Stephen Hawking's black hole paradox

[beecee]

https://phys.org/news/2022-03-scientists-stephen-hawking-black-hole.html

Scientists may have solved Stephen Hawking's black hole paradox

Researchers may have solved Professor Stephen Hawking's famous black hole paradox—a mystery that has puzzled scientists for almost half a century.

According to two new studies, something called "quantum hair" is the answer to the problem.

In the first paper, published in the journal Physical Review Letters, researchers demonstrated that black holes are more complex than originally thought and have gravitational fields that hold information about how they were formed.

The researchers showed that matter collapsing into a black hole leaves a mark in its gravitational field—an imprint referred to as a "quantum hair."

In a follow-up paper, published in a separate journal, Physics Letters B, Professor Xavier Calmet from the University of Sussex's School of Mathematical and Physical Sciences and Professor Stephen Hsu from Michigan State University said quantum hairs resolve Hawking's Black Hole Information Paradox.

more at link...................

 

the paper:

https://www.sciencedirect.com/science/article/pii/S0370269322001290?via%3Dihub

Quantum hair and black hole information:

Abstract

It has been shown that the quantum state of the graviton field outside a black hole horizon carries information about the internal state of the hole. We explain how this allows unitary evaporation: the final radiation state is a complex superposition which depends linearly on the initial black hole state. Under time reversal, the radiation state evolves back to the original black hole quantum state. Formulations of the information paradox on a fixed semiclassical geometry describe only a small subset of the evaporation Hilbert space, and do not exclude overall unitarity.

 

[MigL]

These advances come about by the limited application of uantum Mechanical thinking to purely classical ideas.
Makes you wonder how many 'secrets' a full Quantum Gravity theory will unlock.

[beecee]

1 hour ago, MigL said:

These advances come about by the limited application of uantum Mechanical thinking to purely classical ideas.
Makes you wonder how many 'secrets' a full Quantum Gravity theory will unlock.

When you say a full quantum gravity theory, you mean one that can be observationally validated, correct? This seems to be the big stumbling block, observing at those quantum/Planck levels.

[swansont]

19 hours ago, beecee said:

When you say a full quantum gravity theory, you mean one that can be observationally validated, correct? This seems to be the big stumbling block, observing at those quantum/Planck levels.

I don’t think so. It’s a matter of basing it in QM vs extrapolating from classical physics, as they currently do

Also nobody observes gravitational effects at the Planck scale. 

[beecee]

2 hours ago, swansont said:

Also nobody observes gravitational effects at the Planck scale. 

I was of the opinion that this was the stumbling block. Such observational data are supposedly only evident at much higher energies then what we can achieve in the LHC. I've heard it said about string theory and its derivatives. 

2 hours ago, swansont said:

I don’t think so. It’s a matter of basing it in QM vs extrapolating from classical physics, as they currently do

So how could that be achieved, without the much higher energies that are needed? What size are we talking about? How would the cancelled SSC have faired in that regard?

[swansont]

2 hours ago, beecee said:

I was of the opinion that this was the stumbling block. Such observational data are supposedly only evident at much higher energies then what we can achieve in the LHC. I've heard it said about string theory and its derivatives. 

The first stumbling block, I would think, is not having a theory.

2 hours ago, beecee said:

So how could that be achieved, without the much higher energies that are needed? What size are we talking about? How would the cancelled SSC have faired in that regard?

I’m not sure the SSC was going to test quantum gravity

[beausconce]

good