Pulsars, rapidly spinning neutron stars, were first discovered in 1967. As a pulsar spins, it emits a continuous beam of radio energy that rotates along with the star. Like a lighthouse beam sweeping the sky, to the stationary observer--such as an earthbound researcher--this beam is perceived as a pulse. These pulses are regular to within a few hundred nanoseconds per year.
In 1974, Taylor, then on the faculty of the University of Massachusetts, and his graduate student, Russell A. Hulse (now at Princeton's Plasma Physics Laboratory), discovered the first binary pulsar--a pulsar orbiting about an unseen stellar companion (Astrophysical Journal, 195:L51-L53, 1975). They had no idea at the time that their work would provide the first experimental evidence for the existence of gravitational waves, the "ripples in the geometry of space and time" predicted in 1916 in Albert Einstein's general theory of relativity.
"At the outset, we knew binary pulsars ...
