In an interview conducted for a CBS documentary in the early 1990s, she talked about her life with her famous parents and how it took her until the age of forty-five to come to terms with her father’s fame. Nella regretted not reverting to the family name when she divorced her husband, Milton Weiner, in 1965. For her, Los Alamos was a great adventure, but she confessed to an irrational sense of guilt for the bombings of Hiroshima and Nagasaki. She also understood the complexities of the moral dilemma faced by her father and his colleagues as they worked to design and build the terrible weapon.
Nella’s daughter Alice (who later changed her name to Olivia Fermi) remained close to her grandmother Laura. In her last years, Nella would urge Olivia to “Put your grandmother Laura first, ahead of Enrico.” The words are somewhat opaque, but we can guess at their meaning: Enrico was a star that the world would remember and it was important to foster Laura’s legacy. Nella felt Laura was important in her own right and was unjustly overshadowed by her husband.
Nella contributed to a commemorative event organized at Cornell by Jay Orear in 1991, regaling the audience with anecdotes of her childhood with her father. She died in 1995, a victim of lung cancer. By this time, she had made peace with her father’s fame and role in the history of science and was comfortable speaking publicly about him and about their relationship.
Giulio had a harder time of it. He never felt comfortable living in his father’s shadow and did what he could to distance himself from Enrico. In his adolescence he changed his name to Judd and used an American pronunciation of his last name, “FIR-mee” rather than “FAIR-mee,” rarely speaking of his famous father. He chose not to pursue physics, although he had the innate ability to do so. Instead, he pursued a rarified program in pure mathematics, leaving Oberlin early for a mathematics PhD at Princeton. His Oberlin friend Robert Fuller joined him there. After Princeton Judd did a post-doc at Berkeley, where he met and married Sarah Duncan Pietsch, an artist and a literary scholar. They moved to Washington, DC, where Judd held a position at the Institute for Defense Analysis, a distinguished defense policy think tank, for a decade. He eventually became bored in Washington and took a position working in the lab of Nobel Prize winner Max Perutz at Cambridge University, where he developed mathematical models of complex proteins. The severe depression of his adolescence never returned, but he was a quiet and shy man, who actively withdrew from the limelight, happy to contribute to the work of others, but with little interest in generating his own projects. A heavy smoker, he died of a heart attack in 1995 at the age of sixty. His health problems may have been aggravated by the stress he felt when the British government insisted that researchers at government-funded science labs present research projects of their own or else find new work.
Whereas Nella resembled her father, Judd had a greater resemblance to his mother, although his eyes were Enrico’s—hazel gray and, for those who knew Enrico, very familiar. Richard Garwin recalls lecturing at Cambridge in the 1980s and noticing someone in the audience who reminded him of Fermi. The eyes, he thought, were unmistakable. It was Judd, who afterward introduced himself as Enrico’s son, much to Garwin’s astonishment and pleasure.
Of the following generation, Nella’s daughter, Olivia, and Judd’s daughter, Rachel, have been most publicly involved with their grandparents’ legacy. A psychotherapist living in Vancouver, Olivia has embraced the family history. She has two blogs—one about the Fermi family and another about nuclear policy issues. Rachel pursued a career in photography and fine arts but also embraced her grandfather’s legacy. In 1995, she produced a comprehensive photographic history of the Manhattan Project, Picturing the Bomb, with coauthor Esther Samra. She lives in the north of Scotland with her artist husband and their family.
For both Olivia and Rachel, Laura looms large in childhood memories. Neither had been born when Enrico died, so they know him only through family anecdotes passed down by their grandmother and their parents. Yet the legacy of the Manhattan Project fascinates and disturbs them. For this generation of Fermis, Fermi-Dirac statistics, beta decay, and pion-nucleon scattering all take second place to their grandfather’s work on the atomic bomb.
