Astronomy 101 (Basic Astronomy), Fall 2009

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.

Our textbook is The Essential Cosmic Perspective , 5th edition, by Bennett, Donahue, Schneider, and Voit. Buying a new book gets you the serial number that allows you to create an online account to access their website. (There will be web-graded homework.) If you throw away the code that comes with your book, it costs something like 27 dollars to buy access to the website.

The website for the book is www.masteringastronomy.com

If you are in section 502 of Astronomy 101, the course title on the web is "ASTR 101 sec 502". The course ID is MAKRISCIUNAS101502.

If you are in section 504 of Astronomy 101, the course title on the web is "ASTR 101 sec 504". The course ID is MAKRISCIUNAS101504.

In the Fall of 2009 we will be using clickers in the classroom. When you buy your book you should choose one that comes with a 10 dollar rebate coupon for an iclicker, and you should buy an iclicker too. Both of my ASTR 101 sections will use clickers, as will Nick Suntzeff's and Kim-Vy Tran's. Darren DePoy's sections will not use clickers this semester. So if you really, really don't want to use clickers, then somehow or other you have to get into one of Prof. DePoy's sections.

Downloadable handouts, assignments, and Powerpoint talks

Syllabus for Fall, 2009, sections 502 and 504.

Angular size experiment (due Sep 18). Actually, better to use the handout in class, as it has some diagrams drawn in by hand, but this has all the prose.

Cut-out for making cross staff.

Powerpoint with contact information for help with Mastering Astronomy website

Project 2: time by the stars (due Nov 18).

Northern sky circumpolar star chart for Project 2.

Week 1: Introduction and some basic concepts

Week 1: Significant figures and errors of measurement

Week 2: Introduction to the sky

Weeks 2/3: Phases of the moon. Eclipses.

Weeks 3/4: History of astronomy - Part I.

Week 4: History of astronomy - Part II.

Weeks 4/5: Newton, gravity, tides, Relativity

Weeks 5/6: Light and spectra