Mohanty (at whiteboard) talking with (from left) graduate students Zuojun Guo and Qin Wang and Meghan Gibson ’11. Photograph: Lee Pellegrini

Strange things happen throughout the natural world—in our cells, on the high seas, in the Chestnut Hill Reservoir—and describing how they occur is a problem that can confound scientists. For more than a year and a half, Boston College chemist Udayan Mohanty has explored theoretical techniques for describing “rare processes,” as scientists refer to them, in certain chemical reactions; during the coming year he will continue that work with the aid of a fellowship from the John Simon Guggenheim Memorial Foundation.

In a chemical reaction, when the pathway from reactant to product is understood—iron reacts with oxygen to create rust, for example—scientists know how to reproduce the process for the purposes of experimentation and further exploration. Some reactions, though, involve unfamiliar pathways and rare, unexplained fluctuations in energy levels and timescale. “If the pathways are not known, the question is, how does one describe what happens,” Mohanty says.

He offers a few familiar examples of rare processes. The dynamics of rogue waves—spontaneous, often enormous ocean waves once thought to be the stuff of nautical folklore—involve rare processes. The diffusion of molecules in supercooled liquids—those that drop below their freezing point without turning solid, such as the liquid water sometimes found on the otherwise frozen Chestnut Hill Reservoir—is a little-understood rare process.

Another unsolved mystery, the one that Mohanty will tackle with his Guggenheim fellowship, involves the interaction between ribosomes and tRNA. Ribosomes are cell structures that translate genetic code, in the form of messenger RNA, into proteins. They do this with the aid of a type of nucleic acid called transfer RNA, or tRNA. “There are steps in these processes,” Mohanty notes, “where certain events occur very rarely and nevertheless contribute to the rate at which this ribosome, this little machine, makes the protein molecules.” One of his goals, as he puts it, is to “quantitatively describe the rotational motion” of certain molecules during protein synthesis “as a function of magnesium concentration.” When this rotation occurs, “it’s like the ignition of the car is on; all kinds of chemical steps happen,” he says.

Mohanty’s research is part of the broader effort to apply sophisticated mathematics to problems in chemistry. In preparation for his current work, he spent last summer brushing up on breakthroughs in stochastic process, an aspect of probability theory that deals with random events, and he will draw on the work of a team of biologists and physicists at Berkeley and Stanford that was able to observe how a single ribosome interacts with a single piece of tRNA. Mohanty characterizes his research as “multidisciplinary in the real sense of the word.” His training is in physical chemistry and biophysics, “but I also need to borrow tools in what is called soft condensed matter physics [a field that deals with complex fluids like colloids, polymers, and liquid crystals] . . . as well as in applied math and biology.”

The Guggenheim Fellowship, which was established in 1925, rewards scholars who have a significant track record in their field. Applicants—almost 3,000 this year—are judged by the foundation’s network of experts, and fellowship winners receive money to pursue their investigations (the average award in 2008 was $43,200). Among the 180 scholars, artists, and scientists named as Guggenheim Fellows this year, Mohanty is the only chemist. Fifteen chemists have received fellowships since 2000.

Mohanty’s plans include travel to the Center for Theoretical Biological Physics at the University of California, San Diego, and Yale University to study the ribosome problem with other scientists, but the professor, who came to Boston College 24 years ago, has no designs on staying away from his own lab for very long. “I’m a really hands-on guy,” he says. “That’s the fun of research.”

Read more by Tim Czerwienski