Joseph Hooton Taylor Jr. | |
---|---|
Born | Philadelphia, Pennsylvania, U.S. | March 29, 1941
Nationality | American |
Alma mater | Haverford College Harvard University |
Known for | Pulsars, WSJT-X |
Awards | Dannie Heineman Prize for Astrophysics (1980) Henry Draper Medal (1985) Magellanic Premium (1990) John J. Carty Award (1991) Wolf Prize in Physics (1992) Nobel Prize in Physics (1993) |
Scientific career | |
Fields | Physics |
Institutions | Princeton University University of Massachusetts Amherst Five College Radio Astronomy Observatory |
Doctoral students | Victoria Kaspi, Ingrid Stairs |
Joseph Hooton Taylor Jr. (born March 29, 1941) is an American astrophysicist and Nobel Prize laureate in Physics [1] for his discovery with Russell Alan Hulse of a "new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation."
Taylor was born in Philadelphia to Joseph Hooton Taylor Sr. and Sylvia Evans Taylor, both of whom had Quaker roots for many generations, and grew up in Cinnaminson Township, New Jersey. He attended the Moorestown Friends School in Moorestown Township, New Jersey, where he excelled in math. [2]
He received a B.A. in physics at Haverford College in 1963, and a Ph.D. in astronomy at Harvard University in 1968. After a brief research position at Harvard, Taylor went to the University of Massachusetts Amherst, eventually becoming Professor of Astronomy and Associate Director of the Five College Radio Astronomy Observatory.
Taylor's thesis work was on lunar occultation measurements. About the time he completed his Ph.D., Jocelyn Bell (who is also a Quaker) discovered the first radio pulsars with a telescope near Cambridge, England.
Taylor immediately went to the National Radio Astronomy Observatory's telescopes in Green Bank, West Virginia, and participated in the discovery of the first pulsars discovered outside Cambridge. Since then, he has worked on all aspects of pulsar astrophysics.
In 1974, Hulse and Taylor discovered the first pulsar in a binary system, named PSR B1913+16 after its position in the sky, during a survey for pulsars at the Arecibo Observatory in Puerto Rico. Although it was not understood at the time, this was also the first of what are now called recycled pulsars: Neutron stars that have been spun-up to fast spin rates by the transfer of mass onto their surfaces from a companion star.
The orbit of this binary system is slowly shrinking as it loses energy because of emission of gravitational radiation, causing its orbital period to speed up slightly. The rate of shrinkage can be precisely predicted from Einstein's General Theory of Relativity, and over a thirty-year period Taylor and his colleagues have made measurements that match this prediction to much better than one percent accuracy. This was the first confirmation of the existence of gravitational radiation. There are now scores of binary pulsars known, and independent measurements have confirmed Taylor's results.
Taylor has used this first binary pulsar to make high-precision tests of general relativity. Working with his colleague Joel Weisberg, Taylor has used observations of this pulsar to demonstrate the existence of gravitational radiation in the amount and with the properties first predicted by Albert Einstein. He and Hulse shared the Nobel Prize for the discovery of this object. In 1980, he moved to Princeton University, where he was the James S. McDonnell Distinguished University Professor in Physics, having also served for six years as Dean of Faculty. He retired in 2006.
Joe Taylor first obtained his amateur radio license as a teenager, which led him to the field of radio astronomy. Taylor is well known in the field of amateur radio weak signal communication and has been assigned the call sign K1JT by the FCC. He had previously held the callsigns K2ITP, WA1LXQ, W1HFV, and VK2BJX (the latter in Australia). [3]
His amateur radio accomplishments have included mounting an 'expedition' in April 2010 to use the Arecibo Radio Telescope to conduct moonbounce with Amateurs around the world using voice, Morse code, and digital communications. [3]
He has been active in developing several computer programs and communications protocols, including WSPR and WSJT ("Weak Signal/Joe Taylor"), a software package and protocol suite that utilizes computer-generated messages in conjunction with radio transceivers to communicate over long distances with other amateur radio operators.
WSJT is useful for passing short messages via non-traditional radio communications methods, such as moonbounce and meteor scatter and other low signal-to-noise ratio paths. It is also useful for extremely long-distance contacts using very low power transmissions.
Taylor was among the first group of MacArthur Fellows. He has served on many boards, committees, and panels, co-chairing the Decadal Panel of that produced the report Astronomy and Astrophysics in the New Millennium that established the United States's national priorities in astronomy and astrophysics for the period 2000–2010. He was a guest of honor in the 2009 International Physics Olympiad.
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are", which is studied in celestial mechanics.
Russell Alan Hulse is an American physicist and winner of the Nobel Prize in Physics, shared with his thesis advisor Joseph Hooton Taylor Jr., "for the discovery of a new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation".
Michel Gustave Édouard Mayor is a Swiss astrophysicist and professor emeritus at the University of Geneva's Department of Astronomy. He formally retired in 2007, but remains active as a researcher at the Observatory of Geneva. He is co-laureate of the 2019 Nobel Prize in Physics along with Jim Peebles and Didier Queloz, and the winner of the 2010 Viktor Ambartsumian International Prize and the 2015 Kyoto Prize.
A pulsar is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth, and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays.
A millisecond pulsar (MSP) is a pulsar with a rotational period less than about 10 milliseconds. Millisecond pulsars have been detected in radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The leading hypothesis for the origin of millisecond pulsars is that they are old, rapidly rotating neutron stars that have been spun up or "recycled" through accretion of matter from a companion star in a close binary system. For this reason, millisecond pulsars are sometimes called recycled pulsars.
