Lessons From On High

By Sam Allis

"Don't put the earth upside down," warns Mark Petricone as his 13 students struggle with coat hangers and pliers. "And remember, folks, the earth isn't really in the middle of the universe. This is an incorrect scale model, but astronomers have been using it for a couple of thousand years."

The goal for the juniors and seniors at Watertown High in Watertown, Mass., is to mount a thimble-size metal earth on a coat hanger in the middle of a melon-size clear-plastic sphere that is supposed to be the universe. The students then use Magic Markers to trace onto the universe a computer-drawn map of a few hundred of the brightest stars in the night sky. They draw a line around the sphere to represent the ecliptic, or path of the sun through the constellations, and then they are ready for some gnarly astronomy.

Like the universe, Petricone's classroom is a study in controlled chaos. "Are the Pleiades part of Taurus?" Franco Mastantuono asks no one in particular. Classmate Lisa David explains the difference between a crescent and a gibbous moon -- a waxing gibbous, at that. Barry Lyons solves the mystery of the moon's phases for a visitor by drawing an impromptu diagram. "What was the moon last night?" Petricone bellows. "A waxing crescent," Karyn Woodbury shoots back as she assembles her celestial sphere. "What about tonight?" Petricone pushes. "A first quarter," pipes another voice.

This is classic instruction for Project STAR (Science Teaching Through Its Astronomical Roots), a program taught in 18 schools in 13 states. STAR is based on the premise that books are abysmal tools for learning science. "It's impossible to understand an astronomy diagram without using three dimensions at proper scale," says Irwin Shapiro, the irrepressible director of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and the man who dreamed up STAR six years ago. "High school science textbooks are impossible. They are dense with concepts and jargon. No one understands what's going on." Adds Kenneth Mirvis, who writes STAR course materials: "This is not a curriculum of vocabulary but of concepts." And, explains Shapiro, "facts are easy; concepts are hard."

In his years at Harvard and M.I.T., Shapiro has been struck by the difficulty even well-educated adults have with basic scientific concepts. Last year he and some colleagues produced a half-hour film titled A Private Universe in which half a dozen Harvard seniors were asked on graduation day to explain why there are seasons. All blithely described how the earth is closer to the sun in summer and farther away in winter. Wrong. The seasons result from the tilt of the earth's axis relative to its orbit. When the sun is highest in the sky, we have summer. In fact, the earth is closest to the sun in January.

Through Project STAR, which received $833,000 in seed money from the National Science Foundation in 1985, Shapiro hopes to correct such misunderstandings. The goal of the program is not merely to teach astronomy to high school students but also to use astronomical examples to instill basic concepts of math and science. Thus students may master the inverse-square law of physics by seeing that when a star doubles its distance from a certain point, it becomes one-quarter as bright. Why choose astronomy for this purpose? "It's not as abstract as chemistry and physics," says Shapiro, "and the sky is always there."

Teachers involved in the program, which aims ultimately to reach half a million students, spend about a month at the astrophysics center learning the fundamentals of the STAR approach. They are taught that the road to enlightenment lies in the third dimension. "To convert from three dimensions to two and back to three again leads to special reasoning ability," says project director Philip Sadler.

Consequently, STAR students use a variety of props. With 3-D models of the universe, they can visualize just how the light of the sun on the moon produces different moon phases. They make their own telescopes from cardboard, paper-towel cylinders and plastic lenses. (The result is a telescope more powerful than the one first used by Galileo.) They record in journals the movement of the moon and sun and chart the arrivals and departures of the constellations.

The classes, which are separate from the ordinary high school science curriculum, tend to attract curious students and science buffs. Still, it is often an uphill battle to disabuse kids of fallacies that have become ingrained even by age 17. "You want to defend your old misconceptions, but you can't," says Matthew Liebman, a STAR student at Massachusetts' Framingham North High School. Despite the difficulties, preliminary studies by Shapiro's team suggest that STAR students have a better grasp of basic scientific concepts and mathematics than students in ordinary courses. "We're definitely making headway and in directions we hadn't expected," says Sadler, who is continually searching for fresh teaching methods.

For students, the gains can be rich. Some of Sadler's initial findings reveal that STAR students do about 30% better than ordinary students in absorbing concepts and learn about twice as much math as their regular counterparts. "I used to look up at the night sky and say, 'Yeah, so what?' " recalls Aphrodite Kapetanakos, a Watertown junior. "Now I show my friends a constellation and say, 'Check it out!' All they know is the Big Dipper."