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Cover design by RBDA Studio To Joanne, Matthew and Karen CONTENTS

INTRODUCTION CHAPTER ONE A SMALL GLOBAL COMMUNITY CHAPTER TWO ROME CHAPTER THREE SPLIT ATOMS CHAPTER FOUR HEISENBERG IN MICHIGAN CHAPTER FIVE WAR CHAPTER SIX HEAVY WATER CHAPTER SEVEN 1941 CHAPTER EIGHT THE MANHATTAN PROJECT CHAPTER NINE HEAVY WATER II CHAPTER TEN CHICAGO CHAPTER ELEVEN CONSTRUCTION CHAPTER TWELVE HEAVY WATER III CHAPTER THIRTEEN LOS ALAMOS CHAPTER FOURTEEN HUNTING HEISENBERG CHAPTER FIFTEEN HEAVY WATER IV CHAPTER SIXTEEN KIDNAP CHAPTER SEVENTEEN DARK DAYS CHAPTER EIGHTEEN ALSOS CHAPTER NINETEEN RESTRICTED AREA CHAPTER TWENTY BATTLE OF THE BULGE CHAPTER TWENTY-ONE HUNTING HEISENBERG II CHAPTER TWENTY-TWO CAPTURE CHAPTER TWENTY-THREE THE HUNT IS OVER CHAPTER TWENTY-FOUR PLUTONIUM CHAPTER TWENTY-FIVE JAPAN CHAPTER TWENTY-SIX FARM HALL CHAPTER TWENTY-SEVEN HIROSHIMA CHAPTER TWENTY-EIGHT PEACE ACKNOWLEDGMENTS BIBLIOGRAPHY END NOTES ABOUT THE AUTHOR INTRODUCTION

I FOUND THE PHOTO while browsing the internet: five men dressed in jackets and ties, smiling and posing for the camera somewhere on the campus of the University of Michigan. The picture was taken at an annual physics conference in Ann Arbor during the summer of 1939. I recognized two of the men: one, Werner Heisenberg, would go on to spearhead Adolf Hitler’s atomic bomb program, the other, Enrico Fermi, would become a top Manhattan Project scientist working on the Allied atom bomb. A third, whom I didn’t recognize, Samuel Goudsmit, would become a top Allied intelligence officer tasked with gathering information on the German atom bomb and, in the final months of the war, capturing Hitler’s atomic scientists before the Soviets could nab them. I later learned, to my surprise, that the three were longtime friends and that Heisenberg also knew Robert Oppenheimer, the future scientific director of The Manhattan Project. That photo, taken just a month before the start of World War II, provided the inspiration for “Chasing Heisenberg: The Race for the Bomb.” My interest in the rivalry between Allied and German scientists dates back to 1993 when I produced a report on J. Robert Oppenheimer for “The MacNeil/Lehrer NewsHour” on PBS. I’ve been reading about that history off and on for years, looking for a compelling narrative that would breathe new life into what was arguably one of the greatest scientific and engineering feats of the twentieth century. That 1939 photo alerting me to Heisenberg’s friendship with Fermi, Oppenheimer and Goudsmit showed me the way. I thought I knew the bomb’s history fairly well before I began digging into the lives of those four men, but I was wrong. My research uncovered twists and turns and fascinating details I had not known before, and along with them, the makings of a great story. CHAPTER ONE A SMALL GLOBAL COMMUNITY

3-13-38 CBS RADIO WORLD NEWS ROUNDUP

AUSTRIAN INVASION

Tonight the world trembles . . . Right at this moment Austria is no longer a nation, but is now officially a part of the German empire . . . The Nazis are driving with all their might to bring Austria under complete Nazi domination . . . Jews, Catholic leaders and former Austrian officials are being jailed. Hitler . . . is preparing . . . a roundabout triumphal tour of the land of his birth . . . In Berlin, Field Marshal Herman Goering has served notice that Germany intends to go after the Germans in Czechoslovakia already ringed on several sides by German troops.

BY THE SUMMER OF 1939, a little over a year after that radio broadcast, Adolf Hitler had all but shredded the Versailles Treaty, the peace agreement ending World War I. While Germany’s erstwhile enemies sat idly by, he’d rebuilt his nation’s military, sent German troops into the demilitarized Rhineland, annexed Austria, bullied the Czechs into surrendering the Sudetenland, occupied the rest of Czechoslovakia and stripped German Jews of their civil rights, forcing many to flee the country. After years of grabbing territory through political chicanery, Adolf Hitler was ready to go to war; his plan, to create a Third Reich, a racially pure Germanic Empire in Europe. As the date for the opening attack, an invasion of Poland, neared, scientists attached to the German War Office began research on a revolutionary weapon, a bomb that would draw its destructive power not from conventional man-made explosives like TNT, but from a primordial energy locked deep inside the uranium atom. No one had ever tried to harness that energy. No one knew if the weapon would work. But if it did, one “atomic” bomb would be able to destroy an entire city. Loaded into a long- range strategic bomber or onto a guided rocket, it might spread Nazism across the globe. With the world on the brink of war, Werner Heisenberg, a 37-year-old physics professor at the University of Leipzig, a Nobel Prize-winner and future architect of Hitler’s nascent atom bomb program, boarded an ocean liner and set sail for New York City. Heisenberg was one of the most brilliant physicists of his time. His work in the field of Matrix Mechanics was considered every bit as revolutionary as that of Albert Einstein and his theory of relativity. 1 A loyal son of the fatherland and a corporal in the reserve force that supported Germany’s regular army, Heisenberg sympathized with the Nazi goal of restoring Germany to a position of prominence in Europe. 2 But he condemned what he called “the excesses” of Nazism, especially the anti- Semitic policies that drove Jewish scientists, some of the nation’s best, to flee the country. 3 At the time, there were only about a hundred scientists in the world doing research in Heisenberg’s field of theoretical physics. 4 The rise of Nazism had estranged him from that small global community, and he looked forward to seeing old friends. Some he had known since the 1920s when he was a teaching assistant and they, postdoctoral fellows in Göttingen, Germany. Among them: a 34-year-old Jewish physicist named J. Robert Oppenheimer. 5 Göttingen was the world capital for theoretical physics. Oppenheimer had come there to study in 1927. He had read and admired Heisenberg’s work and looked forward to meeting him. Heisenberg was teaching elsewhere at the time, but when he came to the campus for a short visit Oppenheimer sought him out and introduced himself. Both men had brilliant and original minds. Drawn together by their shared interest, the future rivals developed what may not have been a friendship, but was certainly a relationship built on mutual respect. 6 During his trip Heisenberg reconnected with another former Göttingen student, Enrico Fermi, a Nobel Prize-winning Italian physicist. Fermi’s seven months at Germany’s elite university had been difficult. He felt uncomfortable and insecure. Göttingen attracted the world’s brightest physicists, future Nobel Laureates like Heisenberg and Wolfgang Pauli. Fermi worried that he would not measure up. Nevertheless, he and Heisenberg became close friends. 7

Enrico Fermi, Werner Heisenberg, Wolfgang Pauli (Photograph by Franco Rasetti, Courtesy AIP Emilio Segrè Visual Archives, Segrè Collection)

The two reunited at the University of Michigan in Ann Arbor, where they attended an annual meeting of theoretical physicists. A photo taken at the time captures the moment. It shows them with three Michigan faculty members: Samuel Goudsmit, Clarence Yokum and Edward Kraus. Goudsmit, another Göttingen graduate, was a close friend of Heisenberg.

