Sky & Telescope November 1987 [antikvár]

focal pointSecret Weapon: AstronomyIN RECENT YEARS the pubhc outcry about the sorry state of precollege science education in the United States has reached a fever pitch. Yet the sobering reality is that the average high school student in this country still takes only one year of science.The reason is all too obvious. Today's physics, chemistry, and biology courses may be challenging to motivated students, but such offerings can be overwhelming. They attempt to cover everything with a density of concepts that often proves incomprehensible. Students respond by not enrolling, thus prematurely shortening their scientific education.A stimulating and understandable astronomy course could attract high schoolers back to science. Granted, astronomy is neither more worthy nor more important than other sciences traditionally taught in schools. But it is more visual. It is on the frontier of scientific discovery yet not so esoteric that the student cannot grasp the subject matter. Moreover, astronomy like sports involves adults long after their school days. This is amply demonstrated by the continued popularity of planétariums, swelUng attendance at public observing sessions, and strong sales of small telescopes.So, we might ask, can astronomy be enlisted to fight in the war for scientific literacy? Absolutely! And at present the National Science Foundation is supporting a program to do just that at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. Project STAR (Science Teaching through its Astronomical Roots) is developing a curriculum that aims to increase the quantity and quality of astronomy taught in high school.In Project STAR we deal with a limited number of concepts, returning to them in a variety of settings ranging from the classroom to the universe at large. Astronomy provides a diversity of scales of size and distance with which students can work. They can see the same principles at play throughout the universe, and by repeating the same basic concepts, they can master them.While astronomy is the disciplinary focus of Project STAR, the goal is to help students grasp the essence of science and mathematics in general. Much of the mathematics of astronomy is familiar to the student but has rarely been applied to real situations. Ratios, similar triangles,estimation, and graphing come alive in astronomy as powerful tools that help students and scientists make sense of the world.Project STAR directly challenges students' misconceptions. For example, interviews show that most adults think it is hotter in summer than in winter because the Earth is closer to the Sun in summer. The traditional textbook explanation of the real cause of the seasons apparently makes little impression on them. On the other hand, when students determine for themselves that the Earth is farther from the Sun during northern summer, they see that they need a new explanation.We humans seem to learn best by doing. How would you feel, after all, about being cut open by a surgeon who has never operated on anyone before, but who has read many books on the subject and done very well on many fill-in-the-blanks tests on surgery? Think of something you can do well; how did you learn it? Effective science teaching is based on activities lots of them.One does not need powerful, large-aperture telescopes to investigate the sky. Many exciting observations can be made using simple telescopes costing less than 75 cents yet superior to Galileo's. Students can map the Moon's "seas" and highlands, estimate the sizes of its largest craters, and discover the variety of creatures in the astronomical zoo.Astronomy is a spatial science. However, most students have great difficulty mastering the spatial relationships posed in most textbooks. So STAR has developed a 50-cent celestial sphere that stu-dents assemble. With it they determine the changing position of the setting Sun throughout the year, find the constellations overhead at 9:00 p.m. tonight, and plot dim objects to observe with telescopes or binoculars. Later they go on to build three-dimensional models of constellations and groups of galaxies.How bright is the Sun? How far away are the stars? The distance-brightness relationship is a fundamental tool in astronomical measurement. Students easily find the power output of the Sun using a light bulb and a simple null photometer made from paraffin and aluminum foil costing less than a quarter. Using this as a reference, and assuming the brightest stars in the sky are similar in output to our Sun, students estimate stellar distances with a flashlight and a short length of optical fiber.Late last year we completed a census of the astronomy offerings in U. S. high schools. We located 408 teachers of semester-length or longer high school astronomy courses and estimate that twice that many remain to be identified.Many of these teachers belong to astronomical organizations and read Sky & Telescope regularly. For them astronomy is not just a course they teach but a lifelong avocation. Most have developed a unique astronomy course or written their own curriculum materials and laboratory activities. What other subject generates that sort of grass-roots interest?