Laurence A. Marschall, PASA, 17 (2), 129.
Next Section: Project CLEA: Digital simulations
Title/Abstract Page: The Universe on a
Previous Section: The Universe on a
On The Difficulty of Providing Hands-on Exercises in Astronomy
Educational research in recent years has affirmed the common perception that experience is the best teacher, especially in introductory science courses. (Hake, 1998) Hands-on activities, usually in a laboratory setting, help students learn through several processes. In the first place, experiential work helps clarify concepts by compelling students to apply their understanding of a subject to a concrete situation. If all works as expected, the student's confidence grows, and the student is motivated by an increasing sense of mastery. Even if an experiment "fails", that is, if it does something strange or unexpected, a student may be forced to rethink pre-conceived notions, and thereby gain a firmer understanding of what might otherwise have been shaky misconceptions.But astronomers have never been as successful as other scientists in providing effective exercises for the introductory laboratory. Part of the problem, of course, is that astronomy is observational, rather than experimental. Observing at night is the least of the problem. A simple measurement of the height of a lunar mountain requires observing the shadow of the mountain at a particular phase of the moon, one or two nights, perhaps, of a month. If those nights are cloudy, the observing exercise is an exercise in futility. Or consider the measurement of the light curve of an eclipsing binary star. If the period of the star is several days, it may take weeks, or even months, to sample the entire cycle of variations. Complete phase coverage is particularly difficult if the period of variation is close to an integral number of days.
Astronomy teachers have addressed these difficulties, for the most part, by providing students with predigested data: images taken by professional astronomers, spectra from observatories, and tables of reduced data from journal articles. In these "dry lab" exercises, students measure the photographs with magnifying glasses and rulers, or transfer the tabulated data onto a graph and answer a few questions about the result. (Bruck, 1990; Culver, 1984; Ferguson, 1990; Hoff, Kelsey and Neff, 1992; Johnson and Canterna, 1987). Not surprisingly, many students view such labs as little more than clerical work, an activity designed to fill up a few hours, with very little excitement and even less intellectual content. But what else are astronomers to do?
The development of digital astronomy in the 1980s provided an attractive solution to this problem. By the end of the decade, astronomical observation was regularly performed using computer-controlled instruments, data was stored in digital format, and data reduction was invariably carried out on a computer. As a result, it became possible to simulate real observations with surprising fidelity using desktop PC's. Actual data from on-line archives could be used, making it possible for simulation programs to incorporate the look and feel of real-time telescopes, and to produce results as authentic as those from a professional observatory. Students could now conveniently and effectively obtain a grounding in the basic techniques and strategies of modern astronomy.
The growing availability of simulations in the astronomy laboratory was a natural outgrowth of the computer revolution of the 1980s, but the use of simulations to teach technical subjects was not unprecedented. Aircraft pilots have been trained on simulators for almost half a century. Simulations are also used widely for training in certain medical fields, like endoscopic surgery, where remote sensing and remote manipulation were standard operating-room procedures. The attraction of simulations in these fields, as in astronomy, was the ability to effectively impart a hands- on experience without the risk or expense of a real-world exercise.
Next Section: Project CLEA: Digital simulations
Title/Abstract Page: The Universe on a
Previous Section: The Universe on a
© Copyright Astronomical Society of Australia 1997