  The book on Mechanics of the Physics at Berkeley, by C. Kittel, W.D. Knight
and M.A. Ruderman, is proposing at the end of its first chapter some problems
of simple astronomy within the solar system. The discussion begins with two
amateur astronomers who set for themselves the goal of determining the diameter
and mass of the Sun. Here we discuss the problems proposed by the book and some
other matters on ancient and modern astronomical studies of the solar system.
