For the first time in history, scientists have detected ripples in spacetime, proving right Albert Einstein — and Syracuse University has announced that three of its professors lent an instrumental hand in the process.

Using two twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, physicists were able to observe gravitational waves that were produced during the tail end of a merger between two black holes, according to an SU News release. Although scientists have predicted this sort-of astronomical event, they have never bore witness to it.

The two black holes collided to form one larger black hole, according to the release. The collision finally confirmed Einstein’s general theory of relativity, which describes gravity as “not a force, but a curvature of spacetime,” said Peter Saulson, professor of physics at SU and contributing researcher for the project, in the release.

Duncan Brown, associate professor of physics, and Stefan Ballmer, assistant professor of physics, also participated in the discovery.

Gravitational waves carry information about the nature of gravity that is unobtainable elsewhere. They are formed, according to the release, during cataclysmic events in the distant universe and are extremely difficult to detect.

“Gravitational waves stretch space, but their effect is almost imperceptible,” Saulson said. “It has taken 21st-century technology, a team of hundreds of experts and decades of effort to detect them.”

LIGO detectors are giant laser interferometers that function by first splitting a laser beam, then sending it down a pair of 2.5 mile-long tunnels, according to the release. Mirrors positioned at the end of the tunnels then send the light back up the tube.

Because the tunnels are equal in length, the light’s trip down and back in both tunnels should take the same amount of time — unless a gravitational wave passes through Earth, which is what happened inside of the LIGO observatories that led to the discovery.

The sudden arrival of the wave changed the length of the tunnels, meaning the light beams’ trips back up the tunnel occurred at different times. LIGO was then able to compare both beams and thus measure the stretching of spacetime caused by the gravitational waves, according to the release.

Brown said in the release that the detectors witnessed the black holes collide “at nearly half the speed light.”

“As they collided, some of their mass was converted into energy, according to Einstein’s formula E=mc²,” Brown said. “The peak power output was about 50 times that of the light emitted by all the stars in the universe. It is these gravitational waves that LIGO has observed.”

Brown and his fellow LIGO collaborators used a high throughput computing environment known as Orange Grid, along with the Crush supercomputer, to detect black holes. The supercomputer takes up permanent residence in the Green Data Center located on South Campus, according to the release.

Ballmer, who spent a considerable amount of time building the detector as part of LIGO’s design team, said in the release that the moment of discovery was unforgettable.

“I was in the LIGO control room the night before for the final detector tuning,” he said. “When I returned the next morning, there was a buzz in the air. I’ll never forget staring at the first plots, getting goose bumps.”

At its core, the discovery was made possible by the enhanced capabilities of Advanced LIGO, which, according to the release, “increases the sensitivity of the instruments compared to the first generation LIGO detectors, enabling a large increase in the volume of the universe probed.”

Advanced LIGO was able to detect the groundbreaking gravitational waves during its first observation run, according to the release.

“We have just taken our first look at the universe in a completely new way, “ Ballmer said. “There is so much to learn from gravitational waves in the coming years, and likely many surprises.”

Published on February 11, 2016 at 10:08 am

Contact Brigid: brkenned@syr.edu