Forward:

A book of this type must often get into discussions of scientific details. Every effort has been made to keep them as readable as possible for the layperson. The more technical details have been put into Appendixes at the end of the book. These can be ignored by readers with less interest in details. For readers with more interest in these, references are given which can be used as starting points for further reading. Personal inquiries about further information or references are always welcome.

Each chapter is broken up into sections. If a reader is not interested in the subject of a particular section or finds it to be too technical, it can usually be skipped over without loss of continuity.