Niels Bohr, Revised Edition delves into the life and work of the founder of the modern atomic theory, highlighting his research on the atom and its structure, the subsequent development of the nuclear age, and his efforts to use his influence to promote peace. This revised edition offers new sidebars on subjects of interest, including the tools of physics, biographical profiles, and the recent play and film ""Copenhagen"", which has raised ethical concerns surrounding the relationship between science and society during wartime. Additionally, a new final chapter looks at string theory, the hypothesis that attempts to solve the universal paradoxes that have puzzled so many since Bohr's time.