A snapshot of the 3D gravitational waveform from a general relativistic simulation of binary black holes. Gravitational waves from such binary mergers are routinely observed by LIGO. With space missions such as LISA, the evolution of these binaries can be monitored years in advance, allowing multi-frequency constraints on astrophysical formations and tests of general relativity. (Credit: Jani, K., Kinsey, M., Clark, M., Center for Relativistic Astrophysics, Georgia Institute of Technology.)
