i found this to be a finely written story of an interesting life - how rare and refreshing to have a complicated scientific subject described in good english that is neither condescending nor too complicated.

well done mr brown! i look forward to your further works.

If you ask a typical physics undergrad for who discovered the neutron, you'll likely get a null answer. Chadwick is not widely remembered these days, which is why Brown's biography of him is a salutary reminder of his achievements.

We see how Chadwick's life spanned the seminal developments of modern physics, to which he made his worthy contributions. The book is also a good exposure to the international academic environments before World War 2. Especially the traditional British ivory tower.

It is the chapters on WW2 and later that we see Chadwick, and indeed physics generally, emerge and interact strongly with the real world. His efforts in directing the British contribution to the Manhattan Project may indeed be mostly overlooked today. But that may be primarily that the remembrance of the entire British effort was always overshadowed by the prodigious investment in manpower and resources that the Americans were able to bring to bear, in developing the atomic bomb.

Chadwick's involvement in the Manhattan Project was certainly appropriate. The chain reaction involves a heavy nucleus capturing a slow neutron. Which triggers fission and the production of more neutrons and excess energy. As the discoverer of the neutron, and the premier authority on how to generate and manipulate these, he was one of the obvious, key members of the Project.

In order to become more well-rounded in his studies of physics, Chadwick went to Germany before the outbreak of the first world war and was locked up as an enemy of the Germans when the war came. The total breakdown in the existing order of things might help explain why the British were so keen on finding the subatomic particle structure of matter. The previous discovery of the mass and charge of an electron and experiments with radium, which naturally decays, had indicated that atoms might be capable of being broken into smaller parts. The discovery of the neutron in 1932 paved the way for experiments in chain reactions in which neutrons, which were the products of splitting atoms, were used to split other atoms. The powers which have had uses for this knowledge have been so quick to put it to use that it is still considered a great secret from anyone that isn't a member in good standing of their club. This book may be read as a description of the life of a man who was a member of the club before anyone knew that there was a club. About the earliest sign in the book that some kind of club was being formed was when Chadwick obtained some German radioactive toothpaste, for people who need to have teeth that glow in the dark, and tried to figure out what was in it during World War One.