Number 123, April 9, 1993 by Phillip F. Schewe and Ben Stein
INTERSTELLAR DUST HAS BEEN DETECTED for the first time. Dust from within
the solar system has been observed by numerous satellites and even by high-flying
aircraft, but scientists analyzing data recorded by the Ulysses spacecraft
(now past its encounter with Jupiter), particularly the directionality
and speed (in excess of the escape velocity of the solar system) of the
dust, conclude that some of the micron-sized specks come from outside the
solar system. Certain other dust particles detected by Ulysses appear to
be coming from Jupiter itself in periodic bursts. (Nature, 1 April 1993.)
TROPOSPHERIC RIVERS , immense flows of water vapor in the lower atmosphere,
can persist for more than 10 days and carry as much water as the Amazon
(Geophysical Research Letters, Dec. 1992). Reginald Newell of MIT used
satellite measurements of humidity and atmospheric reflectivity to monitor
the movement of water vapor worldwide. The resultant maps show coherent
rivers of water moving across the globe. (Physics World, April 1993.)
BUCKYBALL MOLECULAR FUSION has been observed by a team of scientists
at the University of Freiburg in Germany (E. Campbell et al., Phys. Rev.
Lett., 18 Jan.). They injected a 1-keV beam of C-60 ions into a chamber
filled with a C-60/C-70 mixture and detected the collision products, including
many carbon clusters such as C-120 and C-130. Hans Lutz of the University
of Bielefeld (Germany) points out that there is a certain analogy between
these cluster-cluster collisions, which take place in the atomic realm---on
a size scale of 10**-10 m---and the fusion that can take place between
colliding nuclei---at the nuclear size scale of 10**-15 m. (Physics World.)
THE PHYSICS TEACHER , the monthly magazine of the American Association
of Physics Teachers (AAPT), is thirty years old this month. Articles in
1963 covered such topics as satellite orbits, physics for girls, and sinking
ice. This anniversary issue contains articles about an effort to legislate
the value of pi (the Indiana State House tackled this tough issue in 1897),
electrorheological liquids, Isaac Newton's 1701 experiment on thermometry,
tips on how to use a blackboard eraser as a physics demonstration prop,
and a list, formulated by Vladimir Braginshin of Moscow State University,
of some of the outstanding problems in physics today. Examples include
the search for discrepancies between the electric charge of the proton
and electron, the equivalence of inertial and gravitational mass, and the
search for a nonzero electric dipole moment for the neutron (The Physics
Teacher, April 1993.)
THE NATIONAL LABS mostly score higher than the U.S. average in terms
of citations per research paper for a variety of physical science areas,
according to a study performed by the Institute for Scientific Information.
For example, in the category of general physics for the period 1988-92,
Brookhaven led other national labs with 9.44 citations per paper, compared
to a national average of 5.80. Considering only national labs, the citation
leaders in some of the other research categories included Argonne in applied
physics/condensed matter, Berkeley in materials science, and Sandia in
chemical physics. (Science Watch, March 1993.)
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