All Questions
Tagged with spacetime event-horizon
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About space/timelike intervals and event horizon of observed universe
How does interval between us (e.g earth) and the spacetime outside of observable universe (above the event horizon) can be described in terms of timelike and spacelike intervals?
Is it just spacelike ...
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Define event horizon using only the notions of events and causality
Does this work?
Consider a set $B$ of events which satisfies
If $x$ belongs to $B$ and $x$ causes $y$ then $y$ belongs to $B$. The event horizon of $B$ is the set of events that are not in $B$ but ...
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Are Black Holes 4 dimensional?
I was thinking about if Black Holes are 4th dimensional.
I know that spacetime inside a black hole scrambles (not sure if this is the correct term) very fast to produce more space, like a bag that ...
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Time coordinate in general relativity [closed]
In special relativity, an inertial observer, for instance, in 1+1 dimensions, a world line of an object could be paramatrized, and the time measurement of the inertial observer between two points of ...
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Penrose diagram for two black holes?
Is there a Penrose diagram for two black holes near each other. Perhaps they are colliding or circling each other? Or can this method only describe a single black hole.
user84158
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Kerr Black hole EH and Ergosphere embedding
Goodmorning everyone. I would like to share with you a question that has been gripping me for some time, but which I have never been able to give a convincing answer. When representing the ergosphere ...
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What do we see if we observe the spaceship coming from a planet that's inside the event horizon? [closed]
Well, after watching the movie Interstellar, I just ask myself:
What would I see if I observe the ship that Cooper and the other girl in, coming from the planet inside the event horizon of Gargantua? ...
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Is there a general definition of a causal horizon?
In the Schwarzschild spacetime with metric in standard Schwarzschild coordinates
$$ds^2=\rho(r)dt^2-\rho(r)^{-1}dr^2-r^2d\Omega^2,\quad \rho(r)=1-\dfrac{2GM}{r},$$
we have a coordinate singularity ...
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What happens to the space in a black hole? [closed]
What's the smallest unit of space and is space static? What happens when a black hole passes through space? Does it escape the grips of a black hole? does it pull it with? Is space a inseparable ...
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What happens to the space a black hole passes through? [closed]
I want to know what happens to the space a black hole crosses over as our galaxy travels through space.
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Can matter actually go "inside" a black hole? [duplicate]
Pardon my question but I am no astro-physicist.
If a black hole is a singularity, A.K.A. a single point in space-time which is infinitely small and which has an infinitely high density, can matter ...
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Could all matter in a black hole be actually only on its surface (Schwarzschild radius)?
Layman here, sorry if I miss something obvious.
Black hole entropy depends linearly on its surface. If all matter in a black hole would actually be located only on its surface (or very near), wouldn'...
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Is it possible the space-time manifold itself could stop at a black hole's event horizon?
This is a repost of a question I saw here:
Could the spacetime manifold itself end at the event horizon?
which was closed because it apparently didn't seem clear as to what the poster there was ...
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Black Holes 2D or 3D?
Are black holes 2 dimensional or 3 Dimensional. If they were 3 Dimensional it would make more sense that wherever you approach it the gravity would be the same. But images on the internet show it as a ...
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Thoughts on Black Holes [duplicate]
Given that time slows to a stand-still at the event horizon of a Black Hole, how long would it take a black hole to form, from the perspective of an outside observer?
It would seem, as a massive star ...
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