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Science

First Acoustic Black Hole Created 165

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."
Networking

Why the Mediterranean Is the Net's Achilles' Heel 195

An anonymous reader writes "A spate of broken cables has brought disruption for many of the world's Web users in 2008 — and the Med has been at the center of the problems. For political reasons, the Mediterranean Sea is an Internet bottleneck through which the majority of traffic between Europe and Asia is squeezed. That traffic must run the gauntlet of earthquakes and heavy maritime traffic to reach its destination. Better and stronger cables are urgently needed to avoid a re-occurrence of the 2008 outages."

Comment Re:False Advertising (Score 1) 743

Good point. However, I think M. F. I. Warehouses Ltd. v. Nattrass is relevant here: 'reckless' is interpreted more liberally than it suggests, as 'without having regard to whether their advertisements are true or false'. It is obvious that 'unlimited' in the advertising is not the same as 'limited to 5 Gb' in the terms and conditions, so it seems reckless in the sense given here.

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