All Questions
Tagged with spacetime black-holes
322
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Are black holes the edge of our universe?
Are black holes the actual edge of the universe? Because spacetime is another dimension, I would assume the universe doesn’t have perceived corners or edges. At least humans cannot perceive it.
The ...
- 11
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Why are there two interior regions in this diagram?
Why are there two interior regions in this diagram? There seems to be two inner horizons, and two wormhole regions.
Where do the two such regions comes from? What determines which reason someone falls ...
- 2,908
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442
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Where does the parallel universe in the Penrose diagram come from?
In this diagram, as well as our universe, you have a parallel universe.
Where does this come from? Is this just a artifact of the diagram, or is it predicted by the maths in some sort.
- 2,908
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Question on apparent super efficiency of the magnetic penrose process
Accordingly to this paper $[1]$, the efficiency of the so called Magnetic Penrose Process (MPP) is, for supermassive black holes of mass $M∼10^{10} M_{\odot}$ immersed in a magnetic field having $B∼10^...
- 3,085
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How exactly does Hawking radiation occur? [duplicate]
I understand some parts of the theory, I've read from here https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Supplemental_Modules_(Astronomy_and_Cosmology)/Cosmology/Carlip/...
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Does spacetime move? With respect to what?
Can spacetime itself rotate along a body, like a black hole? Would it move like a wave?
- 495
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262
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Why are there multiple universes in the Reissner-Nordström solution?
I am trying to make sense of the Penrose diagram of a non extremal Reissner-Nordström spacetime, that is, the solution with two horizons. The coordinates are
$$ v'=\text{exp}\left(\frac{r_+-r_-}{2r_+^...
- 873
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How does according to modern physics collision between two massive black holes create new space or new spacetime?
Now (hypothesis) -- And the Physics of Time
In this page the author talks about (find in page) (in the context of LIGO Observatories-->) "In their most powerful event, reported just this past ...
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Question on non-diagonal Einstein Field Equations and the interpretation of Energy-momentum tensor components
Considering an EFE like:
$$\begin{pmatrix}G_{00}& 0 & 0& G_{03}\\0 &G_{11} &0 &0\\ 0&0 & G_{22}&0\\ G_{30}& 0& 0&G_{33} \end{pmatrix} = 8\pi\begin{...
- 315
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Question about the energy-momentum tensor and tetrad formalism
Given a metric tensor, you have an Einstein tensor associated with it. If your Einstein tensor is diagonal, you can "match it" with a diagonal energy-momentum tensor. More over, if your ...
- 315
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4
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773
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Orbital Velocity Formula in Schwarzschild metric
What is the orbital velocity formula in Schwarzschild metric assuming that the orbit is circular? this formula should also work for relativistic velocities.
- 31
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Conformal Diagram for Astrophysical Black Hole
I have a question about the conformal diagram of an ‘astrophysical’ black hole which forms in finite time (but with no evaporation).
Usually I see the conformal diagram presented as something similar ...
- 55
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2
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133
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When a new black hole forms does the universe shrink/contract?
I know that scientists debate if the universe is infinite, but for the purposes of this question let’s assume that the universe is finite and has a boundary. When a new black hole forms does the ...
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2
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188
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Curvature of space in a black hole
This is a very simplistic view from an interested structural design engineer (retired).
Mass curves space. Taking the case of a sphere of uniform density the point at which you have as much mass ...
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Has it been observed so far an object moving towards a BH along the trajectory of the polar astrophysical jet?
If we assume that the cause of the astrophysical jet is the magnetism of the BH than an object falling towards the BH in counterdirection of 'polar jet' emitions should not feel any strong deflection ...
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