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Could this be Einstein's big day? LIGO to deliver news on gravitational waves

Traci Watson
Special to USA TODAY
The Andromeda galaxy, made by the Hubble Space Telescope.

If the excited whispers are correct, scientists scanning the cosmos have made the kind of discovery that comes along only once or twice in a lifetime: the existence of powerful waves rippling through the fabric of the universe, distorting time itself as they travel.

Researchers have searched for these “gravitational waves” for decades, but have only been able to infer that the waves exist. Now, however, reports are circulating that twin observatories in Louisiana and Washington State have captured direct evidence of gravitational waves released when two black holes merged.

The National Science Foundation promises a status update at 10:30 a.m. today at the National Press Club with scientists from Caltech, MIT and the LIGO Scientific Collaboration on efforts to detect them the gravitational waves. Scientists hope the press conference will deliver the big news.

Gossip about a potential discovery has circulated for months in the scientific community. Most recently, theoretical physicist Cliff Burgess of Canada’s McMaster University emailed colleagues with second-hand information about the detection. The email, which ends “Woohoo! (I hope)”, was tweeted by one of the recipients and reported in Science.

The discovery, if confirmed, would have profound implications for our understanding of the universe. It would shore up Einstein’s theory of general relativity, which predicts the existence of gravitational waves. It would also provide solid new evidence that black holes really do exist. Until now, scientists have glimpsed only the X-rays and other radiation produced when matter is swallowed by a black hole, but gravitational waves are emitted by black holes themselves.

And just as the invention of the telescope gave humanity a view onto the stars, the detection of gravitational waves hands scientists an entirely new tool for probing the universe. By studying gravitational waves from black holes or neutron stars, researchers will learn about the nature of objects that have been too distant or elusive for us to grasp.

This undated file photo shows the famed German borne physicist Prof. Dr. Albert Einstein, author of the theory of Relativity. (AP-PHOTO) ORG XMIT: APHS [Via MerlinFTP Drop]

If it’s true that gravitational waves have been seen at last, it will open “a whole new window on the universe,” says theoretical physicist and cosmologist Lawrence Krauss of Arizona State University. “It’s a discovery of monumental importance.”

If researchers are cautious, it’s because there have been gravitational-wave sightings before – and all have been disproved. But this finding is different. It was made by a team numbering into the hundreds working at the Laser Interferometer Gravitational-wave Observatory, a gigantic facility of mindboggling sensitivity.

Each of LIGO’s twin facilities, one in Livingston, La., and the other in Hanford, Wash., includes two shafts arranged in the shape of an L, each arm of the L stretching 2½ miles long. A gravitational wave passing through the arms would change the shafts’ length – by a mere 1/10,000th the width of a proton, one of the miniscule particles that makes up an atom. A complex system of mirrors and lasers allows the LIGO team to detect such changes and identify the type of object in the cosmos that generated the wave.

The first incarnation of LIGO ran from 2002 to 2010 without finding a thing. After a five-year upgrade, a much-improved version of the observatory began collecting data in September.

Its quick success in finding a gravitational wave might mean that the objects that generate the waves are more common than thought. Or it might be stupendous good luck.

Either way, if LIGO has indeed caught a gravitational wave, “it’s a testament to the ingenuity and perseverance of scientists … that we can build these kind of detectors,” Krauss says. “It’s better than science fiction.”

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