Samuel Goudsmit, Clarence Yokum, Werner Heisenberg, Enrico Fermi and Edward H. Kraus at the University of Michigan, summer 1939 (AIP Emilio Segrè Visual Archives, Crane-Randall Collection, Goudsmit Collection)

Heisenberg’s last trip to the annual summer meeting was in 1939. Two years later, the Japanese attack on Pearl Harbor thrust him and his three American friends into the front lines of World War II where they squared off against each other in a race to build the atom bomb. This is the story of that race told through the lives of four scientists: Werner Heisenberg, the scientific head of Germany’s nuclear program, and Robert Oppenheimer, Enrico Fermi and Samuel Goudsmit, principal players in the Allied effort. It begins in Rome, Italy, in 1934 with Enrico Fermi’s pioneering experiment probing the atom’s nucleus. It had been almost three decades since Albert Einstein revolutionized atomic physics with his theory that an atom’s mass is really energy in a different form. In the following years, his famous equation E=mc 2 had become part of popular culture. Publishers lured readers with sensational headlines highlighting the potential dangers of atomic energy: “Tinkering With Angry Atoms May Blow Up the Earth” and “Nature’s Greatest Secret, the Might of the Atom Stirs Scientists.” 8 In 1914, in his novel The World Set Free , H.G. Wells looked into his crystal ball and conjured the horror of 1959, the year the world’s nations became engulfed in an atomic war. “From nearly 200 centres . . . roared the unquenchable crimson conflagrations of the atomic bombs,” he wrote, “the flimsy fabric of the world’s credit had vanished, industry was completely disorganized and every city, every thickly populated area was starving or trembled on the verge of starvation.” When Wells wrote his apocalyptic novel, atomic energy was a mysterious, almost mythical force of nature. Hidden in the inner sanctum of the atom’s nucleus and protected from inquisitive scientists by multiple layers of defense, it was virtually impossible to reach. Impossible, that is, until Enrico Fermi began chipping away at those defenses. CHAPTER TWO ROME

“CLEAR THE WAY; LOOK OUT,” shouted Enrico Fermi as he exited his laboratory clutching an irradiated sample of aluminum, and sprinted to a Geiger counter in a lab down the hall. It was winter 1934. Fermi, a physics professor at the University of Rome, was attempting some modern-day alchemy, bombarding samples of aluminum and other non-radioactive atoms with neutrons, trying to turn them radioactive. The radiation would last just a short while, often less than a minute. To make certain that errant neutrons didn’t contaminate the results, he placed the neutron source and the Geiger counter that measured the intensity of the radiation at opposite ends of the building. Thus, the 33-year-old Fermi and his post-graduate students racing down the hall like crazed schoolboys became a familiar sight all during that winter, spring and fall. 9 Fermi prided himself on his fleetness of foot and his ability to out-run, out-hike and out- swim his young associates. 10 These were exciting times for Fermi and his “boys,” as they were called. Scientific understanding of radiation and atomic structure had advanced dramatically over the past decades, and the recent discovery of neutrons promised to open the atom’s nucleus to still greater exploration. The inspiration for Fermi’s experiment came from two French scientists who had bombarded atoms with positively charged particles. Their choice of ammunition, however, had one drawback. Atomic nuclei have a positively charged outer barrier that repels positively charged particles. Their experiments could only induce radiation in lighter atoms, those with weaker barriers. 11 Fermi reasoned that neutrons, which have no electric charge, could penetrate even the strongest defenses. In preparation for their experiment, Fermi’s associates visited Mr. Troccoli, owner of Rome’s largest chemical supply store. There, they purchased samples of aluminum, carbon, platinum, gold and other elements, some 60 in all. 12 Back in the lab, they began the tedious process of irradiating each sample. One by one, they wrapped them around a glass tube containing a source that spewed out thousands of neutrons a second and then placed the whole in a lead-lined box. 13 If all went according to theory, some of the unguided neutron missiles would penetrate atoms within the sample and be absorbed into their nuclei. The nuclei would become unstable, begin to decay and emit radiation. By the fall of ’34 Fermi and his “boys” had induced radiation in 40 different atoms, far exceeding the successes of the French scientists. Thanks to Fermi and his neutron missiles, the nucleus, a tiny speck of mass floating in the atom’s vast inner space, was now open for exploration. For their final test Fermi and colleagues targeted uranium. Uranium was naturally radioactive, so no one was certain how it would react, if at all. To find out, they followed the bombardment with a chemical analysis. But instead of producing clarity, the tests left the Italian explorers scratching their heads. Scientists classify atoms according to the number of protons and neutrons in their nuclei. An atom with one proton is hydrogen; two protons, helium; 29 protons, copper; 92 protons, uranium. After analyzing the test results, Fermi was surprised to find that nuclei that had once contained 92 protons now contained 93. The bombarded atoms had undergone a chemical makeover. No longer uranium, they had been transformed into a heavier “transuranic” atom. If the results were accurate (Fermi wanted to do more testing to make sure), he was the first scientist ever to manufacture a brand new atom, an atom unlike any other on planet earth. Treading cautiously, Fermi and his associates co-authored a paper reporting that the evidence “ suggests the possibility” that a new element had been created. 14 A short while later, without consulting Fermi, his boss, the director of the Physics Institute at the University of Rome, announced unequivocally that Fermi had manufactured a new atom. The world’s press took notice. The New York Times trumpeted Fermi’s achievement with the headline “Italian Produces 93rd Element by Bombarding Uranium.” 15 FERMI HAD PIONEERED THE USE of neutrons as vehicles for nuclear exploration. Some speculated they might lead to the wellspring of atomic energy. But, as quickly as the speculation surfaced, it was shot down. The Nobel laureate Ernest Rutherford called the idea “moonshine”. Albert Einstein concurred, saying that using neutron bombardment to harness atomic energy would be like “shooting in the dark at scarce birds.” Despite the naysayers, it was clear that something strange and exciting was going on within the nuclei of bombarded atoms. And the surprises kept coming. In October 1934, Fermi was on his way back from a lecture tour in South America, when his colleagues telegrammed him that something was wrong. The intensity of the artificial radioactivity seemed to vary from experiment to experiment. Fermi had just delivered an important lecture describing their experiments. He was not pleased, and he let his young associates know it. While Fermi was away, they had bombarded aluminum in the lead-lined box and then tried to verify the results by repeating the experiment. To their dismay the two experiments produced different results. The divergent findings meant that their months of work were now in question. Determined to find out what was going on, they designed a new test. In one experiment, they placed an aluminum sample and neutron source in a corner of the box; in a second experiment, they placed it in the center. To their surprise, they got different results. Similarly, an experiment conducted on a wooden table turned out differently than the same experiment laid out on a marble table. 16 One day, still searching for an explanation, Fermi’s associates set up an experiment to test what would happen if a piece of lead were inserted between the neutron source and a piece of silver. They were out of the lab, proctoring student exams, when Fermi wandered in and decided to go ahead with the experiment. On a whim, he removed the lead and substituted a piece of paraffin wax instead. After conducting his experiment, Fermi grabbed the silver sample and sprinted down the hall to the Geiger counter as he had done dozens of times before. But this time the results were unlike any he had seen. The radioactivity level soared. The intensity reached a level more than a hundred times greater than in any previous experiment. When his colleagues arrived, they repeated the experiment. And, according to Enrico’s wife Laura, pandemonium broke out. “The halls of the physics building resounded with loud exclamations: ‘Fantastic! Incredible! Black magic!’” 17 Fermi theorized that the neutrons had collided with the hydrogen atoms in the paraffin. The ricocheting back and forth had slowed them down and reduced their energy before they reached the silver target. The marble and wooden table tops in the previous experiments and the walls of the lead-lined box had apparently had a similar weakening effect. But, why slow neutrons induced greater radioactivity than fast ones was still a mystery. That night, as Fermi and his students gathered at the home of a colleague to write a report on their findings, no one imagined that an act of sheer whimsy, creating those slowpoke neutrons, would unlock “nature’s greatest secret.” 18

