String Theory and Quantum Chromodynamics

String Theory has long been the best candidate for a unified theory of
physics. Unfortunately, its lack of predictive power and its abstract
nature made it more of a beautiful mathematical construction than a
theory relevant to our physical experience. This has dramatically
changed in the last years with the discovery of a gauge/gravity duality.

I will review the gauge/gravity duality and how it has changed our
understanding of String Theory. I will describe the ongoing search for a
string theory dual of Quantum Chromodynamics (QCD) . I will also discuss
how the existence of this dual would make it possible to calculate QCD
observables directly from string theory.