We have followed our usual tradition in that this new edition of the text is yet anotherthorough update of the content and its presentation. Our goal is to keep the bookflexible to use, accessible to students, broad in scope, and authoritative, withoutadding bulk. However, it should always be borne in mind that much of the bulk arisesfrom the numerous pedagogical features that we include (such as Worked examples,Checklists of key equations, and the Resource section), not necessarily from density ofinformation.