TAMING THE ATOM

Take seriously that subtitle—for what this fascinating book is all about are devices and procedures that allow the imaging of even a single atom suspended in a tiny doughnut-shaped trap. Von Baeyer (Physics/College of William and Mary), who charmed lay and professional readers alike with his Rainbows, Snowflakes and Quarks (1984), takes his main title from the fox in Saint ExupÇry's The Little Prince, who described ``taming: as establishing bonds—a process that happens slowly and with patience.'' So it has been, von Baeyer contends, with the history of atomic theory from Democritus to Einstein down to the latter-day stars of quantum mechanics. He reminds us that no less a giant of physics than Ernst Mach stoutly denied the existence of atoms at the end of the 19th century. Now, while there are no doubters, there remain the paradoxes of quantum mechanics—such as wave- particle duality: In the ``Copenhagen'' interpretation, an electron is potentially either a wave or a particle and the act of measurement determines which. Einstein rejected that notion, arguing instead that there is an objective reality beyond acts of measurement. Von Baeyer sorts out the history and experiments behind the paradoxes to bring us up to date with new theories to resolve them—including the use of ingenious devices such as a ``quantum eraser'' sensitive to a photon extracted from a single atom. Other clever atom-taming devices in the author's marvelous catalog include an apparatus that can prevent the spontaneous emission of an atom; ``tuned'' lasers that can detect impurities in a sample down to a single atom; and the ``magic wrist''—a machine that ``feels'' the ``surface roughness of the atomic landscape.'' And all this told in that combination of depth of knowledge and eyewitness narrative that marks the best science writing. (Eight pages of color illustrations—not seen.)