Borderline five stars, only not because that should be reserved for the really, truly momentous stuff. That said, this is an important book with many lessons that extend beyond it's direct subject matter. This is a book about thinking, about diversity of thought, about doing science in diverse ways, and about the institutionalized slow death of revolutionary thought in the field.

Smolin begins by providing a layman's reading of important scientific discoveries of the past century or so, emphasizing what Einstein's ideas were and why they were so important. He also explains how Einstein had a lot of bad and incorrect ideas, as did Isaac Newton and many other scientists whose legacies now are often reduced to demagoguery. This is an important point to make, because it shows that science is full of wild misses, and that's okay! That's how science gets done, through attempts at explaining things, which may or may not reveal great truths about the universe. Even wrong ideas often reveal right ideas as a byproduct of simply doing the research. Science often makes progress on accident.

Smolin is remarkably sympathetic toward string theory in that regard, explaining how, even though it is likely not correct and had thus far not gathered any experimental evidence, it has revealed great mathematical insight. He describes the problem with string theory as not being a problem with the science, but with the academia behind the science. Modern (and, he often stresses, *American*) science is beleaguered by a need for grant funding, which often is given to people doing popular science in a time when the field of theoretical physics is stagnating aimlessly and in need of revolutionary thought.

We should read this book as a criticism of a deeply problematic idea, but also as a criticism of how modern science gets done and the way it ostracizes the kind of thought that science depends upon.