4
votes
2answers
80 views

When does a singularity start to exist during a black hole formation?

Excuse me if the question is naïve. I am not a physicist. Let's imagine formation of a black hole from a homogeneous collapsing star. At certain moment when enough of matter is inside of a small ...
1
vote
3answers
76 views

What happens to objects pulled in by black hole? [closed]

What happens to the particles/elements/objects that sink into the gravitational pull and ultimately go to the interior part of a black hole? If, according to popular notion, it is crushed by the ...
0
votes
3answers
60 views

Size of black hole

I am wondering about size of black hole. How is it possible that we have black holes of different sizes? As I know the singularity is point which is infinite small and is infinite dense. So my ...
2
votes
2answers
72 views

Relativity and volume of black hole

Does Einstein's theory of special or general relativity incorporate volume? In a particle accelerator two particles smash together at relativistic speeds and "create" new particles (quarks etc) due ...
10
votes
6answers
915 views

Why must a singularity form inside a black hole? [duplicate]

What is the exact reason that normal matter can not exist within an event horizon? I can understand how a super-dense object like a neutron star could accrete mass until its physical radius is less ...
1
vote
3answers
170 views

What is the relationship between the Schwarzschild radius and Black hole Singularity?

What is the relationship between the Schwarzschild radius and Black hole Singularity? Can the Planck length be the length of singularity? Or is the length of the Schwartzschild shorter than the ...
6
votes
1answer
108 views

What happens if you let a cable roll slip into a black hole?

Does the cable roll spin faster the more cable goes into the black hole in reference of a observer standing next to it? Can gravity pull the cable that it exceed the speed of light inside a black ...
2
votes
1answer
116 views

What happens when a black hole dies?

It just vanishes into space leaving nothing behind or does it expel some material? Also, talking more about black holes, as far as i understand the term "temperature", it is defined by the amount of ...
0
votes
2answers
106 views

Photons hitting the Black Hole Singularity

I was watching one of Dr. Susskind's Lectures on String theory and he was talking about black hole singularities (see the 40 minute mark of this lecture ...
9
votes
3answers
477 views

Are black holes really singularities?

A popular assumption about black holes is that their gravity grows beyond any limit so it beats all repulsive forces and the matter collapses into a singularity. Is there any evidence for this ...
3
votes
2answers
1k views

What is the shape of a black hole?

I was thinking; what shape does a black hole have?. By 'Shape', I mean its form (e.g, circle , cylinder, sphere, torus, etc..). We usually think of black holes as if they're plugholes (e.g, a flat ...
1
vote
6answers
246 views

Is black hole bright at center?

As we know that light photon cannot escape the gravity of black hole so I was thinking that if that is the surface of the black hole would be bright as all the photons would be there only. Am I right ...
6
votes
3answers
473 views

Fighting a black hole: Could a strong spherical shell inside an event horizon resist falling in to the singularity?

As a thought experiment imagine an incredibly strong spherical shell with a diameter a bit smaller than the event horizon of a particular large black hole. The shell is split into two hemispheres, ...
6
votes
2answers
754 views

Can we have a black hole without a singularity?

Assuming we have a sufficiently small and massive object such that it's escape velocity is greater than the speed of light, isn't this a black hole? It has an event horizon that light cannot escape, ...
7
votes
4answers
2k views

If an anti-matter singularity and a normal matter singularity, of equal masses, collided would we (outside the event horizon) see an explosion? [duplicate]

If an anti-matter singularity and a normal matter singularity, of equal masses, collided would we (outside the event horizon) see an explosion?