AFTER HIS DEATH, FERMI’S CELEBRITY PROMPTED THE USE OF HIS name to commemorate him in any number of ways. The Chicago institute now bears his name, as does the huge national laboratory built in the early 1970s fifty miles west of the city. A space telescope designed to focus on gamma-ray sources in deep space is called the Fermi Telescope. Nuclear reactors in the United States and in Italy are named after him. Countless towns in Italy have streets and plazas named after him. Train stations in Rome and Turin bear his name.
Among all these tributes he would probably be most proud of the prize bearing his name that the US AEC awards annually, first granted to Fermi on his deathbed. The US Department of Energy describes it in the following terms:
The Fermi Award is a Presidential award and is one of the oldest and most prestigious science and technology honors bestowed by the U.S. Government. The Enrico Fermi Award is given to encourage excellence in research in energy science and technology benefiting mankind; to recognize scientists, engineers, and science policymakers who have given unstintingly over their careers to advance energy science and technology; and to inspire people of all ages through the examples of Enrico Fermi, and the Fermi Award laureates who followed in his footsteps, to explore new scientific and technological horizons.
Recipients of this honor include an impressive array of men and women in science: in chronological order, von Neumann, Lawrence, Wigner, Seaborg, Bethe, and Teller were the first recipients, beginning in 1956. The award of the prize to Oppenheimer in 1963 was widely seen as an act of contrition by the US government for the way it treated him in 1954. The award of the prize to the trio of scientists who discovered fission—Hahn, Meitner, and Strassman—in 1966 was a belated recognition of Meitner’s crucial contribution to the discovery. More recently, Wheeler, Zinn, Bradbury, Agnew, Peierls, Anderson, Alvarez, Weisskopf, Garwin, and Rosenfeld have all received the prize named after their friend and mentor, as have many other luminaries. Many consider it the highest honor they have received.
Several tributes by friends and colleagues are particularly noteworthy. In addition to the warm 1955 recorded tribute, To Fermi with Love, the mid-1960s saw the production of a full-length documentary, The World of Enrico Fermi. One of the most eminent science historians, Harvard’s Gerald Holton, brought the project together with the help of the Canadian National Broadcasting Company. Dozens of colleagues and friends, as well as Laura, discuss Fermi’s life.
One of the most lasting and beautiful of the tributes to Fermi was the development and publication, in two volumes, by the University of Chicago Press in collaboration with the Accademia dei Lincei in Rome, of The Collected Papers. The organizing team of Amaldi, Anderson, Persico, Rasetti, Segrè, Cyril Smith, and Wattenberg, with Laura’s active participation, reset every journal paper and article in beautiful typeface and provided valuable introductions to many of the major papers in the volumes. In a predigital world, culling all the papers, deciding which papers were sufficiently important for inclusion, and ensuring that nothing of importance was missing was an enormous undertaking. There are some 270 papers in all, as well as a brief biography written by Segrè and several useful appendices, including a list of his many honors and a chronology of his life. It should not be considered a complete set of his work, however, because some of his important papers and lectures were only subsequently declassified, but it was as comprehensive as possible at the time.
And then there are his scientific legacies, including discoveries related to the weak interaction, the strong interaction, Fermi-Dirac statistics, and computational physics.
THE WEAK INTERACTION HAS BEEN A RICH SOURCE OF DISCOVERIES. Neutrino physics is an enormous field in itself, and the research into the weak interaction had dominated much of particle physics, resulting in more than a dozen Nobel Prizes, including the recent discovery of the Higgs b
oson. Most interesting, perhaps, is the deep connection between the weak interaction and the electromagnetic interaction first posited by Sheldon Glashow, Mohammad Abdus-Salaam, and Steven Weinberg, a first step in the pursuit of one of physics’ holy grails, the unification of all forces. For this work they shared the 1979 Nobel Prize.
