The History and Science of the Manhattan Project

by Bruce Cameron Reed (Springer-Verlag, Berlin, 2014), ISBN 978-3-642-40296-8, 451p, $60.

In the prologue to The History and Science of the Manhattan Project, Bruce Cameron Reed asks the question with which I approached this review — why do we need another book on the development of the atomic bomb?  As noted by Reed, there are many books including Richard Rhodes 1986 classic The Making of the Atomic Bomb. Reed argues that there has been new information in the last 25 years and that a somewhat different style book is needed for an individual familiar with physics, one that is addressed to an undergraduate student. To a large degree he has succeeded in describing the incredible magnitude, rapid progress, and success of the Manhattan Project (officially the Manhattan Engineering District) at an appropriate and interesting level. Problems, with answers, are provided at the end of many chapters to provide readers a chance to test their understanding.

The introduction and overview give an excellent summary of the fundamental issues and scope of the project, the majority of which took place from mid-1942 to August 1945. One could get a reasonable understanding by going no further; however, the details later in the book add significantly to the reader's understanding of the scientific and engineering challenges to be overcome and the pace at which activities were taking place.

The long second and third chapters on nuclear physics history can be skipped by people with a knowledge of nuclear physics. Although I found Chapter 2 in particular to be a diversion from the actual beginning of the project in Chapter 4, a student might find it useful.  With Chapter 4 the book began to really become quite exciting. The book does not follow a strict time sequence so one is bounced back and forth to some degree. While this confused me at times, it does provide an impression of how much is happening in such a short time. The writing emphasizes the manner in which the necessary components and engineering came very quickly together shortly before the bombs, Little Boy and Fat Man, were dropped.

While there have been numerous accounts of the vital role of Robert Oppenheimer in leading the scientific aspects of the project at Los Alamos, the importance of having General Groves in overseeing the whole project was also absolutely vital. The huge engineering and logistics efforts would not have happened without someone of his capability. The three major facilities (Los Alamos, Hanford, and Oak Ridge) were so distant from each other that coordination and transportation from lab to lab was not trivial. The extensive logistics involved in setting up three “green field” sites were overcome in a remarkably short time. It was a dramatic example of how much can be accomplished if money is not a constraint and risks are accepted, but we must also note that we are still dealing with the legacy issue of nuclear waste, especially at Hanford.

The focus at Los Alamos was on the science of how to make an atomic (fission) bomb actually work. The scientists were remarkable not only for their talent but also for their youth, the most probable age being about 27. The physics considerations to make both the uranium-based Little Boy and the plutonium-based Fat Man actually work were quite different.  Reed describes both in considerable detail. There was a need for a variety of cross section measurements. To provide the equipment to gather the necessary data, accelerators from various universities were packed up and shipped to Los Alamos. This posed logistical issues of dismantling and packing large equipment and then shipping and reassembling it at a remote location, but the logistics paled in comparison to those at Oak Ridge or Hanford.

The efforts at Oak Ridge and Hanford involved enormous amounts of engineering and construction, carried out by industrial firms. The construction of huge facilities at Oak Ridge to enrich uranium-235, quickly followed by operation, in less than 2 years is stunning when one compares with today's construction times. It included borrowing silver from the U.S. mint to make busbars. The construction of the first large production reactors at ORNL and Hanford were another feat. In particular, Hanford’s 250 MW reactors to produce plutonium were constructed in less than a year. To add to the difficulties, upon startup there was a surprise as the enormous neutron capture cross section of one fission product, xenon-135, stopped the reactor (xenon poisoning), requiring post-hoc changes to the reactor to reach the required power level.  In the end the three reactors at Hanford did not all come on line until March of 1945, just 5 months before the plutonium was used in Fat Man.

Reed describes more mundane, but important, considerations such as dummy drops that revealed that the bombs would not fall in a controlled way so their external design had to be modified. There was also an issue of accommodating the bombs' sizes with the bomb-bay doors of the B-29.

This is comprehensive and fast paced read that should be fascinating not only for students but for any physicist.  There were a few issues that could be improved. Some of the pictures could be of higher quality and there are a number of typographical issues.  I also found it distracting in the Introduction to be told numerous times what chapter would address which topic in more detail. I am aware of two statements that should be corrected. Ernest Rutherford’s didn't die from a fall, but from an untreated umbilical hernia. And many physicists would challenge the statement that “nuclear physicists classify the parity of nuclei” according to the evenness or oddness of the number of nucleons. The context for the parity of nuclear states is much different.

These minor issues do not detract from the book capturing the scope Manhattan Project. It is well documented with an extensive list of references and copies of original documents. One of these is a letter from Groves about the readiness of a third bomb; the letter contains a handwritten note from General Marshall that the third bomb is not to be dropped without the express order of the President. The History and Science of the Manhattan Project book is an interesting, informative and entertaining read.

Peter D. Bond
Brookhaven National Laboratory
bond@bnl.gov

These contributions have not been peer-refereed. They represent solely the view(s) of the author(s) and not necessarily the view of APS.