5/8/00

Dawn Levy, News Service (650) 725-1944; e-mail: dawnlevy@stanford.edu

Teacher uses images to make fluid mechanics anything but dry

One of Jeffrey Koseff's greatest joys is an unstirred latte. It's not because he likes a clean interface between the top layer of coffee and the bottom layer of milk. It's because he likes to go in with a "big, mean spoon" and create turbulence.

"I play with food because there's great fluid mechanics there," Koseff said during a May 4 lecture on the value of imagery in teaching. "Students have many different learning styles, and images speak to students in ways that equations or words do not."

Koseff, a professor of civil and environmental engineering and senior associate dean of the School of Engineering, uses images of erupting volcanoes, bursting fire hydrants and flooding gutters to make his fluid mechanics lectures anything but dry.

His lecture was part of the Center for Teaching and Learning's "Award-Winning Teachers on Teaching" series. Koseff has received a number of teaching awards, including the School of Engineering's Tau Beta Pi Award for excellence in undergraduate teaching (1989), an Associated Students of Stanford University Outstanding Teaching Award (1992), the Rhodes Award for Excellence in Undergraduate Teaching (1993), the Eugene L. Grant Award (1995) and a Bing Teaching Fellowship (1995).

Empathy is key in teaching, Koseff said. "I failed my first course in fluid mechanics," he admitted. This failure made the subject of fluid mechanics intriguing and gave him insight as a teacher to "understand where people are falling down."

Koseff received his bachelor's degree from South Africa's University of Witwatersrand in 1976 and master's and doctoral degrees from Stanford in 1978 and 1983, respectively. At Stanford, he extends fluid mechanics to environmental problems and to the interaction between physical and biological processes in natural water systems. Using laboratory experiments, numerical simulations and field work, he explores the effects of turbulence on estuaries, coral reefs and other aquatic ecosystems. From 1991 to 1996, Koseff directed the Environmental Fluid Mechanics Laboratory. He also has advised the San Francisco Estuary Project on management of the Delta.

Fluid mechanics is full of concepts that are difficult for students to wrap their minds around. Take turbulence, for example. As a colleague of Koseff's says: "Turbulence is like pornography. It's hard to define but you know it when you see it."

That's where pretty pictures come in. In a course on transport and mixing, Koseff spent a whole lecture discussing one powerful image: the May 18, 1980, eruption of Mount St. Helen's. Imagery helps students understand phenomena such as the decay of turbulent motions and concepts such as the Reynolds number, which relates density and velocity of flow.

"You find things in nature that people can relate to, bring images into the classroom, and try to relate the concept that you want to talk about," Koseff said. "I can bring back all those thoughts just by picturing Mount St. Helen's."

Koseff's teaching tools include textbooks, the Gallery of Fluid Motion ("beautiful pictures of mixtures collected over the years"), National Science Foundation-sponsored movies and lecture notes: "And then you've got your laboratory, where you desperately want to be in the middle of the lecture, because you want to demonstrate this wonderful phenomenon. How on Earth do you pull it all together?"

Koseff uses a CD-ROM from Cambridge University Press called Multimedia Fluid Mechanics. Developed by Stanford chemical engineering Professor George ("Bud") Homsy, it tells about scientific breakthroughs and scientists' private lives. It uses dramatic imagery to animate fluid flow and simulate experiments on computer.

Koseff advised teachers to build enthusiasm by telling "the war story, a seamless diversion which enriches the subject material." Stanford Professors John Spreiter and Douglas Jardine were masters at making stuffy subjects spring to life with anecdotes, he said.

Don't be afraid to make a fool of yourself in the name of learning, Koseff advised. He recalled the theatrical lectures of mechanical engineering Professor Emeritus Bill Reynolds, a National Academy of Engineering member who would undergo a silly transformation as he acted out how fluids get in vortices at the boundary layer: "His glasses slid down his nose. His voice got a couple of octaves higher. His arms would start flailing around. He'd get this giggle in his voice. How could you resist passion like that when learning about something!"

When Koseff tried the technique himself his results were well-received, as evidenced by this teaching evaluation from a student: "Superbly done! Stunningly original! Koseff acting out the motions of a blob of pollutant in his finest role!"

He advised would-be teachers to find "academic heroes and heroines" admired for their teaching styles, interactions with students and even mannerisms and peculiarities. "Find them and steal from them shamelessly," he advised. "The highest form of flattery is ­ acknowledge them, of course -- stealing in a nice way."

When unforeseen situations present opportunities to capture images, Koseff said, carpe diem. He recalled civil and environmental engineering Professor Stephen Monismith taking a picture of a burst fire hydrant he chanced upon. That picture showed up a week later in an exam.

Images also can help create the right classroom environment. Stanford civil and environmental engineering Professors Bob Street and Leonard Ortolano are Koseff's academic heroes in this arena. In one class Koseff taught, students were intimidated by each other and by the course. The atmosphere the first day of class, he said, was "like a dentist's waiting room, where nobody talks to each other and you know pain will be inflicted. No learning will occur."

During the second class, Koseff dipped an enormous loop into dishwashing liquid and glycerine and waved it over the class. "I had this gigantic bubble hovering over the middle of the room, and there it was wiggling kind of like a sea lion doing the Macarena. Everybody was looking up at this, going, 'Oh my God!' And the next thing ­ pop! ­ this big goober fell right on Sharon Jones's head. 'Ew! Yuck!' From that moment on the tension in the class was broken with the bubble. It was great. The class just took on a whole new dimension."

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By Dawn Levy