The second detection event, like the first, caught the gravitational waves produced when two black holes collided and merged. But this event was much smaller: The first event involved black holes that were 29 and 36 times as massive as the sun, while this new collision, which took place 1.4 billion years ago, brought together black holes of 8 and 14 solar masses. They’re also emitted by “dark” objects — like black holes — that don’t emit light and are therefore difficult to study with optical telescopes. Unlike light waves, gravitational waves pass through solid objects without being changed, so scientists hope they can use them to study distant, ancient events such as the collisions of black holes and neutron stars. (R. Hurt/Caltech-JPL/European Pressphoto Agency)In February, scientists announced a historic discovery: For the first time — after years of waiting — they’d successfully detected gravitational waves, the ripples in space-time produced by massive objects like black holes.

Source: Washington Post June 15, 2016 17:19 UTC