RE: PHYSICS: A liquid 20 million times less dense that air

From: Colin Hales (colin@versalog.com.au)
Date: Sat Jul 27 2002 - 16:09:57 MDT


 Max More
>
> AN ULTRA LOW-DENSITY LIQUID, some 10^13 times thinner
> than water, might form inside Bose-Einstein condensates under the
> action of the "Efimov effect," a quantum phenomenon in which the
> atoms in the cloud attract each other when considered two at a time
> but repel each other when considered three at a time. In such an
> Efimov cloud the atoms would be some 20 times farther apart that
> in a BEC, which is itself pretty sparse a million times thinner than
> air. And yet this new type of condensate would not be a gas but a
> liquid! According to Aurel Bulgac of the University of
> Washington the exquisite coordination of atoms in an Efimov
> condensation would allow it to be self bound (the constraining
> magnetic fields used to keep a BEC from drifting apart would be
> unnecessary); moreover, it would be neither compressible nor
> dilutable. This extraordinary quantum liquid the smallest density
> condensed matter system yet proposed---could probably only be
> formed at much colder temperatures than are now available in BEC
> experiments. Bulgac proposes that Efimov droplets made from
> boson atoms be called "boselets." The fermion version would be
> "fermilets." (Bulgac@phys.washington.edu, 206-685-2988,
> Physical Review Letters, 29 July 2002)
>
>
>

Quite often there is a theme in scifi involving clouds of sentience able to
drift amongst the stars. If you look at this as a cellular automata you can
see, with a little (lots of!) imagination, the potential for computation and
memory in a cloud made from 'Boselets'. Amazing.

Colin



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