Cosmology, the science of the origin, evolution and the ultimate fate of the Universe, is a surprisingly young scientific discipline. For the most of history cosmological questions were dealt with through a philosophical or theological inquiry, but in the early part of the twentieth century it became possible to inquire about these things in a more systematic and scientific manner. The research in Cosmology really gained steam since the 1960s, when the discovery of the Cosmic Microwave Background (CMB) put the Big Bang Theory on a very firm footing. However, the subsequent inquiry revealed something really intellectually curious and potentially disturbing about the Universe: we can only see a very tiny fraction of it. The vast proportion of the “stuff” that makes up the Universe, about 96% of it to be more precise, is invisible. We can only infer its existence from the gravitational effects it has on the “visible” matter. This “invisible” stuff came to be known by a very prosaic couple of names: dark matter and dark energy.

The aim of “The 4% Universe” is to explain our best current understanding of what the dark matter and the dark energy are. The book provides some good physics background to all of these phenomena, and tries to explain how the observation and the research into these topics have progressed over the last half a century or so. Unfortunately, this book goes way overboard in taking the inside look at the workings of the physicists and the astronomers who do research on dark matter and dark energy. It narrates, in painful details sometimes, the comings and goings of the select groups of scientists as they conduct their research, grapple with work-family balance, and engage in petty turf wars with their colleagues and other competing research collaborations. For the most of the book I found myself bored to death with these minutiae – and I am a scientist! Furthermore, I found the information on the actual science, and physics aspects of it in particular, incredibly thin. Reading the Wikipedia articles on this topic is way more informative. This is definitely not a book that I would recommend to anyone who wants to learn more about the Universe and its dark secrets.