Alexander Unzicker
Book Recommendations:
Recommended by Alexander Unzicker
“Robert Sanders explains how astronomers arrived at the conclusion that we cannot see 95 percent of the content of the universe. But he goes much deeper into the theoretical and observational problems. This is done in a nontechnical way and from a historical perspective. The most compelling evidence for dark matter is the absence of a decay in rotational velocity in the outer parts of spiral galaxies, as predicted by Newton's law of gravitation. Consequently, the major part of the book is dedicated to those "flat" rotation curves, their systematics, riddles and still poorly understood features. Since the author actively took part in that research field for decades, it is particularly interesting to follow the complete story of its development, a coevolution of observations and theoretical models. Though Sanders confesses a certain sympathy for alternative gravity theories, the observational material is not biased and the reader is left to draw his own conclusions. As a bonus however, he describes how humans tend to develop theories, the social component of science. Most importantly, the author raises questions about scientific methodology: is the whole concept falsifiable, as long as we explain astrophysical non-detection with increasingly exotic properties of dark matter particles? Can the existence of such particles ever be disproved, if the theoretical predictions, after being unconfirmed by existing accelerators, squeeze out towards higher energies? To summarize, the book is a pleasantly readable survey of the dark matter idea for the interested layman, a treasure for the galactic astronomer and a must-read for the cosmologist who is convinced that the dark matter problem consists of adding more decimals to a number calculated from the power spectrum of the cosmic microwave background. Highly recommended!” (from Amazon)
by Robert H. Sanders·You?
by Robert H. Sanders·You?
Most astronomers and physicists now believe that the matter content of the Universe is dominated by dark matter: hypothetical particles which interact with normal matter primarily through the force of gravity. Though invisible to current direct detection methods, dark matter can explain a variety of astronomical observations. This book describes how this theory has developed over the past 75 years, and why it is now a central feature of extragalactic astronomy and cosmology. Current attempts to directly detect dark matter locally are discussed, together with the implications for particle physics. The author comments on the sociology of these developments, demonstrating how and why scientists work and interact. Modified Newtonian Dynamics (MOND), the leading alternative to this theory, is also presented. This fascinating overview will interest cosmologists, astronomers and particle physicists. Mathematics is kept to a minimum, so the book can be understood by non-specialists.