Time Bomb!FERMI, HEISENBERG, AND THE RACE FOR THE ATOMIC BOMB by Malcolm C. MacPherson (Dutton: $18.95; 293 pp., illustrated)

In the summer of 1939, the German nuclear physicist, Werner Heisenberg, came to the United States on a lecture tour, and, while in New York, met his famous Italian colleague, Enrico Fermi, who had recently emigrated from his home country. According to Malcolm MacPherson, Fermi directly challenged Heisenberg about his intended return to work in Germany, pointing out that atomic physicists would be expected by their respective governments to work on new weapons.

Heisenberg’s response was confused. He rationalized his position with hopes that the war would not really happen, or the belief that “people must learn to prevent catastrophes, not run away from them.” But underlying his response was a basic loathing of being uprooted and leaving Germany. He was never to make any real attempt to prevent the catastrophe of the nuclear power he was uniquely qualified to unlock.

And yet, it would have taken only a relatively small change in the personal circumstances of these two men, the main subjects of this double biography, for their roles to have been reversed. Enrico Fermi left Italy for the United States only in late 1938 when the position of his Jewish wife, Laura, became untenable. At the same time, Heisenberg was being persecuted by the S.S. for being a “Jewish lover.” Only his mother’s friendship with S.S. chief Himmler’s mother prevented his career from ruin and his being driven into exile.

As it was, Heisenberg did return to Germany to play a central role in the attempt to develop a German nuclear weapon while Fermi remained in the United States totally absorbed in the parallel efforts there to produce a bomb. The men never met again during the war, and both quite pragmatically did what was required of them, and here lies the central problem with the book.

MacPherson chronicles with admirable clarity the three-year race between the two sides to test whether nuclear fission would result in the kind of rapid and explosive chain reaction necessary for a bomb. In the early stages, Germany had the resources, the manpower and the political will to make rapid progress. Indeed, if it had not been for a faulty calculation made early on about the suitability of graphite as the moderator--the material surrounding the uranium and cushioning and controlling the rate of fission--it is quite possible that Heisenberg might have been successful in producing a chain reaction. Whether he could then have persuaded Hitler to release the massive industrial resources of the scale the Americans had to use to produce the pure material for a bomb is another question. As it was, Heisenberg struggled to make a reactor using heavy water as the moderator, a material both difficult to obtain and to handle.

In the United States, the initial problems were largely financial and political, and it took Pearl Harbor to transform the situation. Within a year of that, Fermi’s team had produced the first controlled chain reaction and proved that a bomb was possible.

This narrative is handled fully and yet with sufficient clarity and excitement to appeal to a general audience. I might quarrel with MacPherson’s use of journalistic tricks to hype the narrative. For instance, too many sections in the book begin with phrases like “Edward Senigier bounded down the platform at Victoria Station feeling refreshed.” Immediacy is soon clouded by thoughts of parody. But his description of Fermi’s crucial chain reaction experiments under the Stagg Field football stadium in Chicago, based on a number of firsthand accounts, is most dramatic.

But in focusing on these two men, the author, by his own admission, is seeking to do more than provide yet another technical account. He has tried to limit his canvass in order to avoid the profusion of characters involved and to allow exploration of the broader issues of the relationships between war and particular individuals.

In this I believe he has largely failed. First, he has only effectively limited his canvass by ending the detailed story in late 1942 when Fermi’s work was taken up by the scientific teams at Los Alamos and Heisenberg arrived at a stalemate from which he never recovered. Otherwise most of the incidents and characters in the story, many of them with no direct relevance to either Fermi or Heisenberg, are there. He describes the French scientists smuggling the heavy water from Paris, the two commando raids on the Norwegian heavy-water plant and the early British work. He describes them well, but they make for a very fractured view of his two main characters.

Then, as the anecdote at the beginning of this review reveals, at least in part, he has picked on two characters through whom it is very difficult to explore moral dilemmas. Fermi has always remained a closed book even to those who worked closely with him. He neither kept a diary nor did he write memoirs. The author has had to rely heavily on Laura Fermi’s autobiographical book, “Atoms in the Family,” which is an uncritical and largely anecdotal book, providing regrettably little true insight.

As to Heisenberg, the material his book calls upon is more prolific, but even so, the central and crucial question regarding Heisenberg’s reasons and expectations in staying on in Germany is not fully explored. Heisenberg emerges as something of a doubting Thomas, loosely formulating his fears about the direction of the work to Neils Bohr but eventually sublimating them in the notion that he is working for Germany’s self-defense. I am glad for him--and for us--that he was not successful enough to see this notion put to the test.

A double biography is always a difficult form. The two characters must do more than fit where they touch. They must be interesting in themselves, and there must be some quite clear motive for treating both of them. I am left with the strong impression that this biography was motivated mainly by the sense of confusion the author admits to when first he approached this piece of history. He has produced a clear, highly readable general account, but he has failed to achieve the great synthesis he was working toward.