Lecture 3 | String Theory and M-Theory

(October 4, 2010) Professor Leonard Susskind reviews harmonic oscillators, the spin of massless particles (photons and gravitons), the low lying spectrum of strings, the tachyon problem, and the basics of string interactions. String theory (with its close relative, M-theory) is the basis for the most ambitious theories of the physical world. It has profoundly influenced our understanding of gravity, cosmology, and particle physics. In this course we will develop the basic theoretical and mathematical ideas