In the years before his death in 1967, J. Robert Oppenheimer was perhaps the most famous living physicist in the world. A universal genius, he wrote poetry and read the Bhagavad Gita in the original Sanskrit. In the world of physics, he made seminal contributions to our understanding of molecules, quantum field theory, and astrophysics. Despite this work, he never received the Nobel Prize. Then and now, his fame rests on the events of July 16, 1945.
At 5:29 am, dawn burst violet-fingered and terrible over the New Mexican desert near Alamogordo. As the flash faded and the desert trembled to the roar of a new world being born, Oppenheimer thought of a line from the Bhagavad Gita: ‘I am become Death, the destroyer of worlds.’ Less than ten years after he had ushered that awful Trinity of light, smoke, and thunder into existence, Oppenheimer—the archetypal insider and charismatic leader of the scientific community—was a broken outsider: crucified by Communist witch-hunters and the military establishment for his guilty opposition to the nuclear arms race, shunned by many of his colleagues for his shameful and unsuccessful attempt to avoid persecution by naming names.
Hans Bethe, one of the eulogists at Oppenheimer’s funeral, outlived his friend and colleague by several decades, dying in 2005 at the age of 98. Bethe was in many ways the professional mirror of Oppenheimer. Unlike the temperamental ‘Oppie’, whose Berkeley group worked on virtually every significant problem in theoretical physics in the 1930s, Bethe was a ‘master craftsman,’ insisting on a total command of established technique in his chosen field. While Oppie essentially stopped doing physics after World War II, Bethe remained productive into his eighties; while Oppie’s ambition in attacking every difficult problem excluded him from the elite circle of Nobel prize winners, Bethe’s focussed, careful analysis dramatically demonstrated that nuclear reactions were the source of the sun’s energy and earned him the 1967 Nobel Prize in physics. Oppenheimer may have been in some sense more brilliant, but there is no doubt that Bethe was the greater physicist.
Bethe also played a greater role in averting nuclear holocaust. Hand-picked by Oppenheimer to head the theoretical division at Los Alamos during the war, Bethe directed the essential calculations behind the implosion device that dawned over Trinity and devastated Nagasaki. Like almost all Los Alamos scientists, Bethe was deeply disturbed by the reports from Hiroshima and Nagasaki. When the U.S. began its drive for the hydrogen bomb, Bethe declared it ‘a terrible error.’ But when he perceived that its development was inevitable, Bethe realised that he could most effectively advocate disarmament from within Los Alamos. Thus Bethe again played a pivotal theoretical role in the design of a terrible weapon, this one even more fearsome because it was a weapon of genocide. Crucially, it was this continued technical involvement with weapons research that provided Bethe the practical authority to argue for disarmament, and Bethe played a central role in a 1963 ban on atmospheric testing, as well as opposing the Strategic Defense Initiative in the 1980s.
It is through the lives of these two men—not parallel so much as ‘entangled’—that Silvan Schweber examines the timely question: What are the moral responsibilities of the scientist? The book that emerges from Schweber’s ruminations is difficult but important. Although written in the context of an ongoing biographical project on Bethe, In the Shadow of the Bomb is not a biography of either Oppenheimer or Bethe. In fact, it expects that the reader is familiar with much of the contemporary physics and history. But one need not submit to an undergraduate training in physics before approaching this book. Much of the relevant physics and history can be gleaned from reading one of the excellent recent biographies of Oppenheimer. Jeremy Bernstein’s Oppenheimer: Portrait of an Enigma (2004) is a fine, short introduction, with Kai Bird and Martin Sherwin’s American Prometheus (2005) the undisputed authority on Oppenheimer’s life and times. Armed with some background, the reader can appreciate the twin virtues of Schweber’s book: its tight focus on Oppenheimer and Bethe’s moral development and agency, and its extensive use of original sources to drive the story.
In Schweber’s view, both Oppenheimer and Bethe are ‘children of the Enlightenment.’ He takes his understanding of Enlightenment from Foucault, who identified it as ‘an attitude, an ethos, a philosophical life in which the critique of what we are is at one and the same time the historical analysis of the limits that are imposed on us and an experiment with the possibility of going beyond them.’ Both men had imbibed this Enlightenment attitude from their schooling: Oppenheimer in the Ethical Culture School and Bethe in the Gymnasium. But while Bethe remained a true Kantian, believing in the universalism of principles like knowledge, reason, truth, progress, Oppenheimer developed an almost postmodern worldview, striving always to ‘go beyond’ the limits of his present circumstance and moment.
