The Manhattan Project

by Cynthia C. Kelly

  In short, what meager reports we had prior to the Alsos Mission discoveries tended to indicate an active German project. The reports were erroneous. The Germans were, in fact, doing very little and had not even devised, let alone constructed, a self-reacting pile.

  In fact, the kind of reports we received early on indicate either an active “disinformation” project or, as I think to be the actual fact, simply the judgment of the people knowledgeable about the early work in Germany as to what the Germans must be doing given the early start they had in the area and their interest in the Belgian uranium supplies.

  Courtesy the Lansdale family

  Colonel John Lansdale Jr., shown with General Leslie R. Groves, was in charge of security for the Manhattan Project.

  Section Six

  The Trinity Test

  The Trinity Test

  The fear that Germany was developing an atomic bomb was the primary rationale for the Manhattan Project. However, by late 1944, concrete intelligence confirmed that Germany’s work on an atomic bomb had basically stalled in 1942, about the same time that the U.S. effort was beginning in earnest. For Joseph Rotblat, the fact that the German effort was stillborn undermined the rationale for continuing and he left the Manhattan Project. However, Rotblat was the exception. Even though Germany surrendered in May 1945, the Manhattan Project raced on faster than ever, with the target shifting to Japan in an attempt to end the war in the Pacific.

  Some of the scientists who worked on the bomb were aware of what it was and its ultimate purpose. Many debated among themselves the moral and ethical implications of using an atomic bomb and the future of international control of atomic energy, but prior to the end of the war were prohibited from doing so in public by secrecy restrictions. Physicist Robert Wilson organized seminars at Los Alamos that Oppenheimer attended. With a strong sense of responsibility for creating the bomb, Leo Szilard, Eugene Rabinowitch, and others at the University of Chicago’s Metallurgical Laboratory worked on the Franck Report issued on June 11, 1945, and drafted a petition to President Truman, signed by 155 scientists, on June 17, 1945. While their recommendations against the use of the bomb did not prevail, they accurately predicted a nuclear weapons arms race and formulated proposals for international controls to try and prevent it. This section includes excerpts from the scientists and government officials who wrestled with the problem of how to control this new danger to mankind.

  For most, the experience of witnessing the detonation of the first atomic bomb on July 16, 1945, was awesome, both magnificently beautiful and terrifying. Beyond the sheer spectacle, the participants felt a great sense of relief that everything had worked and hoped that the war would soon be over. The section concludes with several eyewitness accounts of the Trinity test and a novelist’s interpretation: “This was the real secret. Annihilation. Nothing else. A chemical pulse that dissolved finally in violet light. No stories. Now we would always be frightened.”

  Leaving the Bomb Project

  Joseph Rotblat reflects here on his decision to leave the Manhattan Project early and return to England. Toward the end of 1944 it became clear that Germany did not have an atomic bomb. Thus, Rotblat’s rationale for working on an atomic weapon—to create a deterrent to Hitler’s using one—no longer existed. While he departed before Christmas 1944, he spent the rest of his life working with an international community of scientists to abolish nuclear weapons and renounce war. With the organization Pugwash, he shared the Nobel Peace Prize for 1995.

  From “Leaving the bomb project”

  BY JOSEPH ROTBLAT

  In March 1944 I experienced a disagreeable shock. At that time I was living with the Chadwicks in their house on the Mesa, before moving later to the “Big House,” the quarters for single scientists. General Leslie Groves, when visiting Los Alamos, frequently came to the Chadwicks for dinner and relaxed palaver. During one such conversation Groves said that, of course, the real purpose in making the bomb was to subdue the Soviets. (Whatever his exact words, his real meaning was clear.) Although I had no illusions about the Stalin regime—after all, it was his pact with Hitler that enabled the latter to invade Poland—I felt deeply the sense of betrayal of an ally. Remember, this was said at a time when thousands of Russians were dying every day on the Eastern Front, tying down the Germans and giving the Allies time to prepare for the landing on the continent of Europe. Until then I had thought that our work was to prevent a Nazi victory, and now I was told that the weapon we were preparing was intended for use against the people who were making extreme sacrifices for that very aim.

