Number 19, January 29, 1991 by Phillip F. Schewe and Ben Stein
IMAGES OF AN ELECTROPLATED MONOLAYER OF COPPER , with atomic-resolution, have been made in situ by an atomic force microscope. Paul Hansma (805-893-2523) and his colleagues at Santa Barbara studied the deposition of copper atoms on a gold substrate in two different electrolytic solutions. Such atomic-resolution electrochemistry will be particularly important for the study and design of fuel cells and sensors. (Science 11 Jan. 1991.)
THE STRUCTURE OF ACTIVE GALACTIC NUCLEI (AGN) have been studied by astronomers using data from the International Ultraviolet Explorer (IUE). Concentrating on the AGN at the heart of the Seyfert galaxy NGC5548, they measured both the continuous-spectrum radiation coming from the primary-energy source (perhaps containing a black hole) and the emission-line (broad, discrete spectral lines) radiation from the clouds of material surrounding the source. The pattern of variability of the two light curves over eight months allowed the astronomers (contact: Julian Krolik, Johns Hopkins, 301-338-7926) to surmise that highly-ionized material (e.g., N (4+)) is distributed rather spherically (at about a radius of 30 light days) around the core, while less-ionized material (e.g., C (2+)) is arranged in a disk or ring at a distance of 20 to 100 light days. (Physics World, December 1990.)
FLUORESCENCE FROM SINGLE IMPURITY MOLECULES has been observed by scientists at IBM Almaden. Using a very thin (1-10 microns) crystal of the organic compound p-terphenyl cooled to 1.5 K and a laser with a very small spot size (5 microns), the fluorescence of individual impurity molecules (the organic molecule pentacene) could be monitored. The change in the molecule's spectrum over a period of minutes provided information about the impurity's local molecular environment. (Nature, 17 Jan. 1991. Contact W.E. Moerner, 408-927-2426.)
THE MILKY WAY HAS BEEN PHOTOGRAPHED AT A WAVELENGTH of 205 microns for the first time by the Cosmic Microwave Explorer satellite. The intensity and pervasiveness of this radiation, which comes from ionized nitrogen, was unexpected. This and other microwave and far-infrared measurements made by COBE contribute to a better understanding of star formation in our galaxy. (Science News, 19 Jan.)
"SCIENCE: THE END OF THE FRONTIER?" A report by AAAS president-elect Leon Lederman calls for a doubling of the federal science budget. Although allocations are slightly higher (in constant dollars) than in the "golden age" of the late 1960s, the higher-than-inflation rise in the cost of advanced apparatus and the much higher larger number of doctoral candidates competing for support necessitates the huge increase now, Lederman believes. (Supplement in the 11 Jan. 1991 issue of Science.)
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