Thermal analog black hole agrees with Hawking radiation theory

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A team of researchers at the Israel Institute of Technology has found that a thermal analog black hole they created agrees with the Hawking radiation theory. In their paper published in the journal Nature, the group describes building their analog black hole and using data from it to test its temperature. Silke Weinfurtner with the University of Nottingham has published a News and Views piece on the work done by the team in the same journal issue.

One of Stephen Hawking's theories suggested that not all matter that approaches a black hole falls in—he argued that in some cases in which entangled pairs of particles arise, only one of them would fall in, while the other escaped. The escaping particles were named Hawking . Hawking also predicted that the radiation escaping from a black hole would be thermal and that its temperature would depend on the size of the black hole. Testing the has been difficult because of the nature of —any radiation escaping from them would be too faint to observe. To get around that problem, researchers have been working on creating black hole analogs in the lab. In this new effort, the researchers built one designed to absorb sound instead of light. With such an analog, pairs of phonons served as stand-ins for the entangled particles in a real black hole.

The experiment consisted of chilling a group of rubidium atoms and using lasers to create a Bose-Einstein condensate. The atoms were then forced to flow in a way that resembled the trapping that occurs with a real black hole. With such a flow, were unable to escape under normal circumstances. In their experiment, the researchers were able to force one of a pair of phonons to fall into the flow of atoms while the other was allowed to escape. As they did so, the researchers took measurements of both phonons, allowing them to estimate their temperature to .035 billionths of a kelvin. And in so doing, they found it agreed with Hawking's prediction. They also found agreement that the radiation from such a system would be thermal.

The work does not prove the theory, of course; the only way to do that will be to develop technology capable of actually measuring the radiation from a real black hole—but it does give the theory more credence.


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More information: Juan Ramón Muñoz de Nova et al. Observation of thermal Hawking radiation and its temperature in an analogue black hole, Nature (2019). DOI: 10.1038/s41586-019-1241-0
Journal information: Nature

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Citation: Thermal analog black hole agrees with Hawking radiation theory (2019, May 30) retrieved 24 August 2019 from https://phys.org/news/2019-05-thermal-analog-black-hole-hawking.html
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May 30, 2019
Physicists have recently reasonably extended quantum field theory to the event horizon - which is used to describe the Hawking radiation mechanism - by showing that low energy perturbation methods can describe black hole merger external interactions. That and the radiation mechanism consistency across disparate physical systems is encouraging.

"It's working!" [SW quote on a hunk of junk of pieced together mechanisms.]

May 30, 2019
NO ONE ON THIS PLANET knows what a black hole is, much less be able to simulate it! This is blatant snake oil and these so called scientists are frauds!

May 30, 2019
In search of black holes and dark matter astrophysicists are relying on indirect observations. It would seem that the measurement of the event horizon of a black hole directly would be a direct evidence. However, by the nature of a horizon, any real measurement of the event horizon will be indirect. The Event Horizon Telescope will get picture of the silhouette of the Sgr A* which is due to optical effects of spacetime outside of the event horizon. The result will be determined by the simple quality of the resulting image that does not depend on the properties of the spacetime within the image. So, it will be also indirect and an existence of BH is a hypothesis.
https://www.acade...ilky_Way

May 30, 2019
NO ONE ON THIS PLANET knows what a black hole is, much less be able to simulate it! This is blatant snake oil and these so called scientists are frauds!


Then grow a pair, and go into print and point out where they are going wrong, you bag of hot air. Instead of giving your uneducated, anonymous, worthless opinions on here.

May 31, 2019
One thing that has always made me question hawking radiation is how does a virtual particle, which is bound by a mutual force so that they collide and annihilate ever have one of the particles reach escape velocity from a black hole?

If you work under the assumption that the particles aren't traveling at the speed of light, since they collide with eachother after spawning into existence then what situation can occur where the second particle doesn't follow it's partner in to the blackhole?

At the event horizon, we know that gravity just outside of it would allow light to escape, but would still suck in anything going slightly slower, which we already assume the virtual particles are moving at sublight speeds. so both would fall in.

If further away from the black hole at the point where their accel is countered by gravity so that one is sucked in but the other is not, the force that exists to cause their annihilation with eachother would pull the other in with it as well.

May 31, 2019
So, what situation occurs that allow the other particle to reach escape velocity?

at the event horizon, they're both not going the speed of light so ...it doesn't make sense that either would escape.

Further away, the force that attracts them is stronger than gravity anyway and continues to exert it's force as the infalling particle moves, dragging it's friend with it as well. So in my mind, they either always fall in or always annihilate. The only way the force that attracts them to eachother is not felt by the other particle is at the event horizon, and unless the particles can move at the speed of light and curve in on themselves to collide, i dont see how the other could move fast enough to escape the gravity well. Either gravity pulls them both in or the force that attracts them anyway drags the other in with it.

anyone know how?

May 31, 2019
Then grow a pair, and go into print and point out where they are going wrong, you bag of hot air. Instead of giving your uneducated, anonymous, worthless opinions on here.


To what end? No one here has the education or the brains to understand it....

May 31, 2019
@Darth Ender.

Agreed. I also pointed out such things in another forum years ago.

Moreover, Hawking radiation hypothesis was framed at a time when BH Event Horizon was considered 'razor sharp' dividing line between inside/outside black hole where virtual particle 'pairs' would 'separate'.

Since then reasonable physicists realised QUANTUM uncertainties' and chaotic processes immediately near EH would cause any 'incipient' virtual particle 'potential pairs' to be disrupted before actually 'manifesting'; and/or cause both to be dragged inwards during the very short period they form/annihilate because the local incoming ordinary REAL energy/matter flows would 'entrain' any particle-pairs that may materialise that close to EH.

In short: BH EH is no longer deemed a 'sharp dividing line'; but a FUZZY turbulent quantum CHAOTIC region where a lot of surrounding INCOMING REAL energy/matter forms a physical barrier to 'escape' of ANY particle in that region, virtual or otherwise. :)

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