Brian Greene is an American theoretical physicist and string theorist. He has been a professor

Professor

A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 at Columbia University

Columbia University

Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...

 since 1996. Greene has worked on mirror symmetry, relating two different Calabi-Yau manifold

Calabi-Yau manifold

A Calabi-Yau manifold is a special type of manifold that shows up in certain branches of mathematics such as algebraic geometry, as well as in theoretical physics...

s (concretely, relating the conifold

Conifold

In mathematics and string theory, a conifold is a generalization of a manifold. Unlike manifolds, conifolds can contain conical singularities i.e. points whose neighbourhoods look like cones over a certain base...

 to one of its orbifold

Orbifold

In the mathematical disciplines of topology, geometry, and geometric group theory, an orbifold is a generalization of a manifold...

s). He also described the flop transition, a mild form of topology

Topology

Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...

 change, showing that topology

Topology

Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...

 in string theory

String theory

String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...

 can change at the conifold

Conifold

In mathematics and string theory, a conifold is a generalization of a manifold. Unlike manifolds, conifolds can contain conical singularities i.e. points whose neighbourhoods look like cones over a certain base...

 point. He has become known to a wider audience through his books for the general public, The Elegant Universe

The Elegant Universe

The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory is a book by Brian Greene published in 1999, which introduces string and superstring theory, and provides a comprehensive though non-technical assessment of the theory and some of its shortcomings...

, Icarus at the Edge of Time

Icarus at the Edge of Time

Icarus at the Edge of Time is a 2008 novel by physicist Brian Greene, illustrated by Chip Kidd with images from the Hubble Space Telescope. It was adapted into a 40-minute orchestral piece by Philip Glass with a film by AL and AL in 2010....

, The Fabric of the Cosmos

The Fabric of the Cosmos

The Fabric of the Cosmos: Space, Time, and the Texture of Reality is the second book on theoretical physics, cosmology, and string theory written by Brian Greene, professor and co-director of Columbia's Institute for Strings, Cosmology, and Astroparticle Physics .- Introduction :Greene begins with...

, The Hidden Reality, and a related PBS

Public Broadcasting Service

The Public Broadcasting Service is an American non-profit public broadcasting television network with 354 member TV stations in the United States which hold collective ownership. Its headquarters is in Arlington, Virginia....

 television special.