» An experiment that reaches across our galaxy has detected the first signs of a possible 'sea' of ripples in space-time An experiment that reaches across our galaxy has detected the first signs of a possible 'sea' of ripples in space-time Morgan McFall-JohnsenJan 13, 2021, 20:18 IST An artist's concept of a supermassive black hole surrounded by a swirling disk of material falling onto it.NASA/JPL-Caltech Scientists might have discovered the first signs of the gravitational-wave background: a sea of ripples in space-time reverberating throughout the universe. Albert Einstein first predicted the existence of gravitational waves. They have recently been detected following violent collisions of black holes and neutron stars.