Oppenheimer’s moral stance was certainly relativist. He wrote to George Kennan in 1951, ‘What I question is our ability to put ourselves, as a nation, in the place of these other peoples and decide what is right or wrong in the light of their standards and traditions.’ This moral relativism, remarkable in its Cold War context, was complemented by a vigorous intellectual pluralism. In 1959 Oppenheimer wrote, ‘Only a malignant end can follow the systematic belief that all communities are one community; that all truth is one truth; [...] that total knowledge is possible.’ One year later he noted that ‘No part of science follows, really from any other in any usable form [...] One is dealing with a wholly different order of nature.’ These prophetic words are a refreshing counterpoint in the current debate on ‘consilience,’ the unity of all human knowledge. They present a modest and humanist vision of science’s scope, an antidote to contemporary scientific triumphalism.
Oppenheimer’s relativist and pluralist stance externalized a radical personal complexity. His friend George Kennan described him as ‘a bundle of marvelous contradictions’; his nemesis Edward Teller testified in Oppenheimer’s 1954 security hearing that ‘I would like to see the vital interests of this country in hands which I understand better and therefore trust more.’ Oppenheimer’s science mirrored his drive to ‘go beyond’ and his failure to integrate his internal contradictions and complexity. He pushed constantly and everywhere along the boundary of the known, driven to tackle problems too difficult even for one of his genius. Schweber notes that Oppenheimer, ‘conscious of his fracturedness,’ yearned for ‘wholeness and a more integrated self.’ Yet this unity would forever evade him; Schweber makes a moving comparison to Nietzsche’s ‘man without any power to forget who is condemned to see “becoming” everywhere.’ At last, ‘he will hardly dare to raise his finger.’
In contrast, Bethe’s Kantian universalism flowed into, and perhaps from, his personal and professional integrity. His friends speak of his remarkable serenity, of his ability to ‘act decisively as a moral agent’; he was not a man in conflict with himself, but could rationally integrate (perhaps rationalise) his actions, even so far as deciding to work on the H-bomb. Bethe’s drive towards integration even appeared in his science, which was characterized both by the synthesis of fields (in the case of his many famous review articles) and by the analysis of how reductive parts combine into synthetic wholes (for example, his work on nuclei or the source of energy in the sun).
Bethe and Oppenheimer’s experience of community provides an interesting lens through which to examine their personalities, integrated and fractured. Both men treasured community, and indeed Oppenheimer was the leader of two of the most remarkable communities in the history of physics. In addition to the extraordinary laboratory at Los Alamos, Oppie’s group at Berkeley comprised the largest and the best school of theoretical physics that America had ever seen. Bethe wrote of Los Alamos that ‘it was an unforgettable experience [...] I never observed in any one of these other groups quite the spirit of belonging together, quite the urge to reminisce about the days of the laboratory, quite the feeling that this was really the great time of their lives.’
In both cases, Oppenheimer was not first among equals—he was the animating genius. At Berkeley, he was the centre of his students’ intellectual and social world, while at Los Alamos he was, in Bethe’s words, ‘a leader [who] brought out the best in all of us, like a good host with his guests.’ Both communities were urgently committed to their goals, and this common purpose allowed Oppenheimer to overcome his personal flaws and bring his enormous charisma to bear in forging ‘the spirit of belonging together.’
But in the post-atomic wasteland, with moral and intellectual bearings universally disordered and fragmented, Oppenheimer’s charisma and reach proved his undoing. Overconfident from his success at Berkeley and Los Alamos, Oppenheimer sought, and briefly wore, the mantle of scientist-statesman, becoming the representative of the entire scientific community. In assuming this enormous responsibility—in effect shouldering the entire moral burden of the scientific community himself—Oppenheimer unwittingly began the journey to his personal Calvary. Oppenheimer approached Truman in 1946 and explained that ‘I have blood on my hands,’ deeply offending the President. Oppenheimer’s subsequent, tireless activity within the corridors of power, particularly his effort to prevent the design of the H-bomb and forge a ‘Soviet-American agreement to ban [its] testing,’ made him the symbol of the scientific community’s meddlesome presumption among dissenting elements of the military and national security apparatus. As these political enemies plotted Oppenheimer’s downfall, seeking to make him a cautionary example, his all-too-human moral failures rendered him an unwitting accomplice. Schwerber writes extensively of Oppie’s appalling conduct in betraying Bernard Peters to the House Committee on Un-American Activities, and quotes Victor Weisskopf’s plaintive letter to Oppenheimer on the Peters affair: ‘we are all losing something that is irreparable. Namely confidence in you.’
