Dear class, Here are some pointers on how to study for the midterm coming up next week on Thursday (March 15). It will be held in class (i.e., McDonnell A02), at the usual time. We will start at 3 PM sharp, and end at 4:20 sharp, by my watch. The exam will be such that most students should be able to finish comfortably in that timeframe. The exam will include material through Lecture 10 (March 8). The course is defined by the material covered in lecture and homeworks. Therefore, you should study your own lecture notes and the lecture outlines given on the course web site. There is a lecture-by-lecture list of recommended reading from your textbooks on the web site as well; use this as guidance of how to read the textbooks. You are *not* responsible for material in the textbooks that has not been covered in class or in the homeworks. The midterm will have problems that will be reminiscent of those on the homeworks, so study the homeworks, in particular the solution sets on the web. Note the strong usage in the solutions of the setting up of ratios of various quantities; this is a technique that will serve you well in the exam. There will also be a section of the exam in which you will be asked to write two or three brief (1-3 paragraph) essays describing various material in the course. The exam is closed-book, as you know (therefore, do not bring the course textbook, your notes, any on-line material from the course web page or elsewhere, etc., etc...), but you will be furnished a ``cheat-sheet''. You are familiar with the formula sheet on the course web site: http://www.astro.princeton.edu/ast203/formulas.pdf The midterm cheat-sheet will include the formulas on the first page and a half. Please look this over carefully before the exam, and make sure you are familiar with it. Calculators are allowed, but the problems will be set up to make the arithmetic particularly easy. And if you do want to use a calculator, make sure that its batteries are fully charged! I will NOT have backup calculators on hand. Wednesday night (3/14) at 7:30 PM, we will have a review session in 10 Guyot Hall. Note the change of venue; I'll summarize what I think are the most important concepts you should have learned in the class thus far, and will answer questions. I will also go over the formulas sheet mentioned above. The following is a list of these most important concepts, in roughly the order we talked about them: The importance of liquid water for life. The fact that all life on Earth shares the same basic biochemistry (DNA and proteins). The difficulty of defining "life". The Aristotelian and modern worldviews, and the relationships between the nature of celestial and Earthbound objects. The modern understanding of the scientific method. The Copernican revolution, and the Copernican Principle. Kepler's laws of planetary motion, especially his third law. Newton's laws of motion; Newton's law of gravity. The concept of an orbit. The concept of the Celestial Sphere, and coordinate systems on the sky. The concept of kinetic energy, and how it relates to temperature. The electromagnetic spectrum and the nature of light. Radioactive decay, and the age-dating of rocks. Black-body radiation. The inverse square law of light. The distinction between brightness and luminosity. The effect of impacts on the Earth, and the oldest life on Earth. The equilibrium temperatures of planets, the greenhouse effect, and the carbon dioxide cycle. Water on Mars and Europa. Search for extraterrestrial life, including SETI. The relationship between distance, angles, and sizes of objects (the small-angle formula). Using parallax to measure distances to stars. The structure of atoms, and emission and absorption from individual atoms. The Hertzsprung-Russell diagram. The spectra and colors of stars. The chemical composition of stars. The energy sources of stars; thermonuclear reactions. There you have it: the entire course thus far reduced to a series of sound-bites! Anatoly Spitkovsky