Number 211, January 19, 1995 by Phillip F. Schewe and Ben Stein SUPERLUMINAL JETS FROM AN OBJECT only 10,000 light years away in the Milky Way may help astronomers to better understand the much bigger jets shooting out of distant galaxies. First spotted by the Gamma Ray Observatory in July 1994, the nearby object GRO J1655-40 is probably a double-star system. Matter from the lighter of the two stars is drawn away by gravity onto an accretion disk closely surrounding the heavier (and collapsed) companion, which is thought to be a neutron star or a (few-solar-mass) black hole. One artifact of this process is the flaring up of x rays and gamma rays from the much-heated disk. Indeed GRO J1655-40 is at times the most powerful source of x rays and gamma rays in the galaxy. Another artifact is the production of energetic radio-emitting jets of material which project away from the core object perpendicular to the plane of the disk. These jets appear to be traveling at greater-than-light speeds. This is actually an optical illusion owing to the alignment of the object relative to us, but it does testify to the violent physics taking place in the core. Only one other object in the Milky Way, GRS 1915+105, has been seen to have superluminal jets, but the complex structure of GRO J1655-40 has been mapped with greater resolution, in this case by the Very Long Baseline Array of radio telescopes. One of the astronomers who spoke at last week's astronomy meeting in Tucson, Robert Hjellming of the National Radio Astronomy Observatory, called GRO J1655-40 an astronomical "Rosetta Stone" because studies of the movement of individual blobs within the jets (sometimes on a daily basis) may provide insights about the energy mechanisms at work in the colossal extra-galactic jets produced by presumed supermassive black holes. IN PHOTOSTRICTIVE MATERIALS light can be turned directly into mechanical energy. At December's meeting of the Materials Research Society in Boston, Kenji Uhcino of Penn State reported work on a material called PLZT, so named because it contains atoms of lead, lanthanum, zirconium, and titanium in a crystalline array that harnesses both the photoelectric and piezoelectric effects. One goal is to create a communications device (a "photophone") that could use light to make sound directly. Working models tested so far are operating only in the lower end of the audible sound range. (Science, 16 December 1995.) 1369 NEW PHYSICS PHDs were awarded in the U.S. during the 1992-93 academic year, up slightly from the year before. Of these, 170 (or about 12.4%) went to women; 13 (about 1%) went to blacks; and 43 to Hispanics. The total number of physics graduate students for the period was 13,042, of which 42% were foreign students, a fraction which has held steady for several years. The number of physics bachelor's awarded edged downward to 4800. In astronomy, 119 PhDs were granted in 1992-93, the most recent academic year surveyed in the "Enrollment and Degrees Report" issued by the Education and Employment Statistics Division of the American Institute of Physics. (For more information, contact Patrick Mulvey at 301-209- 3076.)