LIGO again detects gravitational waves

For the second time, scientists have directly detected gravitational waves — ripples through the fabric of space-time, created by extreme, cataclysmic events in the distant universe (Learn more: ). The team has determined that the incredibly faint ripple that eventually reached Earth was produced by two black holes colliding at half the speed of light, 1.4 billion light years away. Video produced and edited by Melanie Gonick/MIT Two Black Holes Merge into One simulation: SXS LI