EARLY ON THE MORNING OF November 10, 1938, the telephone bell rang in the Fermi’s spacious Rome apartment. Laura Fermi rushed into the hall to answer it. “I wish to inform you,” the caller said, “that this evening at six Professor Fermi will be called on the telephone from Stockholm.” 19 Fermi had been tipped off a month earlier, while attending a conference in Copenhagen, to expect the call. Excited, Laura asked her husband to take the day off. Out on the Roman streets, Laura and Enrico went on a buying spree. They bought expensive watches. She bought a beaver-skin coat. Unlike diamond purchases, which were recorded and might draw official scrutiny, watches and beaver coats did not leave a paper trail. Equally important, they could be resold and turned back into cash when needed. Following an afternoon of shopping, they returned to their apartment. The telephone rang. It was a friend, calling to see if they had heard yet. At six o’clock, still waiting, they turned on the radio. The news was not good. Italy’s dictator, Benito Mussolini, had just announced new restrictions on the rights of Italian Jews. Enrico was Catholic and their children were raised Catholic, but Laura was Jewish. Jews made up only a tiny fraction of the population and Italians, for the most part, were not anti-Semitic. Yet months earlier, Mussolini, following in the footsteps of Adolf Hitler, had launched a campaign against Italy’s Jews. 20 Now, it seemed, every day brought more bad news. This time, the commentator announced laws excluding Jewish children from public schools, dismissing Jewish teachers and restricting Jewish professionals to working for Jewish clients only. To make matters worse, authorities announced that the passports of Italian Jews would soon be confiscated. Laura and Enrico had lived a comfortable professorial life up to now: a nice apartment in Rome; summers at a cabin in the Alps; interesting travel with lecture tours in South America and the United States. Now, looking ahead, they saw only hardship and despair. They had planned to abandon their home and leave Italy early in the new year, but it now seemed time was running out. Shortly after six o’clock, the telephone bell rang again. It was the secretary of the Swedish Academy of Sciences in Stockholm. Enrico took the phone and the woman on the other end read him the citation on his Nobel Prize: “For his identification of new radioactive elements produced by neutron bombardment and his discovery . . . of nuclear reactions effected by slow neutrons.” 21 When the news of Fermi’s Nobel Prize got out, friends rushed to his apartment to join in the celebration. But Laura was torn. Mussolini’s latest pronouncement had left her shaken. “I did not know whether to be happy or sad, whether to heed the telephone or the radio.” Enrico, his usual confident self, assured her everything would work out. The timing of the Nobel Prize was a godsend. 22 As the Fermis planned their escape from Italy, fanatical anti-Semitism in Germany erupted into widespread violence. On the night of November 9, 1938 and into the following morning, Nazi mobs all across Germany burned and vandalized Jewish synagogues, homes and businesses. They killed 100 Jews, arrested 30,000 more and sent them to concentration camps. The paroxysm of violence came to be known as the “night of broken glass,” in German Kristallnacht . German anti-Semitism had inspired localized violence before, but Kristallnacht was the first government-orchestrated nationwide outbreak. A month later, Enrico, Laura, their young son and daughter and their nursemaid traveled to Stockholm where Fermi accepted his prize and a large monetary award. The Fermi’s did not return home. Instead, they used the prize money to book passage on an ocean liner bound for New York City. Anticipating their escape, Enrico had accepted a job offer at Columbia University.

Laura, Giulio, Nella and Enrico Fermi (AIP Emilio Segrè Visual Archives, Wheeler Collection) CHAPTER THREE SPLIT ATOMS

THE FAMILY HAD BEEN in New York for just two weeks, looking for an apartment and getting settled, when the liner Drottningholm sailed into New York harbor. On an upper deck, peering down at the welcoming crowd was the Danish Nobel Prize-winning physicist Niels Bohr. Bohr was a mentor to Werner Heisenberg and a luminary in the theoretical physics community. He brought with him incredible news: two German scientists had proven Einstein’s theory correct. Otto Hahn and Fritz Strassmann had split the uranium atom, unlocking a mighty storehouse of atomic energy. And they had done it using the procedure Fermi had pioneered: bombarding uranium with slow-moving neutrons. In the world of physics there were two kinds of scientists: the theoreticians like Einstein who use their fertile imaginations to explain natural phenomena, and the experimentalists who search for answers using laboratory experiments. As Fermi’s work in Rome demonstrated, he excelled at both; a rare combination. Back in Rome his students, awed by Fermi’s brilliance, had nicknamed their professor “Il Papa,” the Pope, because they believed that he, just like the head of the Catholic Church, was infallible. But the atomic nucleus was a place of mystery, a new world that scientists had only begun to explore. And this time, “Il Papa” had lost his way. The news that Hahn and Strassmann had split the atom left Fermi uneasy. His thoughts raced back to his own neutron bombardment experiments at the University of Rome five years earlier. He recalled his difficulty trying to decipher the uranium results. Was element 93 not a new atom as he had thought? Was it, in fact, a composite of split atoms? The more he considered the possibility, the more he realized the answer had to be yes. He too had split the atom, but didn’t know it. Embarrassed, Fermi acknowledged the apparent error in a footnote to his not-yet-printed Nobel acceptance speech: “The discovery by Hahn and Strassmann,” he wrote, “. . . makes it necessary to re-examine all the problems of transuranic elements, as many of them might be found to be products of a splitting of uranium.” 23

THE RESULTS OF THE NEUTRON bombardment experiment had baffled the two Germans just as they had Fermi. It appeared that a neutron had penetrated the uranium nucleus and broken off a large chunk of the atom. But that was impossible. Scientists using atom-smashing cyclotrons had fired particles packing 9,000,000 volts of energy at atoms and failed to do any damage. 24 The idea that an exhausted neutron could break one apart was beyond absurd. Unable to explain what had happened, the two German chemists wrote their former collaborator Lise Meitner, a Jewish physicist who had been forced to flee Nazi Germany. It was she who unraveled the mystery. In the atom’s nucleus, positively charged protons repel each other. They push; they shove; they battle trying to get away from each other, but never can. That’s because something called the “strong force” holds them captive. Fermi’s snail-paced neutrons had disrupted that force. The question was how. Meitner was on Christmas vacation, skiing with her nephew, when the answer came to her. All of a sudden she understood what her German colleagues had not. A tiny, slow-moving neutron has very little energy. But, like the straw that broke the camel’s back, it was just enough to tip the balance. The additional muscle it brought to the fight enabled the protons in the uranium nucleus to overpower the restraining strong force. In a process later called nuclear fission, the nucleus split, expelled two of its neutrons and along with them a burst of atomic energy. Why slowing the neutrons down made them more effective was still a mystery. The energy generated by each atom was infinitesimal, only enough “to make a visible grain of sand visibly jump.” 25 But multiply that energy by trillions and trillions of atoms, and the total would become staggering. According to one estimate, “the energy in the mass of one raisin would supply most of New York City’s energy needs for a day.” 26 The news of Hahn and Strassmann’s breakthrough rocked the scientific world. Distinguished scientists in three countries had performed Fermi’s neutron bombardment experiment, and none of them had understood what happened. “Everyone kicked themselves,” says atom bomb historian Richard Rhodes. Rhodes interviewed U.C. Berkeley physicist Glenn Seaborg who had also missed the historic discovery. “And he told me, ‘I spent the next three days in a blue funk.’” 27

