MIT Physics News Spotlight
“I am just myself, … but out of that comes something positive.” –Nergis Mavalvala
Vijaysree Venkatraman, MySciNet
June 1, 2012
Quantum Physicist and Professor of Physics, Nergis Mavalvala.
Photo courtesy of the John D. & Catherine T. MacArthur Foundation.
Nergis Mavalvala, professor of physics at the Massachusetts Institute of Technology (MIT) in Cambridge, can check off a whole lot of boxes on the diversity form. She isn't just a woman in physics, which is rare enough. She is an immigrant from Pakistan and a self-described “out, queer person of color.” “I don’t mind being on the fringes of any social group,” she says.
With a toothy grin, the gregarious mother of a 4-year-old child explains why she likes her outsider status: “You are less constrained by the rules.” She may still be an outsider, but she's no longer obscure; her 2010 MacArthur Fellowship saw to that. In addition to the cash and the honor, the award came with opportunities to speak to an interested public about her somewhat esoteric research. “That is the best part,” she says.
Mavalvala and her collaborators are fashioning an ultrasensitive telescope designed to catch a glimpse of gravitational waves. Albert Einstein predicted the existence of these ripples in spacetime nearly a century ago, but they haven’t been observed directly yet. Theoretically a consequence of violent cosmic events—the collisions of black holes, the explosive deaths of stars, or even the big bang—gravitational waves could provide a brand new lens for studying the universe.
When she became a MacArthur fellow, former female students wrote to her saying that she was a model for what was possible for women. At different points in her scientific career, lesbian and gay students and colleagues mentioned something similar: They had been inspired by the example she had set for them.
She embraces her role as role model. Something important is happening, she believes. “I am just myself,” she says. “But out of that comes something positive.” By being just herself, she is a source of inspiration for a wide range of individuals from groups underrepresented in the physical sciences.
The girl from Karachi
Mavalvala, who came to this country as a teenager to attend Wellesley College in Massachusetts, has a natural gift for being comfortable in her own skin. “Even when Nergis was a freshman, she struck me as fearless, with a refreshing can-do attitude,” says Robert Berg, a professor of physics at Wellesley.
While many professors would like to treat students as colleagues, Berg observes, most students don’t respond as equals. From the first day, Mavalvala acted and worked like an equal. She helped Berg, who at the time was new to the faculty, set up a laser and transform an empty room into a lab. Before she graduated in 1990, Berg and Mavalvala had co-authored a paper in Physical Review B: Condensed Matter.
Her parents encouraged academic excellence. She was by temperament very hands-on. “I used to borrow tools and parts from the bike-repair man across the street to fix my bike,” she says. Her mother objected to the grease stains, “but my parents never said such skills were off-limits to me or my sister.” So she grew up without stereotypical gender roles. Once in the United States, she did not feel bound by U.S. social norms, she recalls.
Her practical skills stood her in good stead in 1991, when was scouting for a research group to join after her first year as a graduate student at MIT. Her adviser was moving to Chicago and Mavalvala had decided not to follow him, so she needed a new adviser. She met Rainer Weiss, who worked down the hallway.
“What do you know?” Weiss asked her. She began to list the classes she had taken at the institute—but the renowned experimentalist interrupted with, “What do you know how to do?” Mavalvala ticked off her practical skills and accomplishments: machining, electronic circuitry, building a laser. Weiss took her on right away.
To catch a wave
In the early 1990s, Weiss, a pioneer in the measurement of the cosmic microwave background, maneuvered his research group into a new field: the detection of gravitational waves. Advances in laser technology made it plausible, but big practical challenges remained. Gravitational waves stretch and compress spacetime, subtly distorting objects they pass through. If they pass through a pair of objects, the distance between the objects changes. Up till now, those changes have been imperceptible.
In principle, a laser interferometer, with its two equally spaced mirrors, can use the change in interference patterns to register the passage of gravitational waves. The displacement of its mirrors would be tiny, however, roughly the equivalent of a thousandth of a proton’s radius. And just about anything can move the mirrors by much larger amounts: a car speeding in the distance, a seismic tremor, a clap of thunder. Even the distortion caused by the laser beam itself would need to be accounted for after the system had been shielded against all those external disturbances.
