cover image Gravity's Lens: Views of the New Cosmology

Gravity's Lens: Views of the New Cosmology

Nathan Cohen. John Wiley & Sons, $19.95 (237pp) ISBN 978-0-471-63282-5

Einstein predicted that the gravitational bending of light rays by massive objects could actually be observed. Yet it wasn't until the 1978 discovery of a twin quasar that astronomers witnessed a ``gravity lens'' in action. Since then, scientists have become keenly interested in exploiting the lens-like action of aligned galaxies to probe the structure of far-flung matter and measure the distances between stars. Gravity lenses are just one among many exciting developments in cosmology surveyed in this short, basic primer. The book also reviews the 1987 discovery of a ``brown dwarf'' (a star not quite hot enough to trigger its own nuclear fires), the mapping of megaclusters of galaxy clusters, and reviews trendy superstring theory, which posits clone universes and multiple dimensions. Cohen, a physics professor at Boston University, uses scores of computer-enhanced photographs and diagrams to illustrate key points. Avoiding overly technical discussion, he crams in an abundance of material, from subatomic particles to the frustrating search for ``dark matter'' hidden somewhere in the universe. (August)