Path is critical in learning tough topics, thermodynamics professor says

By Dawn Levy

"Wow, this is the most obvious subject I've ever seen!" Chris Edwards recalled thinking of thermodynamicsinfamous for its difficultyupon taking his first class in the late 1970s. "Energy is conserved. It tends to disperse. Things become more random. You could build really cool stuff. You could fly airplanes; you could build cars, go zoom, make flames!"

Decades later, Edwards' intuitive feel for thermodynamics is apparent in his award-winning teaching. As an associate professor of mechanical engineering, he conducts research into advanced combustion and propulsion systems and teaches sophomores in E 30 (Engineering Thermodynamics), juniors and seniors in ME 140 (Advanced Thermal Systems) and graduate students in ME 370B (Energy Systems II). On Nov. 30, he shared his "best practices" for teaching tough topics with those crowded into the Hartley Conference Center for his "Award-Winning Teachers on Teaching" talk.

"Life is a path function," he began, referring to a thermodynamics term. "You begin life, you end lifethat's not so interesting, right? But quality of life is a path function. It's the path that you take from the beginning to the end, the integral of that path, that's the special part."

Choices along the path are hugely important in teaching, Edwards said. "It's a lot like raising kids. They're special at each age, and they have different requirements as you go."

Edwards said he tries to "impedance match" his lessons to students' capacities at different stages. His course for sophomores introduces the analytical side of engineering, whereas his course for juniors and seniors incorporates software tools so students can learn to write code to solve real-world problems. Upperclassmen need to make the transition from student to engineer, he said, "from a view where you had these well-posed problems in the back of a book with no extraneous information that you could solve on a green pad to a gas turbine engineis it good or is it not? Should I invest or should I not?"

Fundamental concepts don't change but tools always do, Edwards said. When making assignments, it's important to separate the concepts from the tools.

Sophomores flying home for the holidays may be impressed with their newly found knowledge of the workings of a jet engine. "By the time you get to the [master's] level, they've seen all that stuff. There's no more 'cool' in 'this is how the jet engine works.' The cool comes from 'this is how the state-of-the-art GE H System power plant works, and if you write the code, you'll get those numbers, and if you modify that, you could argue with the people at the GE systems group about how to improve it.' That's the level you've got to get up to."

En route, students are more likely to get the academic equivalent of cod liver oil ("This is good for you! You need it!") than coddling from Edwards. He recommended "hitting hard" the first week when students are primed and excitedit'll get your class on their radar screen in terms of time commitmentand teaching the big picture before the details. He also advised holding students responsible for things they should know. Backing up three weeks to cover prerequisites risks losing the middle of the class and will definitely bore top students, he said.

When juniors and seniors arrive in ME 140, they've done "really heavy lifting" intellectually, and the set of tools has got to move up, Edwards said. "It can't be problems on green pads coming out of the back of the book. The problems have to come out of a laboratory. Go in, run the jet engine, measure all the states, reverse-engineer that. 'How am I going to get real numbers for that?' You're going to put in real properties. 'How am I going to do that?' You're going to write code. 'Why am I going to do that?' That's how we really solve problems."

Edwards continues to stretch his students academically when they hit the master's level. Tools get more sophisticated, and concepts are brought in as problems dictate.

"When you walk out [of ME 370B], you will not have seen every concept you will ever need to do the world's energy systems," he warned. "You'd better have seen enough things that surprise you that you can now say, 'OK, I'm going to do that system. It requires this concept. I will go and get the concept. I will build the tool or find the tool. I will integrate [it] and I will do it. I will not be stopped.'"

Edwards said he was "bit by the teaching bug" as an undergraduate at the University of Santa Clara, where he obtained his bachelor's degree in mechanical engineering in 1981. He went on to the University of California-Berkeley to earn master's and doctoral degrees in mechanical engineering in 1982 and 1985, respectively.

To gain real-world experience, he next went to work for Sandia National Laboratory, where he was named a distinguished member of the technical staff in 1995. That year he came to Stanford to pursue his passion for teaching. He has served as director of Stanford's Advanced Energy Systems Laboratory and inaugural deputy director of the Global Climate and Energy Project.

With more than 90 research publications and two patents, Edwards, the John Henry Samter University Fellow in Undergraduate Education, demonstrates that it's possible to succeed at both research and teaching. His Stanford teaching awards include a Bing Fellowship, Professor of the Year from the Society of Women Engineers and prizes from Tau Beta Pi and Phi Beta Kappa.

The Center for Teaching and Learning sponsors the "Award-Winning Teachers on Teaching" lecture series. Donald Barr, a professor of sociology, will deliver the next talk Feb. 1 at noon in the Hartley Conference Center of the Mitchell Earth Sciences Building.