Harvard physics professor David Weitz tried everything — spectacular demonstrations and experiments with combustion and colors — to motivate undergrads in his introductory physics course.

None of that captured the interest of non-science majors who are required to take at least one course in quantitative reasoning.

“I tried to motivate and excite students, but I often teach physics to people who study other things and don’t like physics. Therefore, the students hate me,” Weitz said in jest. “They were not that interested, no matter how hard I tried.”

Then he got an idea that made his course one of the most popular and oversubscribed at Harvard, “Science and Cooking.” It uses so-called molecular gastronomy, also called molecular cooking and culinary physics, to explain principles of physics.

Molecular cooking uses physics and chemistry to transform ingredients while cooking to create intriguing dishes that don’t taste the way they look. A piece of sushi might be made from fruit, faux caviar might be made of juice in spheres. Chefs work in lab-like kitchens with special equipment to change ingredients’ physical properties.

Course enrollment virtually exploded.

Weitz recently gave a talk about his course to 350 top Chinese high school students at a young leaders summit organized by Harvard students. He asked if they liked physics, and by a show of hands, most said they did not.

His course started taking shape more than four years ago when Canadian-American Weitz invited famous Spanish chef Feran Adria, considered one of the world’s best chefs, to give a lecture. Feran is a pioneer in molecular cooking and was head chef at El Bulli, which has three Michelin stars.

“The lecture was a great success. We later explored future interactions. We decided that teaching a course together would be the best way of doing it.”

Weitz is the director of Harvard Materials Research Science and Engineering Center and co-director of the BASF (German chemicals giant) Advanced Research Initiative. The focus is on the physics of soft condensed matter, materials that change shape under external stresses, electric or magnetic fields, and thermal changes. Colloids, emulsions, drops and gels are studied — making Weitz’s specialty a good match with molecular gastronomy. Weitz earned his master’s and doctoral degrees in physics at Harvard.

The Science and Cooking course, designed with Professor Michael Brenner, covers soft-matter physics. Each week a well-known chef delivers a lecture and demonstrations. Students do some cooking as well as science in the lab.

“The goal is to teach science to non-scientists by teaching about cooking and motivating them to study science,” Weitz said.

The first time the course was offered four years ago, 697 students signed up for 300 seats.

“The class was jammed. There were no empty seats or spaces. I’ve never seen people lining up to take a physics class,” Weitz said.

The chefs teach a class on Tuesdays while professors Weitz and Brenner teach a science class on Thursdays. Students conduct culinary and other lab experiments. Visiting chefs also give lectures.

“We make food and eat food in our lab with scientific tools and cooking tools. Students have to make something good to eat, and eat it as well,” Weitz said.

Chocolate cake is a signature dish. “Just by measuring how long it takes to cook the cake and how much it cooks we can understand and teach you something about how temperature goes through foods to warm them up,” he explained.

The students also cooked fish by changing the pH in the laboratory.

The professor isn’t a gourmand or cook, but says one of the few things he can cook are eggs. He conducted an experiment cooking eggs, demonstrating that, contrary to popular belief, eggs don’t really cook at 100 degrees Celsius, when water boils, but at around 65 degrees.

Throughout his remarks, Weitz told students not to be afraid of trying new things and asking questions.

“I learned an expression at Harvard,” he said. “Never ask for permission, ask for forgiveness,” recalling his decision to launch the course four years ago. He also welcomes chefs in Shanghai to lecture at Harvard. The Science and Cooking course goes online in October.

Professor Weitz answered questions from Shanghai Daily in an e-mail interview.

Q: Before “Science and Cooking,” how did you teach?

A: I taught a traditional introductory physics course to undergraduates, using the kind of textbooks that have been used for 50 years. There was no calculus or complicated math.

To motivate and excite students, I tried many demonstrations and experiments. However, this never worked well and students overall were not that interested, no matter how hard I worked at it.

Q: Please describe the new course.

A: We have four lectures a week. In the first class on Tuesday, either I or Professor Michael Brenner give a half-hour lecture on the science behind the cooking we will discuss that week. In the next hour, a chef talks about one aspect of cooking. On Thursday, there’s an-hour-and-a-half lecture about the science studied that week.

Each student must use the lab each week, preparing one or two recipes of interesting food and do the science experiments that help demonstrate the concepts we have been talking about.

Each week, we invite a different world famous chef to lecture about their specialty, but we ask them to focus a bit on the general science topic of the week. 

Since the chefs are so famous, we give a fourth lecture each week, not part of the formal class, to share our experience with the public at Harvard.

Q: How did you find the chefs?

A: Ferran Adria chose the chefs initially. Now we know many chefs and many want to be invited. Speakers include Joan Roca, who runs Barcelona’s Can Roca currently acknowledged as the world’s best restaurant. We have invited Wylie Dufresne, a well-known chef in New York City; Jose Andres, a chef who often appears on American TV and runs restaurants in many US cities. We have invited Bill Yosses, pastry chef at the White House.

Each gives wonderful lectures about their cooking. All the public lectures have been posted on YouTube and iTunes.

Q: How did the cooking explain the physics?

A: The cooking mainly helps give students a proper perspective on the science we teach. It provides motivation to study what we teach in class, and it shows students that the science we are teaching actually does have a direct use.

Q: What dishes have you prepared?

A: Some of the weird foods include spherified juice, which is a ball of juice wrapped in a very thin layer of a gel — it is solid, yet inside it remains liquid and still tastes like a fluid. We teach how to make proper aioli, which is a mayonnaise-like dish that is solid-like but is made only from olive oil, garlic and a bit of water. We have made olive-oil gel, a jellied dessert made from olive oil and sweetener.

Q: How does it remain popular?

A: It remains popular because we continue to have visiting chefs, we do interesting science, and it remains a good way for students to take the class requirements for science. More students apply than we can accommodate in the 300-seat classroom.

To put it in perspective: At Harvard, we have 6,400 undergraduates, or 1,600 each of the four years. So, in any given year, around 20 percent of the students are taking the course.

Q: What’s your impression of Chinese students?

A: I was most impressed that all the students who asked questions (and a lot did) spoke very good English. Many had adopted an English name, which is very valuable if they want to be successful outside of China. They seemed very internationalized, which is not something I had ever encountered in all my visits to China.