NOTE: Please notice the special start time. Speaker: Nick Warner Prof. at University of Southern California Title: Microstate Geometries: where the most semi-classical bodies are buried Abstract: Microstate geometries are smooth horizonless geometries with the same boundary conditions as a black hole. I review what is currently known about the extensive families of such BPS geometries, how they resolve black-hole singularities and how they represent states of BPS black holes in the "typical sector." I also discuss the phenomenon of "entropy enhancement" for fluctuating geometries and describe possible new families of fluctuating BPS microstate geometries. I will also outline recent progress on microstate geometries from non-BPS, extremal black holes.