Physics 306 (Basic Astronomy), Spring 2008

A philosophical perspective

Astronomy is the oldest of the sciences. Before there were towns and cities, when there was no light pollution or air pollution, most ancient people were familiar with the sky at night. They understood very little of what they saw, but they were familiar with the phases of the Moon and knew that different constellations were visible at different times of the year. They used observations of the Sun and stars to formulate calendars, by which they could plant, harvest, and survive.

A basic astronomy course is a survey of the entire universe. As a result, one can cover very little in any depth over the course of an academic semester. Still, we're going to do our best!

Astronomy is a natural science (as opposed to a social science) meaning that many aspects of the objects of study (celestial bodies) can be described numerically. Thus, it is a quantitative science. But when all is said and done, the most important things to understand about astronomy are qualitative . How do we know that the Earth is not the center of the solar system? How do we know that the Sun is not at the center of the Galaxy? What will be the eventual fate of the universe? In your university education, perhaps the most important question you can ask is: "How do I know what I know?" Do I accept at face value what some person has said, what some other person has written, or have I determined it independently, on my own?

The study of astronomy is not just the study of planets, stars, and galaxies. It is also the study of the people who were motivated to investigate the universe. Some of these curious people formulated questions that were "impossible" to answer, yet a few decades (or centuries) later other people came up with definitive answers. As the poet Robert Browning said, "... a man's reach should exceed his grasp, or what's a heaven for?"

Five basic themes of basic astronomy

As Bennett, Donahue, Schneider, and Voit point out in their text The Essential Cosmic Perspective , it makes sense to built a one semester course on beginning astronomy around five basic themes:

I. We are a part of the universe and thus can learn about our origins by studying the universe.

II. The universe is comprehensible through scientific principles that anyone can understand.

III. Science is not a body of facts but rather a process through which we seek to understand the world around us.

IV. A course in astronomy is the beginning of a lifelong learning experience.

V. Astronomy affects each of us personally with the new perspectives it offers.

For example, the Apollo 8 astronauts took the following picture of the Earth rising over the Moon's horizon on December 24, 1968.

Each day you can see something interesting as the Astronomy Picture of the Day.

Note about the Bennett book website (www.masteringastronomy.com). The course ID's this semester are as follows: PHYS306SECTION502 and PHYS306SECTION503 .

Downloadable handouts, assignments, and Powerpoint talks

Syllabus for Spring, 2008, sections 502 and 503.

Homework #1. Due Wednesday, January 22.

Cross-staff experiment (due Feb 20).

Cut-out to make an astronomical cross-staff.

The web assignment related to chapter 2 (via www.masteringastronomy.com) is due February 12th at 11 AM.

The web assignment related to chapter 5 (via www.masteringastronomy.com) is due February 26th at 11 AM.

The web assignment related to chapter 11 (via www.masteringastronomy.com) is due March 25th at 11 AM.

The web assignment related to chapter 12 (via www.masteringastronomy.com) is due April 4th at 11 AM.

The web assignment related to chapter 16 (via www.masteringastronomy.com) is due April 29th at 11 AM.

Telling time by the stars (due April 16). For this you will need a circumpolar star chart like the one handed out in class.

Week 1: Introduction and some basic concepts