Black Hole Cinema

Abstract: With luck, the Event Horizon Telescope is now embarking on its second set of observations with an array capable of generating images of known supermassive black hole candidates that resolve their horizon. The primary targets of the EHT are highly variable, known to generate flares and ejections on timescales as short as 30 minutes and extending to weeks. Therefore, we are about to enter an era of dynamical, horizon-scale studies of black hole physics. I will describe some of the origins of this variability, and how it can be exploited to learn about the growth of black holes, how they launch the relativistic flows responsible for their inordinate impact on the universe, and the nature of gravity in their vicinity.