EINSTEIN'S CLOCKS AND POINCAR'S MAPS: Empires of Time

Harvard historian of science Galison approaches our understanding of time at the beginning of the 20th century through two related dimensions. The first, extremely practical perspective focuses on our ability to accept a common definition of time at various locations. Before our current system of time zones existed, time was a local construct, making it extremely difficult to coordinate events, have trains run smoothly or determine longitude. The second, far more theoretical perspective deals with the basic laws of physics and addresses the question: is time absolute or relative? Galison focuses his narrative through the eyes of the two scientists most responsible for crafting our present understanding of time, Albert Einstein and Henri Poincaré. While Einstein needs no introduction, the less well-known Poincaré does. He was one of the world's most renowned mathematicians and president of the French Bureau of Longitude. Galison explains how, in the case of each of these scientists, the practical dimension helped shape their understanding of the theoretical dimension, and, in turn, how they helped transform the world. Although Galison's material is of great interest, his writing is often obtuse and overly technical, making the book's ideas less accessible to a general audience. 46 illus. (Aug.)