The 1993 Nobel Prize in Physics was awarded jointly to Russell A. Hulse and Joseph H. Taylor, Jr., “for the discovery of a new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation.”
The Science: Pulsars and Gravitation
In 1974, the two winners of the 1993 Nobel Prize in Physics used the the 300 meter radiotelescope at Arecibo, Puerto Rico, to search space for pulsars.
Pulsars had been discovered in 1967 (an achievement recognized with the 1974 Nobel Prize in Physics, in fact), but Taylor and his research student Hulse discovered something new: a pair of binary pulsars.
Binary stars are a pair of stars that orbit around each other. This binary system of pulsars allowed for a study of the behavior of gravitation between them, which greatly advanced physicists’ understanding of the general theory of relativity developed by Albert Einstein. Specifically, these systems seem to indicate a loss of energy which is consistent with the gravity waves predicted by Einstein’s theory. This is partly because the “pulse period” between sweeps of the pulsar’s beacon of light is incredibly stable, seeming to increase by no more than 5% during 1 million years (assuming the time we’ve been looking at it is representative, of course). In essence, this means that this binary pulsar can be used as a very precise cosmological clock.
It is important to recognize that this observed loss of energy is only an indirect indication of the existence of gravity waves, and hardly a smoking gun that confirms the existence of gravity waves.
Scientists continue to search for them today with experiments such as the Laser Interferometer Gravitational-Wave Observatory (LIGO), consisting of 4-kilometer-long detectors located in Hanford, Washington, and Livingston, Louisiana.
Russell A. Hulse
Russell A. Hulse was born on November 28, 1950, in New York City. He attended the Bronx High School of Science and then attended Cooper Union for his undergraduate degree, which he earned in 1970. He proceeded to the University of Massachusetts in Amherst for his doctorate, completed in 1975. It was while working on his thesis that he conducted the radio astronomy research that resulted in this Nobel Prize.
The National Radio Astronomy Observatory in Charlottesville, Virginia, provided post-doctoral work from 1975 to 1977. He began work at the Princeton University Plasma Physics Laboratory (PPPL) in 1977, where he remained for many years. In 2003, Hulse became Founding Director of the University of Texas at Dallas Science and Engineering Education Center (SEEC).
Joseph H. Taylor Jr.
Joseph H. Taylor Jr. was born on March 29, 1941, in the city of Philadelphia in the state of Pennsylvania, United States. Taylor attended Haverford College (which he describes as a “Quaker institution” in his own biography) before going on for graduate studies in physics at Harvard University. Following his graduate work, he proceeded to positions at the University of Massachusetts (where he worked with Hulse on the research that earned him the Nobel Prize) and then ultimately he, too, went on to work at Princeton University in 1980. At Princeton University, Taylor was the James S. McDonnell Distinguished Professor in Physics. He retired in 2006.