Charles's Reviews > Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions

The Standard Model of particle physics is the most successful scientific theory ever produced. It's capable of making predictions that turn out to be incredibly accurate, down to many decimal places. It's produced surprising predictions that turn out to be true. The discovery of the Higgs boson a few years ago cemented in the capstone of its success. But it also has a massive, gaping hole in the middle of it, a flaw that has consumed the efforts of several generations of physicists and continues to represent an impenetrable mystery. Where is gravity? Why is gravity?

This book is ten years old now, but still presents an absorbing account of the efforts being made to unravel this mystery in a readable and approachable manner and is an excellent starting point for anyone looking to find out about string theory, supersymmetry and extra dimensions. This is a cluster of theories that can interact in surprising ways, but Randall manages to plot a course through the thicket that makes a degree of sense. As with all popular science books it's hobbled by the requirement to translate purely mathematical concepts into semi-intuitive ideas. This will always present problems, as an intuitive understanding is inherently flawed--if you really want to grasp the nature of these theories you need to do the maths (I'd recommend Leonard Susskind's The Theoretical Minimum: What You Need to Know to Start Doing Physics and its companion on Quantum Mechanics).

There are a few problems with the book that might have been improved. As others have noted, she opens with several chapters concerning higher dimensions and how they could fit into what appears to be a strictly three dimensional world, but then veers off into presenting relativity, uncertainty and the Standard Model, only returning to the subject of dimensionality 10 chapters later. Unfortunately there's no way of discussing these subjects properly without shoehorning in all the undergraduate spadework that needs to be covered for anything else to make sense. The book would probably have flowed a bit more elegantly if the introduction to dimensionality were moved later in the work. But since the book is fundamentally about the physics of extra dimensions I can understand the motivation to dive in from the start.

Written in 2005, this book presents an excellent overview of the previous couple of decades of work into Physics Beyond the Standard Model. What it really needs is a second edition, perhaps in a couple of years when we have results from the LHC at 13TeV. In many places through the book she talks about the predictions being made and looks forward to the LHC results. It's no secret that many of these predictions have fallen flat. Some variants, like Minimal Supersymmetry, are already dead in the water, with no evidence of the relatively light superpartners they predict. Most of the others are looking very troubled. Where do we go from here? It's not enough to carp from the sidelines, like Smolin, and complain that these theories are all bunk. We need answers and a way to plug up the yawning void sitting at the heart of the Standard Model.

The road that science takes is littered with the husks of thousands of dead theories--once-promising ideas that had to be cast aside for better alternatives. There's no doubt that many of the theories presented in Randall's book will join their number. But if ideas are a vector we need to know where it's starting from, and Prof. Randall presents an excellent overview of the state of play in PBSM in the early years of this century.