This book combines two themes, as its title rightly indicates: the necessarily sparse biography of a very private person, and the way in which nuclear physics changed and thereby changed the world in the middle decades of the 20th century. Naturally the two themes are linked, since James Chadwick's personality had a major effect in making him so influential at a crucial time.
On the personal side I find a few points worth noting in spite of Chadwick's reticence about private matters. He came from a very modest home, yet rose rapidly at school and at university to work in the most advanced departments. As the author comments, this would scarcely have been possible a generation earlier (though Michael Faraday and T.H. Huxley come to mind as counter-examples), but the thought crosses my mind as to how easy such progress would be today. We are far better than our predecessors in educationally advancing young people of interest and ability irrespective of their social and economic background, but are we quite as good at ensuring rapid progress for the extremely able as was the case 90 years ago?
Still on the personal side, I find it remarkable how speedily the reticent Chadwick, usually slow to thaw, appreciated the outstanding qualities of the young Joe Rotblat when he arrived in Liverpool from Warsaw with little money and less English.
Next, I was puzzled by the frequent references to Chadwick's ill- health, particularly during his American sojourn and after. The author does not even speculate whether and to what extent the trouble was purely psychosomatic, or had an identifiable organic cause.
In Chadwick's long and varied career there were quite a number of critical occasions which make fascinating reading, but they are rather buried amongst the more ordinary events. Indeed, my chief criticism of this excellent volume is that one is told this remarkable story in a monotone, so that the reader has to find his own highlights. I do not think this is necessitated by the scholarly character of the book, with a wealth of well-annotated references. But the importance of what we are told is so great that I would urge readers not to be deterred.
The story of the discovery of the neutron is well told, showing how Chadwick's thoroughness led to his success. Would such deliberate methods be advisable in our hurrying age?
Irreverently, the thought crosses my mind that it was perhaps not unfortunate for Lord Rutherford's reputation that he died, relatively early, in October 1937. During the war his influence would certainly have been overpowering and perhaps not always forward looking and in the best interests of Britain.
As the book describes well, a similar disagreement appears a few years later (in 1941/2), when the UK had to decide whether it wanted the atomic bomb to be built at home or in North America. For some time Chadwick was so strongly affected by his (then perhaps justified) view of the superiority of nuclear physics in this country that he wanted this wartime project to be carried out here. His younger colleagues, notably Mark Oliphant, immediately saw that this huge task required the enormous resources of the United States. Chadwick came round to this view before long, but the delay, as the author writes, may well have diminished British influence and standing in the joint undertaking. Only when they saw the gigantic scale of the American effort did many on this side of the Atlantic appreciate that it would have been nonsense to attempt to accomplish this huge task in wartime Britain with all its shortages, especially of skilled personnel, not to speak of the threat of bombing.
One can see echoes of this issue in present British society - the over-rating of research and science in comparison with development and engineering continues to this day. The attitude is still with us that if the idea is good, its translation through development into production and marketing is a mere, though perhaps expensive, "technicality". With the significance of good engineering still widely undervalued, is it surprising that only a modest proportion of the academically most able young people choose engineering as a career? And even those who have studied it do not necessarily stay in a field in which real responsibility (which is what ambitious young people crave to be given) is often long delayed, at least in part because the contribution of engineering is under-valued.
The scale and especially the space requirements of the American programme calmed fears that Germany was seriously working towards an atomic bomb, as this would easily have been detected from the air. But this view neglects that, until they were driven back by the Red Army, the Nazis controlled a vast slice of territory in the east where much could have been hidden.
Perhaps the most intriguing part of the book describes how the quiet, reticent Chadwick, wholly immersed in laboratory science, became an excellent and universally trusted diplomat in the tangled field of UK-US nuclear links. Indeed the relation between him and General Leslie Groves (who was anathema to many scientists) are very well described, including the mutual respect as well as the difficulties caused by British loyalty to the French foothold in the field. (As a personal sociological comment, I find it amazing that these nuclear researchers, colleagues of Lise Meitner and of the Curies -mother and daughter - in their correspondence invariably refer to physicists as "men". Maybe we have improved a little in some respects.) I can warmly recommend this book to all interested in the life of a remarkable scientist who played a crucial role in a formative period of the modern world. No technical knowledge is required, but a little persistence is needed to take the reader from one important section to the next one.
Sir Hermann Bondi wasformerly master, ChurchillCollege, Cambridge.
The Neutron and the Bomb: A Biography of Sir James Chadwick
Author - Andrew Brown
ISBN - 0 19 853992 4
Publisher - Oxford University Press
Price - £29.50
Pages - 384