Wave away your efforts

The difficulties of Alastair Rae's Quantum Physics are summed up early in the book. Chapter two begins by assuming that "many people"

associate wave-particle duality with quantum physics, and then introduces waves as if they were the epistemic preserve of those who had visited the seacoast or travelled on a ship. This is more than a style issue: throughout this book I was unsure of its intended readership.

Although packaged as popular science, the mathematical boxes, figures, chapter summaries and footnotes leave no doubt this book is here to inform rather than entertain. Indeed, the only thing missing from the textbook format is the exercises. The overall structure is highly didactic, opening with a 24-page physics glossary (ironically titled "Quantum physics isn't rocket science") that the reader is expected to master before proceeding. Rae assumes that because he has put all the formulae into boxes, everything else will be clear despite its lecture-like delivery and lack of narrative. Juicy concepts such as the Pauli exclusion principle, for example, are hidden in mundanely titled subsections rather than being drawn out to help the reader along.

The guts of the book are five chapters highlighting the role of quantum physics in everyday phenomena. Rae mostly does a good job of this, such as elucidating why fossil fuels burn and explaining the molecular origin of the greenhouse effect. But the reader is still made to work for it. The chapter "Semiconductors and computer chips" offers ten pages of dry exposition about band gaps and rectifiers before we get to the important point of transistors, and three more before the reader is told what transistors have got to do with Pentium chips.

Another slightly irritating aspect of the practical examples is the subtext that we would still be stuck in the dark ages without quantum physics. In fact, few of the examples Rae gives are the direct result of applying quantum mechanics. For example, in his glorification of the theory of low-temperature superconductivity Rae fails to point out that the theory cannot help materials scientists predict new superconductors, or that after 20 years quantum physics has no explanation for high-temperature superconductivity.

The practical examples, along with parts of the final pseudo-philosophical chapter unimaginatively titled "What does it all mean?", will provide useful supplemental reading on an undergraduate course on quantum mechanics - perhaps dovetailing with Rae's excellent textbook on the subject. But here he runs the risk of shortchanging students by omitting slightly heavier mathematics such as the Schrödinger equation.

The Nobel prizewinning physicist Tony Leggett introduces the book by stating that any reader who is prepared to put in a little effort will come away with a good understanding of basic quantum physics. I would say that the lay reader would need to put in an unrealistic amount of effort and need to be determined enough not to get disheartened by numerous disclaimers and "words of warning" about how a proper treatment of quantum physics is way beyond the scope of the book. But, then, readers who are this keen should probably sign up for an Open University course instead and at least get something in return for their efforts.

Matthew Chalmers is features editor, Physics World. He was formerly an experimental particle physicist at Cern.