Spacetime in String Theory

We give a brief overview of the nature of spacetime emerging from string theory. This is radically different from the familiar spacetime of Einstein’s relativity. At a perturbative level, the spacetime metric appears as “coupling constants” in a two dimensional quantum field theory. Nonperturbatively (with certain boundary conditions), spacetime is not fundamental but must be reconstructed from a holographic, dual theory. To appear in “Spacetime 100 Years Later”, eds J. Pullin and R. Price (2005).