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Feature: December 11, 1996
ORIGINS
In new intro courses, students learn science by doing it
By Caroline Moseley
A clear April night. Fitzrandolph Observatory is open to the sky, its 36-inch telescope aimed at the star Sirius, a mere nine light years away. Samantha Mazo '99, bundled up against the nocturnal chill, studies a computer terminal, while David T. Wilkinson, the Cyrus Fogg Brackett Professor of Physics, perches atop a ladder to keep the telescope accurately tracking the subject star.
Attached to the telescope is a spectrometer that separates light into constituent wavelengths. On the computer, the wavelength is plotted against light intensity, producing spectra from which Mazo hopes to infer Sirius's chemical composition.
Jockeying the telescope back and forth, recording spectra as the light is captured-this is a job that calls for teamwork. In this case, one member of the research team is Wilkinson, a senior university scientist and authority on the cosmic background radiation, the faint afterglow of the Big Bang, which created the universe; the other is a freshman humanities student.
Both are participants in a new, two-semester science course for nonscientists created by the Science and Technology Council. STC 198, Origins and Beginnings: Origins of Life, satisfies the university's science and technology distribution requirement and is taught in the spring by Wilkinson and Maitland Jones, Jr., the David B. Jones Professor of Chemistry. It is followed in the fall by STC 199, Origins and Beginnings: Origins of the Human Condition, taught by STC chairwoman Shirley M. Tilghman, the Howard A. Prior Professor in the Life Sciences, and Rosemary Grant, a lecturer in ecology and evolutionary biology.
Mazo's hours in the observatory were part of a research effort, undertaken with lab partners Matthew Coldiron '99 and Christopher Laporte '99, to record spectra of the stars Sirius, Arcturus, and Cappella. The project was the capstone of their Origins and Beginnings experience, their initiation as laboratory scientists.
Origins and Beginnings is unusual, says Wilkinson, "because it is interdisciplinary, because it is primarily for nonscientists, and because it emphasizes lab work." At most other schools, he says, "it is common for courses for nonscientists to have no labs at all. Princeton, thank goodness, is almost unique in hanging on to the lab requirement."
Tilghman notes that, in developing Origins and Beginnings, she and her colleagues "decided on a few really critical things we wanted to do." These included "creating an interdisciplinary course that would break down the somewhat artificial boundaries between scientific disciplines." Hence, last spring's course was as interdisciplinary as Wilkinson and Jones felt they could make it. "As much as we want to mix physics and chemistry," says Wilkinson, "we've found we have to have a block of three weeks to concentrate on some basic ideas, or else you lose substance. You can't bounce around with every other lecture, or half a lecture, in one science or the other."
Laporte observes, "In this course we saw the subjects come together-the physics led into the chemistry and the chemistry led into the physics. In class, the professors and the TAs [graduate-student teaching assistants] were always discussing things and questioning each other. One of our physics TAs did the chem labs with us, just for interest."
Jones, a celebrated teacher of organic chemistry who has been at Princeton since 1964, and Wilkinson, a member of the faculty since 1963, brought different personalities and expertise to the enterprise. One student described Jones as "something of a jokester," who "made everyone laugh with his chemical humor and quick remarks." He was also known for densely covering any available blackboard with multicolored diagrams. Wilkinson is described as "more laid back." Students characterized both professors as "extraordinary," "talented," and "caring," and the teaching assistants as "stellar." According to John Griffin '99, instruction by Jones and Wilkinson offered "the best of both worlds, as well as the best of two sciences, chemistry and physics."
Continuity is important to Origins and Beginnings, and both parts of the course are considered integral to the whole. While students do not have to take both 198 and 199, the faculty members who teach them hope they will, and, indeed, most of the freshmen in 198 elected to take 199. Last spring, says Jones, "David talked about atoms. I took David's atoms and made molecules of increasing complexity-proteins. Shirley takes those proteins and make organisms, and Rosemary will show how those organisms have developed."
STC 199, says Tilghman, a professor of molecular biology, looks at "the role of genes in defining our humanity, and how it was the mutation and selection of our genes through evolution that resulted in what we know as the human condition."
The professors were also concerned that both semesters of Origins and Beginnings emphasize "scientific method over scientific facts," says Tilghman. "We all felt it was the lab aspect of the science-requirement courses that was most problematic, and that, if we were really to improve teaching nonscientists, the best thing we could do was to improve the labs."
Wilkinson and Jones remember their own beginning science labs "all too well," according to Wilkinson. As an undergraduate at the University of Michigan, Wilkinson participated in "traditional fill-in-the-blanks labs." Jones, who as a high-school student had worked in a research lab, "survived" his Yale chemistry labs-which he says are much better now-"because I already knew science was discovery and excitement, not simply following some deadly menu."
Origins and Beginnings labs focus on discovery. For example, says Jones, "We show the students how to take spinach apart into its component molecules and then let them choose something else to analyze on their own. Some of the projects aren't going to work. We don't say, 'These five work and these five don't.' Students will learn by making mistakes, then going back the way a real scientist would, to ask, 'How come it didn't work? What should I have done differently?' "
Thus, early on in the course, students learned basic lab techniques in both chemistry and physics to prepare them to embark on their own experiments later in the semester. The "spinach lab," led by Jones and chemistry graduate students Caryn Bowe, Andri Smith, and Dasan Thamattoor, introduced them to the materials and methods of organic chemistry. As air conditioners roared in a huge, bright, mostly empty Frick 1, 10 fledgling chemists huddled together for a lecture on lab safety. Then they got down to business: learning to extract pigments from spinach and to analyze them by thin-layer chromatography and column chromatography.
