I had actually started reading this book over a year ago but never had the time to get past the first few chapters, so when I picked it up again just over a month ago, I decided to read it in full, from the beginning.
I guess another appropriate title for this would be "A Hitchhiker's Guide to the Galaxy (Nonfiction) by Not Douglas Adams". It really is a comprehensive guide to atomic physics, astronomy, chemistry, and biology for the layperson.
Bryson starts by discussing the origins of the universe and its measurement, both in terms of age and size. He continues by going into the developments of measurements of the Earth's age, chemistry, and modern physics. He then segues into the origins of life, continuing into full-blown biology, and finally concludes with a history of mankind.
Even though this is not a textbook by any means, I thoroughly enjoy it as an overview of the sciences for several reasons.
First, Bryson always tries to engage the reader by making the tone very conversational and by (rightfully) assuming that the average reader has no prior technical expertise in any of the fields; in fact, part of the humor comes from Bryson being humorously scornful of topics that are too technical for the average reader to understand. More important than that, though, is that Bryson makes the whole study of science more human by keeping the technical aspects at a minimum and focusing more on the personalities that have discovered the various sciences. For example, Carl von Linné (better known as Carolus Linnaeus) is hailed as the person who saved taxonomy by introducing the revolutionary 7-tiered classification system. However, I never knew that he was ridiculously obsessed with the methods that sometimes start human reproduction (I will not say that word here because this blog may then be blocked by parental controls). Those few pages of the book were enormously entertaining and enlightening (in that they shed light on the kind of character Linnaeus was). There are many other such pages of the book. Through it all, Bryson succeeds in bringing science to the layperson through his ability to show a very human side of science. I highly recommend this book to anyone who wants to learn a little more about science but finds conventional resources too technical (and hence, too inaccessible).