Introduction

This course is designed to give students a basic grounding in the physical principles people have employed to describe the World at large, that is, the Universe. We will cover, mainly, the development of Cosmology from the ancient Greek thinkers to the modern views. There are other ancient people, notably the Babylonians, who had a significant effect on the development of Greek Astronomy. However, the line of thought from the present day back into antiquity most clearly points to a Greek origin.

Present day Cosmology is very much a geometrical construct. This is most clearly seen in the General Theory of Relativity which treats  gravitational dynamics as a type of geometrical theory. Geometrical concepts have, indeed, dominated the entire scientific development of Astronomy from Eudoxus ( circa 360 BC ) through Ptolemy, Copernicus, Newton, and Einstein.

Another natural theme of Cosmology is the question of origins. How did the Universe start? Does it have an age? Does the Universe evolve? Will the Universe end? These are deep questions which have exercised human ingenuity for thousands of years, and likely for thousands more to come. We will explore how people have tried to answer these questions scientifically from antiquity to the present. Other approaches to answer these questions, such as by religion or legend, will not be dealt with explicitly in this course, which limits itself to measurable, i.e., scientific, methods.

This packet contains exercises to be completed during the lecture time and activities to be done outside the lecture. The goal of these exercises is to allow the students to apply mathematical techniques to astronomical problems. You should view this as an opportunity. How many of us would really go home on our own and calculate the mass of the galaxy using Kepler's laws? Since this course does not require more than GE mathematics, students will not be graded on their ability, or inability to do mathematical calculations. However, the instruction would be remiss if it did not expose you to the beauty and power of mathematics in dealing with astronomical phenomena. Your instructor may not use all the exercises in this packet and may add others. His/her instructions supersede whatever appears in this packet.

                                                                                                                    Konrad A. Aniol
                                                                                                                    Spring 2021

"I was almost driven to madness in considering and calculating the matter. I could not find out why
the planet (Mars) would rather go on an elliptical orbit.... With reasoning derived from physical
principles agreeing with experience, there is no figure left for the orbit of the planet except for a
perfect ellipse.... Why should I mince words? The truth of Nature, which I had rejected and chased
away, returned by stealth through the back door, disguising itself to be accepted....I thought and
searched, until I went nearly mad, for a reason why the planet preferred an elliptical orbit."

Kepler in, Astronomia Nova (1609)

as quoted in
The Mechanical Universe, Steven C. Frautschi, Richard P. Olenick, Tom. M. Apostol, David L.
Goodstein, Cambridge University Press, 1986, pp. 431-435