Niels Bohr: On the Constitution of Atoms and Molecules

Niels Bohr’s atomic theory of 1913 is one of the absolute highlights in  the history of modern science. It was only with this work that  physicists realized that quantum theory is an essential ingredient in  atomic physics, and it was also only with this work that Rutherford’s  nuclear model dating from 1911 was transformed into a proper theory of  atomic structure. In a longer perspective, Bohr’s quantum atom of 1913  gave rise to the later Heisenberg-Schrödinger quantum mechanics and all  its marvellous consequences. This book is a detailed account of the  origin of the Bohr atom centred around his original scientific articles  of 1913 which are here reproduced and provided with the necessary  historical background. In addition to the so-called trilogy – the three  papers published in Philosophical Magazine – also two other and less  well-known yet important papers are included.

The present work  starts with a condensed biographical account of Bohr’s life and  scientific career, from his birth in Copenhagen in 1885 to his death in  the same city 77 years later. It then proceeds with a chapter outlining  earlier ideas of atomic structure and tracing Bohr’s route from his  doctoral dissertation in 1911 over his stays in Cambridge and Manchester  to the submission in April 1913 of the first part of the trilogy. The  reproduction of Bohr’s five articles is followed by notes and comments  directly related to the texts, with the aim of clarifying some of the  textual passages and to explicate names and subjects that may not be  clear or well known. The reception of Bohr’s radically new theory by  contemporary physicists and chemists is discussed in a final chapter,  which deals with the immediate reactions to Bohr's theory 1913-1915  mostly among British, German and American scientists.

Historians  of science have long been occupied with Bohr’s atomic theory, which was  the subject of careful studies in connection with its centenary in 2013.  The present work offers an extensive source-based account of the  original theory aimed at a non-specialist audience with an interest in  the history of physics and the origin of the quantum world. In 1922 Bohr  was awarded the Nobel Prize for his theory. The coming centenary will  undoubtedly cause an increased interest in how he arrived at his  revolutionary picture of the constitution of atoms and molecules.