Slashdot Mirror
Laser Light Re-creates 'Black Holes' in the Lab
yodasz writes "The New Scientist reports that a team of researchers from the UK were able to recreate a black hole's event horizon in the lab by firing a laser pulse down an optical fibre. The team's observations confirm predictions made by cosmologists and now they are trying to prove Hawking's hypothesis of escaping particles, dubbed Hawking radiation. 'The first pulse distorts the optical properties of the fibre simply by traveling through it. This distortion forces the speedy probe wave to slow down dramatically when it catches up with the slower pulse and tries to move through it. In fact, the probe wave becomes trapped and can never overtake the pulse's leading edge, which effectively becomes a black hole event horizon, beyond which light cannot escape.'"
As long as they didn't create a real black hole.
That would suck.
No Nyarlathotep, No Chaos
Know Nyarlathotep, Know Chaos
That sounds safe, to reproduce the effects of the point at which all matter collapses into a virtual singularity. Where were they testing this again? Somewhere on Earth? Alrighty then... Taxi!
stuff |
As far as I can tell, they're using this technique to develop a technique to measure hawking radiation--which, you're correct, involves gravitational forces et al.
However, up until now, we had no real way to measure it unless we happened to see a small black hole blow up, something that we haven't figured out how to find.
In Xanadu did Kubla Khan
A stately pleasure dome decree
I was under the impression it was due to quantum particle pairs forming spontaneously. Under "normal" conditions we don't see these things because the pairs collide and sort of evaporate back to wherever the hell those things come from. However, in a black hole one of the particles escapes leaving the energy balance, well, in balance. The only reason that radiation escapes is that its partner went into the black hole absorbing some of its energy. Apparently, this phenomenon will cause all black holes to shrink to nothing over a long enough period of time.
I read about it in "The Physics of Star Trek", but Wikipedia has something on it too:
http://en.wikipedia.org/wiki/Hawking_radiation
Not to be picky, but you do know there's a little bit more to the event horizon of a black hole than the fact that light can't get out of it? Let's not confuse interesting optical effects with singularities. They are...different.
Bret: Pretty scrawny black hole. It must be hungry.
Cubert: Duh! Black holes don't need food.
Bret: Neither do nerds!
Move on, nothing to be seen here ...
-- Cave quid dicis, quando, et cui
could someone give me a little prep on this article.. A paragraph or two on how the universe works would be good. cheers. /obligatory
CommentBot 0.7a running with args "-module irritate,disagree -target random"
IANAP, but as I understand it, Hawking radiation is caused by virtual particles pairs being created such that rather than annihilating each other and returning local space to a base 'zero' state, one of the pair escapes the singularity's gravity and the other does not.
One fortunate consequence of this is that smaller black holes 'evaporate' more quickly, and the microscopic black holes we'll likely be generating at the Large Hadron Collider will cease to exist before they've even had sufficient time to absorb a neutrino.
Yeah, I'm no physicist either, but I don't quite follow this. They haven't simulated a black hole at all, just the optics of its event horizon.
Artificial event horizon != Artificial black hole.
Somehow I highly doubt that even if they can get the fiberoptics to 1000 degrees centigrade and perform this experiment that they'll get any hawking radiation out of it.
Curiosity was framed, Ignorance killed the cat.
Warning: do not look into laser with remaining good eye.
Sorry, my karma just ran over your dogma.
The experiment is cool, but as far as I can tell, this is nothing like a black hole in the cosmological sense. Simply reproducing one superficial property of black hole ("light cannot escape") does not make it a gravitational singularity with an event horizon and its associated properties. For example, I seriously doubt electron-positron conversions in their light cavity would behave at all like said conversions at a real event horizon since the charged particles would be subject to very different kinds of forces from those near a real black hole. Also, Hawking radiation is related to black hole evaporation. This would not occur with the lasers in an analogous way because the mechanics of this light bubble "evaporation" is totally different. It sounds to me like a case of one subfield (photonics) sexing up their lingo by adopting the lingo of another subfield (general relativity) to get press. IAAP, but not a cosmologists/GR expert, so I'm willing to stand corrected.
i\hbar\dot{\psi}=\hat{H}\psi
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
It would blow Hawking Radiation
Please, New Scientist is not a credible source for news on physical science. I wish people would stop posting New Scientist articles. If you want to find out what's hot in physics the Physical Review Focus is a great accessible source of real science stories that are important, and unlike the PRL they are free to read. http://focus.aps.org/
"I call it a Hawking Hole".
If I knew the wedgies I gave you back in 6th grade would have resulted in this . . . I might have taken a moments pause.
