Scientists announced Thursday that they have spotted a gravitational wave, a major discovery that will forever impact astronomy. The announcement comes 100 years after Albert Einstein predicted the existence of gravitational waves, or ripples in the fabric of spacetime, as part of his general theory of relativity.
Gravitational waves are significant because they carry information about not only their own origins, but also about the nature of gravity, information that cannot be gathered any other way.
The waves were spotted by the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration and the Virgo Collaboration using data from two detectors built to detect small vibrations caused by passing gravitational waves.
David Reitze, a physicist and LIGO executive director at California Institute of Technology, made the announcement, as his “We did it!” shout gained a cheerful roar from those attending the National Science Foundation Conference.
“Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity,” Reitze said.
The waves were created when black holes combined, known as a binary black hole merger, to make a single black hole approximately 1.3 billion years ago. Two LIGO observatories, one in Washington, D.C. and the other in Livingston, La., nearly simultaneously detected the waves Sept. 14, 2015 at 5:51 a.m.
The frequency of the wave signal went up as time went on.
“What was amazing about this signal is that it’s exactly what you would expect when Einstein’s theory of general relativity would predict for two massive objects for black holes,” Reitze said to the crowd.
The announcement wasn’t made until today because the scientists involved wanted to thoroughly check, analyze, and recheck what was spotted by the two observatories before making the finding public.
According to Reize, the discovery of the waves is one of the more important breakthroughs in the history of astronomy.
“This is just not just about the detection of gravitational waves—that’s the story today—but what’s really exiting is what comes next,” he said. “Four hundred years ago Galileo [Galilei] turned a telescope to the sky and opened the era of modern observational astronomy. I think we’re doing something equally important today. I think we’re opening a window into the universe—a window of gravitational wave discovery.”
The LIGO Observatories are funded by the National Science Foundation. They were planned, built, and are operated by the California Institute of Technology and the Massachusetts Institute of Technology.