Listen up

Gravitational waves help us listen to the cosmos

Scientists have been listening in to these ripples in space-time for five years.

Caltech

On September 14, 2015, scientists detected the first gravitational waves using the Laser Interferometer Gravitational-Wave Observatory (LIGO). The waves were ripples in space-time created by two colliding black holes, 1.3 billion years ago.

NASA

100 years earlier, Einstein's Theory of General Relativity predicted the existence of gravitational waves. The theory stated that when objects accelerate through space, they create ripples in space-time around them that move at the speed of light.