Overview

I hope these lectures have given you some idea how the electrical properties of materials come about and how they can be modified and exploited for useful ends. You must be better equipped now to understand the complexities of the physical world and appreciate the advances of the last few decades. You are, I hope, also better equipped to question premisses, to examine hypotheses, and to pass judgment on things old and new. If you have some feeling of incompleteness, if you find your knowledge inadequate, your understanding hazy, don't be distressed; your lecturers share the same feelings.

The world has changed a lot since the first edition of this book. The quiet optimism reigning thirty-three years ago is no longer the order of the day. Nowadays people tend to be either wildly optimistic, envisaging all the wealth our automatic factories will produce, or downright pessimistic, forecasting the end of civilization, as we run out of energy and raw materials. The optimists take it for granted that the engineers will design the automatic factories for them, and even the pessimists have some lingering hopes that the engineers will somehow come to the rescue.