## String Theory for Pedestrians

Since high school I have been a follower of theoretical physics. Today, I present you with a three part series on string theory. If you enjoy the lectures I recommend reading The Elegant Universe by Brian Greene and watching The Elegant Universe on PBS-Nova.

**Video Introduction (Via Scitalks & CERN):**

This 3 lecture series will discuss the basics of string theory, some physical applications, and the outlook for the future. It will begin with the main concepts of the classical theory and the application to the study of cosmic superstrings. The lecture will then turn to the quantum theory and discuss applications to the investigation of hadronic specra and the recently discovered quark-gluon plasma. The lecture concludes with a sketch of string models of particle physics and shows some avenues that may lead to a complete formulation of string theory.

**Background on String Theory (Via Wikipedia):**

String theory is a still-developing mathematical approach to theoretical physics, whose original building blocks are one-dimensional extended objects called strings. Unlike the point particles in quantum field theories like the standard model of particle physics, strings interact in a way that is almost uniquely specified by mathematical self-consistency, forming an apparently valid quantum theory of gravity.

Since its birth as the dual resonance model which described the strongly interacting hadrons as strings, the term *string theory* has changed to include any of a group of related superstring theories and larger frameworks such as M-theory, which unite them. One shared property of all these theories is the holographic principle.

String theory is of interest to many physicists because of the mathematics involved, and because of the large number of forms that the theories can take. String theory strongly suggests that spacetime has eleven dimensions, as opposed to the usual three space and one time, but the theory can easily describe universes with four observable spacetime dimensions as well.