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Physicists create 'black hole for sound'

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posted on Jun, 16 2009 @ 07:28 PM
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An artificial black hole that traps sound instead of light has been created in an attempt to detect theoretical Hawking radiation. The radiation, proposed by physicist Stephen Hawking more than 30 years ago, causes black holes to evaporate over time.

Astrophysical black holes are created when matter becomes so dense that it collapses to a point called a singularity. The black hole's gravity is so great that nothing – not even light – can escape from a boundary around it called an event horizon.

But physicists have also been developing 'black holes' for sound. They do this by coaxing a material to move faster than the speed of sound in that medium, so that sound waves travelling within it cannot keep up, like fish swimming in a fast-moving stream. The sound is effectively trapped in the stream-like event horizon.

The team cooled 100,000 or so charged rubidium atoms to a few billionths of a degree above absolute zero and trapped them with a magnetic field. Using a laser, the researchers then created a well of electric potential that attracted the atoms and caused them to zip across the well faster than the speed of sound in the material.

This setup created a supersonic flow that lasted for some 8 milliseconds, fleetingly forming an acoustic black hole capable of trapping sound.

The implications of such work could be profound, as it could lead to the first detection of Hawking radiation.

Quantum mechanics says that pairs of particles can spontaneously appear out of empty space. These pairs, which consist of a particle and its antiparticle, should exist for a fleeting moment before they annihilate each other and disappear.

But in the 1970s, Hawking proposed that if the pair was created near the edge of a black hole, one particle might fall in before it is destroyed, leaving its partner stranded outside the event horizon. To observers, this particle would appear as radiation. In acoustic black holes, Hawking radiation would take the form of particle-like packets of vibrational energy called phonons.




Please visit the link provided for the complete story.





Text and image courtesy of newscientist.com


Interesting to say the least, so now we are able to create 'acoustic black holes', I bet CERN will be able to create the 'electromagnetic black holes'. Our grasp of technology and the Universe is ever growing, it should not be too long before we start to really see some 'Star Trek-like' technology.




posted on Jun, 16 2009 @ 08:10 PM
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Oh, by the way....The image is a picture of the atoms trapped in the acoustic black hole.



posted on Jun, 16 2009 @ 08:15 PM
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reply to post by jkrog08
 


Thats cool, especially for Hawking. How cool is that to have radiation named after you? Anyway, this just goes to show that things thought of 30 years ago can now be placed into action and experimented upon. This is awesome. Nice Find



posted on Jun, 16 2009 @ 08:23 PM
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reply to post by TheMythLives
 


Thanks, it is crazy how we ca manipulate sound nearly at will now, just a short 50 or so years after breaking the sound barrier. Is this is what is in store for light speed? I hope so.



posted on Jun, 16 2009 @ 08:32 PM
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reply to post by jkrog08
 


Light is already being attacked.


"Two years ago we slowed it down to 38 miles an hour; now we've been able to park it then bring it back up to full speed." Lene Hau isn't talking about a used motorbike, but about light – that ethereal, life-sustaining stuff that normally travels 93 million miles from the sun in about eight minutes.


Harzard makes light come to a complete stop



posted on Jun, 16 2009 @ 08:40 PM
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reply to post by TheMythLives
 


Good relevance in bringing that up. Yes, I believe this was at Harvard University correct? Anyways the point is that we are making huge strides in 'theoretical' physics and some are openly challenging Einsteins 'speed limit' of c.



posted on Jun, 16 2009 @ 08:43 PM
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reply to post by jkrog08
 


Yes it was Harvard. I thought I mentioned that, need to fix that. Anyway, I am all for expanding, revising or tearing through theories if it means leading to complete, awesome experiments.... which work..lol



posted on Jun, 16 2009 @ 09:04 PM
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I wonder what the effect of the phonons is on the "black hole"? "Phonons" are usually interpreted to mean either that there is a perturbation or heat. This is in relation to electronics and circuitry.

However, what the phonon actually represents is an errant high frequency acoustic wave. "Noise" in the "signal". How many of these would it take to cause a complete breakdown of the unidirectional flow of the atoms that are holding the "black hole" together? How much noise could the black hole withstand before it falls apart?



posted on Jun, 16 2009 @ 09:14 PM
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Call me skeptical but I think the most important line is



The implications of such work could be profound, as it could lead to the first detection of Hawking radiation.


