By SETH BORENSTEIN AP Science WriterWASHINGTON (AP) — In an announcement that electrified the world of astronomy, scientists said Thursday that they have finally detected gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago. Astronomers hailed the finding as an achievement of historic proportions, one that opens the door to a new way of observing the universe and the violent collisions that are constantly shaping it.Read more on NewsOK.com