Eward Witten (born August 26, 1951) is an American theoretical physicist and professor at the Institute for Advanced Study. He is one of the world's leading researchers in superstring theory. He has made extensive contributions to theoretical physics, and in 1990 he was awarded the Fields Medal for his influence on the development of mathematics. In 1995, he suggested the existence of M-theory at a conference at the University of Southern California, and used M-theory to explain a number of previously observed dualities, sparking a flurry of new research in string theory called the second superstring revolution.