristically, like a pair of trousers, and the (one) singularity inside the merged hole is at the future end of the trousers (the "waist").

Jerrrrrrry 3 days ago

very good, but I would say (since "light cone" is of such common parlance) that the physical 3d analogous projection would be two slightly overlapping 3d-venn diagram funnels conjoining at an "indefinitely" (asymptotically smaller) small space-time minkowski manifold.

naked singularities themselves, however, do not exist.

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pdonis 3 days ago

> the physical 3d analogous projection would be two slightly overlapping 3d-venn diagram funnels conjoining at an "indefinitely" (asymptotically smaller) small space-time minkowski manifold.
I'm not sure what you mean by this, but it doesn't seem to correspond to any actual physical model that I'm aware of.

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- Jerrrrrrry 3 days ago
  
  both objects have a space cone that is overlapping - since they can observe each other, but also have a small bit they xor can observe, since they are a spatialtime distance apart.
  regardless, once they are inside the event horizon, their spacetime ends in a "singularity" - that only they experience, since everyone else just saw an ever-slowing couple of observers that never quite reached the event horizon (to the outside observer, who would eventually be either iron or protons, depending if God had decided if they protons should decay or not yet)
  i was just pointing out cone versus cylinder, since the black holes' effect is polynomial af
  
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  pdonis 2 days ago
  
  > both objects have a space cone that is overlapping
  Again, I don't know what you mean by this, but it doesn't look like any actual physical model that I'm aware of.
  > i was just pointing out cone versus cylinder
  The cylinder I referred to is the outgoing side of the light cones at the horizon. The horizon itself is a lightlike surface. So the distinction you appear to be trying to draw here is simply invalid for a black hole horizon.
  
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daxfohl 3 days ago

But there's still two singularities until one falls into the other.

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pdonis 2 days ago

> there's still two singularities until one falls into the other.
No, there aren't. There is just one, at the "waist" of the trousers. Again, the singularity is not a thing in space. It's a moment of time. A moment of time can't fall into anything.

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