PSR J0737−3039 is the first known double pulsar. It consists of two neutron stars emitting electromagnetic waves in the radio wavelength in a relativistic binary system. The two pulsars are known as PSR J0737−3039A and PSR J0737−3039B. It was discovered in 2003 at Australia's Parkes Observatory by an international team led by the Italian radio astronomer Marta Burgay during a high-latitude pulsar survey.
Tests of general relativity serve to establish observational evidence for the theory of general relativity. The first three tests, proposed by Albert Einstein in 1915, concerned the "anomalous" precession of the perihelion of Mercury, the bending of light in gravitational fields, and the gravitational redshift. The precession of Mercury was already known; experiments showing light bending in accordance with the predictions of general relativity were performed in 1919, with increasingly precise measurements made in subsequent tests; and scientists claimed to have measured the gravitational redshift in 1925, although measurements sensitive enough to actually confirm the theory were not made until 1954. A more accurate program starting in 1959 tested general relativity in the weak gravitational field limit, severely limiting possible deviations from the theory.
The Hulse–Taylor pulsar is a binary star system composed of a neutron star and a pulsar which orbit around their common center of mass. It is the first binary pulsar ever discovered.
Ronald William Prest Drever was a Scottish experimental physicist. He was a professor emeritus at the California Institute of Technology, co-founded the LIGO project, and was a co-inventor of the Pound–Drever–Hall technique for laser stabilisation, as well as the Hughes–Drever experiment. This work was instrumental in the first detection of gravitational waves in September 2015.
The gravitational wave background is a random background of gravitational waves permeating the Universe, which is detectable by gravitational-wave experiments, like pulsar timing arrays. The signal may be intrinsically random, like from stochastic processes in the early Universe, or may be produced by an incoherent superposition of a large number of weak independent unresolved gravitational-wave sources, like supermassive black-hole binaries. Detecting the gravitational wave background can provide information that is inaccessible by any other means about astrophysical source population, like hypothetical ancient supermassive black-hole binaries, and early Universe processes, like hypothetical primordial inflation and cosmic strings.
A binary pulsar is a pulsar with a binary companion, often a white dwarf or neutron star. Binary pulsars are one of the few objects which allow physicists to test general relativity because of the strong gravitational fields in their vicinities. Although the binary companion to the pulsar is usually difficult or impossible to observe directly, its presence can be deduced from the timing of the pulses from the pulsar itself, which can be measured with extraordinary accuracy by radio telescopes.
Gravitational waves are transient displacements in a gravitational field—generated by the motion or acceleration of gravitating masses—that radiate outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as the gravitational equivalent of electromagnetic waves. In 1916, Albert Einstein demonstrated that gravitational waves result from his general theory of relativity as ripples in spacetime.
Gravitational-wave astronomy is a subfield of astronomy concerned with the detection and study of gravitational waves emitted by astrophysical sources.
Carl Eugene Heiles is an American astrophysicist noted for his contributions to the understanding of diffuse interstellar matter through observational radio astronomy.
A pulsar timing array (PTA) is a set of galactic pulsars that is monitored and analyzed to search for correlated signatures in the pulse arrival times on Earth. As such, they are galactic-sized detectors. Although there are many applications for pulsar timing arrays, the best known is the use of an array of millisecond pulsars to detect and analyse long-wavelength gravitational wave background. Such a detection would entail a detailed measurement of a gravitational wave (GW) signature, like the GW-induced quadrupolar correlation between arrival times of pulses emitted by different millisecond pulsar pairings that depends only on the pairings' angular separations in the sky. Larger arrays may be better for GW detection because the quadrupolar spatial correlations induced by GWs can be better sampled by many more pulsar pairings. With such a GW detection, millisecond pulsar timing arrays would open a new low-frequency window in gravitational-wave astronomy to peer into potential ancient astrophysical sources and early Universe processes, inaccessible by any other means.
Matthew Bailes is an astrophysicist and Professor at the Centre for Astrophysics and Supercomputing, Swinburne University of Technology and the Director of OzGrav, the ARC Centre of Excellence for Gravitational Wave Discovery. In 2015 he won an ARC Laureate Fellowship to work on Fast Radio Bursts. He is one of the most active researchers in pulsars and Fast Radio Bursts in the world. His research interests includes the birth, evolution of binary and millisecond pulsars, gravitational waves detection using an array of millisecond pulsars and radio astronomy data processing system design for Fast Radio Burst discovery. He is now leading his team to re-engineer the Molonglo Observatory Synthesis Telescope with a newly designed correlation system for observation of pulsars and Fast Radio Bursts (FRBs).
Maura Ann McLaughlin is an astrophysics professor at West Virginia University in Morgantown, West Virginia known for her work on fast radio bursts (FRBs).
Chiara Mingarelli is an Italian-Canadian astrophysicist who researches gravitational waves. She is an assistant professor of physics at Yale University since 2023, and previously an assistant professor at the University of Connecticut (2020–2023). She is also a science writer and communicator.
John Antoniadis also known as Ioannis Antoniadis is a Greek astrophysicist. He is mostly known for his research of radio pulsars, a type of rapidly rotating neutron stars.
Ingrid Stairs is a Canadian astronomer currently based at the University of British Columbia. She studies pulsars and their companions as a way to study binary pulsar evolution, pulsar instrumentation and polarimetry, and Fast Radio Bursts (FRBs). She was awarded the 2017 Rutherford Memorial Medal for physics of the Royal Society of Canada, and was elected as a Fellow of the American Physical Society in 2018.
Born in Philadelphia in 1941, he grew up on a peach farm in Cinnaminson, New Jersey, that has been in his family for more than two centuries – "a plot of green," he recalls, in the industrial belt along the Delaware River north of Camden. ... As a high school student at Moorestown (N.J.) Friends, Taylor excelled in mathematics, a subject he pursued at Haverford College before switching to physics.