All Questions
Tagged with spacetime event-horizon
108
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Are objects that fall into a black hole *always* silhoutted against the Hawking radiation coming out?
There are many questions on this site about whether you can really fall into a black hole - some seem to say clearly yes, some say clearly no. So let's try one more stab at this one with a narrower ...
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Why can't anything return after crossing the event horizon? [duplicate]
I know that the escape velocity exceeds the speed of light but, what stops a rocket which can thrust constantly from returning, like, to escape earth we don't have to exceed escape velocity if we have ...
11
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Do black holes exist in 1+1 dimensional spacetime?
I'm currently working in 1+1 dimensional spacetime and would like to know if black holes can exist in such a manifold? I think they can because the Schwarzchild metric has the coordinate singularity, ...
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What closed 3D space looks and behaves like? (Relativistic Black Hole)
So I wanted to ask a question that is a copy of Why can't you escape a black hole?
From the answers, the conclusion I draw is: it's impossible to escape a black hole.
any trajectory inside the ...
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4
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Does the singularity travel along the time axis?
Let's assume that all matter travels along t axis roughly at the speed of light, in the direction of worldline for rest mass.
Let's also assume that there is a ...
- 302
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Black rings in 4D gravity
In Introduction to Black Hole Physics by Valeri P. Frolov, Andrei Zelnikov there is a discussion of gravity solutions. They present some examples of solutions with non-spherical horizon topology:
But ...
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What's the inner ergosphere in a Kerr black hole?
(My book uses the notation "ergosphere" as the hypersurface of static limit, "ergoregion" as the hypervolume within.)
Studying the Kerr BH, I've come to the part about horizons and ...
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Why are black holes so special? [closed]
When reading about black holes, I have also read about things relating to black holes like holographic principles, parallel universes, black hole connecting multiple universes, etc. But black holes ...
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What does it mean that the event horizon is a global concept?
In Chapter 6 of Spacetime and Geometry by S. Carroll, he says
‘‘Because the event horizon is a global concept, it might be difficult to actually locate one when you are handed a metric in an ...
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Why can't light travel past the event horizon?
Since the event horizon is defined as the boundary within which the escape velocity is greater than the speed of light, and escape velocity is the speed required for that object to reach infinity away ...
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Particles falling towards a singularity [duplicate]
This is a revision of my earlier question. Sorry. I'm a beginner here and on a learning curve regarding format.
If the gravity well steepens to infinity at the point of a singularity, then so does ...
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Does time exist without Gravity?
If you travel the universe and move into an area where there is negligible gravitational influence, does time stop? As an observer, would this be like watching someone cross the event horizon of a ...
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Does spacetime interval at event horizon become light-like for all trajectories?
I have been reading up few papers against the black hole paradigm specifically ECO, and i came across the argument raised by them that at r = 2GM, ds does indeed vanish. Is it correct? Please provide ...
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What does an external observer see if you shine a laser pointer while crossing an event horizon?
If I understand correctly, the event horizon of a black hole is the boundary beyond which we cannot perceive or describe any events, and all objects appear to freeze when falling in until their light ...
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What would the eternal black hole look like?
The white hole and black hole regions in a Kruskal diagram are said to be actually two different locations. Given the problems with white holes it might be a silly question but, hypothetically, what ...
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