  My concern about the purpose of our work gained substance from conversations with Niels Bohr. He used to come to my room at eight in the morning to listen to the BBC news bulletin. Like myself, he could not stand the U.S. bulletins which urged us every few seconds to purchase a certain laxative! I owned a special radio on which I could receive the BBC World Service. Sometimes Bohr stayed on and talked to me about the social and political implications of the discovery of nuclear energy and of his worry about the dire consequences of a nuclear arms race between East and West which he foresaw.

  All this, and the growing evidence that the war in Europe would be over before the bomb project was completed, made my participation in it pointless. If it took the Americans such a long time, then my fear of the Germans being first was groundless.

  When it became evident, toward the end of 1944, that the Germans had abandoned their bomb project, the whole purpose of my being in Los Alamos ceased to be, and I asked for permission to leave and return to Britain.

  Why did other scientists not make the same decision? Obviously, one would not expect General Groves to wind up the project as soon as Germany was defeated, but there were many scientists for whom the German factor was the main motivation. Why did they not quit when this factor ceased to be?

  I was not allowed to discuss this issue with anybody after I declared my intention to leave Los Alamos, but earlier conversations, as well as much later ones, elicited several reasons.

  The most frequent reason given was pure and simple scientific curiosity—the strong urge to find out whether the theoretical calculations and predictions would come true. These scientists felt that only after the test at Alamogordo should they enter into the debate about the use of the bomb.

  Others were prepared to put the matter off even longer, persuaded by the argument that many American lives would be saved if the bomb brought a rapid end to the war with Japan. Only when peace was restored would they take a hand in efforts to ensure that the bomb would not be used again.

  Still others, while agreeing that the project should have been stopped when the German factor ceased to operate, were not willing to take an individual stand because they feared it would adversely affect their future career.

  The groups I have just described—scientists with a social conscience—were a minority in the scientific community. The majority were not bothered by moral scruples; they were quite content to leave it to others to decide how their work would be used. Much the same situation exists now in many countries in relation to work on military projects. But it is the morality issue at a time of war that perplexes and worries me most.

  After I told Chadwick that I wished to leave the project, he came back to me with very disturbing news. When he conveyed my wish to the intelligence chief at Los Alamos, he was shown a thick dossier on me with highly incriminating evidence. It boiled down to my being a spy: I had arranged with a contact in Santa Fe to return to England, and then to be flown to and parachuted onto the part of Poland held by the Soviets, in order to give them the secrets of the atom bomb. The trouble was that within this load of rubbish was a grain of truth. I did indeed meet and converse with a person during my trips to Santa Fe. It was for a purely altruistic purpose, nothing to do with the project, and I had Chadwick’s permission for the visits. Nevertheless, it contravened a security regulation, and it made me vulnerable.

  Fortunately for me, in their zeal the vigilant
agents had included in their reports details of conversations with dates, which were quite easy to refute and to expose as complete fabrications. The chief of intelligence was rather embarrassed by all this and conceded that the dossier was worthless. Nevertheless, he insisted that I not talk to anybody about my reason for leaving the project. We agreed with Chadwick that the ostensible reason would be a purely personal one: that I was worried about my wife whom I had left in Poland.

  And so, on Christmas Eve 1944, I sailed for the United Kingdom, but not without another incident. Before leaving Los Alamos I packed all my documents—research notes as well as correspondence and other records—in a box made for me by my assistant. En route I stayed for a few days with the Chadwicks in Washington. Chadwick personally helped me to put the box on the train to New York. But when I arrived there a few hours later, the box was missing. Nor, despite valiant efforts, was it ever recovered.

  The work on the Manhattan Project, as I said at the outset, has had an enduring effect on my life. Indeed, it radically changed my scientific career and the carrying out of my obligations to society.