At the minute Hawking Radiation is wishful thinking at best Hawking has never had a theory of his proven correct and has been outright wrong by his own admission in the past. I find it worrying the media seems to constantly state it as as fact when it is not at least not yet anyway.

This is an interesting experiment but in my mind it's a big leap of faith to call it black hole although I'm all for finding out as much as safely possible before colliders like the LHC possibly produce the real thing.



posted on Jun, 16 2009 @ 09:30 PM
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reply to post by bigfatfurrytexan
 


I am not sure, I have never heard of this before, I am much more versed in the EM fields of physics and astronomy/cosmology. Although I would speculate that this would depend on the many things, including the speed at which the atoms enter. I would speculate, or rather postulate (if I may,lol) that hypersonic speed atoms would collapse the hole, as well as any influx exceeding the Swartzchild Radius(lol, if that applies to an acoustic hole) maximum volume.

[edit on 6/16/2009 by jkrog08]



posted on Jun, 16 2009 @ 09:32 PM
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reply to post by Teknikal
 


Agreed, but Hawking has put foth some major theories and was the one who postulate the Big Bang singularity. Plus a lot of his theories are currently unable to test until CERN gets to them.

[edit on 6/16/2009 by jkrog08]



posted on Jun, 16 2009 @ 10:26 PM
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Great find Jkrog!
Rather interesting, even just being able to cool something to a fraction above absolute zero is amazing to me!

S&F4U!
-E-



posted on Jun, 16 2009 @ 11:07 PM
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Originally posted by jkrog08
reply to post by bigfatfurrytexan
 


I am not sure, I have never heard of this before, I am much more versed in the EM fields of physics and astronomy/cosmology. Although I would speculate that this would depend on the many things, including the speed at which the atoms enter. I would speculate, or rather postulate (if I may,lol) that hypersonic speed atoms would collapse the hole, as well as any influx exceeding the Swartzchild Radius(lol, if that applies to an acoustic hole) maximum volume.

[edit on 6/16/2009 by jkrog08]


Phonons are a quantum function. Here is the Wiki on it:

en.wikipedia.org...


In physics, a phonon is a quantized mode of vibration occurring in a rigid crystal lattice, such as the atomic lattice of a solid.[1] The study of phonons is an important part of solid state physics, because phonons play a major role in many of the physical properties of solids, including a material's thermal and electrical conductivities. In particular, the properties of long-wavelength phonons give rise to sound in solids—hence the name phonon from the Greek φωνή (phonē) = voice.[2] In insulating solids, phonons are also the primary mechanism by which heat conduction takes place.


The above paragraph highlights why folks were so surprised when it was announced last year that a computer utilizing phonons for data relay was in the works. The phonon usually is associated with overheating and data corruption in the circuits of other computers.

Regardless, it seems to me that what they are measuring is something that they think would be an analog for Hawking radiation. I think the presence of phonons will ultimately bring the demise of the "black hole", but only because their function would be to disturb not only the fast moving atoms (at least, while they might be locked in somewhat of a lattice form), but they would also introduce heat into the environment, further reducing the overall environment needed to sustain the acoustic black hole. The more "phonons" created, the greater the effect will be.

This is a different mechanism than the proposed Hawking radiation, which is more of a dissipation of the actual mass contained within the black hole.



posted on Jun, 16 2009 @ 11:21 PM
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reply to post by bigfatfurrytexan
 



I think the presence of phonons will ultimately bring the demise of the "black hole"


Are you talking about an acoustic hole or EM hole?



posted on Jun, 17 2009 @ 04:12 AM
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Time travel's possible, folks.

If they can mute sound waves through "sound black holes", it's probably possible to stop "light waves".

That means time travel's VERY MUCH POSSIBLE.

Can't wait for the scientific possibilities in the future!

That is, only if the world doesnt disintegrate to a dusthill in 2012.



posted on Jun, 17 2009 @ 08:06 AM
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Originally posted by jkrog08
reply to post by bigfatfurrytexan
 



I think the presence of phonons will ultimately bring the demise of the "black hole"


Are you talking about an acoustic hole or EM hole?


The acoustic hole.

While there may be an analogy to the overall result of the acoustic black hole, and a true black hole, there is very little similarity beyond that.

That does not diminish the interest of the article or the importance of the experiments.
I definitely flagged this thread, as it falls in line with some of my interests.




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