Kip Stephen Thorne, (born June 1, 1940) is an American theoretical physicist, known for his contributions in gravitational physics and astrophysics. A longtime friend and colleague of Stephen Hawking and Carl Sagan, he was the Feynman Professor of Theoretical Physics at the California Institute of Technology (Caltech) until 2009 and is one of the world’s leading experts on the astrophysical implications of Einstein’s general theory of relativity. He continues to do scientific research and acted as a scientific consultant in the science fiction film Interstellar.
Life and career
Thorne was born in Logan, Utah on June 1, 1940, the son of Utah State University professors D. Wynne Thorne and Alison (née Cornish) Thorne, a soil chemist and an economist, respectively. Raised in an academic environment, two of his four siblings also became professors. Thorne’s parents were members of The Church of Jesus Christ of Latter-day Saints and raised Thorne in the LDS faith, though he now describes himself as atheist. Regarding his views on science and religion, Thorne has stated: “There are large numbers of my finest colleagues who are quite devout and believe in God […] There is no fundamental incompatibility between science and religion. I happen to not believe in God.”
Thorne rapidly excelled at academics early in life, becoming one of the youngest full professors in the history of the California Institute of Technology. He received his B.S. degree from Caltech in 1962, and Ph.D. degree from Princeton University in 1965. He wrote his doctoral thesis,Geometrodynamics of Cylindrical Systems, under the supervision of relativist John Wheeler. Thorne returned to Caltech as an associate professor in 1967 and became a professor of theoretical physics in 1970, the William R. Kenan, Jr. Professor in 1981, and the Feynman Professor of Theoretical Physics in 1991. In June 2009 he resigned his Feynman Professorship (he is now the Feynman Professor of Theoretical Physics, Emeritus) to pursue a career of writing and movie making. His first film project was Interstellar, working with Christopher Nolan.
Throughout the years, Thorne has served as a mentor and thesis advisor for many leading theorists who now work on observational, experimental, or astrophysical aspects of general relativity. Approximately 50 physicists have received Ph.D.s at Caltech under Thorne’s personal mentorship.
Thorne is known for his ability to convey the excitement and significance of discoveries in gravitation and astrophysics to both professional and lay audiences. In 1999, Thorne made some speculations on what the 21st century will find as the answers to the following questions:
- Is there a “dark side of the universe” populated by objects such as black holes?
- Can we observe the birth of the universe and its dark side using radiation made from space-time warpage, or so-called “gravitational waves”?
- Will 21st century technology reveal quantum behavior in the realm of human-size objects?
Thorne and Linda Jean Peterson married in 1960. Their children are Kares Anne and Bret Carter, an architect. Thorne and Peterson divorced in 1977. Thorne and his second wife, Carolee Joyce Winstein, a professor of biokinesiology and physical therapy at USC, married in 1984.
Gravitational waves and LIGO
Thorne’s work has dealt with the prediction of gravity-wave strengths and their temporal signatures as observed on Earth. These “signatures” are of great relevance to LIGO (Laser Interferometer Gravitational Wave Observatory), a multi-institution gravity-wave experiment for which Thorne has been a leading proponent – in 1984, he cofounded the LIGO Project (the largest project ever funded by the NSF) to discern and measure any fluctuations between two or more ‘static’ points; such fluctuations would be evidence of gravitational waves, as calculations describe. A significant aspect of his research is developing the mathematics necessary to analyze these objects. Thorne also carries out engineering design analyses for features of the LIGO that cannot be developed on the basis of experiment and he gives advice on data analysis algorithms by which the waves will be sought. He has provided theoretical support for LIGO, including identifying gravitational wave sources that LIGO should target, designing the baffles to control scattered light in the LIGO beam tubes, and – in collaboration with Vladimir Braginsky’s (Moscow, Russia) research group – inventing quantum nondemolition designs for advanced gravity-wave detectors and ways to reduce the most serious kind of noise in advanced detectors: thermoelastic noise. With Carlton M. Caves, Thorne invented the back-action-evasion approach to quantum nondemolition measurements of the quadrature amplitudes of harmonic oscillators – a technique applicable both in gravitational wave detection and quantum optics.
Black hole cosmology
Thorne has made contributions to black hole cosmology. Thorne proposed his Hoop Conjecture that cast aside the thought of a naked singularity. The Hoop Conjecture describes an imploding star turning into a black hole when the critical circumference of the designed hoop can be placed around it and set into rotation. That is, any object of mass M around which a hoop of circumference can be spun must be a black hole. As a tool to be used in both enterprises, astrophysics and theoretical physics, Thorne has developed an unusual approach, called the “Membrane Paradigm“, to the theory of black holes and used it to clarify the “Blandford-Znajek” mechanism by which black holes may power some quasars and active galactic nuclei. Thorne has investigated the quantum statistical mechanical origin of the entropy of a black hole and the entropy of a cosmological horizon in aninflationary model of the universe. With Wojciech Zurek he showed that the entropy of a black hole of known mass, angular momentum, and electric charge is the logarithm of the number of ways that the hole could have been made. With Igor Novikov and Don Page he developed the general relativistic theory of thin accretion disks around black holes, and using this theory he deduced that with a doubling of its mass by such accretion a black hole will be spun up to 0.998 of the maximum spin allowed by general relativity, but not any farther. This is probably the maximum black-hole spin allowed in nature. He, along with his mentor John Wheeler, additionally proved that it was impossible for cylindrical magnetic field lines to implode. Both Hawking and Thorne have theorized that a singularity exists in the interior of a black hole.