Computer Simulation and Computer Algebra (PDF)

Computers play an increasingly important role in many of today's activities, and correspondingly physicists find employment after graduation in computer­ related jobs, often quite remote from their physics education. The present lectures, on the other hand, emphasize how we can use computers for the purposes of fundamental research in physics. Thus we do not deal with programs designed for newspapers, banks, or travel agencies, i.e., word processing and storage of large amounts of data. Instead, our lectures concentrate on physics problems, where the computer often has to work quite hard to get a result. Our programs are necessarily 5 quite short, excluding for example quantum chemistry programs with 10 program lines. The reader will learn how to handle computers for well-defined purposes. Therefore, in the end, this course will also enable him to orient himself in computer-related jobs. The first chapter deals mainly with solutions of the Newtonian equation of motion, that force equals mass times acceleration, which is a precursor to the molecular dynamics method in statistical physics. The second chap­ ter considers, by means of several examples, another method for statistical physics, Monte Carlo simulation. These two chapters deal with numbers, the traditional territory of computers. In contrast, analytic formula manipulation, 3 5 4 3 such as (a+27b -4c)5 = a + 135a b - ... , is taught in the last chapter and is important, for instance, in analytic integration or for evaluating expressions in Einstein's general theory of relativity.