Physics and Dance in a Pas de Deux
Amy Kohler and Kenneth Laws
In a small lecture room at the Atlanta City Ballet, ballerina Amy Kohler is demonstrating sequences of movements for the benefit of the audience, which includes not only physicists in town for the APS Centennial meeting last March, but local non-science residents as well. The purpose of the performance is not simply artistic appreciation: After each sequence, physicist Kenneth Laws analyzes the movements using physics principles to explain such phenomena as balance and the way torques are applied to produce rotational motion.
"The moving human body provides an intriguing opportunity to apply the laws of classical mechanics to visually accessible and interesting phenomena," says Laws. "Dance is a human movement that is particularly rich in variety and beauty." And he should know. For the last 20 years, he has been combining his life as a physics professor at Dickinson College in Carlisle, PA, with delivering lectures and demonstrations on the physics of dance. He believes such research enhances understanding and appreciation of both disciplines, as well as improving the techniques of dancers.
Physics came first. Laws recalls becoming interested in the subject as a high school student, although he enrolled at the California Institute of Technology intending to major in mechanical engineering. But a sophomore physics course convinced him that the world of physics was far more fascinating and he opted instead to focus on that. Then ("because I didn't have anything better to do," he quips) he went on to complete an MS from the University of Pennsylvania and taught for a year before going back to earn his PhD in solid state physics, this time from Bryn Mawr College. He joined the faculty of Dickinson College shortly afterward, and has been teaching there ever since.
Laws' passion for dance was ignited relatively late in life, after he'd already established himself in the physics profession. He took his first ballet class at the age of 40, initially to be near his children, then 5 and 7, who had just started ballet lessons at the Central Pennsylvania Youth Ballet. He started working backstage pulling the curtain for performances, and while watching a pas de deux during one, he was so moved by its simple beauty that "I ended up with tears streaming down my face. It turned my life upside down." His son quit after a year and a half; his daughter retired "at the ripe old age of 13 after a long and illustrious career," he says. But Laws couldn't give it up, and continued taking lessons, eventually serving as president of CPYB's Board of Directors. He even had the opportunity to perform in minor character roles, including one of the suitor princes in Sleeping Beauty.
A few years into his ballet studies, Laws noticed that the instructor was asking students to perform movements that seemed to be physically impossible - yet many young students were able to do them. He began investigating the physical principles and developing explanations for why dancers can perform such feats. "So the dance captured me first because of its beauty and the way it works with music, and then I discovered the way physics applies," he says. Since then, he has published over 30 articles on the physics of dance in various scientific and dance publications, and eventually authored The Physics of Dance in 1984, published by Schirmer Books - although only after Laws had collected 21 rejection slips from other publishers, a testament to his persistence. His faith in the project paid off: the book ended up selling over 10,000 copies and is currently out of print. [Laws is negotiating with Oxford University Press to publish a new, updated edition next year.]
The Physics of Dance was followed in 1994 by Physics, Dance and the Pas de Deux, co-authored by Cynthia Harvey, a former principal dancer with the American Ballet Theater in New York City, which included an accompanying video, as well as a chapter devoted to the physics of ice skating. Although neither book sold enough copies to generate a significant source of income, it did establish Laws' credibility in both physics and dance, and launched what has become almost a second career of traveling around the country delivering lectures and residency programs on the physics of dance. He teamed up with Kohler, a freelance dancer based in Chicago, last year, and hopes to continue the partnership despite her planned relocation to North Carolina to start her own dance company. "She's just the right size, shape and ability for me to work with, and she has the interest and personality needed to go with it," he says.
Through such presentations, which seem to appeal to scientists, dancers and the general public in equal measure, "Dance can be seen with a new perspective, physics can be seen in an unusual application, and the links between science and art are expanded," says Laws. Through it all, he has continued to teach at Dickinson. "Physics is my vocation and I enjoy it very much, but dance is my passion."