Brian Randolph Greene (born February 9, 1963) is an American theoretical physicist and string theorist. He has been a professor at Columbia University since 1996 and chairman of the World Science Festival since co-founding it in 2008. Greene has worked on mirror symmetry, relating two different Calabi–Yau manifolds (concretely, relating the conifold to one of its orbifolds). He also described the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point.
Greene has become known to a wider audience through his books for the general public, The Elegant Universe, Icarus at the Edge of Time, The Fabric of the Cosmos, The Hidden Reality, and related PBS television specials. He also appeared on The Big Bang Theory episode "The Herb Garden Germination", as well as the films Frequency and The Last Mimzy. He is currently a member of the Board of Sponsors of the Bulletin of the Atomic Scientists.
Greene is well known to a wider audience for his work on popularizing theoretical physics, in particular string theory and the search for a unified theory of physics. His first book, The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory, published in 1999, is a popularization of superstring theory and M-theory. It was a finalist for the Pulitzer Prize in nonfiction, and winner of The Aventis Prizes for Science Books in 2000. The Elegant Universe was later made into a PBS television special of the same name, hosted and narrated by Greene, which won a 2003 Peabody Award.
Greene's second book, The Fabric of the Cosmos: Space, Time, and the Texture of Reality (2004), is about space, time, and the nature of the universe. Aspects covered in this book include non-local particle entanglement as it relates to special relativity and basic explanations of string theory. It is an examination of the very nature of matter and reality, covering such topics as spacetime and cosmology, origins and unification, and including an exploration into reality and the imagination. The Fabric of the Cosmos was later made into a PBS television special of the same name, hosted and narrated by Greene.
Greene's third book, The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, published in January 2011, deals in greater depth with multiple universes, or, as they are sometimes referred to collectively, the multiverse.
A book for a younger audience, Icarus at the Edge of Time ISBN 978-0-307-26888-4, which is a futuristic re-telling of the Icarus myth, was published September 2, 2008. In addition to authoring popular-science books, Greene is an occasional Op-Ed Contributor for The New York Times, writing on his work and other scientific topics.
The popularity of his books and his natural on-camera demeanor have resulted in many media appearances, including Charlie Rose, The Colbert Report, The NewsHour with Jim Lehrer, The Century with Peter Jennings, CNN, TIME, Nightline in Primetime, Late Night with Conan O'Brien, and the Late Show with David Letterman. It has also led to Greene helping John Lithgow with scientific dialogue for the television series 3rd Rock from the Sun, and becoming a technical consultant for the film Frequency, in which he also had a cameo role. He was a consultant on the 2006 time-travel movie Déjà Vu. He also had a cameo appearance as an Intel scientist in 2007's The Last Mimzy. Greene was also mentioned in the 2002 Angel episode "Supersymmetry" and in the 2008 Stargate Atlantis episode "Trio". Through his film credits, combined with his research publications in mathematical physics, Greene is one of the few people to have a defined Erdős–Bacon number. In April 2011 he appeared on The Big Bang Theory in the episode "The Herb Garden Germination" as himself, speaking to a small crowd about the contents of his most recent book.
Greene often lectures outside of the collegiate setting, at both a general and a technical level, in more than twenty-five countries. In 2012 his teaching prowess was recognized when he received the Richtmyer Memorial Award, which is given annually by the American Association of Physics Teachers.
In May 2013, the Science Laureates of the United States Act of 2013 (H.R. 1891; 113th Congress) was introduced into Congress. Brian Greene was listed by one commentator as a possible nominee for the position of Science Laureate, if the act were to pass.
In March 2015, an Australian spider that uses vibrations to detect prey, Dolomedes briangreenei, was named in honor of Brian Greene.