Paper
An Exercise for Introductory Earth-Science Classes on Using Globular Clusters to Determine the Size of the Milky Way Galaxy and Our Position in It
Published Nov 1, 1993 · J. Shea
Journal of Geological Education
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Abstract
In an effort to provide additional opportunities for active and cooperative learning by students in introductory earth-science classes, I have developed an exercise on the use of globular clusters to determine the size of the Milky Way Galaxy and our position in it. The exercise has the added virtue of dealing with one of the fundamental astronomical questions of the twentieth century, namely the nature of the Milky Way Galaxy and Earth's position in the Galaxy. In the early years of this century, the most widely accepted model of the Milky Way Galaxy was that developed by J.C. Kapteyn who postulated that the Galaxy is a flattened ellipsoidal system of stars with a diameter of 50 to 60 thousand light years, with the earth located a bit above the plane of the system and only about 2 thousand light years from the center. It was the opinion of most astronomers at the time that the Milky Way Galaxy was the cosmos, the Universe. An alternative model was proposed by H. Shapley in the years 1915-17 on the basis ...
This exercise uses globular clusters to determine the size of the Milky Way Galaxy and our position in it, challenging the widely accepted model of the galaxy and promoting active learning in introductory earth-science classes.
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