Kip Thorne

Kip Stephen Thorne(born June 1, 1940) is an Americantheoretical physicistandwriterknown for his contributions ingravitational physicsandastrophysics. Along withRainer WeissandBarry C. Barish, he was awarded the 2017Nobel Prize in Physicsfor his contributions to theLIGOdetector and the observation ofgravitational waves.
A longtime friend and colleague ofStephen HawkingandCarl Sagan, he was theRichard P. FeynmanProfessor of Theoretical Physics at theCalifornia Institute of Technology(Caltech) until 2009and speaks of the astrophysical implications ofthe general theory of relativity. He continues to do scientific research and scientific consulting, a notable example of which was for theChristopher NolanfilmInterstellar.
Thorne was born on June 1, 1940, inLogan, Utah. His father, D. Wynne Thorne (1908–1979), was a professor ofsoil chemistryatUtah State University, and his mother, Alison (née Comish; 1914–2004), was an economist and the first woman to receive aPhDin economics fromIowa State College.Raised in an academic environment, two of his four siblings also became professors.Thorne's parents were members ofthe Church of Jesus Christ of Latter-day Saints(LDS Church) and raised Thorne in the LDS faith, though he now describes himself asatheist.  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, winning recognition in theWestinghouse Science Talent Searchas a senior atLogan High School.He received hisBSin physics degree from theCalifornia Institute of Technology(Caltech) in 1962, and his master and PhD in physics fromPrinceton Universityin 1964 and 1965 under the supervision ofJohn Archibald Wheelerwith adoctoral dissertationentitled "Geometrodynamicsof Cylindrical Systems".
Thorne returned to Caltech as an associate professor in 1967 and became a professor of theoretical physics in 1970, becoming one of the youngest full professors in the history of Caltech at age 30. He became the William R. Kenan, Jr. Professor in 1981, and theFeynmanProfessor of Theoretical Physics in 1991. He was an adjunct professor at theUniversity of Utahfrom 1971 to 1998 and Andrew D. White Professor at Large atCornell Universityfrom 1986 to 1992.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 wasInterstellar, on which he worked withChristopher NolanandJonathan Nolan.
Throughout the years, Thorne has served as a mentor and thesis advisor to many leading theorists who now work on observational, experimental, or astrophysical aspects of general relativity. Approximately 50 physicists have received PhDs 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. His presentations on subjects such asblack holes,gravitational radiation,relativity,time travel, andwormholeshave been included inPBSshows in the U.S. and on theBBCin the United Kingdom.
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 was set up on ablind datewithLynda Obst, later afilm producer, by physicistCarl Sagan. They dated in 1979-1980, and parted and remained friends, to the extent that they later collaborated onInterstellar.Thorne and his second wife, Carolee Joyce Winstein, a professor ofbiokinesiologyand physical therapy atUSC, married in 1984.
Thorne's research has principally focused onrelativisticastrophysicsandgravitation physics, with emphasis onrelativistic stars, black holes and especiallygravitational waves.He is perhaps best known to the public for his controversial theory that wormholes can conceivably be used for time travel.However, Thorne's scientific contributions, which center on the general nature ofspace, time, andgravity, span the full range of topics in general relativity.
Thorne's work has dealt with the prediction of gravitational wave strengths and their temporal signatures as observed on Earth. These "signatures" are of great relevance toLIGO(Laser Interferometer Gravitational Wave Observatory), a multi-institution gravitational wave experiment for which Thorne has been a leading proponent – in 1984, he cofounded the LIGO Project (the largest project ever funded by theNSF) 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 themathematicsnecessary to analyze these objects.Thorne also carries outengineeringdesign analyses for features of the LIGO that cannot be developed on the basis ofexperimentand he gives advice ondata analysisalgorithmsby 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 controlscattered lightin the LIGO beam tubes, and – in collaboration withVladimir Braginsky's (Moscow, Russia) research group – inventingquantum nondemolitiondesigns for advanced gravity-wave detectors and ways to reduce the most serious kind ofnoisein advanced detectors:thermoelastic noise. WithCarlton M. Caves, Thorne invented the back-action-evasion approach to quantum nondemolition measurements of theharmonic oscillators– a technique applicable both in gravitational wave detection andquantum optics.
On February 11, 2016, a team of four physicistsrepresenting theLIGO Scientific Collaboration, announced that in September 2015, LIGO recorded the signature of two black holes colliding 1.3 billion light-years away.  This recorded detection was the first direct observation of thefleeting chirp of a gravitational waveand confirmed a prediction of the general theory of relativity.
While studying for his PhD at Princeton University, his mentorJohn Wheelerassigned him a problem to think about: find out whether or not a cylindrical bundle of repulsive magnetic field lines will implode under its own attractive gravitational force. After several months wrestling with the problem, he proved that it was impossible for cylindricalmagnetic fieldlines toimplode.
