The time to pop the champagne had finally arrived. Applause, whoops and a serenade of “chirps” erupted inside Cal State Fullerton’s Gravitational-Wave Physics and Astronomy Center on this early February morning.
The first direct detection of gravitational waves — ripples in the fabric of space-time — had just been announced to the world, opening a new window onto the cosmos. An international collaboration of scientists, including researchers from Cal State Fullerton, heard the distinctive “chirp” — a pair of black holes colliding over 1 billion years ago in the distant universe that produced the gravitational waves. The observation of the black-hole merger also confirmed a major prediction Albert Einstein made 100 years ago in his general theory of relativity: gravitational waves exist.
Simulation of two black holes merging (SXS, the Simulating eXtreme Spacetimes project)
As key contributors in the discovery, Titan researchers and their students gathered inside the gravitational-wave research center in McCarthy Hall to witness the announcement by the National Science Foundation and international Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration. After LIGO scientists proclaimed, “We did it!” at the news conference in Washington, D.C., the Titans cheered with their colleagues across the globe.
Leading the CSUF research team is Joshua Smith, associate professor of physics, with Jocelyn Read and Geoffrey Lovelace, both assistant professors of physics, and Alfonso Agnew ’94 (B.A. math, B.S. physics), professor of mathematics. Read and Smith are leaders in the LIGO Scientific Collaboration working groups that searched for and validated the gravitational-wave signal.
The LIGO Scientific Collaboration involves more than 1,000 scientists from universities around the United States and in 14 other countries, including CSUF. Additionally, more than 40 CSUF undergraduates and master’s-level students have worked on this groundbreaking research and shared in the discovery.
Cal State Fullerton’s significant contributions focused on different aspects of LIGO gravitational-wave research. Smith’s work centered on identifying and removing sources of noise in the Advanced LIGO instruments to improve the quality of the data in searching for gravitational waves. Read, an astrophysicist, explored how neutron stars can produce gravitational waves. Lovelace, a computational relativist, created computer simulations and visualizations to better predict the sources of gravitational waves, such as colliding black holes or a black hole tearing apart a neutron star. Agnew has developed mathematical methods to find and study cosmological solutions to Einstein’s equations in the past, and is currently working toward building and studying models of objects that emit the gravitational-wave signals.
Faculty members also have received more than $2 million in funding from the National Science Foundation and the Research Corporation for Science Advancement for their research.
“In all of human existence, people have been mystified by the skies. Nearly everything we’ve learned about astronomy, we’ve learned from light waves,” says Smith, Dan Black Director of the Gravitational-Wave Physics and Astronomy Center. “What I’m most excited about with this first gravitational-wave detection, is it opens up a new field of astronomy, where scientists use gravity to see astronomical objects like black holes, neutron stars and supernova explosions. What we’ll learn will have long-term benefits to society that are impossible to predict.”
Colossal Black-Hole Collision
The violent merging of the two black holes was incredibly powerful, radiating the equivalent of three times the mass of the sun into pure energy, explains Smith. Gravitational waves had been predicted but never observed — until 2:50:45 a.m. Pacific Standard Time Sept. 14, 2015, when the identical LIGO detectors, located in Livingston, Louisiana, and Hanford, Washington, captured the gravitational-wave signal, sending the physicists into a whirlwind of excitement.
“The fact that such a strong signal was observed suggests that the heavens may be brighter with gravitational waves and black-hole collisions than previously expected,” says Smith.
The Titan scientists, together with their colleagues from all over the world, worked around the clock for the next several months to rule out a false signal and confirm the discovery before announcing it to the world.
Alone in her office, Read first heard the “chirp” as the data, sent by a colleague, streamed from her laptop. She exploded with excitement. “It was like recognizing an old friend you never expected to see.”
Lovelace, who simulates colliding black holes on the University’s specially built supercomputer known as the Orange County Relativity Cluster for Astronomy (ORCA), was amazed by the astrophysical observation: “This is the most powerful event in the universe that humans have ever seen. It’s thrilling to see this first glimpse of space and time warping under the most extreme conditions in the universe.”
The scientists also kept the discovery a secret for nearly five months — until Feb. 11, the day of the news conference.
The Discovery Paper
A journal article about the gravitational-wave discovery was published in Physical Review Letters the same day as the news announcement. As members of the LIGO Scientific Collaboration, Smith, Read and Lovelace, along with Joseph Areeda, a computation specialist in the Gravitational-Wave Physics and Astronomy Center, and six physics graduates all are co-authors. Lovelace and his students also contributed simulations of two black holes merging that are featured in the article.
Read also edited the public science summary explaining the discovery, and Smith served as one of the primary editors of the discovery article, along with physicists from Caltech, MIT, Albert Einstein Institute in Germany, University of Paris and University of Rome.
For the last several years, the Titan physicists have served in leadership roles with the LIGO Scientific Collaboration. Smith has chaired the collaboration’s detector characterization group and served on its executive committee. Read currently serves as co-lead of the binary neutron star sub-group and has served as co-chair of the Academic Advisory Committee and an editor of LIGO Magazine. Lovelace serves on the executive committee of the Simulating eXtreme Spacetimes numerical-relativity collaboration, a multi-institutional research effort, which includes Cal State Fullerton.