  Work on the atom bomb convinced me that even pure research soon finds applications of one kind or another. If so, I wanted to decide myself how my work should be applied. I chose an aspect of nuclear physics which would definitely be beneficial to humanity: the applications to medicine. Thus I completely changed the direction of my research and spent the rest of my academic career working in a medical college and hospital.

  While this gave me personal satisfaction, I was increasingly concerned about the political aspects of the development of nuclear weapons, particularly the hydrogen bomb, about which I knew from Los Alamos. Therefore, I devoted myself both to arousing the scientific community to the danger, and to educating the general public on these issues. I was instrumental in setting up the Atomic Scientists Association in the United Kingdom, and within its framework organized the Atom Train, a traveling exhibition which explained to the public the good and evil aspects of nuclear energy. Through these activities I came to collaborate with Bertrand Russell. This association led to the foundation of the Pugwash Conferences, where I met again with colleagues from the Manhattan Project, who were also concerned about the threat to mankind that has arisen partly from their work.

  After 40 years one question keeps nagging me: have we learned enough not to repeat the mistakes we made then? I am not sure even about myself. Not being an absolute pacifist, I cannot guarantee that I would not behave in the same way, should a similar situation arise. Our concepts of morality seem to get thrown overboard once military action starts. It is, therefore, most important not to allow such a situation to develop. Our prime effort must concentrate on the prevention of nuclear war, because in such a war not only morality but the whole fabric of civilization would disappear. Eventually, however, we must aim at eliminating all kinds of war.

  Anticipating the End of War

  As development of the atomic bomb neared completion, some scientists at Los Alamos began to question the implications of their work, especially when it became clear that Germany would soon be defeated and the weapon would not be used against the Nazis. Physicist Robert Wilson took the lead in organizing a number of discussions in which scientists shared their opinions about continuing work on the “gadget” and whether the bomb should be used. To no one’s surprise, Oppenheimer’s views prevailed.

  From American Prometheus

  BY KAI BIRD AND MARTIN SHERWIN

  By late 1944, a number of scientists at Los Alamos began to voice their growing ethical qualms about the continued development of the “gadget.” Robert Wilson, now chief of the lab’s experimental physics division, had “quite long discussions with Oppie about how it might be used.” Snow was still on the ground when Wilson went to Oppenheimer and proposed holding a formal meeting to discuss the matter more fully. “He tried to talk me out of it,” Wilson later recalled, “saying I would get into trouble with the G-2, the security people.”

  Despite his respect, even reverence, for Oppie, Wilson thought little of this argument. He told himself, “All right. So what? I mean, if you’re a good pacifist, then clearly you are not going to be worried about being thrown in jail or whatever they would do—have your salary reduced or horrible things like that.” So Wilson told Oppenheimer that he hadn’t talked him out of at least having an open discussion about an issue that was obviously of great importance. Wilson then put up notices all over the lab announcing a public meeting to discuss “The Impact of the Gadget on Civilization.” He chose this title because earlier, at Princeton, “just before we’d come out, there’d been many sanctimonious talks about the ‘impact’ of something else, with all very scholarly kinds of discussions.”

  To his surprise, Oppie showed up on the appointed evening and listened to the discussion. Wilson later thought about twenty people attended, including such senior physicists as Vicki Weisskopf. The meeting was held in the same building that housed the cyclotron. “I can remember,” Wilson said, “it being very cold in our building.… We did have a pretty intense discussion of why it was that we were continuing to make a bomb after the war had been [virtually] won.”

