Smolin really delivers with this volume. It's pretty weighty, but the concepts are presented very neatly and without a lot of the technical jargon. The real strength of this book is Smolin's real objectivity when surveying the landscape of modern physics research. With all the hype over String Theory, it's nice to see someone take a step back from the giddying beauty and symmetries of the theory(ies) and provide a realistic assessment as to whether or not the theory has delivered. I think some of the best parts of this book are the last few chapters that deal with the sociological and philosophical aspects of science in general for the 21st century. Smolin's insights into the profession, particularly his critique for how new graduates are hired, given tenure, or research grants are pointed and disconcerting. Whether or not String Theory is the real deal, or the worst fad in physics since the aether, Smolin's approach to the subject is one that is well wroth embracing. The lesson that professionals and amateurs alike can take from this is never to put all your eggs in one basket. There've just been too many precedents of fundamental assumptions being overthrown in the past 300 years.