Gravitational Waves: What Their Discovery Means for Science and Humanity

People around the world cheered yesterday morning (Feb. 11) when scientists announced the first direct detection of gravitational waves — ripples in the fabric of space-time whose existence was first proposed by Albert Einstein, in 1916. The waves came from two black holes circling each other, closer and closer, until they finally collided. The recently upgraded Large Interferometer Gravitational Wave Observatory (LIGO) captured the signal on Sept. 14, 2015.