Number 27, March 28, 1991 by Phillip F. Schewe and Ben Stein|
CONDENSED MATTER PHYSICS IN THE 1990's. In the 1980's, membership in the APS Division of Condensed Matter Physics (DCMP) doubled; the number of papers delivered at the APS March Meeting (largely concerned with condensed matter) doubled; the number of faculty members and graduate students in condensed matter doubled; and the number of condensed matter papers published in Physical Review doubled; nevertheless, during this same time non-defense funding for materials science research (which overlaps closely with condensed matter physics) remained the same. These statistics come from a report of the DCMP Strategic Planning Committee; the report was summarized at the APS March Meeting held last week in Cincinnati by Michael Schluter (201-582-3106) of AT&T Bell Labs, chairman of the committee.
MATERIALS SCIENCE IN THE 1990's. At the same meeting, Bill Appleton (615-574-4321) of Oak Ridge summarized "A National Agenda in Material Science and Engineering," a report following up on last year's study, "Materials Science and Engineering in the 1990's," released by the National Research Council. The new report, presented to the President's science advisor, D. Allan Bromley, last month, calls for a strategic planning process emphasizing initiatives in six areas of national importance where MS&E can have a critical impact: (1) information/communications, particularly in the miniaturization of electronic devices; (2) transportation, such as in the design of new structural materials; (3) energy, particularly materials for energy conversion and conservation; (4) health--developing biocompatible materials; (5) environment--designing materials that are recyclable; and (6) "maintaining leadership in materials research," meaning the continuing pursuit of new synthesis and processing techniques and the creation of new instrumentation.
A LASER-DRIVEN SCANNING TUNNELING MICROSCOPE has been developed by scientists at the Max Planck Institute in Garching, Germany. M. Volcker and his colleagues couple laser radiation into the tip of an STM and, because the device can be operated without any dc current between tip and sample, it may be possible to study insulators, which cannot be imaged with conventional STM's. (Upcoming article in Physical Review Letters.)
THE SPEED OF LIGHT CAN BE REDUCED BY A FACTOR OF 10 in certain disordered materials, according to Ad Lagendijk of the University of Amsterdam. The zigzag scattering of light in opaque substances like milk or white paint is a common phenomenon, but Lagendijk believes that if the size of the obstacles (in this case individual milk globules or pigment droplets in paint) is comparable to the light's wavelength then the light waves may be trapped for a time in the droplets, as if in a cavity, before moving on to another scattering encounter. If this retardation is not taken into account, Lagendijk insists, experimental determinations of the light's mean free path--the average distance between scattering with an obstacle--will be incorrect. (Science News, 23 March 1991.)