Yet Oppenheimer’s deepest disappointment came at the Institute for Advanced Study in Princeton, where he had become director in 1947. Driven by his catholic interests and near-infinite intellectual reach, Oppenheimer had hoped to create there a replica of the camaraderie of Los Alamos. While surveying the fractured intellectual landscape and accepting that it would be misguided to search for any unifying system of ideas, he dreamed that at least a community of respect and fellowship could be built across the disciplines. In this he experienced bitter failure. His friend Kennan wrote that ‘he himself remained so largely alone in his ability to bridge in a single inner world those wholly disparate workings of the human intellect.’ In both cases Oppenheimer had sought to write large a personal struggle: in the first case, to wash his hands of the blood of Hiroshima and Nagasaki; in the second, to maintain integrity against the centrifugal force of his manifold intellectual passions. Yet in both instances, his inability to leave his personal struggles behind condemned him to speak of a fellowship and a community he himself could never achieve, and from which he was forever excluded.
Bethe’s modesty and the circumscription of his aims allowed him to succeed where Oppenheimer failed. Oppenheimer had come away from Los Alamos convinced of both his terrible personal responsibility and of his enormous powers to forge and lead a community. Bethe, who had been a loner before his Los Alamos days, took away the true meaning of Los Alamos: the importance of community as an end in itself, and the value of ‘small’ aims in shaping and guiding that community. Although the design and construction of the first atomic bomb was certainly enormously difficult and of world-historical import, as an aim it was specific and ‘small,’ nothing compared to the moral struggle or the pan-disciplinary community Oppenheimer had envisioned after the war.
Hence Bethe understood that the struggle to prevent nuclear holocaust was the responsibility of the entire scientific community, and never sought the mantle of scientist-statesman. Rather he was content to remain a craftsman, participating in weapons research on a technical level, and it was this continued engagement with the weapons community that gave him the moral gravity and technical insight to argue for the goals of disarmament to which he was committed. He remained convinced that the H-bomb was an ‘evil thing,’ writing in 1950:
It is argued that it would be better for us to lose our lives than our liberty; and this I personally agree with. But I believe that this is not the question; I believe that we would lose far more than our lives in a war fought with hydrogen bombs, that we would in fact lose all our liberties and human values at the same time, and so thoroughly that we would not recover them for an unforeseeably long time.
These words were remarkable in the moment, and it is even more remarkable (and perhaps disturbing) that they remain relevant in the present-day war on terror. Bethe saw that the existential threat posed by Soviet communism necessitated, in a way, the balance of terror. But after this threat had passed, Bethe spoke in 1995 at Los Alamos to ‘call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons.’ He had succeeded where Oppenheimer had failed; there was no blood on Bethe’s hands when he died. He also succeeded in building a vibrant intellectual community, indeed a family, at the Cornell physics department, where he would remain until his death. It was this community that afforded Bethe the occasion, and perhaps the courage, to take ‘forthright stands’ during the McCarthy era for the rights and the democratic values he cherished, displaying great moral strength in defense of his colleague Philip Morrison—in stark contrast to Oppenheimer’s moral weakness in the Peters case.
In the end, Oppenheimer and Bethe represent two possible responses to the failure of Enlightenment values in the nuclear age. Both responses emphasise the importance of fellowship, with one’s fellow scientists and with one’s fellow human beings. But in practice Oppenheimer’s response was deeply personal. He held himself ultimately and irredeemably responsible for the tragedy of Trinity, and could never forgive himself this terrible sin, nor forget the blood on his hands. His act of radical ambition—to take up responsibility for science’s fall from grace—drove Oppenheimer into a personal wilderness from which he could only cry out, exhorting the listener of his 1954 lecture on Christmas Day ‘to cling to what is close to him, to what he knows, to what he can do, to his friends and his tradition and his love, lest he be dissolved in a universal confusion and know nothing and love nothing’. Bethe’s response is heart-wrenchingly summarised by Schweber: he ‘lived the life that Oppenheimer had described.’ Because he learned to ‘express love through his work’ and ‘to express his love openly in words,’ Bethe was able to transcend the sins of Los Alamos; he ‘helped himself, helped others, and helped mankind.’
Oppenheimer’s thoughts at Trinity proved prophetic. In the shattered landscape of the atomic age, Oppenheimer stood apart and alone, a July morning’s mushroom cloud reminding us that in its shadow ‘we can help, because we can love, one another.’ As for Bethe, he remained ‘til the end of his days as he had been at Trinity, standing before the ruin with his colleagues—his friends.
Bethe remarked after Trinity, ‘It was too much to say anything.’ We owe a debt of gratitude to this brave man, who would learn to say something through both his words and his life. To make this debt so plain is Schweber’s greatest triumph.
Jacob Foster is a DPhil student in mathematical physics at Balliol College, Oxford, and a PhD student in complexity science at the University of Calgary. His current interests include the mathematical properties of complex networks to the geometry of the Big Bang.