Brian Greene_

Brian Randolph Greene is an American physicist known for his research on string theory. He is a professor of physics and mathematics at Columbia University, director of its center for theoretical physics, and the chairman of the World Science Festival, which he co-founded in 2008. Greene co-discovered mirror symmetry, relating two different Calabi–Yau manifolds. He also described the flop transition, a mild form of topology change, and the conifold transition, a more severe transformation of space, showing that topology can smoothly change in string theory.