Catching Future Waves
The discovery was made possible by the enhanced capabilities of Advanced LIGO, which involved a major technological upgrade to the observatories in 2015. Plans are underway for scientific collaboration with India, which is building an advanced gravitational-wave detector.
“Our work to improve the sensitivity of our instruments, better understand the full array of possible gravitational-wave sources, and learn as much as possible from this detection and from future observations will give us lots to do,” says Smith. “Together with our students, and with scientists around the world, we will continue to explore this new frontier of astronomy.”
On Dec. 25, 2015 at 7:38 p.m. Pacific Standard Time, CSUF scientists helped to identify a second direct detection of gravitational waves, produced during the final merger of two black holes. That detection was announced in June. In July, CSUF was awarded a $937,368 National Science Foundation grant to recruit students from underrepresented groups to study gravitational-wave science and to provide a pathway to enter the doctoral program in gravitational-wave astrophysics at Syracuse University in New York.
Students Share in Discovery
Physics major Alyssa Garcia is among the students captivated with the emerging field of astronomy. Her research involves analyzing gravitational-wave data from computer simulations and studying black holes.
“This work is helping me achieve my academic and career goals by giving me the chance to experience what it is like to do research in a big scientific collaboration,” says Garcia, who plans to pursue a doctorate in astrophysics after earning her bachelor’s degree next year.
“Gravitational-wave research is important because it will help us learn more about our universe. What I find fascinating about this field is that there is still so much to learn and discover.”
Seven alumni are currently enrolled in doctoral programs related to gravitational-wave research at such institutions as Caltech and Louisiana State University, located near the LIGO Livingston Observatory. Among Titans working on an advanced degree is Fabian Magaña-Sandoval ’12 (B.S. physics), a doctoral student at Syracuse University who is conducting research to increase the effectiveness of noise-reduction technologies to improve gravitational-wave detection.
Magaña-Sandoval, one of the student co-authors of the ournal article describing the discovery, credits his undergraduate experience and faculty mentors who encouraged him to pursue a doctorate.
“In the process of learning how gravitational-wave detectors work, I get to learn about cutting-edge laser technology, modern optics, electronics and astronomy. Gravitational-wave research will help develop a whole new way to observe our universe.”
For the Cal State Fullerton scientists, the wonder and mysteries of the universe captured their attention and imaginations early in life, yet each never imagined one day being a part of a cosmic discovery.
Smith grew up in northern New York’s Indian Lake, where he explored nature and gazed up at the stars in the Adirondack Park. In high school, Smith’s “amazing physics teacher” introduced him to the world of astronomy. “He got me interested in black holes and space-time,” he recalls.
As an undergraduate at Syracuse University, Smith knew he wanted to do “cool science.” He adds: “Who knew that 17 years later, I would be helping to make a significant astronomical discovery?” smiles Smith, who earned his doctorate in physics from Leibniz Universitat in Hannover, Germany.
Read had no inclination of becoming a scientist. She wanted to be a writer and pen science fiction novels. “I loved reading science fiction stories and learning about elaborate worlds, stars, solar systems and planets. These stories left me awestruck. As humans stuck on this planet, I realized there was so much we needed to understand about the universe.”
To be successful in creating those kinds of celestial stories, she decided to study mathematics and physics at the University of British Columbia, unknowingly setting herself on a path to become an astrophysicist. She earned her doctorate in physics from the University of Wisconsin–Milwaukee and completed postdoctoral work at the Albert Einstein Institute in Germany.
“At first, I just wanted to learn more about the universe. Then I realized during my undergraduate research that I could contribute to science — and that was pretty inspiring,” recalls Read.
As a boy, Lovelace had a favorite Nintendo game that allowed him to “fly” around in space: “One day I fell into a black hole and thought it was the most mysterious thing: You could fall in and you can’t ever come back! From then on, I became very curious about black holes.”
Lovelace often tells that childhood story to his students. “They love hearing that the moral of the story is that video games are good for your career,” he laughs.
In high school in Lansdale, Pennsylvania, he read “Black Holes and Time Warps: Einstein’s Outrageous Legacy” by Caltech’s Kip Thorne, a renowned theoretical physicist and one of the co-founders of LIGO. Afterward, he announced to his teacher that one day he would go to Caltech to study black holes.
“The teacher told me, ‘We’ll see about that!’”
Lovelace earned his doctorate in physics at Caltech, where Thorne was his gravitational-wave research mentor.
Agnew’s passion for physics and math was ignited by a high school teacher and a school book fair, where he picked up Einstein’s “Relativity: The Special and General Theory.”
“The successful detection of gravitational waves is an enormous event for anyone working in relativity. First of all, it was an actual physical phenomenon predicted by the theory as Einstein showed on paper 100 years ago,” says the CSUF alumnus, who earned a doctorate in mathematics from Oregon State University. “Its empirical verification is a major success for the theory and those who have spent their careers developing it. For many years, nobody knew if such a detection would ever really be possible.
“I look forward to a new era of testing Einstein’s theory as the leading model of space, time and gravity. The implications of being able to ‘see’ the universe with a completely new wave spectrum are mind-boggling. And in the fullness of time, I suspect that what gravitational-wave astronomy will reveal is a universe that not even science fiction could dream up.”