Escaping gravity's clutches: The black hole breakout

Aug 11, 2011

New research by scientists at the University of York gives a fresh perspective on the physics of black holes.

Black holes are objects in space that are so massive and compact they were described by Einstein as "bending" space. Conventional thinking asserts that black holes swallow everything that gets too close and that nothing can escape, but the study by Professor Samuel Braunstein and Dr Manas Patra suggests that information could escape from black holes after all.

The implications could be revolutionary, suggesting that gravity may not be a fundamental force of Nature.

Professor Braunstein says: "Our results didn't need the details of a black hole's curved space geometry. That lends support to recent proposals that space, time and even gravity itself may be emergent properties within a deeper theory. Our work subtly changes those proposals, by identifying quantum information theory as the likely candidate for the source of an emergent ."

But is the theory of light and atoms, and many physicists are skeptical that it could be used to explain the slow evaporation of without incorporating the effects of gravity.

The research, which appears in the latest issue of , uses the basic tenets of quantum mechanics to give a new description of information leaking from a black hole.

Professor Braunstein says: "Our results actually extend the predictions made by well-established techniques that rely on a detailed knowledge of space time and black hole geometry."

Dr Patra adds: "We cannot claim to have proven that escape from a black hole is truly possible, but that is the most straight-forward interpretation of our results. Indeed, our results suggest that quantum information theory will play a key role in a future combining quantum mechanics and gravity."

Explore further: What is Nothing?

More information: Black Hole Evaporation Rates without Spacetime, Phys. Rev. Lett. 107, 071302 (2011) DOI:10.1103/PhysRevLett.107.071302

Abstract
Verlinde recently suggested that gravity, inertia, and even spacetime may be emergent properties of an underlying thermodynamic theory. This vision was motivated in part by Jacobson’s 1995 surprise result that the Einstein equations of gravity follow from the thermodynamic properties of event horizons. Taking a first tentative step in such a program, we derive the evaporation rate (or radiation spectrum) from black hole event horizons in a spacetime-free manner. Our result relies on a Hilbert space description of black hole evaporation, symmetries therein which follow from the inherent high dimensionality of black holes, global conservation of the no-hair quantities, and the existence of Penrose processes. Our analysis is not wedded to standard general relativity and so should apply to extended gravity theories where we find that the black hole area must be replaced by some other property in any generalized area theorem.

Provided by University of York

4.5 /5 (17 votes)

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Husky
not rated yet Aug 11, 2011
meaning?
antialias_physorg
4 / 5 (5) Aug 11, 2011
For those interested here's a link to the full article:
http://arxiv.org/...26v2.pdf
JustCurious
not rated yet Aug 11, 2011
Offtopic: What would happen if a normal matter black hole and a anti matter black hole colided? Just curious :)
rawa1
1.7 / 5 (6) Aug 11, 2011
meaning?
I don't understand this math, but thermodynamical principle is actually consistent with aether model of Boltzmann gas. In this theory the concept of Hawking radiation is extended, the black holes can evaporate the matter depending on their mass. It could mean, the jets of black holes doesn't emerge from accretion of matter into black hole only, but they could origin from material of black hole itself (which is evaporating into radiation in this way a much faster, than Hawking mechanism allows). As the observable evidence can serve the existence of quasars, which are shining brightly without accretion of mass. This model could further constrain the accretion of matter: such matter would often evaporate faster, than it can be swallowed with event horizon - from perspective of external observer it's repelled with accretion radiation, which counteract the gravity. So that only slight portion of matter is swallowed at the very end, the rest is simply evaporated.
gwrede
2.5 / 5 (2) Aug 11, 2011
Our result relies on a Hilbert space description of black hole evaporation, symmetries therein which follow from the inherent high dimensionality of black holes, global conservation of the no-hair quantities, and the existence of Penrose processes.


The rest is mere conjecture, except for the part with no-hair.

@JustCurious: Depends on who you ask. If they believe in positive gravity for both, then the black holes will merge, and when eventually the "cores" meet and violently explode, they will anyhow be within the event horizon. Unless of course, we take literally the bit about matter being squeezed to zero volume. Then they obviously can never meet. With finite volume they will annihilate, instantaneously causing an undoing of the space curvature, leading to dispersal of the event horizon.

With negative gravity of antimatter, you'll get another equally off-the cuff "opinion", served as the truth. -- Anyhow, every person (or scientist) will tell you a different story.
antialias_physorg
1 / 5 (1) Aug 11, 2011
This model could further constrain the accretion of matter: such matter would often evaporate faster, than it can be swallowed with event horizon

I'm not sure this follows as the emission of information (or mass) is dependent on very specific circumstances which need not be met:
1) Particles split into two within the ergosphere
2) One of the parts may have negative energy

If the part with positive energy escapes angular momentum can be reduced (note that this mechanism does not constitute a reduction of the event horizon but only of the ergosphere until it coincides with the event horizon and the engular momentum of the black hole becomes zero. From then on only Hawking radiation will reduce the size of a black hole)