NOW THAT THE ATOMIC GENIE was out of the bottle, there was no turning back. Each new experiment brought new evidence that split atoms emit neutrons. In theory, those neutrons could go on to split more atoms, yielding more neutrons triggering a chain of events that would produce more and more atomic energy. In late January 1939, Fermi and colleagues at Columbia University confirmed the theory. Their chain reaction generated what The New York Times called “the greatest amount of atomic energy so far liberated by man on earth.” 28 But the Columbia research only hinted at the atom’s true potential. Once dismissed as the stuff of science fiction, an atom bomb was now— theoretically at least—within reach. Scientists were at the frontier of a strange new world that was at once exciting and terrifying. The earth’s atmosphere was 78 percent nitrogen. Would an atom bomb ignite the atmosphere? Would it turn the hydrogen in the oceans ablaze? Scientists didn’t think so, but no one could say with absolute certainty. AS THE RUMBLINGS OF A WAR in Europe grew louder, the specter of Adolf Hitler armed with an atomic bomb terrified many scientists, especially those Jewish scientists who had fled Nazi anti-Semitism. They took comfort, however, knowing that myriad problems still lay ahead. When the Danish physicist Niels Bohr, now a visiting professor at Princeton University, identified one problem that seemed to push the possibility of a bomb into the far distant future, they all breathed a sigh of relief. Bohr was at breakfast with colleagues in the Princeton faculty club when the conversation turned to nuclear fission. The scientists were puzzling over why slow-moving neutrons had split the atom’s nucleus and not fast ones, when Bohr, trailed by a young associate, suddenly jumped up and raced to his office across campus. Breaking several pieces of chalk in his rush to get his thoughts down on a blackboard, he drew a diagram of two atomic nuclei—one, extremely rare; the other, extremely common. The rare atom, which accounted for less than one percent of all uranium atoms in nature, was Uranium 235 (U235). Admiring his work, Bohr explained to his associate that the U235 nucleus was the secret storehouse where nature hid its nuclear energy. The other atom, Uranium 238 (U238), was, in effect, its security guard. For every storehouse there were 139 guards standing sentry, capturing neutrons, absorbing them and preventing them from gaining access to the U235 storehouse. 29 Under normal conditions the defenses were impenetrable, but nature’s grand design had one weakness. Nature had programmed U238 atoms to capture intermediate and fast-moving neutrons, but not slow ones. Low- energy slowpokes could sneak past the guards and break into the nuclear energy storehouses undetected. Fermi didn’t know it in 1934, but he had stumbled upon a back door, a secret passage into those storehouses open only to slowpokes. That discovery enabled him and Hahn and Strassmann in Germany to split the U235 nucleus. As long as the scarce U235 atoms remained buried among all those U238 atoms, the chances of anyone releasing enough nuclear energy to fuel a bomb were virtually nil. In 1939 there was no practical way to separate U235 atoms from U238, at least not on the mammoth scale required. And, even if one were invented, conventional wisdom held that it would take years to harvest enough U235 atoms for a single bomb. Some experts estimated that “over 191 years would [roll by] before a single gram of U235 was obtained, and 75,000 years for a single pound.” 30 “It can never be done,” Bohr told his colleagues, “unless you turn the United States into one huge factory.” 31 H.G. Wells’ vision of a world shattered by “crimson conflagrations of atomic bombs” was still just science fiction. Across the Atlantic, British Prime Minister Winston Churchill assured his Secretary of State for Air, “the fear that this new discovery has provided the Nazis with some sinister, new, secret explosive with which to destroy their enemies is clearly without foundation.” 32 But, then again, if any nation had the scientific know-how and the industrial capacity to overcome all the obstacles, it was Nazi Germany. In the 1920s and ’30s Germany was the indisputable world leader in physics, chemistry and mathematics. German scientists had won one-third of the world’s Nobel Prizes in science. 33 Germany’s chemical and armaments industries were second to none. Germany had access to the latest nuclear fission research from British, Soviet, Italian, American and French scientists, all of whom had openly published their work before the war. Nazi Germany controlled the world’s largest uranium mines in occupied Czechoslovakia and the Belgian Congo. And it was the fatherland of a man universally recognized as a leading light in the field of atomic physics, Germany’s youngest full professor at age 26 and a Nobel Prize-winner at 33, Werner Heisenberg. CHAPTER FOUR HEISENBERG IN MICHIGAN

(Werner Heisenberg Sueddeutsche Zeitung Photo / Alamy Stock Photo)

