College of Wooster Physics Majors Present Research at Annual APS Meeting

Joe Thomas, Mark Wellons, Frank King, and Kelly Patton share their work with 7,000 others in New Orleans

Representing Wooster at the 2008 American Physical Society Meeting in New Orleans were (from left) Todd McAlpine, Mark Wellons, Frank King, Joe Thomas, John Lindner, and Kelly Patton.

WOOSTER, Ohio - Four physics majors from The College of Wooster were invited to present their research at the American Physical Society (APS) annual meeting, the largest gathering of physicists in the country, held last month in New Orleans. Representing Wooster among the approximately 7,000 presenters were Joe Thomas, Mark Wellons, Frank King, and Kelly Patton. The group was accompanied by John Lindner, professor of physics, and Todd McAlpine, visiting assistant professor of physics.

Thomas, a senior from St. Louis, presented work done with Susan Lehman , assistant professor of physics at Wooster. His topic, titled "Does Hot Water Freeze Faster than Cold? Investigation of the Reproducibility and Causes of the Mpemba Effect," centered around the common observation by non-scientists that hot water appears to freeze faster than cold water. Previous scientific studies of this effect have found conflicting results, which appear to be due, in part, to inconsistent definitions of freezing and determining whether one can tell if the water is frozen simply by looking at it. Thomas and Lehman investigated the Mpemba Effect by continuously monitoring the temperature of a container of water to find the amount of time needed for the water to turn completely to ice. They successfully observed the effect repeatedly and found it to be dependent on the sample's temperature history rather than the sample temperature when placed into the freezer. Room temperature water that had been briefly heated to boiling and cooled back to room temperature froze in just half the time as room temperature water that had not been heated. "Many scientists think that hot water freezing faster than cold is a myth, so we were surprised initially at how clear our results were confirming this effect," said Lehman. "This has been a great project because the idea is so simple that you would expect the physics would be completely known, and yet there's so much going on that still hasn't been explained."

Wellons, a senior from Charleston, W.Va., and King, a junior from Needham, Mass., discussed work done with McAlpine, titled "Simulating a Charged Spherical Pendulum in Time-Varying Electric and Magnetic Fields." Wellons was continuing work for his Senior Independent Study Project that King had started as part of the Physics National Science Foundation Research Experience for Undergraduates (NSF-REU) summer program. Wellons, King, and McAlpine simulated and analyzed the dynamics of a charged spherical pendulum in time-varying electric and magnetic fields. The time-varying electric field was directed perpendicular to the gravitational field and served as a driving force for the pendulum. The magnetic field was directed parallel to the gravitational field and served to deflect the motion of the pendulum. The group analyzed the dynamics of the system to determine the conditions for chaotic behavior. They also included viscosity to look for strange attractors. The equations of motion were integrated using Objective-C, and the graphical user interface (including the three-dimensional graphical representation of the system) was developed using the Cocoa Application Programming Interface under Mac OS X.

Patton, a senior from Wooster, presented work done with Lindner and Wooster NSF-REU summer student James Gallagher, a sophomore at Ohio Northern University. The project was titled "Experimental Observation of Solitons Propagating in a Hydro-Mechanical Array of One-Way Coupled Oscillators." Two-way coupled systems have been studied extensively and are well understood, according to Lindner. One-way coupled systems have only been studied in the past five years, mostly through theoretical or computational work. These systems seem to be impossible, as they appear to violate both Newton's Third Law and energy conservation. Nonetheless, Patton, Lindner, and Gallagher have built mechanical one-way coupled arrays that are powered by falling water. These arrays display the propagation of solitary waves known as solitons, a defining feature of one-way coupled systems. The dynamics of the mechanical arrays compared well to their theoretical and computational predictions.