Joseph Hooton Taylor Jr.

Joseph Hooton Taylor Jr. was born in 1941 in Philadelphia and raised on a New Jersey peach farm in a Quaker family. He earned a bachelor's degree in physics from Haverford College in 1963 and a PhD in astronomy from Harvard in 1968, where his thesis work used lunar occultations to pin down the positions of radio sources. The discovery of pulsars in 1967 by Jocelyn Bell Burnell and Antony Hewish redirected his career: the rapidly spinning neutron stars were nature's most precise clocks, and Taylor recognized that timing them could probe physics no laboratory could reach.

In 1974, as a young professor at the University of Massachusetts Amherst, Taylor and his graduate student Russell Hulse used the giant Arecibo dish in Puerto Rico to run a sensitive pulsar survey. They found PSR B1913+16, a pulsar in a tight binary orbit — the first ever discovered. Over the following years Taylor led the painstaking timing campaign that measured the system's relativistic effects: the advance of periastron, the gravitational redshift, and, most importantly, the slow shrinking of the orbit. By 1979 the orbital decay matched Einstein's quadrupole formula for gravitational-wave emission, providing the first observational evidence that gravitational waves are real.

Taylor moved to Princeton University in 1980, where he continued to develop pulsar timing into one of the most precise tools in physics. He and his collaborators refined the Hulse–Taylor measurements over three decades; by 2005 the agreement between the observed orbital decay and the general-relativistic prediction was better than 0.2 percent — a clean, parameter-free confirmation. Taylor also pioneered techniques for discovering and timing millisecond pulsars, the foundation of today's pulsar timing arrays that hunt for nanohertz gravitational waves.

In 1993 Taylor shared the Nobel Prize in Physics with Hulse "for the discovery of a new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation." He served as a dean of the faculty at Princeton and remained an influential figure in radio astronomy, mentoring a generation of pulsar astronomers. His work established the binary pulsar as the definitive indirect test of gravitational radiation, two decades before LIGO detected the waves directly.