William & Mary

Physics students are a part of LIGO gravitational-wave discovery

  • Gravitational wave contributors
    Gravitational wave contributors  Undergraduate students Melissa Guidry (left) and Eve Chase are part of the international collaborative that reported observation of gravitational waves, as was Hunter Rew (not pictured), who was a co-author on the discovery paper.  Photo by Joseph McClain
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Melissa Guidry heard The Rumor in September and mentioned it to Eve Chase.

The Rumor had it that the LIGO Science Collaborative had recorded signals believed to be gravitational waves and were analyzing them. Chase did her own analysis.

“I had access to all of LIGO’s data up through mid-October, so when Melissa told me that she had heard rumors about a possible detection, I went online and decided to go into their databases to see what they were dealing with,” Chase said.

The Rumor was true of course and results of the LIGO gravitational waves observation were announced in a much-anticipated and webcast press conference on Feb. 11. LIGO observatories in Washington and Louisiana had both recorded the passing gravitational waves that resulted from the merging of two black holes about a billion years ago. The event was so far away that the waves, traveling near the speed of light, just rippled through Earth last fall.

Chase ’16 and Guidry ’17 are physics majors at William & Mary, participants in the international LIGO collaborative. A third William & Mary undergraduate, Hunter Rew ’16, is a co-author on the Physical Review Letters paper describing the groundbreaking observation, along with Eugeniy Mikhailov, assistant professor in William & Mary’s Department of Physics and two graduate students, Mi Zhang and Gleb Romanov. William & Mary is the only Virginia university participating in the LSC — the LIGO Science Collaboration.

All of the William & Mary LIGO collaborators, as well as most of the other physicists involved, were able to keep the secret over the months between the Sept. 14 observations and the Feb. 11 announcement.

“I'd known about the detection for a few months, as has the rest of the collaboration,” Rew said. “I'm always hearing people say how difficult it was to keep the secret when asked about it, but being the low profile member that I am, I never had that problem!”

Rew has been a member of the LSC — the LIGO Scientific Collaboration — for the past two years. He became involved in gravitational wave research after meeting Mikhailov and becoming a member of the Quantum Optics Group at William & Mary. His introduction to LIGO came years before, though.

“I was about 15 when I first heard of LIGO from an episode of Numb3rs where Larry's lab is robbed,” Rew said. “Larry exclaims ‘MY LIGO LAB?????’ and it was a memorable line for me. Since then ‘LIGO’ has been an idealized/romanticized name to me, like NASA and CERN. It was a dream come true to be a part of it in the first place and I hope my luck streak continues.”

His work with the Quantum Optics Group involves using a phenomenon called electromagnetically induced transparency to reduce quantum background noise Rew explains that the effect can be used as a frequency filter to enhance LIGO’s sensitivity.

In addition, Rew spent the summer of 2014 working at the LIGO observatory in Livingston, Louisiana, through the Caltech Summer Undergraduate Research Fellowships (SURF) program. He worked on the measurement and modeling of optical scatter in the interferometer, a topic unrelated to his work with the William & Mary Quantum Optics Group.

Chase and Guidry became involved in gravitational wave research through a National Science Foundation-sponsored Research Experience for Undergraduates (REU) program at the University of Florida.

“It’s a very interesting REU,” Chase said. “They take 15 or so undergrads from the U.S. who all study physics and send them to different places in Europe, Asia, Australia and they all work on different projects related to gravitational wave physics.”

Through the REU program, Chase went to Paris in the summer of 2014 to work at the Laboratoire AstroParticule et Cosmologie. She created an original computer program that modeled the spiraling and eventual merger of two black holes — the very cosmic phenomenon that created the gravitational waves that passed through the earth a year later and were detected by the LIGO interferometers.

In summer of 2015, Chase participated in the Caltech SURF program. She worked in Los Angeles, but her group took a trip to the Livingston observatory. It’s an immense facility; Chase believes she could see the miles-long arms of the interferometer from the airplane on her flight to Livingston.

While Chase was at Caltech, Guidry worked at the LIGO-Virgo facility in Cascina, Italy, as a participant in the Florida-NSF REU program. She said the Virgo interferometer was so large that it served as a venue for a biathlon.

“What you do is you run down the arm of the interferometer and then you tag your teammate,” Guidry explained. “Then they run down the arm — then someone bikes around the other one.”

At Virgo, Guidry’s job involved examination of local magnetic fields to find an area that was most free of magnetic interference.

“To perform this work, I operated a large, bazooka-looking magnetometer, carrying it from site to site,” Guidry said. “At one point I even traveled through the Tuscan mountains to measure a very quiet signal.”

All three of the undergraduates say that the felt the full sense of scientific accomplishment and even its place in history that came with the NSF’s Feb. 11 announcement.

“I was in Small Hall watching the official announcement with other students and faculty, and it was very exciting to see everyone's enthusiasm,” Rew said. “I was expecting that, coming from fellow physics nerds —what I didn't expect was how widespread and popular the news would be.”

Chase wore her LIGO t-shirt on the day of the announcement and said she couldn’t sleep the night before. She is the co-president of the William & Mary Astronomy Club and said that her interest in physics was kindled in the darkness of her high school’s planetarium. She says she is especially interested in the prospect of gravitational wave astronomy.

“I thing gravitational wave astronomy will be almost commonplace in the world of physics and astronomy in 40 years,” Chase said. “We’ll be detecting more and more binary black hole systems, maybe neutron stars, supernovae — maybe getting down to the nitty-gritty of gravitational waves from the Big Bang. But what I hope to be working on eventually is gravitational wave signals that we don’t even expect to be out there.”

Guidry summed up her initial reaction to the LIGO announcement in one word: bliss.

“It’s a really good feeling to know that you’re part of something so big and so far outside of yourself that’s going to affect and improve humanity forever,” she said. “It feels good, but it’s the kind of thing where you wonder if it’s ever going to happen again in the rest of your life.”