All Questions
6
questions
1
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If two black holes orbit around each other should their tidal forces cause a shrinking of the closer parts of their event horizons?
I recently asked a question about the influence of external gravitational fields on the stability of the geometry of a part or all the event horizon of a black hole. I understood the answer in a ...
- 2,255
6
votes
2
answers
715
views
Can two relativistic black holes' event horizons overlap and separate again?
I have read this question:
What I have not seen is a purely classical argument for the non-separation of a black hole merger. One can obviously take the time reversed spacetime manifold of a merger ...
- 29k
5
votes
1
answer
423
views
Is there an approximate expression for the force between two black holes?
Just curious: is there an approximate expression for the gravitational attraction between two Schwarzschild black holes of masses $M$ and $m$, held without relative speed at some center to center ...
user85598
7
votes
1
answer
283
views
Theoretical solution to binary black hole merger based on Hawking and Ellis
Following Hawking and Ellis, Chapter 9, Fig. 60, Pg. 322, the following figure is meant to illustrate the contrast between apparent horizons and event horizons in the case of a binary black hole ...
- 245
2
votes
2
answers
216
views
Time dilation, and curvature of space caused by two black holes of unequal masses
If you were to try to find the time dilation in a region of space near a black hole you would use the equation
$$t_r=\sqrt{1-\frac{2GM}{rc^2}}$$
Would the time dilation from two black holes be this?
...
- 780
16
votes
3
answers
41k
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How do we determine the mass of a black hole?
Since by definition we cannot observe black holes directly, how do astronomers determine the mass of a black hole?
What observational techniques are there that would allow us to determine a black ...
grassman