Saturday, March 08, 2008

Hawking radiation "heard"

The physics arXiv blog (don't get too confused by the officially sounding name!) has pointed out a pretty entertaining condensed matter "experiment":
Carusotto et al. (preprint)
The Italian team has constructed an acoustic counterpart of a gravitational black hole out of a flowing one-dimensional Bose-Einstein condensate. The velocity creates a sonic barrier, a version of the event horizon.

And this "acoustic black hole" indeed does emit Hawking radiation composed of phonons, as demonstrated by long-range patterns in the density-density correlation function of the gas i.e. by everything strange about the picture above away from the yellow diagonal line.

I haven't told you one more disappointing thing. Even the acoustic "experiment" has so far only been done numerically. Some skillful experimenters will hopefully do better. ;-)


  1. I just read this yesterday:

    They can't observe the analogue of Hawking radiation yet, but at least they say they can form an optical black hole.

  2. This is not directly related to this post.

    I was curious to see if one could approach real analysis from a more physical standpoint. I am not aware of similar work.

    I would welcome any comments

  3. Hi Lubos,
    where are you right now?
    I find this on Wiki:"Luboš Motl... He currently has no known academic affiliation, though in July, 2007 he announced his plans to return to the Czech Republic after leaving academia.[1] His blog[2] lists his current location as Pilsen, Czech Republic."

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