Dances with Computers
SOMMER GENTRY
Massachusetts Institute of Technology
Sandia National Laboratories — California
Story by Victor D. Chase
Sommer Gentry was a swing dancer long before she became a fellow in the DOE Computational Science Graduate Fellowship (DOE CSGF) program, so when the demanding world of computers, mathematics and practical engineering entered her life, she did not let it replace her first love. Rather, she found a way to combine the two seemingly disparate endeavors, while approaching each with equal gusto.
By literally combining business and pleasure, Gentry, 26, was able to bring the precision of mathematical analysis to her more intuitive pastime, while working to make computers more responsive to the subtleties of human touch. In fact, the vivacious Massachusetts Institute of Technology Ph.D. candidate says, it was the requirements of the fellowship that provided her with the opportunity to combine her vocation and avocation, and that also led her to change her dissertation topic.
The Los Angeles area native earned a bachelor’s degree in mathematical and computational science and a master’s in operations research from Stanford University in 1998. Her affiliation with both DOE and swing dancing began right after graduation, when she took a job as a systems engineer at DOE’s Lawrence Livermore National Laboratory near San Francisco, a hotbed of swing dancing, where she caught the bug.
A year later, she decided to brave the cold and moved to Cambridge, Massachusetts, to begin working toward a doctorate at MIT. At the time, her primary area of research was an esoteric field known as “inverse optimization.” Then one day in 2000, on her way to class, Gentry saw a poster promoting the DOE CSGF, and her life was about to change.
“I thought, ‘computational science, that sounds like me,’ ” said Gentry, so she applied and in 2001 was awarded a fellowship. One of her first hurdles was to satisfy the requirement that fellows include some real-world engineering classes in their curriculum. At first she tried to convince the powers that be that her prior work had satisfied that requirement, but “They said, no, no, those are math classes, you need something hands-on,” she recalls. In response, she signed up for a class entitled “Space Biomedical Engineering,” in which she learned about the mechanics of jointed systems, robots and humans alike. And that’s where swing dancing comes in.
It’s About Illusions
Swing dancing is a historical dance form, and Gentry and her husband, Dorry
Segev — a surgeon and transplant fellow at Johns Hopkins Hospital, whom she
met through dancing — specialize in the Lindy Hop, popular during the Big Band
Era of the 1930s and ’40s. In fact, Gentry and her friends attend dance events
for which they dress up in clothing from that era and dance to the sounds of Benny
Goodman and Glenn Miller. They also watch videos of the original swing dancers
strutting their stuff, which often leads to intense discussions of who is doing what
to whom in this largely improvisational dance form.
“A lot of dance is about illusions,” says Gentry. “It may look like one person is pushing on another when they really aren’t, or it may look like something is really light and effortless but two people are working very hard to hold each other up.” Hence, she adds, “The most difficult thing to do in swing dancing is to learn how something feels.”
So it was to learn from the now-departed swing dance masters of yesteryear that Gentry created her first project for the biomedical engineering class. To do so, she applied her inverse optimization expertise to calculate the forces between people by observing their moves on the videos.
This involved watching someone move and then calculating how much force was applied to make the move. “I wanted to take it out of the realm of artistic judgment and say that, physically there’s something going on. There is a person who weighs a certain amount, and is balanced in a certain place, and either he is holding her up or he’s not,” says Gentry.
In doing so, she also brought peace to her swing dance community. “I just wanted to help my swing dancer friends who were arguing about what a video really showed; was this person pulling on the other person or not? I wanted to be able to give a definitive answer, and that’s really what I did.”
