The enormously complicated subject of "time" which extends itself into the natural and philosophical sciences is explored and to a large extent made coherent by author-scientist Isaac Asimov. In investigating the various means by which man has attempted to tell time, the devices they have used, and the concepts they have held, The Clock We Live On of necessity includes the subjects of astronomy, mathematics, geography, physics, and philosophy. A meaningful analysis, marked by erudition and lucidity.