Thursday, August 9, 2012

Physics research on roller coasters

Tim Slesinger ’14 boarded Dominator, a popular roller coaster at King’s Dominion that reaches nearly 70 miles per hour. Like other riders, he was seeking thrills from the speed, twists, turns, and dives.

Unlike others, he was seeking scientific data.

This year, Slesinger joined an ongoing research project on the physics of roller coasters. Several years ago, Peter Sheldon, a Randolph physics professor, and Kacey Meaker ’08 set out to use scientific equipment to measure the speed, acceleration, and other forces experienced by roller coaster riders. They have been working on a book that uses roller coasters to explain physics to a mass audience.
How does riding a roller coaster connect with scientific
research? Watch this video to learn how a Randolph professor,
student, and graduate explore the physics of roller coasters.

“The project started because I really like roller coasters,” said Meaker, now a Ph.D. candidate at the University of California at Berkley.

As Dominator shot forward, Slesinger raised his hands in the air and cheered along with other riders. Meanwhile, an iPod Touch in his pocket recorded measurements from its accelerometer, an internal device that detects orientation and motion.

He said that his goal was to find out if the accelerometer could be used to perform inertial navigation—like a four-dimensional GPS that doesn’t need satellites.

Sheldon explained that airplanes and large boats use inertial navigation regularly with the help of expensive equipment that tracks exactly where they are—including latitude, longitude, and elevation—at any given point in time. But that equipment is so expensive that inertial navigation is out of reach for educational applications.

“Physics teachers have, for years, taken their students to ride roller coasters, but they really can’t do a lot of useful measurements,” Sheldon said. “We’re trying to develop a way to do inertial navigation on a small, less expensive scale. We’re trying to develop methods that would allow people to do this in the classroom.”

This summer, the research team rode roller coasters while carrying iPod Touches and gyroscopes as well as real inertial navigation equipment. Slesinger then compared readings from devices to determine whether the data from the accelerometer and gyroscope could map the same travel path recorded by the expensive equipment.

“Mostly, we want to be able to know that we can do inertial navigation with these devices,” Meaker said. Slesinger added that inertial navigation could have many applications in high school and college physics classes if it can be performed with affordable equipment.

The calculations showed that accelerometer data can map out an accurate path with enough computation, but this fall, the project will be continued in hopes of more detailed findings.

The Summer Research project was a good opportunity to learn more about the research process and practice computer programming, Slesinger said. It also strengthened his appreciation for the educational environment at Randolph College. “You really get to know professors here on a personal level,” he said. “It doesn’t feel like college, but it feels like family when you’re learning.”

Meaker agreed with that sentiment. “Every summer I’m lucky enough to get to come back,” she said. “It’s like I’m coming home.”