SETI bioastro: Fw: Physics News Update 606

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From: LARRY KLAES (ljk4@msn.com)
Date: Wed Sep 25 2002 - 15:15:03 PDT


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From: physnews@aip.org
Sent: Wednesday, September 25, 2002 2:02 PM
To: ljk4@MSN.COM
Subject: Physics News Update 606

PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 606 September 25, 2002 by Phillip F. Schewe, Ben Stein, and James
Riordon

BELL LABS/LUCENT RESEARCHER DID FABRICATE DATA. The committee of
independent scientists investigating charges of misconduct in the way
certain Lucent experiments were performed or reported in scientific journals
issued its report today. The committee asserts that "The evidence that
manipulation and misrepresentation of data occurred is compelling." They
conclude that Hendrik Schon, but not the co-authors on his many articles,
falsified and fabricated data. (Lucent press release with links to the
committee report: http://www.lucent.com/news_events/researchreview.html.)

POLARIZATION IN THE MICROWAVE BACKGROUND has been measured by the Degree
Angular Scale Interferometer detector (DASI:
http://astro.uchicago.edu/dasi/), situated at the South Pole. DASI
was one of the first detector groups to see (Update 537:
http://www.aip.org/enews/physnews/2001/split/537-1.html) several peaks in
the spectrum of the cosmic microwave background, the radiation originating
from that era in the early universe (some 300,000 years after the big bang)
when stable atoms first formed. The modern theory of cosmology says that
these microwaves received an orientation (polarization) when they emerged
from the seething plasma (the "surface of last scattering") then pervading
the cosmos. DASI's measurement of a faint polarization, reported last week
at the COSMO-02 meeting in Chicago, is consistent with the theoretical
prediction. (Preprint at http://arXiv.org/abs/astro-ph/0209478.)

MAKING BOSONS ACT LIKE FERMIONS. In what would represent an unprecedented
manipulation of matter, physicists in Germany and Austria have proposed ways
of making bosons, one of the two major classes of matter, act like fermions,
the other kind of matter. Fermions (such as electrons) obey the Pauli
exclusion principle: If you put multiple electrons in a box, they all must
differ from each other in some way, for example by being in a different
place or having a different value of a quantum property such as spin.
Bosons (such as photons and the hydrogen atom) have no such restrictions: a
limitless number of them can be in the identical quantum state. Physics is
replete with examples of making the fussy fermions behave like the more
easygoing bosons, thanks to the phenomena of superconductivity and
superfluidity. Causing fermions to pair up, as they do in superconductors,
gives the pairs the same key properties as bosons, and so they act just like
bosons.
But the reverse--making the normally undiscriminating bosons act like picky
fermions--has never been done before. Now, researchers (Belen Paredes, Max
Planck Institute for Quantum Optics, Belen.Paredes@mpq.mpg.de) have a couple
of proposals for accomplishing this. One way, they suggest, would be to
rotate a Bose-Einstein condensate. At rest, the BEC has several different
low-energy levels due to different possible values of angular momentum in
the atoms. However, rotating the BEC at just the right rate causes these
levels to become equal to one another in energy since the rotation will
cancel out the energy gains due to angular momentum. All stuck in the
low-energy well, the atoms would be forced to minimize their repulsions with
one another, and they'd do this by assuming slightly different values of
angular momentum, thereby acting like fermions. Rotating BECs is now
possible with lasers or mechanical devices. But to observe "fermionization"
in BECs with currently obtainable rotation speeds, researchers would need to
create a BEC with only a handful of atoms, say 5, instead of the typical
10,000 or so. But in case this turns out to be infeasible, the researchers
have another proposal: rotate an optical lattice, a light-based web of atom
traps, containing 5 atoms in each trap. Such a situation is experimentally
possible and could produce a stronger signal than that from a single BEC.
(Paredes, Zoller and Cirac, Physical Review A, tent. September 2002; also
Paredes and Cirac, cond-mat/0207040)

SOLAR SURGERY. Even some large hospitals find laser surgery too expensive.
So physicists at the Blaustein Institute for Desert Research in Israel
resort to nature. They collect and focus sunlight, and then transport it in
an optical fiber to a surgery theater where it can be brought to bear on
tissue (figures at http://www.aip.org/mgr/png/2002/163.htm). In general, the
advantage of using laser light for surgery is not its coherence but high
power density at adequate power levels. In this regard the solar unit can
match typical surgical lasers in terms of power (8 watts) and power density
(10 watts/mm^2). Jeffrey Gordon (jeff@menix.bgu.ac.il, 972-8-659-6923) and
his colleagues report that tests on chicken breasts and chicken livers have
been successful and that the next step will be to perform surgery on live
mice with the solar optical fiber system. The goal for the project is to
deliver cheap sunlight for killing human cancers with minimally invasive
procedures. (Gordon et al., Applied Physics Letters, 30 September 2002;
homepage, www.bgu.ac.il/BIDR/research/staff/gordon.html) UPDATE HERE

***********
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