Penn State Researcher Leads Effort In Gravitational Wave Discovery
The Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that it detected gravitational waves directly for the first time on February 11, proving Albert Einstein’s Theory of General Relativity formulated 100 years earlier. Penn State alumnus Dr. Chad Hanna is a 12-year member of the LIGO Scientific Collaboration, and currently serves as a co-leader for one of LIGO’s four astrophysics groups.
“There are four astrophysics working groups,” Dr. Hanna said. “One of those working groups is the group that searches for compact binary systems.” Hanna continued, “It has somewhere between 150 and 200 people who are currently members, and I am currently one of the co-leaders of that group.”
Although the Theory of General Relativity as it relates to gravitational waves is a complicated phenomenon, Hanna explained the concepts thoroughly. “The idea is that in general relativity, what we know of as gravity, is actually caused by space-time itself curving and warping due to the presence of matter and energy…Whenever you have something massive like a planet, it’s bending space around it.”
Based on this theory, LIGO wanted to detect the changes in space-time from a system billions of light years away, but small size of the change LIGO would need to observe made this detection difficult. “A change in distance between the two arms caused by these gravitational waves is [1×10^21],” Hanna said.
In a new field like directly detecting gravitational waves, it’s nearly impossible to imagine what advancements and progress may be made over the next few decades. Hanna emphasized his excitement about continuing these experiments and improving upon the research in the future, especially while serving in a leadership role within LIGO. “For me personally, I’m looking forward to spending the next 30 years or so in this field,” Hanna said.
While only time will tell where Hanna ends up within LIGO in the next 30 years, it would be hard to replicate the shock and excitement he said he encountered after the announcement of the discovery. “I was pretty shocked, I would say. I had been waiting for 12 years, and my colleagues had been waiting longer. When it happened, it was almost a little hard to believe just because we had spent so much time waiting.”
Even with the initial thrill of the discovery, Hanna said the team had to remain composed in order to properly proceed with the analysis of the data. “We had to impede our excitement because even though we made the detection in September 2015, we didn’t make the announcement until February,” Hanna said. “We spent the next couple months trying to curb our enthusiasm and make sure to do all of the analysis as carefully as possible.”
The official announcement to the world on February 11 was a pinnacle of every LIGO researcher’s career. “It really will open a new window up to the universe,” Hanna said of his excitement for future discoveries. “We’ll understand the universe from a completely different perspective.”
As this field continues to grow and more research develops from observing these gravitational waves, researchers like Hanna hope to continue to expose different ways of seeing the universe. “The way to think of this is a little bit like astronomy now,” Hanna described. “We’re not using telescopes to look at the sky, we’re using these gravitational wave antennas to kind of listen to the sky.”