In order to fully describe gravitational physics, we need Einstein’s theory of General Relativity, which proposes that spacetime, the combination of space and time in which we live, curves due to the presence of matter. The curvature of spacetime then affects the motion of everything, including stars, planets, and light itself. A particularly interesting phenomenon in General Relativity is the existence of black holes, astrophysical objects which have gravity so strong that not even light can escape them! When two black holes orbit around one another in a binary and merge into one black hole in a violent collision, they emit gravitational waves (GWs), ripples in spacetime that we can now observe with GW detectors such as LIGO and Virgo. GWs allow us to answer questions about physics involving the nature and formation of black holes and other compact objects, stellar astrophysics, cosmology, high energy physics, information theory, and the nature of gravity itself. In order to find and study GW signals in noisy GW detector data, we must know what the signals we are searching for look like. Computing predictions for GW signals from merging black holes and other systems with extreme gravity is no easy task, and must be done with the help of supercomputers. We thus enter my research field of Numerical Relativity, or “Einstein on the computer”, simulating the evolution of spacetime and producing predictions for GW signals. Numerical relativity and gravitational wave science are vibrant fields, with over ninety GW events detected to date and more powerful, next-generation GW detectors on the way. In this talk, I will conceptually introduce general relativity, introduce black holes, gravitational waves, and numerical relativity, and discuss how you can contribute to this fascinating field of research.