In the following weeks, Serber touched on many themes, racing to an array of chalkboards to scribble complex formulas and equations. Among other things, he addressed how big a bomb would need to be in order to achieve critical mass--between 13.5 centimeters and 9 centimeters, he calculated--and what the probability of premature detonation might be. (It was, he concluded, always a danger.) At the end of the series, his lecture notes, classified as top secret, were gathered and printed for distribution to later cadres of scientists who came to work at Los Alamos. Years after the war they were declassified, and Serber, who died in May of 1997, took the opportunity to reflect on his work and the strange culture of the laboratory, adding postscripts and other commentary reproduced in the present edition.
Serber's book is an important document in the history of science, and remains one of the most accessible introductions to nuclear physics ever written. (On that note, those who worry that it is all too easy to find bomb-building instructions in the library or on the Web should rest assured: these lectures were tough for the greatest theoretical physicists of the time to follow.) It all makes for provocative reading. --Gregory McNamee