Since Fermi’s passing, the exploration of the strong force holding the atomic nucleus together has had an equally distinguished history. Fermi’s pion scattering experiments led the way to further discoveries about the force that holds the nucleus together. Ultimately, this has resulted in the “quark” theory of matter, first proposed by Fermi’s Chicago colleague Murray Gell-Mann. Quarks are the fundamental building blocks of neutrons, protons, pions, and many other subatomic particles. Quarks are bound to each other by bosons that physicists call “gluons.” The interaction between quarks and gluons defines the strong interaction that holds these particles, and the nucleus itself, together. Fermi’s early pion work was the first step in this direction, and the quark theory, together with our understanding of the electro-weak interaction, constitutes a synthesis called the “Standard Model” of particle physics. The Standard Model explains a lot of the observable world, but it leaves many questions unanswered, questions with which theorists and experimentalists still grapple.
What might Fermi have accomplished if he had lived longer? It is difficult to say. He understood the complexity of the results from his pion scattering experiments in 1951 and 1952, but what he made of it is a different matter altogether. Subsequent advances in organizing and understanding the elementary particle “zoo” relied on group theory. Never a fan of group theory, he learned only as much as he needed to understand the quantum theory work of von Neumann and Weil. It is hard to imagine him willingly diving into group theory in the way required to have come up with the quark theory. Yet doing so may have been more important to him than, say, the QED renormalization completed by others so successfully in the late 1940s. If he decided a problem was sufficiently important, he would invest the time required to solve it, as he did with beta decay.
He was, at heart, a conservative physicist and would have felt uncomfortable with some of the early revelations regarding the weak interaction, particularly the completely unpredicted and revolutionary discovery in 1956, by his former students Lee and Yang, that it did not obey the rules of mirror-image symmetry. In looking to solve specific problems, Fermi rarely if ever chose revolutionary approaches. Yet he certainly would have been fascinated by the theoretical work and the experimental discoveries exploring the weak interaction and would have been an active participant in neutrino physics.
A MORE STRAIGHTFORWARD LEGACY IS THAT OF THE FERMI-DIRAC statistics.
Unlike the beta decay paper (not precisely correct) and the pion experiments (suggestive, but only a stepping stone to our understanding of the strong force), Fermi-Dirac statistics are as valid today as they were when first developed in late 1925 and early 1926. Any analysis of the energy distribution within a system of particles that obey the exclusion principle—gas, liquid, solid, or plasma—involves Fermi-Dirac statistics. In the words of physicist Henry Frisch, if we did not have Fermi-Dirac statistics, physics would be “in the stone age.” The use of Fermi-Dirac statistics is so universal and pervasive across different fields of physics that it is virtually meaningless to give examples. There will always be a debate about which of Fermi’s contributions to physics is his greatest, but those who favor Fermi-Dirac statistics point to the fact that it is still used the way Fermi presented it to the world in 1926.
WHEN FERMI FIRST BEGAN USING COMPUTERS, HE WAS INTERESTED in simulating physical processes. The computers were primitive and only the simplest of problems could be represented in a program. Analysis of data generated by detectors was all done by hand and eye.
Fermi would not recognize the world of computational physics today.
Computer simulations have become an essential part of any hypothesis testing in particle physics and of predicting the outcome of any given experiment. Computers also sift through petabytes of data generated by complex electronic detectors, looking for key signatures that indicate the presence or absence of a specific interaction. Computational physics has become a field of its own; most physicists are familiar with its techniques and some physicists specialize in it as a subfield. The discovery of the Higgs boson would have been impossible without advanced computational techniques. They are also central to many other physics specialties, for example astrophysics, where computational advances have enabled the modeling of complex processes involved in phenomena such as supernovae or the Big Bang.
Perhaps more interestingly, the Monte Carlo simulation techniques Fermi helped to pioneer, even prior to the invention of the electronic computer, are used wherever systematic simulations can shed light on solutions to complex problems, ranging from engineering and genetics to defense policy and nuclear strategy to finance and economics, even to law and social policy. They have been used to explore whether Joe DiMaggio’s fifty-six-game hitting streak should be considered an intrinsically rare event. Reflecting the essence of Fermi’s unique way of thinking about problems, the Monte Carlo technique is perhaps the single most important area where Fermi’s direct influence can be felt in the world outside physics.
