Science enthusiasts, especially physicists, astronomers, and cosmologists, will love The 4% Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality. Richard Panek gives a detailed and thorough account of the history of cosmology (the study of the universe including its birth, composition, and laws). All of the heavy hitters are mentioned along with some I had never heard of (Adam Riess, anyone? Saul Perlmutter?). Mathematics abounds but if you're looking for diagrams or charts you've come to the wrong place which I personally found disappointing. The writing style is not written with the layman in mind. If you're unfamiliar with the standard terminology and not completely cognizant of some of the finer points regarding these specialized science disciplines you might find yourself a bit lost. However, if you are fascinated by what lays beyond our galaxy and how we fit into the grand scheme of things then you should definitely read this book (but be prepared to come away without all of the answers that you seek).