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."

Phonon ey?

[Snowblindeye]

I knew light was quantized, but I had seriously never heard of Phonons, or that sound can be quantized as well.

Well, apparently it can: Phonon [wikipedia.org]

Re:So...Bose sucks?

[Captain Splendid]

Nah, Bose doesn't suck so much as you can get similar quality gear for a better price. It's swanky audio gear for people who don't know anything about audio gear.

Re:And the news is where?

[Anonymous Coward]

I'd mod you off-topic but since this is /. I think it's interesting.

Re:So...Bose sucks?

[FusionFox]

In the same way that finding somebody that judges a person based on what cellphone they use is a nice way to know what type of person they are in advance?

Phonon != Photon!

[Hurricane78]

How do you infer from the effects of phonons, that the same happens to photons? If they had the same effects, this would mean that luminiferous aether would exist. Which as far as we know, is not true, and replaced by the theory of relativity. Or would it be the effect of a quantized space-time? And would those quantums then be some kind of particles?

Or is the analogy just wrong, except for some subsets? ^^

Re:So...Bose sucks?

[dangitman]

The reality is, most people don't have super-discriminating ears, and are therefore not really capable of telling much difference between any speakers.

You don't need super-discriminating ears to know that Bose systems sound like shit. It's perfectly obvious. Bose doesn't even do well against inexpensive systems, let alone ones in the Bose price-range.