Contents

10 July 1987
Vol 237, Issue 4811

About The Cover

Resonant-mass gravitational radiation detector. Energetic astrophysical events, such as supernovae, can produce gravity wave pulses that may induce small mechanical strains in the 4800-kilogram aluminum bar. The bar is suspended in a vacuum chamber and cooled to 4.2 kelvins to reduce background noise. See page 150. [Photography by John Long, Palo Alto, CA 94301]