Lee Smolin in American Scientist:
Gleiser is an accomplished theoretical physicist who holds a distinguished chair at Dartmouth College. His book tells the story of his change of mind about what real science is. Like many people who go into theoretical physics, he began his studies with a fantasy of discovering hidden truths that, when expressed in beautiful mathematical equations, would speak to him of unification and symmetry. He found he was good at this kind of work, and he experienced scientific and professional success. Nonetheless, he came to wonder whether the search for hidden unities in nature is driven more by metaphysical fantasy than by the actual results. Indeed, the results of the search for unification over the past several decades have been disappointing. In the early 1970s theoretical physicists invented what is known as the Standard Model of particle physics, which unifies some, but not all, of the forces in nature and balances nature’s highly symmetric features with its strangely asymmetric ones. In 1975 it was widely believed that this model was just a temporary consolidation of recent discoveries that would soon by superseded by a more unified and symmetric “Grand Unified Theory.” Remarkably, this didn’t happen. The first such theories to be proposed made predictions that were quickly falsified, and later ones made no predictions that anyone knows how to test. What we thought was a narrow ledge offering a place to camp for the night, on the way to a summit of much greater beauty, has turned out to be our ramshackle home theoretically, and we have been stuck there for more than 35 years.
It is possible that this is only a frustratingly long but still temporary setback and that proposals for further unification will turn out to be correct. Certainly most theoretical particle theorists think so. We expect to learn a lot from experiments that have just gotten under way at the Large Hadron Collider outside Geneva and at various deep underground laboratories with dark-matter detectors. But it is also possible that the search for further symmetry and unification has been mistaken, and that the right lessons to draw from the Standard Model reside in its asymmetries and unrealized unities. This is what Gleiser has come to think, and he includes in the book a fascinating report of his exploration of the asymmetries of nature. Whether one agrees with Gleiser’s central argument or not, it is a pleasure to follow his reasoning because the book is so beautifully written.