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Herschel's Star Gages DocumentsThis material has 3 associated documents. Select a document title to view a document's information. Main DocumentHerschel's Star Gages
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Todd Timberlake The EJS Herschel's Star Gages Model illustrates William Herschel's methods of "star gages" by which he attempted to map out the shape of our galaxy in 1785. Herschel's star gages (sic) relied on two important assumptions: that Herschel's telescope (his "large 20 foot" with an 18.5 inch aperture) could see to the ends of the galaxy, and that within the galactic system stars are distributed uniformly. If the first assumption holds then the stars seen in the telescope all lie within a conical region of space with the apex at the telescope and the base at the edge of the galaxy. If the second assumption holds then the number of stars seen in the telescope is proportional to the volume of this cone. Since the volume of the cone is proportional to the cube of its height, the distance to the galactic edge in any direction is proportional to the cube root of the number of stars seen in that direction.
Published December 15, 2011
This file has previous versions. Supplemental DocumentsHerschel's Star Gages Activity HandoutAn activity handout that guides the user through using the Herschel's Star Gages model. The activity helps the user to understand and explore Herschel's method, as well as its limitations, thereby illustrating important concepts about the nature of science. This file is available in multiple formats: .pdf, .doc, .tex
Released under a Creative Commons Attribution-ShareAlike 3.0 Unported
Published December 15, 2011
This file is included in the full-text index. Source Code DocumentsHerschel's Star Gages Source CodeA zip archive containing the Easy Java Simulations source code for the Herschel's Star Gages model.
Published December 15, 2011
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