Curiosity was framed, Ignorance killed the cat.
Earth http://www.amazon.com/Earth-David-Brin/dp/055329024X
The world is made by those who show up for the job.
Properties of the medium. C is only in a vacuum, light has variable speeds all the way down to stop depending on what it's traveling through.
"I disapprove of what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall, re Voltaire
This reminds me of a rindler horizon
A phenomen that has some similarities with a black hole, but without gravitational effects involved.
God made the universe 6,000 years ago. If you do not worship him and subjugate yourself to his will, he will torture you forever. He just put in things like dinosaur bones and black holes to mess with your head, to get you to disbelieve in him, so that he can torture you forever without feeling guilty about it.
He's kinda messed up because he was alone for like, eternity, until he made up some friends in his head, but he's incapable of imagining anything that is actually his peer, so he secretly hates us all for not providing the companionship he needs. That is how the universe works.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Many optical fibers such as the one they are using have nonlinearities. Light of one frequency does not travel at the same speed as light of another frequency. They are exploiting this nonlinearity.
Prediction: The real iPhone killer is going to be sex robots from Japan. Think about it.
Curiosity was framed, Ignorance killed the cat.
FTA:
This makes me wonder how they're differentiating between light produced by their optics cable being on fire, and falloff from the laser. Or do optic cables not ignite at 1000 degrees centigrade? Regardless, it seems that there would be conflicting noise in a (presumably) non-vaccuum, lighted environment.
Does anybody remembers an old SF story in which a black hole is created and contained, and then somehow it _falls_ and start eating the Earth away? Cannot remember name or a author, but it gave me the creeps back then :o)
I remember reading a short story, probably in the 60's, with a plot like this. The story starts with investigators trying to understand a rash of mysterious structural failures around the world, and tracing them to tiny vertical holes drilled through whatever failed; including buildings. It's ultimately traced to a scientist who had been attempting to create a black hole in a mountaintop laboratory. The black hole couldn't be contained or supported (because it sucked in the material), and was basically in an "orbit" that carried it down to the center of the earth, back out the other side until it reached the same distance on the other side, and so on, like a pendulum. The rotation of the earth cause it to cross the surface at various places. The hole was becoming more destructive as it consumed more material and became larger, and the earth was doomed unless a way could be found to get rid of it. I think the story ended without resolution (before the earth is destroyed).
I got the creeps, too. I hope someone finds the title and author.
Hawking radiation is to do with Heisenberg's Uncertainty Principle and the creation of virtual particles (pairs like Quarks/Antiquarks, Electrons/Positrons, Neutrino/Antineutrino, Proton/Antiproton etc) that only exist for a negligible amount of time and they're impossible to detect directly. Usually they annihilate each other but if a pair is created near the event horizon, its possible that one part of the pair gets swallowed by the black hole and the other escapes. As multiple particles do this, they interact creating energy, photons & annihilate each other to create a thermal distribution of energies known as Hawking Radiation.
I saw part of The Teaching Company course covering this yesterday on Understanding The Universe.
I am a free slashdotter. I will not be modded, blogged, DRM'd, patented, podcasted or RFID'd. My life is my own.
The bit that's missing from this article, and that completes the explanation of why this is interesting, is the question of information.
One of the open questions facing physics is whether the event horizon of a black hole destroys information. It's not just the event horizon itself that is interesting, the destruction of information is by itself a legitimately interesting question by itself.
If we can create an optical event horizon that also seems to destroy information, this may allow us to witness how the Universe responds to such information destruction. This is radically easier than creating a large enough black hole to observe these effects. Black hole horizons are interesting in many ways; this may allow us to extract and experiment on one aspect of them.
I've seen a few proposals for the creation of an optical black hole, this is the first claim I've seen that someone may have actually created one.
It was learning about this at Cambridge that made me decide that crystallographers had to be much cleverer than I was ever going to be, so I decided to do something easier instead. Many years later I got promoted because we encountered an engineering problem nobody else in the company could solve. I did not know the answer, but I retained enough knowledge to know that I needed a metallurgist with a specific area of expertise, found one and got the problem fixed. Learning apparently irrelevant stuff may one day be a job saver.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
It is called a shoebox, and with the lid closed no light can escape. Why is this news?
Everybody is an expert!
I wish people would stop posting comments about New Scientist not been a credible source of news. WE ALREADY KNOW THAT. And, even if you don't believe this, WE CAN DISCERN, WITHOUT YOUR HELP, about the credibility of the ULTIMATE source New Scientist is citing. Haven't you notice that some news refers to articles in credible sources?