Clifford Johnson
Department of Mathematical Sciences,
University of Durham, UK
February 26, 2003
Over the last eight years, work in superstring and M-theory has led to a number of exciting developments which serve as examples hinting at an exciting view of the nature of spacetime physics at the most fundamental level. The physics involves deep connections between theories of gravity and gauge theories, the latter being well known to form the foundations of the Standard Model of particle physics. The physical and mathematical consequences have yet to be fully explored. We will review some of the key insights obtained about the structure of superstring and M-theory and what it has to teach us, focussing on the important and useful dynamical extended geometrical objects known as "D-Branes". Applications to the quantum mechanics of black holes are discussed, string theory's "enhançon" mechanism for the resolution of certain spacetime singularities, and the role of the mechanism in black hole thermodynamics.