An artists impression of a black hole

Synthetic Black Hole Event Horizon Created in UK Laboratory

13 Feb , 2008

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Researchers at St. Andrews University, Scotland, claim to have found a way to simulate an event horizon of a black hole – not through a new cosmic observation technique, and not by a high powered supercomputer… but in the laboratory. Using lasers, a length of optical fiber and depending on some bizarre quantum mechanics, a “singularity” may be created to alter a laser’s wavelength, synthesizing the effects of an event horizon. If this experiment can produce an event horizon, the theoretical phenomenon of Hawking Radiation may be tested, perhaps giving Stephen Hawking the best chance yet of winning the Nobel Prize.

So how do you create a black hole? In the cosmos, black holes are created by the collapse of massive stars. The mass of the star collapses down to a single point (after running out of fuel and undergoing a supernova) due to the massive gravitational forces acting on the body. Should the star exceed a certain mass “limit” (i.e. the Chandrasekhar limit – a maximum at which the mass of a star cannot support its structure against gravity), it will collapse into a discrete point (a singularity). Space-time will be so warped that all local energy (matter and radiation) will fall into the singularity. The distance from the singularity at which even light cannot escape the gravitational pull is known as the event horizon. High energy particle collisions by cosmic rays impacting the upper atmosphere might produce micro-black holes (MBHs). The Large Hadron Collider (at CERN, near Geneva, Switzerland) may also be capable of producing collisions energetic enough to create MBHs. Interestingly, if the LHC can produce MBHs, Stephen Hawking’s theory of “Hawking Radiation” may be proven should the MBHs created evaporate almost instantly.

Hawking predicts that black holes emit radiation. This theory is paradoxical, as no radiation can escape the event horizon of a black hole. However, Hawking theorizes that due to a quirk in quantum dynamics, black holes can produce radiation.
The principal of Hawking Radiation (source: http://library.thinkquest.org)
Put very simply, the Universe allows particles to be created within a vacuum, “borrowing” energy from their surroundings. To conserve the energy balance, the particle and its anti-particle can only live for a short time, returning the borrowed energy very quickly by annihilating with each other. So long as they pop in and out of existence within a quantum time limit, they are considered to be “virtual particles”. Creation to annihilation has net zero energy.

However, the situation changes if this particle pair is generated at or near an event horizon of a black hole. If one of the virtual pair falls into the black hole, and its partner is ejected away from the event horizon, they cannot annihilate. Both virtual particles will become “real”, allowing the escaping particle to carry energy and mass away from the black hole (the trapped particle can be considered to have negative mass, thus reducing the mass of the black hole). This is how Hawking radiation predicts “evaporating” black holes, as mass is lost to this quantum quirk at the event horizon. Hawking predicts that black holes will gradually evaporate and disappear, plus this effect will be most prominent for small black holes and MBHs.

So… back to our St. Andrews laboratory…

Prof Ulf Leonhardt is hoping to create the conditions of a black hole event horizon by using laser pulses, possibly creating the first direct experiment to test Hawking radiation. Leonhardt is an expert in “quantum catastrophes”, the point at which wave physics breaks down, creating a singularity. In the recent “Cosmology Meets Condensed Matter” meeting in London, Leonhardt’s team announced their method to simulate one of the key components of the event horizon environment.

Light travels through materials at different velocities, depending on their wave properties. The St. Andrews group use two laser beams, one slow, one fast. First, a slow propagating pulse is fired down the optical fiber, followed by a faster pulse. The faster pulse should “catch up” with the slower pulse. However, as the slow pulse passes through the medium, it alters the optical properties of the fiber, causing the fast pulse to slow in its wake. This is what happens to light as it tries to escape from the event horizon – it is slowed down so much that it becomes “trapped”.

We show by theoretical calculations that such a system is capable of probing the quantum effects of horizons, in particular Hawking radiation.” – From a forthcoming paper by the St. Andrews group.

The effects that two laser pulses have on eachother to mimic the physics within an event horizon sounds strange, but this new study may help us understand if MBHs are being generated in the LHCs and may push Stephen Hawking a little closer toward a deserved Nobel Prize.
Source: Telegraph.co.uk


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Yora Nutcase
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Yora Nutcase
February 13, 2008 5:26 PM

So, first we “simulate” and event horizon. Zounds! So I guess it means we “simulate” a singularity and then somehow we can see if Hawking Radiation exists — even if only simulated!

Justin Garofoli
Guest
Justin Garofoli
February 13, 2008 5:52 PM

I think Hawking would more likely win the Nobel prize in Physics for this one.

Michael Booth
Member
February 13, 2008 6:00 PM

I guess if we all got sucked into the black hole we’d have Peace?

Jose Garcia
Guest
Jose Garcia
February 13, 2008 7:10 PM

Negative mass? Can you explain this? I’ve never understood how virtual particles parting ways at the horizon can remove mass from the black hole. It always seemed to me that the black hole would only get more massive as it stole these virtual particles. This is the first time I’ve seen negative mass mentioned.

stuntcock
Guest
stuntcock
February 13, 2008 7:10 PM

just a note here, wouldn’t this help stephen hawking win the nobel prize in physics not the not the nobel peace prize, there are many catagories of the nobel prize given out, for example anything anti american or anti capitolism will lock you into to getting one without having any hint of intellect or wisdom. see al gore.