WHEN HEISENBERG TRAVELED TO the United States in the summer of 1939 it was a victory lap of sorts. He had just come through a frightening, yearlong investigation by the Waffen SS, the armed wing of the Nazi Party. After watching the Nazis gut German universities of their best Jewish professors and replace them with second-rate party loyalists and then ban the teachings of Albert Einstein, Heisenberg had felt compelled to speak out. Risking his career and his life, he published articles in the Nazi Party and SS newspapers defending the teachings of Einstein and Niels Bohr, two of the world’s most distinguished theoretical physicists, and both Jewish. Johannes Stark, a German Nobel Laureate and Nazi loyalist, responded with a vitriolic attack in which he labeled Heisenberg, who was a Christian, a “white Jew.” That attack triggered the SS investigation. Fortunately for Heisenberg, he had friends in high places. His father had taught high school and had been friendly with the father of Heinrich Himmler, commander of the SS. Heisenberg’s mother wrote Himmler’s mother, and, after all the months of investigation during which his home was bugged, Heisenberg finally received a letter from the SS Commander stating, “I take pleasure in being able to inform you . . . there will be no further attacks on your person.” 34 Thanks to a family connection, Heisenberg had dodged a bullet and struck a blow for German science. Himmler imposed one condition, however. Heisenberg could teach the theories of Jewish scientists, but he couldn’t credit them. With Himmler’s backing, Heisenberg’s application to travel and lecture in the United States won immediate approval. By the time he arrived in the States, hopes of avoiding another world war had all but vanished. The specter of Adolf Hitler armed with an atomic bomb shadowed Heisenberg wherever he went. Yet Heisenberg seemed oblivious. While lecturing to J. Robert Oppenheimer’s Wednesday afternoon seminar at Berkeley, he appeared not to have a care in the world. Afterwards, over tea, he went on at length talking about San Francisco cable cars and the technology that enabled tracks and power lines to cross. 35 To Oppenheimer, Heisenberg’s behavior seemed calculated. To him it was all an act. Writing in 1980 after her husband’s death, Elisabeth Heisenberg insisted it was genuine: “At the time, he still firmly believed in the world community of physicists he spoke about so often.” Long isolated in Nazi Germany, he was happy to be back in that world. “Never having identified himself with the policies of the Nazis,” Elisabeth Heisenberg wrote, “he was of the firm conviction that old friendships could outlast political differences.” 36 That conviction would be tested from coast to coast despite the determination of Heisenberg and his hosts to avoid the discussion of politics. At Berkeley, Robert Oppenheimer warned an associate that Heisenberg “could not be trusted.” 37 Given the treatment of Jews in Germany and the fact that Oppenheimer was Jewish and had relatives there, the distrust was not surprising. But beyond “the smoldering fury” that Oppenheimer felt concerning the treatment of the Jews lay something else. Oppenheimer, it seems, was jealous of Heisenberg. 38 The brilliant young physicist Oppenheimer had met in Göttingen had won a Nobel Prize for his pioneering work in the field of Quantum Mechanics. Nothing short of revolutionary, his work helped develop a new understanding of the atom and the behavior of electrons. Under the old laws of classical physics, electrons were thought to orbit the nucleus just like the earth orbits the sun; their locations were thought to be predictable just like that of the earth, the moon and the stars. Not so, said 25-year-old Heisenberg. The laws of classical physics don’t apply to small objects like electrons. According to his famous “Uncertainty Principle,” it’s impossible to determine both the exact position and velocity of an electron at any given moment. The more precise one measurement, the less precise the other. The best one can do is compute the probability of its being at a specific location or its specific velocity. 39 The world’s most famous physicist, Albert Einstein, disagreed that Quantum Mechanics could be that uncertain. “God doesn’t play dice with the universe,” he argued. 40 Nevertheless, Heisenberg’s “Uncertainty Principle” became a pillar of modern Quantum Mechanics. Oppenheimer was also brilliant, the West Coast doyen of American theoretical physicists. He had done important work in the fields of nuclear physics, astrophysics and spectroscopy, 41 but his star had not risen to the heights that Heisenberg’s had. He wasn’t a Nobel Laureate and didn’t have the global stature of a Heisenberg. And by all accounts that weighed heavily on him. Oppenheimer did not like being second best. At Cambridge, where he studied before coming to Göttingen, he became deeply depressed when he did poorly in experimental physics. Conducting laboratory experiments and meticulously recording the results was a “terrible bore,” he wrote a friend. 42 He regained his intellectual footing at Göttingen where he excelled in theoretical physics. Oppenheimer and Heisenberg met a second time that summer of 1939, at the University of Chicago, where Heisenberg gave a lecture on cosmic rays. The two had competing theories on the subject, and after the lecture Oppenheimer confronted Heisenberg. Heisenberg, like Oppenheimer, had a healthy ego and did not like being challenged. Tempers flared, and they got into a shouting match. The collegiality they had demonstrated at Berkeley had apparently masked their true feelings. After Chicago, Heisenberg boarded a train for Ann Arbor and the University of Michigan where he was scheduled to give a series of lectures. The University ran an annual summer symposium in theoretical physics and invited top European scientists to attend. The seminars offered American physicists an opportunity to learn from German and other European colleagues. In 1939 the impact of Nazi anti-Semitism, and the flight of Jewish scientists, had not yet fully registered, and Germany was still considered the world leader in physics and chemistry. The photo from the event shows a smiling Heisenberg, athletic-looking, his linen jacket open, hands thrust casually in his pockets; he exudes an air of confidence. Next to him on his left is Fermi. The two are the same age, 37, but Fermi, standing stiffly, his suit jacket buttoned, his high forehead rimmed by closely cropped dark hair, seems older. Fermi had time on his hands that summer. His nuclear fission research had stalled for lack of funds. 43 The University of Michigan summer school was always a stimulating and festive gathering, so Fermi was happy to attend.

Samuel Goudsmit, Clarence Yokum, Werner Heisenberg, Enrico Fermi (Courtesy: AIP Emilio Segrè Visual Archives, Crane-Randall Collection, Goudsmit Collection)

Heisenberg had based his “Uncertainty Principle,” in part, on Fermi’s work. The two had been friends for more than a decade, so Fermi had license to press him on the issue worrying them all. “There is now a real chance that atom bombs may be built,” he told Heisenberg. 44 If war came, would he support the German cause? Would he build Adolf Hitler an atom bomb? Heisenberg did not answer. Instead, he dodged the question saying, “Atomic developments will be rather slow however hard governments clamor for them; I believe that the war will be over long before the first atom bomb is built.” 45 Standing to the right of Yokum and Heisenberg in that 1939 photo, dapperly attired in a white double-breasted suit, is Heisenberg’s friend Samuel Goudsmit, a Dutch Jew who immigrated to the United States in the late 1920s. Heisenberg had visited Goudsmit at his home in Holland and stayed with him and his family several summers while attending the Michigan conferences. He tried to convince Heisenberg to immigrate to the United States before it was too late. Everywhere Heisenberg went his American colleagues urged him to bring his family and to accept one of the many university professorships offered him. But Heisenberg, the loyal German, always refused, saying he would be needed at home. He had made his decision before coming to the United States. In his view, incompetent Nazi bureaucrats were undermining the quality of theoretical physics education in Germany. Faced with a choice of escaping the coming war, or staying to defend his disparaged field, Heisenberg put science and the fatherland first. He bought a cabin for his family in the mountains of southern Germany, hoping they would be safe there during the war, while he stayed behind at the university tending to scientific matters. To him, Nazism was merely a passing storm. He told Goudsmit that the Nazi regime would eventually fail and that he and others like him would then step in. 46 He hoped his American friends would understand. From Michigan, Heisenberg traveled to New York City where he boarded the near empty ocean liner Europa for the voyage home. In his luggage he carried photographs of his trip, mementos of happier times. The voyage would take four or five days, plenty of time to reflect on the coming war. As he wandered alone on the deck, peering out at the ocean, he wrestled with the question his visit had left hanging. Heisenberg was a patriot. He loved his country, but had only contempt for the Nazis. What would he do? Was he duty bound to build Adolf Hitler an atom bomb? Time to decide was running out. On September 1, 1939, three weeks after Heisenberg’s return, World War II broke out. And Heisenberg was drafted to work on an atomic bomb. CHAPTER FIVE WAR

WORLD WAR II NEWSREEL

NARRATOR: “Poland, September, 1939, the German Wehrmacht begins its ruthless march of conquest and sets the stage for World War II.”

