Preliminaries

Abstract

This book is about numbers, so it is fitting that this first chapter opens with a section on numbers, emphasizing units and uncertainties. The computer program Error, introduced in Sec. 1.1, assesses the propagation of uncertainty in ordinary calculations. Another major theme in the book is equation solving. Some aspects of that topic are developed in Sec. 1.2 and applied to a selection of gas laws, ranging from the simplest to one of the most complex. The programs presented in Sec. 1.2, in order of increasing complexity and named after the inventors of the gas laws, are Waals, Peng1, Beattie, Anderko, and Keenan1. Also mentioned in Sec. 1.2 are gas laws in the generic virial form and two programs, Virial1 and Virial2, illustrate. A third theme, which will be important throughout the book, is the interpretation of experimental data by fitting data sets to empirical equations. In Sec. 1.3 the technique of least-squares (or regression) analysis is applied to this task, and the program Linreg is introduced.