How could a graviton mediate gravity at places such as a black hole?

In summary: But what I was wondering is why it would collapse into a black hole, because even if it were massive enough, it shouldn't collapse into a black hole unless gravity was proportional to volume or pressure right?Yes, gravity is only proportional to the mass of the object.
  • #1
RagingHadron
18
0
Is there some type of exception to the singularity for gravitons? And if not gravitons then what? I understand the spacetime curvature except why does a sun not collapse in on itself right now when it does after fusion has stopped? I'm told it's from energy creating pressure outwards counteracting the inward pull of gravity but that would suggest that an interaction between particles is taking place, no? And if the pressure created by fusion pushes more against gravity than the normal matter does after fusion has stopped, should the sun not be expanding?
 
Physics news on Phys.org
  • #2
In some string theories, it is my understanding that gravitons are emitted from the surface (event horizon) of the black hole.
 
  • #3
So there is a special exclusion..?
 
  • #4
Not really, it's just that instead of a singularity, it is a 'fuzzball' that is spread out more or less uniformly with the event horizon at its surface.

Again, I have to stress that this is my understanding only, it could be highly flawed.
 
  • #5
And if the pressure created by fusion pushes more against gravity than the normal matter does after fusion has stopped, should the sun not be expanding?

If the pressure from fusion plus the pressure from the internal structure of the matter is equal to the pull from gravity, it will not collapse or expand. If the opposing forces are not equal, it will either expand or contract. Both of these things happen to a star during its normal lifespan. The contraction only turns into a complete collapse if it is a massive enough star (there may be ways for a smaller star to turn into a black hole too, but I think that is less common).

If the star expands a bit, the pressure decreases a bit. That decrease may be enough to make the pressure be less than the gravitational pull... so a cycle begins.
 
  • #6
If the entire black hole is everything inside or is a sort of "solid block" from which gravitons are emitted at it's surface, the event horizon, why is it predicted you could travel down one with normal relativistic effects? It should just be the same facric ofspace crossing the border of the event horizon, and matter should follow that path, and based on our understanding matter isn't destroyed when it passes the horizon, but when it reaches the singularity.
 
  • #7
DrewD said:
If the pressure from fusion plus the pressure from the internal structure of the matter is equal to the pull from gravity, it will not collapse or expand. If the opposing forces are not equal, it will either expand or contract. Both of these things happen to a star during its normal lifespan. The contraction only turns into a complete collapse if it is a massive enough star (there may be ways for a smaller star to turn into a black hole too, but I think that is less common).

If the star expands a bit, the pressure decreases a bit. That decrease may be enough to make the pressure be less than the gravitational pull... so a cycle begins.

But what I was wondering is why it would collapse into a black hole, because even if it were massive enough, it shouldn't collapse into a black hole unless gravity was proportional to volume or pressure right? Since it's only caused by mass then once the internal pressure goes away all that's left is the mass of whatever didn't burn away and the gravity of that isn't enough to form a black hole right? Like I get that there's no internal pressure to counteract gravity but since the gravity is only based on mass, is it that the star would be a black hole if it weren't fusing things together?
 
Last edited:

Related to How could a graviton mediate gravity at places such as a black hole?

1. How does a graviton mediate gravity at a black hole?

A graviton is a hypothetical particle that is thought to be responsible for mediating the force of gravity. In the context of a black hole, the graviton is thought to interact with the immense mass and energy of the black hole, creating the gravitational force that we observe.

2. What is the evidence for the existence of gravitons?

Currently, there is no direct evidence for the existence of gravitons. However, the theory of general relativity, which describes gravity as the curvature of spacetime, has been incredibly successful in predicting and explaining the behavior of massive objects. This lends support to the idea that there is a particle responsible for mediating gravity.

3. How does the presence of a black hole affect the behavior of gravitons?

In the presence of a black hole, the gravitons would be influenced by the immense gravitational pull exerted by the black hole. This would cause the gravitons to curve and follow the curvature of spacetime, creating the gravitational force that we observe.

4. Can gravitons escape from a black hole?

It is currently unknown whether gravitons can escape from a black hole. According to general relativity, nothing can escape from a black hole, not even light. If gravitons behave similarly to photons (particles of light), then they would also not be able to escape from a black hole.

5. How does the concept of a graviton fit into the current understanding of gravity?

The concept of a graviton is still a theoretical concept and is not yet fully integrated into our current understanding of gravity. However, many scientists believe that the existence of gravitons is necessary to fully understand and reconcile the theory of general relativity with quantum mechanics. Research and experiments are ongoing to try and detect and understand the behavior of gravitons.

Similar threads

Replies
4
Views
772
  • Quantum Physics
Replies
6
Views
2K
  • Quantum Physics
Replies
4
Views
773
Replies
12
Views
2K
  • Quantum Physics
Replies
14
Views
2K
  • Special and General Relativity
Replies
4
Views
951
Replies
6
Views
982
  • Sci-Fi Writing and World Building
Replies
5
Views
548
Replies
9
Views
3K
  • Astronomy and Astrophysics
Replies
10
Views
920
Back
Top