Dave
Guest
Dave
February 13, 2008 7:25 PM

Uh… The title “Synthetic black hole event horizon CREATED in a UK laboratory” yet nowhere in the article was this claimed. I really am dissapointed in “Hype” headlines

Peter
Guest
Peter
February 13, 2008 7:29 PM

How good is Mr Leonhardt at creating Catastrophies?? wink)

Hhhhmmm . I think I’ve heard about this before.

http://www.ted.com/talks/view/id/167

David Brin
Guest
February 13, 2008 10:12 PM

Cool stuff. And of course, this eerily resembles the “cavitron” device that makes micro-black-holes in my novel EARTH.

In fact we all have to keep a nasty little voice on our shoulders, reminding ourselves that the Galaxy seems to have fewer intelligent, communicating life forms than we expected, a while ago. This “Great Silence” is puzzling…

…and one possible explanation is that every physics-wielding species eventually makes the same Big Mistake. Shudder.

Keep at it tho…

With cordial regards,

David Brin
http://www.davidbrin.com

Akshat Tanksale
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Akshat Tanksale
February 13, 2008 11:15 PM

Sorry I could not understand one part—You said-“Light travels through materials at different velocities, depending on their wave properties.” and then u say that they fired two lasers of different velocities through a same optical fiber?? If the optical fiber was same how was the velocity of laser faster or slower than the other?? My understanding is that the speed of light is dependent on the medium in which it travels. what other properties will change the speed of light??

ESA Exile
Member
ESA Exile
February 14, 2008 1:00 AM
The speed of light IN A VACUUM is a constant (about 300,000,000 m/s) but in a material e.g. glass, ice or even air it slows down (in glass it is typically around 200,000,000 m/s) however the speed depends on both the medium and wavelength of the light. The change of speed leads to refraction (the bending of light when it enters a new medium) and the difference in speeds for different wavelengths leads to dispersion (the way the colours split up in a prism). By the way, the Chandrasekhar limit is the point at which a white dwarf can no longer support itself, about 1.44 solar masses. Above this the white dwarf will collapse into a neutron star.… Read more »
penny
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penny
February 14, 2008 1:47 AM
One can get the essentially the same formulae for Hawking radiation by considering the propagator for EM in a classical Schwartzchild or Kerr background space–see work by S.T.Yau et alia. I prefer this approach, as it uses only CLASSICAL general relativity, and first quantization propagators. No virtual particles are needed–aka no second Quantized QFT. It is even interesting to consider the CLASSICAL Green Function for EMT in a Schwartzchild background space. There is a classic work called ” The Wave Equation in Curved Spacetime”, but it’s too perturbative for my taste. Another approach to simulation is to use rotating liquids to simulate distorted spacetime. There was a Scientific Amercian Article on this within the last few years. It… Read more »
penny
Guest
penny
February 14, 2008 1:53 AM

I also wonder if one can use the 1990’s method used to slow light to a crawl ( as in recent work on Bose-Einstein Condensates) to simulate event horizons?

Penny Smith

penny
Guest
penny
February 14, 2008 1:57 AM

Perhaps, that is actually what the Saint Andrews people are doing? Hard to tell from the description here.

The quality of popular science journalism is very poor lately.
Essentially, no article is even close to correct. I wonder what causes that, as some of the editors and writers have science educations?

Ed2
Guest
Ed2
February 14, 2008 7:00 AM

Good PR for St. Andrews University. It is apparently true that scientific imagination still has no limits. This is scientific imagination in it’s finest hour, It is conjecture being reported as if it is fact. just waiting to happen. I can think of a thousand experiments that can produce a mini blackhole. Just give me some grant money and i will produce the concepts.

Dark Gnat
Guest
Dark Gnat
February 14, 2008 7:34 AM

“Interestingly, if the LHC can produce MBHs, Stephen Hawking’s theory of “Hawking Radiation” may be proven should the MBHs created evaporate almost instantly.”

Hawking had better be right about that evaporation. Otherwise, we might have problems!

NuttyProfessor
Guest
NuttyProfessor
February 14, 2008 7:43 AM

What’s with the headline. Says “…event horizon created.” I must be stoopid–seems to me they “hope to create” one. Physics is the only science where this kind of unproven garbage gets published on a regular basis as a discovery or advancement of the state of the art. Ha! “Synthetic” event horizons, synthetic singularities, etc. Now wonder physics is the laughing joke of all modern sciences.

Peter
Member
Peter
February 14, 2008 8:08 AM

I’m with Jose Garcia and Akshat Tanksale. Those were poorly laid out in the article. I’ve been trying to get even the semblance of a handle on Hawking radiation and it has NEVER made any sense until you introduced that idea that the particle that goes in has “negative mass”. What the heck is Negative Mass?
Even positronic (or antimatter) mass is positive mass when it comes to Black holes!

K AS Menon
Guest
K AS Menon
February 14, 2008 8:40 AM

Negative mass? And evaporating black hole? All this time we were told that a black hole steals mass from its suroundings etc. So finally it all amounts to a lot of hypothesis and a realisation that we still are groping in the dark.

JamesB
Guest
JamesB
February 14, 2008 10:52 AM

Groping is fun, especially in the dark! Thing is, scientists need to get out of the labority more often if they are going to spend their most of their time doing just that!

This website and it’s sister website has gotten REAL bad reccently about reporting unproven theories as fact. In the case of http://www.livescience.com it has been statements that global warming theory is a proven fact, and now this website reporting that an experiment not even done yet has produced results.

Is there a pulishing catagory for “science tabloid”? Cause there sure are publishers that fit that description!

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