<p>The singularity itself is, by definition, zero dimensional (well...you could argue one dimensional as it exists over time, but it has zero spacelike dimensions).</p>

<p>The event horizon is a two dimensional sphere, just like the surface of a beach ball - whether it can be said to have any thickness is unknown, there might be a thickness down at the Planck scale, but that's currently unknown. </p>

CC BY-SA 3.0
2017-09-02T14:31:13.930Z
2017-09-02T14:31:13.930Z
The Geoff
<p>I think, knowing that what dimension a black hole has depend on approach it with it's geometry. </p>

<p>When we discuss about a black hole and specially it's event horizon, we encounter to some geometry to study it. We should knowing the geometry of space-time and is space-times Flat and curved, if we use the geometry of Minkowski Space-time or other geometry. the Space-time structure is very important here. </p>

<p>In general relativity, it's unknown that what happens in GKP and with which manifold we must mathematically discuss about it!</p>

<p>I think this question that what is the dimensions of black hole, is physically vague and mathematically also. </p>

CC BY-SA 3.0
2017-09-02T17:10:49.957Z
2017-09-02T17:10:49.957Z
Nosrati
<p>Black hole is the densest .... in universe. We know that dimension of universe is 4D . So, what is the dimensions of black hole? Is string theory explains what is it's dimension?</p>

CC BY-SA 3.0
2017-09-02T14:30:04.923Z
Not sure what you mean.  In English "..." means a missing word or phrase. We don't know the Universe is 4D. Spacetime in general relativity is 4D, but that is not true in string theories.  A "blackhole" is a region of spacetime. You could ask the same question of any region: "how many dimensions does your bedroom have?" Also,  in English "what are the dimension of ..." means "how big is ...", though I think this is not what is meant.  You should describe what research you have done, and why you think a blackhole might be different from any other region of spacetime.
James K
CC BY-SA 3.0
2017-09-02T17:51:16.123Z
Shakya I'm sorry, but this question isn't very clear. Please try to rephrase it to make it clearer. For now I would say the dimensions of a black hole are the same as the dimensions of a star, or your bedroom. And that no, string theory does not explain a black hole's dimensions.
John Duffield
<black-hole>
what is the dimension of Black Hole?
Mental Shakya
# what is the dimension of Black Hole?

(Asked by: username_0 on 2017-09-02)

Black hole is the densest .... in universe. We know that dimension of universe is 4D . So, what is the dimensions of black hole? Is string theory explains what is it's dimension?

**Tags:** black-hole
> **Comments:**
> **username_1**: Not sure what you mean.  In English "..." means a missing word or phrase. We don't know the Universe is 4D. Spacetime in general relativity is 4D, but that is not true in string theories.  A "blackhole" is a region of spacetime. You could ask the same question of any region: "how many dimensions does your bedroom have?" Also,  in English "what are the dimension of ..." means "how big is ...", though I think this is not what is meant.  You should describe what research you have done, and why you think a blackhole might be different from any other region of spacetime.  
> **username_2**: Shakya I'm sorry, but this question isn't very clear. Please try to rephrase it to make it clearer. For now I would say the dimensions of a black hole are the same as the dimensions of a star, or your bedroom. And that no, string theory does not explain a black hole's dimensions.  

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## 2 answers

### Answer by username_3 on 2017-09-02. Score: 1

The singularity itself is, by definition, zero dimensional (well...you could argue one dimensional as it exists over time, but it has zero spacelike dimensions).

The event horizon is a two dimensional sphere, just like the surface of a beach ball - whether it can be said to have any thickness is unknown, there might be a thickness down at the Planck scale, but that's currently unknown.


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### Answer by username_4 on 2017-09-02. Score: 0

I think, knowing that what dimension a black hole has depend on approach it with it's geometry.

When we discuss about a black hole and specially it's event horizon, we encounter to some geometry to study it. We should knowing the geometry of space-time and is space-times Flat and curved, if we use the geometry of Minkowski Space-time or other geometry. the Space-time structure is very important here.

In general relativity, it's unknown that what happens in GKP and with which manifold we must mathematically discuss about it!

I think this question that what is the dimensions of black hole, is physically vague and mathematically also.


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