Now while 1) is probably a frequent occurence there is no indication why 2) should be an asymmetric case (i.e. why in a majority of cases the part with the negative energy should be the one that stays inside).
rawa1
1 / 5 (2) Aug 11, 2011
From then on only Hawking radiation will reduce the size of a black hole
At the case of real black holes (i.e. those rotating with fast moving surfaces) these models are becoming more fuzzy, then they appear for stationary solution. IMO black hole jets are actually form of Hawking radiation too - it just manifests under situation, when the even horizon is broken (i.e. it exhibits the "holes" at the poles of rotating black hole). You can imagine such even horizon like doughnut with holes, along which the surface of "naked singularity" (i.e. physical surface of black hole) is visible from outside. It's just exaggerated example of gravitational brightening, which is observable at the case of all fast rotating stars - so you can derive the same result in many alternative ways: the black hole will be brightly shinning, instead of glowing with rather weak Hawking radiation.
JustCurious
5 / 5 (1) Aug 11, 2011
@qwrede: Thank you :)
Raygunner
5 / 5 (2) Aug 11, 2011
I still don't get the "information leak" from a black hole. An elephant goes in, and "information", or the remnants of the elephant in the form of radiation (eventually) leaks out, correct? How is it possible to ever, even with the most advanced technology, piece together the evaporative radiation components to prove an elephant was ever there? How do you associate ANY elementary particle emitted with ANY object that has fallen in? It sounds like a mind game to me to satisfy conservation of energy and causality. Yes, all of the matter that has gone in may eventually leak out in some form, but it is impossible, IMHO, to put Humpty Dumpty back together again! Or maybe I'm missing the point totally. Maybe we are talking information at the quantum level, not the classical level?

I'm just a layman trying to understand some of this - please excuse my ignorance.
Egleton
1 / 5 (1) Aug 11, 2011
Thanks rawa1. That is as close as I can approach the subject.
My understanding of this is that gravity is not a primary
"thing", but that it is a creation of quantum mathematics.
It is good to know that there is still stuff we dont know. It gives me hope that we might be able to truely be able to get out of the gravity well.
antialias_physorg
5 / 5 (1) Aug 11, 2011
I still don't get the "information leak" from a black hole.

In this case it's not about associating input with output but about getting anything back from the black hole at all. The article (and Hawking radiation) shows that over time you can get more out than you put in - which means that there can be a net information flow (apparently *) from the black hole to the outside universe (in contrast to the usual notion that 'nothing' can escape a black hole).

* 'Apparently' because even Hawking radiation does not originate from within the event horizon.
Techno1
5 / 5 (1) Aug 11, 2011
If a particle outside the event horizon "robs" angular momentum from the black hole, increasing it's velocity, and escapes, then the black hole has lost mass.

This would be true in classical mechanics, relativity, and quantum mechanics.

Just look at the classical kinetic energy formula:

Ek = (1/2)mv^2

If you change your angular momentum, you will change your instantaneous linear velocity, at least in most cases, with respect to some reference point, in this case the black hole.

If the velocity went up the energy went up, and the energy had to come from the black hole.

Moreover, since in relativity mass itself goes up with velocity, the particle actually robs "energy" from the black hole on BOTH the "m" variable and the "v" variable.

We ordinarily neglect relativity of mass for small velocities or changes in velocity, but the reality is ANY change in velocity represents a non-zero change in mass.
Raygunner
not rated yet Aug 11, 2011
Thanks for the clarification antialias - that actually clears it up a little.

I guess the word "information" and in context with a black hole is somewhat misleading, at least to me. Particles are considered information? I can see this but it is stretching the meaning a good bit. What is not clear is the point they are trying to make. I guess if you could monitor a BH from beginning to end, count ingoing and outgoing particles (good luck with that), and come up with a figure that shows proper I/O balance... well that seems impossible. It's all theory anyway and I can see where they have to try and work things out the best that they can.
LuckyBrandon
1 / 5 (1) Aug 11, 2011
Offtopic: What would happen if a normal matter black hole and a anti matter black hole colided? Just curious :)


It would suck!
Burnerjack
not rated yet Aug 11, 2011
Another off topic, if you would indulge me...
Is it possible that a BH is hollow with incredible mass surrounding a pure energy core? My imagination tells me that at some point the matter approaching the singularity is literaly crushed out of existence similar to total anihilation.
Also, what might the rpm just outside the singularity be?
yep
1.8 / 5 (5) Aug 12, 2011
Point mass singularities violates General Relativity. Black holes are astronomers Santa Clause.
The Schwarzschild solution and its implications for gravitational waves Stephen J Crothers
http://www.holosc...talk.pdf
hush1
5 / 5 (1) Aug 13, 2011
You are not alone. Stephen J Crothers has not ventured pass mathematics. All this is no longer a question of assigning meaningful physical interpretations to mathematical expressions.

He demands the underlying math contain no calculation errors.

A demand that is unacceptable for the astrophysical society.
Gawad
5 / 5 (2) Aug 16, 2011
Now while 1) is probably a frequent occurence there is no indication why 2) should be an asymmetric case (i.e. why in a majority of cases the part with the negative energy should be the one that stays inside).
The answer is that in a sense both particles are originally negative. That is, you have to remember that both particles are initially virtual, created by a temporary QM borrowing of energy from the surrounding space-time, in this case at an event horizon (EH). The event horizon actually shrinks when the PAIR are created (being borrowed from the space-time at the EH) and returns to its previous size if both annihilate. Just far enough from the EH, outside & inside, the pair can't be separated and will annihilate. It's at the EH that conditions are special. The EH can separate the pair and only get back one of two particles created from the space-time at the BH boundary. That's why the swallowed one is always negative: the BH is getting back just 1/2 the cost of making them.