0
$\begingroup$

Before you read I want you to know that here I'm a layman and I was just wondering.

It is often visualized, how wormhole works using a curved paper like C, and making a short cut through there:

enter image description here

But I don't understand, how this shortcut is made by itself. I mean why spacetime is supposed to be like C in first place?

But I can speculate. If there is a large enough black hole at top of the C, it can make its path through bottom of C, thus making a wormhole? (But probably it would still be a black hole, visible at two sides of spacetime.)

$\endgroup$
3
  • $\begingroup$ Possible duplicate of Are wormholes really a valid shortcut to distant points in the universe? $\endgroup$ Dec 6, 2017 at 15:37
  • $\begingroup$ This is not a duplicate. I don't understand how the answer to the "duplicate" question answers this one. It doesn't even mention how wormholes might be formed, which is central to this question. Please either explain in comments or reopen the question. $\endgroup$ Dec 15, 2017 at 12:46
  • $\begingroup$ @PeterShor I'm not sure I agree with you. The question here is "why spacetime is supposed to be shaped like a c in the first place?", and the accepted answer to the linked question is "the c shape is really not a thing." $\endgroup$
    – rob
    Apr 19, 2018 at 4:49

1 Answer 1

0
$\begingroup$

Yes, they can. The metric of the charged (Reissner-Nordström) or/and rotating (Kerr) Black Holes seems like one of the sides of a wormhole.

There is nothing what would "curve" the spacetime into such a C-like form, only the diagram has to explain something. There is no internal measurement which could differentiate such a C-shaped spacetime from a planar one. An essential point of the General Relativity, that it operates exclusively with intrinsic properties.

The idea of the wormholes is coming that rotating/charged black holes seem to have such a geometry, like if they would bind multiple Minkowski-universes together (or the different points of the same one). But all of this is purely hypothetical.

No one could see a black hole event horizon until now - they are too small, and too far away. The proof behind that black holes even exist is coming from the spectrum of the interstellar gases falling into them. Without this proof, even the existence of the black holes would be only a hypothesis.

enter image description here

$\endgroup$
3
  • $\begingroup$ The ideal Kerr solution is a wormhole. However, the ideal Kerr solution is a black hole that has existed forever and will continue existing forever. This doesn't tell you how the wormhole formed, which was the OP's question. If you take a real Kerr black hole, on the outside it's indistinguishable from an ideal Kerr solution. But it might look very different on the inside. $\endgroup$ Dec 15, 2017 at 12:28
  • $\begingroup$ @PeterShor It means, that a real Kerr BH would look practically the same from outward, while its internal geometry would be very different? It surprises me a little bit, I think the metric of the creation of a real Kerr BH should converge in time to the ideal Kerr BH. $\endgroup$
    – peterh
    Dec 15, 2017 at 14:31
  • $\begingroup$ The interior of the Kerr solution is unstable. See Wikipedia. This means that if you start with a collapsing cloud of particles that is only very slightly circularly asymmetrical, you will end up with something that is completely asymmetrical on the inside. $\endgroup$ Dec 15, 2017 at 18:33

Not the answer you're looking for? Browse other questions tagged or ask your own question.