What Is a 'Black Hole' & What Does It Mean for Particles?

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Discussion Overview

The discussion revolves around the nature of information in relation to black holes, particularly focusing on what happens to the defining parameters of particles that fall into a black hole. It explores theoretical implications from both General Relativity and quantum mechanics, as well as the relationship between the event horizon and information accumulation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that the information falling into a black hole refers to the basic defining parameters of the particles, such as speed and momenta.
  • Others argue that General Relativity suggests information is destroyed, as a black hole is characterized solely by mass, angular momentum, and charge, without regard to the specifics of the matter that fell into it.
  • A participant introduces the concept of unitarity from quantum mechanics, suggesting that if the state of a system is known at one time, it can be calculated at any other time, raising questions about information conservation in black holes.
  • One participant speculates that the surface area of the event horizon may relate to the amount of information accumulated, proposing a Planck scale unit of area and questioning how information from particles is represented and correlated.
  • Another participant reiterates the idea that the surface area of the event horizon is linked to the information content of the black hole, suggesting that this aligns with expectations for a future theory of quantum gravity.

Areas of Agreement / Disagreement

Participants express differing views on whether information is conserved in black holes, with some supporting the idea of information destruction as per General Relativity, while others invoke quantum mechanics to argue for conservation. The discussion remains unresolved with multiple competing views present.

Contextual Notes

There are limitations regarding the assumptions made about the nature of information and its representation in black holes, as well as the dependence on definitions related to quantum gravity and the specifics of the black hole information paradox.

Burt
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When they talk about information falling into a black hole, are they referring to the basic defining parameters of the particles falling into the hole?
 
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Their speed, momenta, and any other quantities.

One way to think of it is this: if you have a black hole, and know its state perfectly, could you determine precisely all of the matter that had fallen into it?

It goes towards the heart of physics, because General Relativity says that the information is destroyed, that there's no property of the black hole that is in any way dependent upon the precise details of the matter that fell into it. A black hole, in General Relativity, has angular momentum, mass, and charge as properties and that's it.

But quantum mechanics, as far as we know, has a property called unitarity: if I know the exact state of the system at time T, then I can, given enough computer power, calculate the precise state of the system at any other time, no matter what.

Since we don't know the precise quantum description of a black hole, we can't say for sure whether or not information is conserved, or what state it's in if it is conserved.
 
So the surface area of the event horizon is related to the amount of information that been accumulated by the black hole. I think we are looking at some sort of Planck scale unit of area here. Perhaps a tessellation of triangles each a Planck length on a side. Each unit area hold a bit of information? So if an elementary particle can be defined by say five bits of information, then for each particle that falls in, five unit areas area added to the area of the event horizon? Would those bits of information be contiguous? If not, how would then be correlated? When Hawking radiation carries information away from the black hole, is that information going out in sets that relate to each particle that fell in, or is there just some sort of random mixing of bits from multiple particles?
 
Burt said:
When they talk about information falling into a black hole, are they referring to the basic defining parameters of the particles falling into the hole?

They are referring to information about the state of the particles falling into the hole.

Burt said:
So the surface area of the event horizon is related to the amount of information that been accumulated by the black hole.

This seems to be the standard expectation of what we will find when we have a theory of quantum gravity. But at this point we don't know.

Burt said:
I think we are looking at some sort of Planck scale unit of area here.

Same comment as above.

For the rest of your post, you might try looking up sources on the black hole information paradox.
 

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