Astro 120  Fall 2003
Essay Question for Exam 1

You will be asked to answer this question during Exam 1 on Thursday, October 2. Please think about how you will answer this question before the exam, and write your answer during the exam time.

PART II: ESSAY (25 points): Answer the question on this sheet front and (if needed) back only.

Name: _________________________        Section Number:________


The dominant model of our solar system for nearly 2000 years was that developed by the Greeks (in particular, Aristotle and Ptolemy). In particular, this model featured three key aspects that were built in and not questioned. Later on, mostly after 1500, this model crumbled because of the work of a few important scientists, resulting in our modern picture of the solar system.

In a brief essay describe these three key aspects of the Greek system, and the observations that they tried to explain. Next discuss the step-by-step refutation of them as the modern model of the solar system developed between 1540 and 1670. In your essay, you should mention the work of Aristotle, Ptolemy, Copernicus, Galileo, Kepler, and Newton (at least).