Einstein Was Right: Gravity Ripples Across the Universe as Waves

Scientists have discovered the existence of gravitational waves, tiny ripples in the fabric of space-time, which have long been predicted but never before been seen or measured. The discovery cements a fundamental premise of how gravity operates and offers astrophysicists a new way to explore the universe.

   “We have detected gravitational waves. We did it,” said David Reitze, the executive director of the Laser Interferometer Gravitational-Wave Observatory (LIGO). “I am so pleased to be able to tell you that.” Direct measurement of these waves is the type of fundamental discovery a physicist can expect to see rarely, if ever.

   Albert Einstein’s Theory of General Relativity predicted the existence of gravitational waves 100 years ago. The theory states that gravity - the warping of space and time by mass - would manifest as ripples.

   Physicists have long had indirect evidence that such exceedingly tiny waves exist but never had technology capable of detecting and measuring them. A gravitational wave is about 10,000 times smaller than the diameter of a proton. The waves stretch and compress space on tiny scales at the speed of light and project the forces of massive bodies such as black holes and neutron stars across vast distances.

   The waves were detected by LIGO at 5:51 a.m. EDT on Sept. 14 and came from the collision of two black holes 1.3 billion light years from Earth. The black holes were 29 and 36 times the mass of the sun, respectively, and as they coalesced into one, they ejected about three solar masses of energy into space as gravitational waves. The merger was consummated in just 20 milliseconds.

Πηγή: bloomberg.com