Explore the cutting-edge research on testing general relativity through black hole mergers in this 46-minute lecture by Frans Pretorius of Princeton University. Delve into the challenges of extracting stringent constraints from LIGO/Virgo observations and the obstacles in predicting waveforms for modified gravity theories. Examine numerical approaches to assess the viability of beyond-GR constructions, including gravitational collapse in Einstein-dilaton-Gauss-Bonnet gravity and the dynamical stability of AdS black bubbles. Gain insights into strong field general relativity, self-consistency tests, and the complexities of non-perturbative gravity beyond current models. Discover the intricacies of modified geometry, modified matter, and two-way traversable wormhole mergers. Analyze the Einstein/Klein-Gordon/Hydrodynamic code, internal flux, and metric variables through example cases, enhancing your understanding of advanced concepts in gravitation and black hole dynamics.