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PHYSICS NEWS UPDATE
A digest of physics news items prepared by Phillip F. Schewe, AIP
Public Information
Number 108   December 28, 1992

NEW MEASUREMENTS OF THE COSMIC MICROWAVE
BACKGROUND (CMB) reinforce the conclusion, reached earlier
this year by scientists using the COBE satellite, that tiny
temperature fluctuations in the early universe can be observed.  A
balloon-mounted detector has now mapped one-third of the sky
(COBE covered the whole sky) at four microwave frequencies
(different from COBE's) with an angular bite of 3.8 degrees (twice
as narrow as COBE's).  For all the differences in the two
detectors, the balloon measurements of the CMB fluctuations were
similar in magnitude and in distribution to those of COBE.  The
new results were reported by scientists from MIT (Stephan Meyer,
617-253-8153), NASA/Goddard, and Princeton at a recent
cosmology meeting in Berkeley.  (Science News, 19 & 26 Dec.
1992.)

TUNGSTEN DISULPHIDE STRUCTURES can form closed
concentric polygons and cylinders.  Before now only carbon
layered structures (e.g., Buckytubes) had been known to exhibit
such closure.  Scientists at the Weizmann Institute in Israel created
WS2  concentric objects in sizes ranging from less than 10 nm to
more than 100 nm.  (Nature, 3 Dec. 1992.)

MONTE CARLO TECHNIQUES, widely used in computer
simulations of physical systems, entail the wholesale generation of
random numbers.  A new study by scientists at the University of
Georgia (Alan Ferrenberg, 404-542-8460) shows that even the
most advanced random-number generators are biased under
certain circumstances (A.M. Ferrenberg et al., 7 Dec. Physical
Review Letters).  Using one state-of-the-art program, the
Marsaglia-Zeman random-number generator, Ferrenberg
discovered that a simulated performance of the two-dimensional
Ising model (which models the behavior of a plane of neighboring
spins) did not agree with the results when calculated exactly by
mathematical methods.  He traced the discrepancy to the random-
number generator.  Other generators tried had differing faults. 
(Science News, 19 & 26 Dec.)

BILL CLINTON'S SCIENCE ADVISOR WILL BE JOHN
GIBBONS, currently head of the Office of Technology
Assessment.  Like many recent presidential science advisors,
Gibbons is a physicist by training.  (The New York Times, 25 Dec.
1992.)

GALILEO GALILEI WAS UNJUSTLY CONDEMNED  by the
Roman Catholic Church for promoting a Copernican cosmology,
says Pope John Paul II.  The Pontiff issued the reassessment of
this famous 1633 case after a special Vatican commission finished
its investigation of the matter.  Mr. Galileo was unavailable for
comment. (Sky & Telescope, Jan. 1993.)

CORRECTION.  The Galileo spacecraft's picture (Update 105)
of the Earth and Moon together in one frame was not the first
such picture (Voyager took one also) but it is the best.  An
Associated Press version of the photo appeared in The New York
Times on December 23, 1992.


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