Customer Reviews

In Search of Dark Matter (Springer Praxis Books / Space Exploration)

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This book sets out the evidence for missing matter in the universe in an entertaining yet thorough way. There is virtually no math in the entire book, and yet each subject area is treated fully. I had thought the first evidence for dark matter was star rotation rates in galaxies as set out by Vera Rubin and others. However this book traces the roots of the "something is wrong with our picture of the universe" back to the 1930s and Fritz Zwicky and Jan Oort--two astronomers who could not be more different from each other. And that is another strength of this book--we learn something about Zwicky and Oort without being seriously sidetracked.

"In Search of Dark Matter" strikes a perfect balance between moving the story along (and it does read like a story) and stopping here and there for brief asides about the personalities and milieu involved at the various stages of dark matter research. Finally, alternatives such as MOND theory are discussed. This book is not a deep tome--it is only roughly 150 pages. But it certainly piqued my interest and made me want to find out more. The authors succeed in bringing up most topics assuming little or no background in astronomy, yet don't get mired explaining the basics. A great read!

The title of this book caught my attention because so-called Dark Matter is an important and puzzling issue in modern astronomy. In brief, the stars we see have insufficient mass to account for the gravity of galaxies and galactic clusters. The missing mass must reside in non-luminous, i.e. Dark Matter.

This book starts out promisingly enough. Ken Freeman and Geoff McNamara do a good job of framing the question and explaining how astronomers found a discrepancy between the amount of visible matter and the observable gravitational effects. After the first few chapters the book loses its way. It becomes more of a survey of the ideas on the subject rather than an effort to choose between them and present a coherent point of view. It is clear that ordinary matter in the form of protons, neutrons, electrons, etc is not present in sufficient quantities to explain the gravitational effects. Something else with a specific distribution that can be inferred from astronomic observations must account for the remaining gravitational effects. This leads to somewhat vague discussions of the possible mass of neutrinos, black holes (massive and small) and of exotic particles like WIMPS (weakly interacting massive particles) and axions. At the end of it all the authors are not inclined to share with us where their preference lies. Instead, they divide the missing mass into Hot Dark Matter (HDM) and Cold Dark Matter (CDM). The difference between them is poorly explained, but at the end the authors tentatively come down on the side of CDM, albeit with caveats. Judging by the tenor of the last few chapters they seem to feel that they have provided a satisfactory account.

The last chapter is actually the best because it is co-authored by Charles Lineweaver, who himself being a contributor to constraints on the cosmological constant is willing to take a clear stand. Unfortunately, this is also the point where it is revealed that in terms of the cosmological constant (omega) baryonic matter accounts for 0.04 of the contents of the universe, (cold) dark matter for 0.27 but a huge 0.73 is Dark Energy (the total being close to the desired 1.0). Dark energy barely gets and discussion. Although this preponderance of dark energy should come as no surprise to the interested layman who has kept up to date with developments in astronomy, it does seem to beg a whole different book with another title.

Notwithstanding the closing paragraph's self-congratulatory but ambiguous remarks, readers will want to go in search of dark energy.

The book is very well organized and enjoyable to read. Well done!

I found this book to be very informative, up to date, and could be understood by the layman