The Odd Quantum

Whenever you cross a street, sad to say, you run the risk of being struck down by a misguided vehicle. The probability of such a tragedy is infinitesimal under most circumstances, but, as the statisticians say, it is non-negligible nonetheless. By the same token, when energy travels, it may bend this way or that in response to the vagaries of gravity, following a seemingly random course. The probability that it will wander in a certain direction given certain conditions is the province of quantum mechanics, a branch of physical science that concerns itself with small-scale phenomena that cannot be observed without instruments--and that cannot be described in the terms of classical Newtonian physics.

Using such phenomena as the disintegration of light and the decomposition of radioactive matter as cases in point, Princeton University physicist Sam Treiman takes his readers through the latest theories of quantum mechanics in his aptly titled primer. He surveys the history of the field, drawing on the 20th-century work of Neils Bohr, Werner Heisenberg, and Max Planck to explain key terms; he then proceeds to enumerate some of the problems that quantum mechanics seeks to describe on the way to showing, in Richard Feynman's cheerful phrase, how the world really is.

Although accessible, Treiman's book is not for novices; its pages bristle with complex formulas and terms like lepton conservation and neutrino oscillations. Nonspecialist readers with some background in physics, however, will find Treiman's discussions to be clear and even elegant, and an altogether useful introduction to the discipline. --Gregory McNamee