Rejecting the trench warfare and static defenses of World War I, the German war machine adopted a strategy it called “blitzkrieg,” lightning warfare. After smashing through Poland’s border defenses, the first wave, made up of German tanks supported by Luftwaffe bombers and fighters, encircled Polish troops. The second wave of motorized infantry followed, securing their gains. Then the regular infantry took over, releasing the motorized infantry to race after the tanks that had already rolled deeper into Polish territory. It took the Wehrmacht just three weeks to defeat Poland’s smaller and poorly equipped forces. In a preview of the atrocities to come, the Germans bombed the city of Warsaw and strafed civilian refugees as they clogged the roads trying to escape. Nazi paramilitary death squads executed 20,000 Poles, most of them Jews and intellectuals, and buried them in mass graves. In all, more than 150,000 Polish civilians were killed. 47 Two days after the invasion, England and France sided with Poland, launching what would become the bloodiest war in history. To celebrate his army’s stunning victory, the Führer delivered a speech in which he extended both an olive branch and an iron fist. He vowed that Germany had “no war aims against Britain and France,” but at the same time threatened any nation that dared oppose it saying, “We will employ a weapon with which we could not be attacked.” 48 Hitler’s threat set off alarms throughout the continent and filled newspapers with speculation about a secret weapon, a Nazi “death ray.” 49

1940-05-13 CBS RADIO NEWS: ELMER DAVIS AND THE NEWS

On the fourth day of the invasions of the low countries the Germans are ahead of schedule, according to Berlin, but as in Norway and Poland, their advances have been made by fast armored divisions, and the mass of troops has not yet caught up with them.

“THE FIGHTING TODAY DECIDES the fate of the German nation for the next 1,000 years,” Adolf Hitler proclaimed. Meanwhile, as German armies rolled across Europe, intelligence pointing to a German bomb program continued to trickle in. Allied analysts monitoring Hitler’s public speeches took special note of his repeated boasts of a “wunderwaffe,” a wonder weapon. Sources reported that the uranium mine in the Czech Sudetenland, now under German control, had stopped exporting uranium and that the Germans were experimenting with a nuclear reactor at a research laboratory outside Berlin. “Every German scientist in this field—physicists, chemists and engineers,” The New York Times reported, “have been ordered to drop all other researches and devote themselves to this work alone.” 50 From the French resistance came word that German scientists had seized an American cyclotron at the College de France in Paris. The Germans had none of their own, and they desperately needed one to take the precise atomic measurements necessary for an atomic bomb. Each bit of information added another piece to the giant intelligence puzzle Allied analysts were assembling, but there were still too few to get a clear picture of Germany’s intentions. In 1940, despite the warning signs, British scientists held to the conventional wisdom that the scarcity of U235 atoms in a pound of uranium made building an atom bomb impossible. A “critical mass,” the mass of U235 atoms sufficient to sustain a nuclear chain reaction, would require many tons of uranium. The bomb would be far too large to carry in an airplane. So said the conventional wisdom. But what if the conventional wisdom was wrong? Early in 1940 two physicists, Otto Frisch and Rudolf Peierls, victims of Nazi anti-Semitism now working at Birmingham University in England, began pondering that question. What if Heisenberg and colleagues could separate the rare U235 atoms from the natural uranium and assemble them into a mass of pure U235? If they did, they wouldn’t need to slow the neutrons down so they could sneak past the U238 guards. What if he bombarded the U235 atoms with fast-moving neutrons instead? No one, at least no one on the Allied side, had considered those possibilities. On a lark, Frisch and Peierls decided to run the numbers and were shocked by what they discovered. The critical mass necessary to build a bomb was no longer measured in tons. It would be just a few pounds! “At that point,” says Frisch, “we stared at each other and realized that an atomic bomb might after all be possible.” 51 Following their discovery, conventional wisdom did an about face. A committee of British scientists set up to study nuclear fission concluded that a U235 bomb was “practicable and likely to lead to decisive results in the war.” 52 It recommended that the bomb be given the “highest priority.” After some delays, those findings eventually made their way across the Atlantic where they reached the desk of President Franklin Roosevelt. The United States was not involved in the war, and the White House had shown little interest in funding nuclear research prior to that. But, in October 1941, the President finally authorized preliminary research on building an atom bomb. 53 LAWMAKERS IN WASHINGTON MAY NOT have paid much attention to nuclear fission, but America’s universities had. At U.C. Berkeley, Glenn Seaborg, the ill-fated physicist who had kicked himself for failing to recognize nuclear fission, was back in his laboratory bombarding uranium atoms in a cyclotron. 54 This time, his persistence paid off. In February 1941, Allied efforts to harness the energy of the atom took a giant leap forward when his experiments produced an atom that had never existed in nature, a new, man-made atom. He called it plutonium. Plutonium was a byproduct of nuclear fission. If scientists could build a machine that sustained a nuclear chain reaction, they could theoretically produce large quantities of plutonium. A plutonium bomb would have great advantages over U235. It would require a smaller critical mass of atoms than U235, so less processing. But more importantly, it could be separated from other uranium atoms using existing chemical procedures. No new separation technology would have to be invented. The plutonium discovery opened a second pathway, one that promised a much faster, more direct route to an atomic bomb.

UNDER NORMAL CIRCUMSTANCES, SEABORG and his collaborators would have trumpeted their discovery from the rooftops. But the war was on, and Allied scientists didn’t want to aid the Nazis, so they filed a secret report with the government, and kept silent. 55 Unfortunately, their self-censorship came too late. A year earlier Seaborg’s colleagues and a Princeton physicist had published two articles in the American scientific journal The Physical Review suggesting that a nuclear chain reaction would produce a fissionable atom. An associate of Heisenberg read it and alerted Germany’s Weapons Research Office. From then on nuclear fission research in Germany, Britain and the United States split along two tracks: one, developing an industrial technology to separate U235 atoms from uranium for a uranium bomb; the other, building a nuclear reactor which could generate power and produce fuel for a plutonium bomb. Enrico Fermi and Werner Heisenberg both focused on the reactor. 56 To get started, Heisenberg needed a “moderator” to slow the millions of speeding neutrons emitted by the chain reaction. Graphite seemed the best choice. Its carbon atoms, arranged in lattice-like layers, would serve as an obstacle course forcing the neutrons to slow down as they passed through. But there was a problem. When Heisenberg’s colleagues ran their experiments, impurities in the graphite absorbed many of the neutrons. Heisenberg decided to use a rare liquid chemical called “heavy water” instead. Meanwhile, Fermi and Leo Szilard, a Hungarian Jew who had fled Europe when Hitler came to power, also tried using graphite. But Szilard, anticipating the impurity problem, went directly to his supplier, the National Carbon Company, and arranged to purchase the purest graphite they could produce. His tests showed the purified graphite would work. Graphite had two important advantages over heavy water: it was relatively inexpensive and readily available.

THE STAGE WAS SET. On a hot August morning in 1941, Fermi, Szilard and colleagues launched their first attempt to build a full-scale nuclear reactor. As Fermi supervised, a hired team of Columbia University football players began hauling eight tons of uranium-filled canisters and 30 tons of graphite blocks into the basement of Columbia’s natural sciences building where they assembled them into a large cube. Albert Einstein had compared the harnessing of nuclear energy to the futility of “shooting in the dark at scarce birds.” It was an apt comparison. Splitting the U235 nucleus with neutrons and shooting the scarce birds were both crapshoots with extremely poor odds of success. Uranium ore contains only one U235 nuclear energy storehouse for every 139 U238 atoms. The neutrons that Fermi used to bombard the uranium were far more likely to encounter one of those other atoms or escape through gaps between atoms as they were to unlock one of the storehouses. To succeed, Fermi had to figure out a way to stack the deck, to ramp up the chances of a neutron/U235 encounter. After months of experimenting with different reactor designs, he and his colleagues came up with a plan: if they took uranium powder (the only form available for purchase), packed that powder to just the right density, just the right moisture content, in cans of just the right size and shape; and, if they embedded those cans in bricks of graphite of just the right purity, and they positioned them just the right distance from each other in a mass of just the right shape and volume, then possibly . . . just possibly . . . they could slow down enough neutrons and direct them to split enough U235 atoms that they could sustain a chain reaction. 57 In September of ’41, Fermi’s first attempt fell short of his goal. The successive generations of split U235 nuclei emitted large numbers of neutrons, but not enough to keep the chain reaction going. CHAPTER SIX HEAVY WATER

