Gravitational wave hunters bag fourth black-hole detection
Scientists have detected another burst of gravitational waves coming from the merger of two black holes.The collision occurred nearly 2 billion years ago, but it was so far away that its shockwave has only just reached us.This is the fourth confirmed detection made by an international team investigating Einstein's Theory of General Relativity.Sheila Rowan of Glasgow University, UK, said the team was now on the threshold of a new understanding of black holes."It is tantalising to see this new story of how black holes formed and evolved through history of the cosmos," she told BBC News."This information is almost within our grasp but we are not quite there yet."Media playback is unsupported on your deviceGravitational waves are ripples in space and time caused by cataclysmic events in the Un...