ASTR 3 Chapter Notes - Chapter 0-4: Ptolemy, Deferent And Epicycle, Nicolaus Copernicus
Document Summary
Textbook notes: chapter 0. 4: the measurement of distance. One distance-measurement method is called triangulation, used to measure faraway objects. Is part of a series of distance-measurement techniques in astronomy that make up thecosmic distance scale. To measure distance a tree across river, imagine a right triangle. Start directly opposite the tree, then move to the right a little bit to another point and determining the angle of the tree with respect to that new point. Then measure the baseline, distance from original point opposite tree to new point. Now you know one length and 2 angles of the right triangle, can find lengths of other sides, including distance to tree! However, sometimes stars are so far away angles are hard to measure, may have to use very large baseline, inconvenient. Two observers at different points on earth can pictures of a distant object relative to much farther away stars.
