An international group of scientists announced on Wednesday that they had discovered the fourth-ever gravitational wave, an event spurred by the collision of two black holes in outer space. On August 14, three sensitive instruments—located in Washington State, Louisiana, and Italy—detected the ripples, which were created when two black holes collided 1.8 billion light-years away. Scientists announced the cosmic discovery at a meeting of G7 science ministers in Italy. The first such incident was detected in September 2015, confirming for the first time Albert Einstein’s General Theory of Relativity.
