Black holes, through theoretical predictions or more recently observations of gravitational waves, have allowed us to gain an understanding of the strongly curved spacetime originally predicted by Einstein. Going hand in hand with this, there has been rapid development in both the theoretical and computational tools we use to study the dynamics of gravity in this strong field regime. In this talk, I will demonstrate that black holes are a unique probe of fundamental physics. I will illustrate this, by numerically solving for the dynamics of black holes in the early universe within the context of bouncing and inflationary models. I will also discuss some recent progress in modeling binary black hole mergers in modified theories of gravity, in the hope to perform model dependent tests of General Relativity.