First Acoustic Black Hole Created

KentuckyFC writes "One of the many curious properties of Bose Einstein Condensates (BECs) is that the flow of sound through them is governed by the same equations that describe how light is bent by a gravitational field. Now, a group of Israeli physicists have exploited this idea to create an acoustic black hole in a BEC. The team created a supersonic flow of atoms within the BEC, a flow that prevents any phonon caught in it from making headway. The region where the flow changes from subsonic to supersonic is an event horizon, because any phonon unlucky enough to stray into the supersonic region can never escape. The real prize is not the acoustic black hole itself but what it makes possible: the first observation of Hawking radiation. Quantum mechanics predicts that pairs of phonons with opposite momentum ought to be constantly springing in and out of existence in a BEC. Were one of the pair to stray across the event horizon into the supersonic region, it could never escape. However, the other would be free to go on its way. This stream of phononic radiation away from an acoustic black hole would be the first observation of Hawking radiation. The team hasn't gotten that far yet, but it can't be long now before either they or their numerous competitors make this leap."

Comments

Re:And the news is where?

[grub]

Bosewave radio

Hey how are those things? They seem a bit pricey, are they really worth it?

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Re:And the news is where?

[rock_climbing_guy]

I saw one on display at a mall. The sound quality was fairly good to my ear, but the price was astronomical. I'd never pay full price for one.

Re:And the news is where?

[grub]

Yeah, it is off topic but I have karma to burn and want to know.

Most people in the real world may say "It sounds good" and leave it at that.
A /.er may post links to logarithmic scaled charts with frequency responses, graphs with acoustical data, YouTube videos of someone installing Linux on it, etc. then end it off with "It sounds good"
:)