The book begins with an analysis of the persistent difficulties of defining inertial mass in a noncircular manner and discusses the related question of whether mass is an observational or a theoretical concept. It then studies the notion of mass in special relativity and the delicate problem of whether the relativistic rest mass is the only legitimate notion of mass and whether it is identical with the classical (Newtonian) mass. This is followed by a critical analysis of the different derivations of the famous mass-energy relationship E = mc2 and its conflicting interpretations. Jammer then devotes a chapter to the distinction between inertial and gravitational mass and to the various versions of the so-called equivalence principle with which Newton initiated his Principia but which also became the starting point of Einstein's general relativity, which supersedes Newtonian physics. The book concludes with a presentation of recently proposed global and local dynamical theories of the origin and nature of mass.
Destined to become a much-consulted reference for philosophers and physicists, this book is also written for the nonprofessional general reader interested in the foundations of physics.
The book begins with a discussion of Einstein's childhood religious education and the religious atmosphere--or its absence--among his family and friends. It then reconstructs, step by step, the intellectual development that led Einstein to the conceptions of a cosmic religion and an impersonal God, akin to "the God of Spinoza." Jammer explores Einstein's writings and lectures on religion and its role in society, and how far they have been accepted by the general public and by professional theologians like Paul Tillich or Frederick Ferré. He also analyzes the precise meaning of Einstein's famous dictum "Science without religion is lame, religion without science is blind," and why this statement can serve as an epitome of Einstein's philosophy of religion.
The last chapter deals with the controversial question of whether Einstein's scientific work, and in particular his theory of relativity, has theologically significant implications, a problem important for those who are interested in the relation between science and religion. Both thought-provoking and engaging, this book aims to introduce readers, without proselytizing, to Einstein's religion.