This is a new book in the science and discovery series- a series which presents the exciting world of science as only scientists know it. The science and discovery books offer clear and enjoyable writing, the elegance of logical ideas, and glimpses of the scientist's new and unfolding view of the universe in the mid-twentieth century. Professor Frisch's book, to quote his introduction, "brings us face to face with the great unsolved problems of physics, concerning the fundamental particles of matter and their interrelations- a fascinating field where every advance liable to change to change our view of the world in which we live." Here is an up-to-date, understandable account of man's new-found sources of atomic energy, of the fantastic machines with which physicists are exploring the nature of matter and energy, and of the revolutionary surprises- in the form of strange particles and the contradictions of time-honored principles, such as the breakdown of parity- which are emerging in the physicists' research. The author concludes his story with a discussion of the future of physics.