Here is a concise up-to-date history of the hypotheses, theories and discoveries that make up the young science of nuclear physics. ""If we imagine an atom as enlarged to the size of a house; its nucleus, enlarged in proportion, would be the size of a pinhead."" Yet, this pinhead would contain about 99.95% of the enlarged atom's mass. By probing the nucleus, scientists have discovered the processes of nuclear fission and fusion that resulted in the atomic and hydrogen bombs. They have created new elements; they have found new elementary particles and anti-particles within the structure of the atom; they have learned a great deal about the size and shape of the nucleus and about the force that holds it together. Now, using their new understandings, scientists are developing hypotheses, that may eventually explain the evolution of the universe into its present form. This book should fascinate young adults and older laymen who have a little background and a lot of interest in this field of science.