GRAVITY WAVE ANALYSIS FROM LIGO PROTOTYPE The Laser Interferometer Gravitational-wave Observatory (LIGO), when fully deployed, will consist of two facilities (Hanford, WA and Livingston, LA). At each site laser beams pass up and down two perpendicular 4-km-long vacuum pipes, reflecting repeatedly from mirrors hung from wires. The presence of a passing gravitational wave would announce itself by a flexing of space-time which would very slightly lengthen the path of light in one arm and shorten the path in the other arm, causing a subtle change in the interference pattern made by the converging light beams from the two arms. The full LIGO, by about November 2001, should be able to detect a strain, defined as the fractional change in the position of the mirrors divided by the length of the arm (4 km), of 10^-21. This is the expected disturbance one expects from the gravity waves emitted by the coalescence of two solar-sized stars at a distance from Earth of 30-50 million light years. But before LIGO scientists possess their full instrument, they do have a 40-m prototype at Caltech, built for doing engineering studies but also capable of sensing gravity waves, albeit with the lesser strain sensitivity of a few times 10^-19. Thus the LIGO team, while testing methods for searching (directly via gravity waves) for binary coalescences, have thereby rendered an upper limit for such events of less than one every two hours in our galaxy. This result is useful for the test of the procedures, but is not significant for astronomers, who have previously established more stringent upper bounds with electromagnetic waves (visible and radio). (Contact Barry Barish at Caltech, 626-395-3853 or 818-601-2643; Stan Whitcomb 626-395-2131; or Bruce Allen, University of Wisconsin-Milwaukee, 626-893-2003 or 414-229-6439; Allen et al., 23 August 1999 article in Physical Review Letters.)