Provided with boxes of formerly frozen, now melting, spinach, and a mortar and pestle, the students were introduced to flasks of various sizes, shapes, and uses: "This is a round-bottomed flask," said Smith. "If you put it on the lab bench it will fall over, so you set it in a little cork ring." Next she showed them "a rotary evaporator, every organic chemist's friend, a very easy way to concentrate your sample." As students dispersed with lab partners to attempt the extraction on their own, questions arose:
"Is there, like, a special stirring rod or anything?" (Yes, in the bench drawer.)
"Where'd you get the thing for the ice?" (Also in the drawer.)
"What are these rubber things?" (Hoses, used to create a vacuum.)
Jones strolled the lab, keeping mainly in the background, stepping in where needed. To a student struggling with still-sodden spinach, he suggested, "Take this spatula and bend the head flat-like this. Then press the spinach down to squeeze out the water. We won't charge you for spatula mutilation."
"Don't throw anything away," he advised another student who was successfully separating out a sample. "I've kept stuff for years. Keep it until the label falls off. Keep it until you forget what it is."
As the lab progressed, one student said to her partner, "This is so interesting, it almost makes me want to take Orgo [organic chemistry]."
In such early labs, Griffin says, it was a matter of learning science by doing it. "We didn't rigorously learn experimental techniques" before entering the lab. "We simply showed up, were instructed on how to proceed, and we proceeded. This allowed us to make our own mistakes, and it gave the labs a sense that the experiments-reproduced 5,000 times before we attempted them-had never been tried before." To Griffin, the lab results had the force of "unique revelations."
Students worked in teams of three and four, says Wilkinson, because "Professors have finally discovered what graduate students have known for years-that you learn a lot more working with other people than when you try to figure things out all by yourself. It's easy to get hung up on a simple problem if you work alone; collaborative learning is far more effective."
For the instructors, STC 198 itself was a laboratory. "No one has done this kind of thing before," says Jones. Both professors point out that it is easy enough to lecture to large numbers of students, but labs can be particularly labor-intensive. Wilkinson, for instance, spent many late-night and early-morning hours in the observatory, his teaching schedule dictated by the rise and fall of various celestial bodies. Why bother? Because, says Tilghman, Wilkinson and Jones "are deeply engaged in education and in creating new and better courses, though they themselves will not benefit directly." Origins and Beginnings is designed for liberal-arts students, she adds. It will produce few, if any, majors in physics or chemistry, so "probably no one in the course" will wind up working in the labs of Wilkinson or Jones.
The challenge of the labs, says Jones, is teaching students "who have not previously been particularly interested in science." He hastens to add, however, that "All human beings are wired to turn over a rock and see what's underneath." He hopes Origins and Beginnings can capitalize on innate human curiosity and "help Princeton students understand how science works. We want Princeton graduates to look forward to reading next Tuesday's [New York Times] "Science Times" or next month's Scientific American. We need to capture their imaginations firmly enough that they will say, 'Hey, this is really interesting.' Only then will they apply themselves seriously to the enterprise."
They also want to make students aware of the limitations of science. "There is great confusion in the popular mind about what science is capable of doing and what it is not," says Jones. "There is tremendous social pressure for science to be wielded in the service of short-term solutions to societal problems. Cure AIDS now. Deal with environmental clean-up now. Do something about global warming-if it exists-now. Science is a poor tool for short-term solutions. It is very good at providing a moving frontier of information, much of which may be useless though fascinating, and some of which will be genuinely useful. But on a two-to three-year basis we can't tell which is which. Twenty to 30 years is probably more realistic."
Adds Wilkinson, "The hardest thing for most students to understand about research is that failure is commonplace and that there are no right answers, only answers that have more or less credibility depending on how strong a case is made in the lab."
As for the origins of Origins, Wilkinson emphasizes "how important Harold Shapiro has been to this enterprise. The Science and Technology Council was primarily his initiative." Wilkinson, who chaired the council when it was established in 1989, believes that the STC, in which "a group of senior scientists and graduate students get together once a month and find ways to improve Princeton's science offerings for nonscientists," is "almost unique. I don't know any other campus where this is happening." When Shapiro became president in 1988, recalls Wilkinson, "I was chair of the physics department. He walked into my office and the first thing he said was, 'What's physics doing about science for nonscientists?' " He also credits the support of Dean of the College Nancy Weiss Malkiel and former Associate Dean Eva Gossman.
By STC 198's final weeks, the science rookies had become science veterans. The same students who couldn't squeeze water out of spinach were now adept at using sophisticated equipment to solve sophisticated problems. They worked on independent research projects, the chemistry projects guided by Jones or a chemistry TA, and the physics projects by Wilkinson or physics TAs Rick Balsano and Weisueh Chiu.
Griffin, whose lab project involved taking spectra of Venus and Jupiter (Wilkinson called this group "The Planeteers"), says the project was "by far the most interesting, amusing, and surprising element of the course. By the end of the project I was identifying the coordinates of visible planets by such variables as right ascension and declination, and then piloting the telescope to these coordinates using panel gauges. I would never have guessed-in fact, if you had told me, I would have laughed at you-that by the end of STC 198 I would know my way around an observatory and a telescope."
Before Origins and Beginnings, observes Matthew Coldiron '97, "I never thought a lot about science. I imagined it as stuffy old people in stuffy old labs doing stuffy old experiments. Now I know it's exciting, and I know I can do it."
Caroline Moseley, a writer in the university's Office of Communications and Publications, is a frequent contributor to PAW.
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