John Morgan is professor and chair of the mathematics department at Columbia University. He was a member of one of three teams that were involved in verifying Grigory Perelman's proof of the Poincaré conjecture and is coauthor with Gang Tian of a forthcoming book giving details of the proof, titled Ricci Flow and the Poincaré Conjecture. Morgan is also the author of The Seiberg-Witten Equations and Applications to the Topology of Smooth Four-Manifolds (Princeton University Press, 1996).