Why won't a cylindrical bundle of magnetic field lines implode, while spherical starswillimplode under their own gravitational force? Thorne tried to explore the theoretical ridge between these two phenomena. He eventually determined that the gravitational force can overcome all interior pressure only when an object has been compressed in all directions. To express this realization, Thorne proposed hishoop conjecture, which 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 circumference4πGMc2{\displaystyle {\begin{matrix}{\frac {4\pi GM}{c^{2}}}\end{matrix}}}can be spun must be a black hole.
As a tool to be used in both enterprises — astrophysics and theoretical physics — Thorne and his students have developed an unusual approach, called the "membrane paradigm", to the theory of black holes and used it to clarify theBlandford–Znajek mechanismby which black holes may power somequasarsandactive galactic nuclei.
Thorne has investigated thequantumstatistical mechanicalorigin of theentropyof a black hole. With hispostdocWojciech Zurek, he showed that the entropy of a black hole is thelogarithmof the number of ways that the hole could have been made.
WithIgor NovikovandDon Page, he developed the general relativistic theory of thinaccretion disksaround black holes, and using this theory he deduced that with a doubling of its mass by suchaccretiona black hole will be spun up to 0.998 of the maximumspinallowed by general relativity, but not any farther. This is probably the maximum black-hole spin allowed in nature.
Thorne and his co-workers at Caltech conducted scientific research on whether the laws of physics permit space and time to bemultiply connected(can there exist classical,traversable wormholesand "time machines"?).With Sung-Won Kim, Thorne identified a universal physical mechanism (the explosive growth ofvacuum polarizationofquantum fields), that may always prevent spacetime from developingclosed timelike curves(i.e., preventbackward time travel).
WithMike MorrisandUlvi Yurtsever, he showed that traversable wormholes can exist in the structure ofspacetimeonly if they are threaded by quantum fields inquantum statesthat violate theaveraged null energy condition(i.e. have negative renormalized energy spread over a sufficiently large region).This has triggered research to explore the ability of quantum fields to possess such extendednegative energy. Recent calculations by Thorne indicate that simple masses passing through traversable wormholes could never engenderparadoxes– there arenoinitial conditions that lead to paradox once time travel is introduced. If his results can be generalized, they would suggest that none of the supposed paradoxes formulated in time travel stories can actually be formulated at a precise physical level: that is, thatanysituation in a time travel story turns out to permitmanyconsistent solutions.
WithAnna Żytkow, Thorne predicted the existence ofred supergiant starswithneutron-starcores (Thorne–Żytkow objects).He laid the foundations for the theory ofpulsationsof relativistic stars and the gravitational radiation they emit. WithJames Hartle, Thorne derived from general relativity the laws of motion and precession of black holes and other relativistic bodies, including the influence of the coupling of theirmultipole momentsto the spacetime curvature of nearby objects,as well as writing down theHartle-Thorne metric, an approximate solution which describes the exterior of a slowly and rigidly rotating, stationary and axially symmetric body.
Thorne has also theoretically predicted the existence of universally antigravitating "exotic matter" – the element needed to accelerate the expansion rate of the universe, keep traversable wormhole "Star Gates" open and keeptimelikegeodesicfree float "warp drives" working. With Clifford Willand others of his students, he laid the foundations for the theoretical interpretation of experimentaltests of relativistic theories of gravity– foundations on which Will and others then built. As of 2005, Thorne was interested in the origin of classical space and time from thequantum foamofquantum gravitytheory.
Thorne has written and edited books on topics in gravitational theory andhigh-energy astrophysics. In 1973, he co-authored the textbookGravitationwithCharles MisnerandJohn Wheeler;that according toJohn C. Baezand Chris Hillman, is one of the great scientific books of all time and has inspired two generations of students.In 1994, he publishedBlack Holes and Time Warps: Einstein's Outrageous Legacy, a book for non-scientists for which he received numerous awards. This book has been published in six languages, and editions in Chinese, Italian, Czech, and Polish are in press.In 2014, Thorne publishedThe Science of Interstellarin which he explains the science behind Christopher Nolan's filmInterstellar; Nolan wrote the foreword to the book. In September 2017, Thorne and Roger D. Blandford publishedModern Classical Physics: Optics, Fluids, Plasmas, Elasticity, Relativity, and Statistical Physics, a graduate-level textbook covering the six major areas of physics listed in the title.
Thorne's articles have appeared in publications such as:
Thorne has published more than 150 articles in scholarly journals.
Thorne has been elected to the:
He has been recognized by numerous awards including the:
He has been aWoodrow Wilson Fellow,Danforth Fellow,Guggenheim Fellow, andFulbright Fellow. He has also received the honorary degree of doctor of humane letters fromClaremont Graduate Universityand an honorary doctorate from the Physics Department of theAristotle University of Thessaloniki. In 2024 he was awarded an honorary doctorate fromUniversity of Cambridge.
He was elected to hold the Lorentz chair for the year 2009Leiden University, the Netherlands.
Thorne has served on the:
Kip Thorne was selected byTimemagazinein an annuallist of the 100 most influential people in the American worldin 2016.