The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality

It has been a while since I’ve posted a book review to this blog, but after finishing a couple new books this past weekend, I thought a few readers might be interested in this one.

The 4 Percent Universe is a fairly typical “popular” physics book, namely one of the dozen or so books that gets published every year to try and simplify modern physics for the casual reader.  Originally, I picked this book up based on a Wall Street Journal review that recommended it as an up-to-date assessment of current theory around dark matter and dark energy.

For those of you who haven’t followed the progress on these topics over the past two decades, dark matter is a the common term given to the matter in the universe that we can detect due to gravitational effect, but can’t see based on any traditional form of observation.  Dark matter, as it turns out, does not emit or react to photons, which are the basis of most forms of astronomic observation.  Dark energy is the term given for the incredibly large volume of energy that has been calculated to exist in our universe, but that once again we haven’t been able to measure.  Both are fascinating outcomes of the development of mathematical theories around cosmology that predict facets of our universe that have not yet been measured or observed.  The “4%” in the book title refers to the fact that only about 4% of our universe is actually the traditional forms of matter and energy that most of humanity assumed was “everything” through the 20th century.

What makes this book different than most is the style of writing.  Instead of a chapter-by-chapter introduction and explanation of concepts, the entire book is presented as narrative, literally walking through the individual stories of the researchers and scientists who played different roles in discovering relevant theories and concepts.  As a result, it’s a much deeper look into the politics and competitiveness between scientists and academics of different disciplines (math, physics, astronomy, cosmology), as well as the bare knuckles process of research, peer-review, and all-too-common resistance to data and/or theories that don’t conform to existing cannon.

Personally, I found the first 150 pages or so fairly boring – too far in the past for me to really engage on the play-by-play discoveries that led to an acceptance of cosmology, big bang theory, and inflation.  These are topics that Stephen Hawking covered fairly well in his books.  However, the last half of the book really drew me in, as the narrative really took over in presenting the mounting evidence for dark energy, with explanations of key experiments and theories in the past decade (as recently as 2007/2008).

As a result, I definitely recommend this book to those who fashion themselves “physics hobbyists”, or those who wish to remain up-to-date on modern cosmology.