A century ago, Einstein predicted the existence of gravitational waves—ripples in spacetime—but believed they were so small that humans would never observe them.
More recently, an MIT physics professor did the math and concluded that Einstein was wrong. So he built the Laser Interferometer Gravitational-Wave Observatory (LIGO), which measures almost infinitesimally small disturbances in spacetime—smaller than anything that’s been measured before. And in 2016, LIGO succeeded, detecting gravitational waves from a massive, faraway collision between black holes.
Watch “Listening to the Universe” to get up close and personal with the scientists of LIGO and their thrilling discovery.