THAT SAME MONTH, ACROSS the Atlantic in London, British intelligence received word that Norsk Hydro, an electrochemical plant in the town of Vemork in Nazi-occupied Norway, had shipped 40 gallons of heavy water to a port in Germany. Producing heavy water required enormous amounts of electricity. The Norsk Hydro plant, chiseled into a 1,500-foot granite bluff alongside a giant waterfall, had a limitless source of energy and was the only plant in the world producing heavy water in large quantities. A byproduct of fertilizer manufacturing, heavy water had no industrial application. But, like graphite, it could be used to slow speeding neutrons. Shortly before the war, the Germans had tried to buy the company’s total heavy water inventory, but were turned down. After the Nazi occupation of Norway, the plant’s management had no choice but to ramp up production. News of the increase and the shipment to Germany all but confirmed that Adolf Hitler was building a nuclear reactor. And there could be little doubt that meant a plutonium bomb. While intelligence officials debated how to respond, the engineer who designed the Norsk Hydro plant escaped to England bringing with him microfilm of the plant’s blueprints. 58 From then on, Allied intelligence made cutting the flow of heavy water to Germany a top priority. British intelligence put together a list of German scientists likely to be involved in Germany’s atomic research. Heisenberg’s name was at the top. In the past, he’d been a frequent contributor to German scientific journals. Now his name was nowhere to be found. Nor did his name appear in any fall 1941 university catalog as teaching a physics course. 59 The results came as no surprise. “No one but Professor Heisenberg,” noted his old friend Sam Goudsmit, “could be the brains of a German uranium project, and every physicist throughout the world knew that.” 60

HEISENBERG RECEIVED HIS SHIPMENT of heavy water at his lab in Leipzig, and immediately began testing the latest prototype of his “uranium machine,” his nuclear reactor. The war was draining the Germany army’s fuel supplies. Shortages loomed. The uranium machine promised limitless energy and, down the road, plutonium for an atomic bomb. Before the war, Heisenberg had risked his life trying to demonstrate the importance of theoretical physics, “Jewish physics,” to anti-Semitic Nazi officials. Thanks to the war, he now had his chance. Building on Fermi’s work with slow-moving neutrons, he had designed a 30-inch wide, one-ton metal sphere with alternating layers of uranium and heavy water. As workers winched the sphere into a tank of ordinary water, Heisenberg and colleagues couldn’t help but feel anxious. Their previous attempts at a chain reaction had all been disappointing failures. This time, for the first time, Heisenberg saw cause for optimism. The sphere generated a modest thirteen percent increase in neutrons. 61 “It was from September 1941,” Heisenberg would later write, “that we saw an open road ahead of us, leading to the atomic bomb.” 62 CHAPTER SEVEN 1941

TWO YEARS AFTER THE launch of World War II the German army appeared unstoppable. France, with the largest army in Europe, had been the one real hope to slow the German advance, but it had collapsed in just 35 days. Hitler’s armies had overrun most of the European continent, from Poland in the east, Norway in the north and France to the west. Nightly bombing raids by the German Luftwaffe had pounded England’s cities for eight months straight. Rallying his countrymen on the radio, Prime Minister Churchill warned, “Upon this battle depends the survival of Christian civilization.” 63 Then suddenly the bombing stopped. In a surprise move, Hitler redirected his forces away from Great Britain and against his erstwhile ally Joseph Stalin.

1941-06-22 BBC RADIO

WINSTON CHURCHILL: At 4 o’clock this morning Hitler attacked and invaded Russia. . . . Suddenly, without declaration of war . . . German bombs rained down from the sky upon the Russian cities.

It was the largest land invasion in military history. Adolf Hitler set out not merely to capture territory, but to annihilate what he believed was a conspiracy of Jews and “Bolsheviks” (Communists) that threatened all of Europe. Enrico and Laura Fermi followed the latest developments from the comfort of their Leonia, New Jersey home. An ocean separated them from the fighting, but they still felt threatened. Ku Klux Klan rallies were increasing. Fascist ideas were becoming more acceptable even among prominent Americans like Charles Lindbergh who praised Adolf Hitler as “undoubtedly a great man.” 64 The number of German Americans joining the German- American Bund, a pro-Nazi organization, was growing. In February 1939, a Bund rally at Madison Square Garden in New York City drew 20,000 supporters. Marching to the beat of snare drums, men in Nazi uniforms carrying American flags and swastikas had paraded into the Garden where they were greeted by rally organizers. In front of a towering portrait of George Washington, a speaker exhorted the crowd to “protect ourselves . . . against the slimy conspirators and the parasite hand of Jewish Communism.” Meanwhile, a newsreel camera chronicled Nazi guards beating a lone man who dared to protest.

WORLD WAR II NEWSREEL

NARRATOR: . . . “and this is Fritz Kuhn, leader of a German-American Bund hiding behind an American flag, but taking his orders from Berlin . . . and copying the methods of Berlin.”

Laura Fermi would later write: “There seemed to be little doubt that Germany would gain a final victory in Europe and that such a victory might mean a Nazi domination of America . . . through increased power of the German Bunds.” 65 Laura and Enrico Fermi worried that Nazism might take root in the United States, so they buried what remained of his Nobel Prize money in their basement for safekeeping. Indulging in gallows humor, they spent evenings with friends plotting their escape from the United States. They figured the Germans would control the Atlantic. So they planned to make their way by sailboat from Florida to an island in the Pacific. “We prepared to become modern Robinson Crusoes in some far away desert island,” wrote Laura Fermi. Enrico’s “delight at the prospect of experimenting with compass and sextant was encouraging.” Laura took charge of their clothing needs, making sure their island “colony would not go naked in years to come.” She debated whether to provision their boat with “cotton seed and spinning wheels or . . . bolts of cloth.” 66 The Fermis thought they had considered every possible contingency. They were mistaken. CHAPTER EIGHT THE MANHATTAN PROJECT

1941-12-8 FDR SPEECH TO JOINT SESSION OF CONGRESS

PRESIDENT ROOSEVELT: Yesterday, December 7, 1941, a date which will live in infamy, the United States of America was suddenly and deliberately attacked by naval and air forces of the empire of Japan.

