Dennis D. McCarthy, P. Kenneth Seidelmann

Dennis D. McCarthy and P. Kenneth Seidelmann are astronomers who specialize in timekeeping and celestial mechanics. McCarthy worked at the U.S. Naval Observatory for over three decades, serving as Director of Time from 1985 to 2005. Seidelmann spent his career at the U.S. Naval Observatory studying planetary motion and coordinate systems. He contributed to the development of astronomical constants and reference systems used by the international astronomical community. Together, they authored "Time: From Earth Rotation to Atomic Physics," which examines the measurement and definition of time from astronomical observations to modern atomic clocks. The book covers the evolution of timekeeping methods and their applications in science and technology. Their work addresses the technical aspects of how time standards are established and maintained. They focus on the transition from astronomical time based on Earth's rotation to atomic time based on cesium frequency standards.

Readers praise "Time: From Earth Rotation to Atomic Physics" for its comprehensive coverage of timekeeping science. Many appreciate the detailed explanations of how atomic clocks work and their relationship to astronomical observations. Scientists and engineers find the technical content accurate and thorough. Readers value the historical perspective on timekeeping methods and the clear explanations of complex concepts. The book receives recognition for connecting theoretical physics to practical applications. Several reviewers note the authors' expertise in the field comes through in their detailed treatment of coordinate systems and reference frames. Some readers find the mathematical content challenging and suggest background knowledge in physics helps with comprehension. A few reviewers mention the writing style can be dense for general audiences. Others note certain sections require careful reading to follow the technical explanations of atomic time standards and their implementation.