  This may not have been the only occasion when the morality and politics of the atomic bomb were discussed. A young physicist working on implosion techniques, Louis Rosen, remembered a packed daytime colloquium held in the old theater. Oppenheimer was the speaker and, according to Rosen, the topic was “whether the country is doing the right thing in using this weapon on real live human beings.” Oppenheimer apparently argued that as scientists they had no right to a louder voice in determining the gadget’s fate than any other citizen. “He was a very eloquent and persuasive guy,” Rosen said. The chemist Joseph O. Hirschfelder recalled a similar discussion held in Los Alamos’ small wooden chapel in the midst of a thunderstorm on a cold Sunday evening in early 1945. On this occasion, Oppenheimer argued with his usual eloquence that, although they were all destined to live in perpetual fear, the bomb might also end all war. Such a hope, echoing Bohr’s words, was persuasive to many of the assembled scientists.

  No official records were kept of these sensitive discussions. So memories prevail. Robert Wilson’s account is the most vivid—and those who knew Wilson always thought him a man of singular integrity. Victor Weisskopf later recalled having political discussions about the bomb at various times with Willy Higinbotham, Robert Wilson, Hans Bethe, David Hawkins, Phil Morrison and William Woodward, among others. Weisskopf recalled that the expected end of the war in Europe “caused us to think more about the future of the world after the war.” At first, they simply met in their apartments, and pondered questions such as “What will this terrible weapon do to this world? Are we doing something good, something bad? Should we not worry about how it will be applied?” Gradually, these informal discussions became formal meetings. “We tried to organize meetings in some of the lecture rooms,” Weisskopf said, “and then we ran into opposition. Oppenheimer was against that. He said that’s not our task, and this is politics, and we should not do this.” Weisskopf recalled a meeting in March 1945, attended by forty scientists, to discuss “the atomic bomb in world politics.” Oppenheimer again tried to discourage people from attending. “He thought we should not get involved in questions about the use of the bomb.…” But, contrary to Wilson’s memory, Weisskopf later wrote that “the thought of quitting did not even cross my mind.”

  Wilson believed it would have reflected badly on Oppenheimer if he had chosen not to appear. “You know, you’re the director, a little bit like a general. Sometimes you have got to be in front of your troops, sometimes you’ve got to be in back of them. Anyway, he came and he had very cogent arguments that convinced me.” Wilson wanted to be convinced. Now that it seemed so clear that the gadget would not be used on the Germans, he and many others in the room had doubts but no answers. “I thought we were fighting the Nazis,” Wilson said, “not the Japanese particularly.” No one thought the Japanese had
a bomb program.

  When Oppenheimer took the floor and began speaking in his soft voice, everyone listened in absolute silence. Wilson recalled that Oppenheimer “dominated” the discussion. His main argument essentially drew on Niels Bohr’s vision of “openness.” The war, he argued, should not end without the world knowing about this primordial new weapon. The worst outcome would be if the gadget remained a military secret. If that happened, then the next war would almost certainly be fought with atomic weapons. They had to forge ahead, he explained, to the point where the gadget could be tested. He pointed out that the new United Nations was scheduled to hold its inaugural meeting in April 1945—and that it was important that the delegates begin their deliberations on the postwar world with the knowledge that mankind had invented these weapons of mass destruction.

  “I thought it was a very good argument,” said Wilson. For some time now, Bohr and Oppenheimer himself had talked about how the gadget was going to change the world. The scientists knew that the gadget was going to force a redefinition of the whole notion of national sovereignty. They had faith in Franklin Roosevelt and believed that he was setting up the United Nations precisely to address this conundrum. As Wilson put it, “There would be areas in which there would be no sovereignty, the sovereignty would exist in the United Nations. It was to be the end of war as we knew it, and this was a promise that was made. That is why I could continue on that project.”

  Oppenheimer had prevailed, to no one’s surprise, by articulating the argument that the war could not end without the world knowing the terrible secret of Los Alamos. It was a defining moment for everyone. The logic—Bohr’s logic—was particularly compelling to Oppenheimer’s fellow scientists. But so too was the charismatic man who stood before them. As Wilson recalled that moment, “My feeling about Oppenheimer was, at that time, that this was a man who is angelic, true and honest and he could do no wrong.… I believed in him.”