Setting traps in the desert
In graduate school, Mavalvala worked on proof-of-principle interferometers at tabletop scale. An actual detector would be huge: The greater the initial distance between the mirrors, the greater the change in distance and the better the chance of measuring a displacement. Size, however, brings its own complications. Two mirrors 4 kilometers apart would have to be aligned precisely with the incoming laser. “If there is misalignment, the beam could just walk off into the desert instead of hitting its partner,” she says. To ensure this doesn’t happen, Mavalvala devised an automatic alignment system for the complex interferometer.
Her thesis work was incorporated in the design of the Laser Interferometer Gravitational-Wave Observatory (LIGO), which is run by MIT and the California Institute of Technology (Caltech) with funding from the National Science Foundation (NSF). In 1997, Mavalvala began a 3-year postdoc at Caltech. When the observatory went up in Washington state (there is also one in Louisiana), she stayed in the high-altitude desert in Hanford for days at a stretch to get the detector ready for data runs. In 2000, she joined the team as a staff scientist.
The cool stillness of mirrors
A decade into LIGO’s existence, no gravitational wave has been detected. But the Advanced LIGO (aLIGO), which should be functional within 3 years, is on the horizon. With aLIGO, researchers hope to detect waves from more-distant sources. “The farther out you can look, the more galaxies, and hence more gravitational wave sources, are visible to you,” Mavalvala says.
“Making the mirrors stay still,” she says, “is something we devote a lot of attention to.” Using lasers to study a tiny displacement means having to contend with the momentum of photons impinging the mirror. There is also jostling from the thermal energy of atoms in the mirror and the suspending wires. Five years ago, her group demonstrated a novel technique to optically trap and cool a coin-sized mirror, bringing it to within a degree of absolute zero (0.8 K).
With that result, Mavalvala found herself at the forefront of an emerging field: quantum optomechanics. Typically, very small things obey quantum mechanics; classical mechanics governs macroscopic objects. But near zero Kelvin, even large objects should show quantum behavior. By exploring this blurring of boundaries, researchers in the new discipline hope to achieve theoretical insights with practical applications such as designing quantum information processors or building a more sensitive LIGO detector.
The genius of good mentorship
Mavalvala says that although it may not be immediately apparent, she is a product of good mentoring. From the chemistry teacher in Pakistan who let her play with reagents in the lab after school to the head of the physics department at MIT, who supported her work when she joined the faculty in 2002, she has encountered several encouraging people on her journey.
In the 10 years since, she has passed on her infectious enthusiasm for the LIGO project to many of her graduate students. “That is exactly what we were hoping for,” says Stanley Whitcomb, LIGO chief scientist at Caltech. “When she speaks to reviewers from NSF, or casual visitors to the observatory, she always made it a point to present technical details clearly. At the same time, she conveys that the work is fun.” The skill and desire to reach out to a broader audience, he remarks, is not a common trait among researchers.
This fall, Mavalvala will be a keynote speaker at Out to Innovate, a 2-day career summit for lesbian, gay, bisexual, and transgender students, faculty, and professionals in science, technology, engineering, and mathematics. There, she will address her sexual identity and its connection to her work. Mavalvala says she was not aware of her sexual orientation as a girl in Pakistan or, later, as a student at the all-women Wellesley College.
Then, in her early twenties, she fell in love. Her girlfriend began visiting her at the lab and became part of her social life. The process was organic. “I have never had negative experiences because of this,” she says. “My work environment was very supportive.”
“Some people venture into places others consider dangerous or unsavory. They are not foolish or fearless. They read a situation and have some confidence in reading it well enough, so they go there.” In coming out, she says, she looked around and took stock of her work environment. Her sexuality, she figured, would make little difference to those around her. Her instincts proved to be right.
Above all, Mavalvala is at ease with herself. “I am not someone who is, at all, ‘in your face,’ ” she says. “I am quite happy to go unnoticed.” But being the invisible outsider in academia is one item this quantum astrophysicist may now have to leave off her wish list.
Vijaysree Venkatraman is a Boston-based science journalist.