How Does Gravity Escape a Black Hole?

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Discussion Overview

The discussion revolves around the nature of gravity in relation to black holes, particularly focusing on how gravity is perceived to escape a black hole's event horizon. Participants explore concepts from both classical and quantum perspectives, including the role of virtual particles and gravitons, as well as the implications of general relativity.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant questions the concept of gravitons escaping the event horizon, suggesting that if gravity travels at the speed of light, it cannot escape a black hole, thus challenging the existence of gravitons and proposing that gravity is better understood as curved spacetime.
  • Another participant asserts that gravity is synonymous with the black hole itself, implying that gravity does not need to escape but is an inherent property of the black hole.
  • A different viewpoint emphasizes that gravity is a field, and once a black hole forms, there is no mechanism for gravity to "get out," as it is simply an existing field.
  • One participant references an external source to provide additional context to the discussion, indicating that the topic has been addressed in other literature.
  • Another contribution clarifies that the gravitational force does not rely on gravitons escaping from a black hole, and that gravitons, if they exist, are not part of general relativity but may be relevant in quantum gravity theories.
  • A participant raises a point about the impossibility of the sun suddenly disappearing, citing local energy conservation as a constraint that complicates thought experiments regarding the speed of gravity.

Areas of Agreement / Disagreement

Participants express differing views on the nature of gravity in relation to black holes, with no consensus reached on the role of gravitons or the mechanisms by which gravity operates in this context.

Contextual Notes

Participants highlight limitations related to the definitions of gravitational concepts and the implications of local energy conservation, which may affect the formulation of thought experiments regarding gravity.

black hole 123
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And how does graviton escape the event horizon? People say it's because those gravitons are "virtual particles" and can travel faster than light, yet many of the posts i read on here say virtual particles don't even exist. Also, gravity TRAVELS at the speed of light, if the sun is suddenly gone we'll still feel its gravity, so please don't tell me somehow the gravity from a black hole manages to travel faster than light. Doesn't this prove gravitons are wrong, and gravity really is curved spacetime? Or uses some other mechanism not the same as the other 3 forces?
 
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Gravity doesn't have to "fight the black hole" it IS the black hole.
 
This is a common point of misunderstanding. Gravity is a field. The gravitational field of a black hole forms as the black hole is forming, so there IS no "getting out of" the black hole, it's just an existing field.
 
To add to what the others are saying:

The gravitational force between two objects is not caused by gravitons (assuming that there is such a thing as a graviton) moving from one to the other, so a black hole's gravitational effects do not depend on gravitons getting out of it.

Gravitons are a hypothetical concept that appears in some theories of quantum gravity, but they are no part of general relativity because it's not a quantum theory. If gravitons do exist, they will show up in the quantum mechanical description of how an object interacts with the local gravitational field in it's immediate vicinity.
 
black hole 123 said:
if the sun is suddenly gone

This can't happen; it would violate local energy conservation. It is actually not trivial to formulate a thought experiment that can test the "speed of gravity" by changing gravitational sources, because of the requirement of local energy conservation, which means that sources of gravity can't be created or destroyed.
 

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