IN ITALY, FERMI’S LEGACY WAS CHAMPIONED BY EDOARDO AMALDI. He directed the physics program in Rome and supported Bernardini’s plans to build a cyclotron in Frascatti, a Roman suburb. He fostered interest in the field by continuing to edit and update Fermi’s textbook for high schools. Edoardo also played a central role in pan-European physics, including the creation of CERN and the European Space Agency. Dismayed by the gulf that secrecy created between him and his old teacher and friend, he wrote bylaws prohibiting CERN from engaging in classified research. Fermi could not have wished for a better keeper of the flame.
The museum of physics at the University of Rome’s department of physics keeps the memory of Fermi alive among young people there, and Via Panisperna, under the auspices of the Italian Physics Society, is being converted to another museum, planned for completion in 2018. It will enable a new generation of Italians to wander the halls where Fermi launched the Rome School, where he conducted classes and seminars, and where he first bombarded uranium with slow neutrons.
The summer school in Varenna, named after Fermi, continues. The Italian Physics Society presents an annual prize, also named after him, to major figures in Italian physics and, more recently, to non-Italians as well.
The centenary of Fermi’s birth gave rise to major celebrations throughout Italy, resulting in some of the best commemorative volumes devoted to his life and work. Italian historians continue to illuminate aspects of his life and work, often providing a useful corrective to received wisdom.
After Fermi’s death, Amaldi shipped Fermi’s notebooks and other archives to the Domus Galilaeana in Pisa, convinced they belonged alongside Galileo’s archives. In so doing, he demonstrated the esteem with which Fermi’s fellow countrymen viewed him. Sixty-odd years later, it is a decision that few would second guess.
THE TWO LEGACIES STEMMING FROM FERMI’S MANHATTAN PROJECT work—the atomic bomb and the nuclear reactor—are perhaps more difficult to evaluate clearly today.
The legacy of the use of nuclear weapons is, not surprisingly, greatest in Japan, two of whose cities were obliterated by these weapons. More than two hundred thousand people perished in these attacks, and Japan has been in the forefront of the anti-nuclear movement. In 2016, President Obama became the first US leader to visit these cities, paying tribute to those who died. In response, Japanese Prime Minister Abe became the first Japanese leader to visit Pearl Harbor. Memories linger, even if enmities do not.
Over the past seventy years, at least eight other countries have learned the secret behind building nuclear weapons. Fermi understood that if it proved possible to make such a weapon, other countries would eventually do so. He had a pessimistic view of human nature and assumed tha
t people would eventually use whatever weapons were available to prosecute warfare. Fortunately, he has been wrong, at least until now. Aside from the initial use against Japan, no nation has used nuclear weapons against another. But as Fermi would surely have agreed, there is no law of physics preventing this from ever happening again.
Aboveground nuclear testing was frequent in the 1950s and early 1960s, leading to an ever-higher level of ambient radiation around the world. As a 2009 report of the Centers for Disease Control and Prevention made clear, even the first nuclear test at Trinity site had unintended, catastrophic fallout effects on local populations, livestock, and farming. Later on, trace levels of radioactive isotopes like strontium 90 found in food and milk throughout the country led to a wave of public health concern. Though aboveground tests have ceased, we live in an environment contaminated by the radioactive residue of these tests, residue that will last for centuries.
The prospect of all-out thermonuclear conflict has receded, owing largely to the end of the Cold War, but the threats of nuclear proliferation and nuclear terrorism loom larger today than in years past. North Korea increasingly rattles a nuclear saber in its fraught dealings with its neighbor to the south, as well as with the United States. Terrorism remains a serious threat. Some nuclear powers are host to active insurgent movements, and nuclear security is almost certainly not as tight as one would wish. The capture of even one nuclear weapon by an insurgent group bent on terror would be catastrophic. Policy analysts barely considered such possibilities when Fermi was alive. Today they dominate national security thinking.
The Last Man Who Knew Everything Page 41