Review of "In Search of Dark Matter," by Ken Freeman and Geoff McNamara

Review of

In Search of Dark Matter, by Ken Freeman and Geoff McNamara, ISBN 0387276165

Five out of five stars

Excellent popular explanation of a fundamental principle

 For some time, it has been known that the universe is expanding. There is a well-defined point of origin that is known as the moment of the Big Bang. As the universe exploded into existence the amount of energy and mass were fixed and the various components few away from each other.

 With this fact established, the next major fact that was pursued was determining the amount of mass in the universe. If the amount was above a certain level, then the mutual gravity would cause the components to eventually slow down, reverse their direction and then come together in an event that was referred to as the Big Crunch. If the amount was less than the threshold, then the universe would continue to expand forever, eventually experiencing a heat death.

 Therefore, there is a concerted effort to determine how much matter is in the universe. Initial computations of the amount of matter that was visible clearly indicated that this was  a small percentage of the total matter. The mutual behavior of the components indicated that there was much more matter in the universe. This missing matter was referred to as “Dark Matter.”

 This book is an excellent popular explanation of all facets of this fundamental issue in our understanding of the universe. It starts with an explanation of the fundamental issue of the ultimate fate of the universe and then moves on to the obvious lack of known matter. Following this there are simultaneous explanations of the various types of potential dark matter and the ways in which the improvements in the collection of astronomical data have made it possible to investigate whether the specific postulated forms of dark matter do in fact exist. All are done with a minimum of equations and with images that encapsulate the information.

 While it is unlikely that any human will live to see the universe approach its end, it is important to learn what that end will be. This book gives a great deal of information regarding the search for this ultimate truth.