A new window into the universe

Barry Barish, one of three to earn the 2017 Nobel Prize Winners in Physics, helped discover gravitational waves — tremors in spacetime itself. Photo courtesy of Nobel Media AB. Photo: Alexander Mahmoud.

Nobel Prize Winner in Physics to share discovery that opens up a new era of space exploration during lecture Oct. 11

More than 400 years ago Galileo looked through a telescope and discovered Jupiter and its four moons. It was the beginning of astronomy, a science that relied on telescopes — and other instruments that use electromagnetic waves such a light and radio waves — to discover the universe.

Today scientists begin a completely new frontier of universe exploration using a different kind of wave. Scholars long predicted — starting with Albert Einstein — that gravitational waves existed. However, these tiny distortions in spacetime were not actually detected until September 2015.

“For the first time, we were able to look at the sky through gravity,” explains Barry Barish, one of three to earn the 2017 Nobel Prize in Physics for the detection of gravitational waves. “This is the beginning of a science where we can explore the universe in a totally different way than we ever have before.”

Barish will share the history, techniques and scientific implications of the detection of gravitational waves during a visit to UW-La Crosse Oct. 11-12, as part of UWL’s Distinguished Lecture Series in Physics. Every year for the last 19 years, UWL has welcomed a Nobel Prize winner in physics to campus to meet with students, faculty and staff and give a public lecture and physics seminar.

Barish’s public lecture “Einstein, Black Holes and Gravitational Waves” will be at 5 p.m. Thursday, Oct. 11, in Skogen Auditorium A, 1400 Centennial Hall. A reception begins at 4:30 p.m. in Cameron Hall of Nations, Centennial Hall. The physics seminar will be from 3:20-4:15 p.m. Friday, Oct. 12, at Skogen Auditorium A., 1400 Centennial Hall. Both events are free and open to the public.

“Detection of Gravitational Waves was long due,” says Interim Associate Dean of the College of Science and Health and Physics Professor Gubbi Sudhakaran. “Physicists have been working on this problem for decades. To me the two most exciting aspects of this discovery are the experimental verification of Einstein’s prediction of gravitational waves and the vast improvements made in detector technology.”

Barish, the Ronald and Maxine Linde Professor of Physics, emeritus, at Caltech, is the founder of the Laser Interferometer Gravitational-wave Observatory (LIGO), a collaborative project with more than one thousand researchers from around the world. LIGO discovered gravitational waves from the collision of two black holes in September 2015.

Barish spent about 22 years working to detect gravitational waves, something Einstein predicted, but doubted could be detected. Finding them was a big goal, but it was one that Barish was never discouraged to achieve. That is not to say it was easy.

For example, the instruments used for detection were so sensitive they picked up on motion researchers didn’t intend to, such as a wind farm some 30 miles away that caused tiny tremors within the ground. “That was a mystery for awhile,” notes Barish.

Researchers had to account for a host of both manmade and non-manmade activity happening on Earth from airplanes to earthquakes to lightning. They eventually built in ways to account for all of these external factors.

As for how Barish stayed motivated despite challenges in the discovery process, he says that was never a question. He describes his research more like a 22-year adventure.

“As a scientist, you get problems that are a challenge to solve and that is all interesting and fun,” he says. “I think research would be boring if you figured out a problem and the only reward was the science itself.”

Similarly, the moment of initially discovering gravitational waves was also met with some new challenges to solve. Barish’s first reaction to news of the detection at LIGO was not celebration, but panic.

“I realized there were two very difficult issues to decide whether this was real: how are we being fooled or how are we fooling ourselves?”

In other words, Barish wanted to determine whether instruments at LIGO were at fault for a potentially false detection or whether a devious person(s) were intending to manipulate the data.

Over the next several months, the team worked to thoroughly analyze the data and determine that it was, in fact, gravitational waves they detected. They also determined the source of the disruption in spacetime: two black holes colliding more than a thousand million years ago.

Before the results of their work were even published, LIGO picked up a second disruption, another black hole merger. At this, Barish says he felt a sigh of relief, knowing the first detection of gravitational waves was even further verified.

With this major scientific milestone under their belts, scientists at LIGO and beyond can now begin to peer through this new lens of gravity to discover new knowledge about the universe.

Considering history, this could be big.

Galileo first observed Jupiter in the early 1600s, and his discovery revolutionized human understanding of where we are in the universe — surrounded by not only our solar system, but distant galaxies, black holes, remote and Earth-like planets, newborn stars and much, much more.

If you go —

What: Public lecture, “Einstein, Black Holes and Gravitational Waves”

When: 5 p.m. Thursday, Oct. 11

Where: Skogen Auditorium A, 1400 Centennial Hall

Reception: A reception begins at 4:30 p.m. in Cameron Hall of Nations, Centennial Hall.

 

What: Physics seminar, “Gravitational Waves: Detectors, Detections and the Future”

When: 3:20-4:15 p.m. Friday, Oct. 12

Where: Skogen Auditorium A., 1400 Centennial Hall.

More on the physics seminar topic: The observation of gravitational waves came after more than fifty years of experimental efforts to develop sensitive enough detectors to finally observe the tiny distortions in spacetime from gravitational waves. The experimental principles, techniques and performance of the Laser Interferometer Gravitational-wave Observatory (LIGO) will be presented, as well as a review of the observations of compact binary mergers to date. The plans and prospects for gravitational- wave science in the future will also be explored.