AT THE TIME OF THE Pearl Harbor attack, nuclear fission research in the United States was a leisurely, poorly funded and loosely coordinated enterprise. British scientists, working with refugees from Nazi Germany, Austria and Hungary, had taken the lead, doing most of the early research. But that changed with America’s entry into the war. Over the next year the U.S. Army Corps of Engineers organized America’s disparate research efforts into a single program. Fission research for the plutonium bomb was consolidated at the University of Chicago in a program code-named “The Metallurgical Lab.” As a result, Enrico and Laura Fermi were forced to relocate to Chicago. After the bombing of Pearl Harbor, thousands of individuals of Italian, German and Japanese ancestry were detained as potentially dangerous “enemy aliens.” For Laura and Enrico Fermi, the new classification brought new rules, new restrictions. They were required to obtain permission from the local United States Attorney before leaving their community. They could not own a shortwave radio, camera or binoculars or live in a building with other enemy aliens. In April 1942, permission in hand, Enrico boarded the “Twentieth Century Limited” at New York City’s Union Station and headed west. His wife and children would join him at the end of the school year. Officials at the independent agency overseeing wartime scientific research had balked at including Fermi because of his “enemy alien” status, but his fellow physicists insisted. He would soon prove invaluable. A brilliant problem-solver with an informal, patient manner, he was well-liked and an excellent team-builder. 67 While Fermi settled in, Glenn Seaborg, one of the Berkeley scientists who’d discovered plutonium, and his colleague Isadore Perlman, boarded “The City of San Francisco” for the two-day train trip east to Chicago. There they would join Fermi who was already at work building another reactor. When they arrived, the weather was dark and gloomy, as was their mood. 68 “The day Iz and I got off the train in Chicago,” Seaborg later wrote, “we had little reason to believe America would win. In fact, the evidence pointed the other way . . . German engineering was the most respected in the world, especially when it came to arms. Those Panzers rolling across Europe in the blitzkrieg seemed unstoppable . . . We were fighting for survival, pure and simple.” 69 Fear of a German victory was ever present, and the bad news kept coming. In the summer of ’42, word spread via the international scientific grapevine that Werner Heisenberg had been named director of the Kaiser Wilhelm Institute for Physics, Germany’s center for atomic research. The concerns his American friends had before the war, now seemed fully justified. They could only conclude that Heisenberg had sold out to the Nazis, that he had agreed to build an atom bomb. 70 Heisenberg, it seemed, was no longer Hitler’s chief atomic theorist; he was the de facto leader of Hitler’s atomic bomb program. From that moment, America’s race to beat Hitler to the bomb became personal. The enemy now had a name and a face. He was a brilliant, arrogant adversary, fiercely loyal to his country. He was the personification of German scientific superiority. And he had a two-year head start. “Everyone was terrified that the Germans were ahead of us,” says physicist Leona Marshall Libby. “That was a persistent . . . fear fed by . . . the fact that our leaders knew those people in Germany and had gone to school with them.” 71 Forty-five-year-old Leslie Groves, a hard-charging Corps of Engineers brigadier general, would run America’s newly organized atomic bomb program, now called The Manhattan Project. The son of an army chaplain, fourth in his class at West Point, he was a skilled manager with a history of tackling large projects, including the construction of the Pentagon. Often impatient and abrasive, he didn’t seem to care how many people he had to offend to get the job done. 72 Fermi and his Chicago colleagues chafed at surrendering control of their nuclear fission research. They had spent months debating the best way to cool nuclear reactors—using water or helium. Groves gave them just five days to make up their minds. He was “the biggest son-of-a-bitch I ever met in my life,” said one Groves subordinate, “but also one of the most capable individuals.” 73 Groves would spend the next three years pushing, prodding, cajoling and bullying government officials, corporate CEOs and pretty much anyone who got in his way, turning what had been an ivory-tower, slow-paced academic exercise into a crash $26 billion (adjusted for inflation) military-run campaign. To stand any chance of beating the Germans, Groves calculated he would have to deliver the first bomb no later than summer of 1945. Robert Oppenheimer and General Leslie Groves (Digital Photo Archive, Department of Energy (DOE), courtesy AIP Emilio Segrè Visual Archives)

GENERAL GROVES MET THE future scientific director of The Manhattan Project, Julius Robert Oppenheimer, on his initial inspection tour of Project research facilities. Groves liked what he saw in the 38-year-old U.C. Berkeley physics professor. “He’s a real genius,” he told an interviewer. “He can talk to you about anything you bring up . . . except sports.” 74 Groves invited him to come to Chicago, where he joined the general onboard the New York-bound “Twentieth Century Limited.” Hours of discussion in Groves’ private compartment sealed the deal. A tall, gaunt, chain-smoking intellectual, Oppenheimer was the son of a wealthy textile importer, a German-born Jew who had immigrated to the United States in 1888 when he was seventeen years old. Oppenheimer was undeniably brilliant, but he had never managed anything larger than a university seminar, and his leftist politics raised legitimate concerns that he might pass atomic secrets to the Soviets. As he himself admitted, “he had donated money to every Communist-front organization on the West coast.” 75 He had never been a party member, but his wife Kitty, brother, sister-in-law and former fiancée had all been members. Kitty had, in fact, been married to one of the Communist Party’s American leaders. 76 Even before Oppenheimer’s name surfaced in connection with the Manhattan Project, he had come to the attention of the FBI, which was investigating suspected Soviet espionage at Berkeley’s radiation lab. After he became a candidate for the Los Alamos position, the FBI passed his file to Colonel Boris Pash, the San Francisco area chief for Army Counter- Intelligence. 77 The son of a Russian émigré, Pash had fought against the Bolsheviks in the Russian Revolution. He was a zealous, some said fanatical, anti-Communist. And he vehemently opposed Oppenheimer’s appointment. Oppenheimer’s political past troubled General Groves as well, but he prided himself on his ability to judge people. He knew that Oppenheimer and Kitty were ambitious, that Oppenheimer yearned for a Nobel Prize, but would probably never get one. Physicists generally do their best work when they’re in their twenties. At 38, Oppenheimer was over the hill. 78 If he succeeded, the atom bomb would bring him something even more prestigious, a place in world history. Groves trusted that would be sufficient to ensure Oppenheimer’s loyalty. He made the appointment over Pash’s objection, but Pash never let up. He kept Oppenheimer under constant surveillance. He tapped his phone, opened his mail, hired counterintelligence agents to be his driver and bodyguard and repeatedly interrogated him. Oppenheimer cooperated with every request, but no matter what he did, he could not convince Pash of his loyalty. With Oppenheimer in place, the battle lines were drawn. Oppenheimer would lead the Allies; Heisenberg, the Germans. Now bitter enemies, the two had a good deal in common. They were both university professors, theoretical physicists, about the same age. Both came from privileged, educated families. (Heisenberg’s father was a professor of medieval and modern Greek studies.) Both had been investigated by the state as subversives: Oppenheimer, for supporting Communists; Heisenberg, for defending “Jewish science”. And both owed their exoneration to friends in high places: Oppenheimer, to General Groves; Heisenberg, to SS Commander Heinrich Himmler. CHAPTER NINE HEAVY WATER II

OPPENHEIMER AND HEISENBERG HAD one more thing in common: a keen interest in the output of the Norsk Hydro plant in Nazi-occupied Norway. By the beginning of 1942, the company had increased its production of heavy water tenfold to 300 pounds a month and was making plans to boost output even further. Word of the stepped-up production convinced British intelligence that it couldn’t wait. 79 It had to prevent that heavy water from reaching Heisenberg. On November 19, 1942, two Halifax bombers towing wooden gliders took off from Wick airfield in Scotland bound for Norway. Each glider carried 34 passengers, British commandos expert in demolition. The gliders and crew planned to land on a glacier a distance from the Norsk Hydro plant, meet up with an advance team already in place, then make their way on skis to the plant. But problems plagued the mission from the start. Just after takeoff, both bombers lost communication with their gliders. The first bomber wasted valuable fuel searching for the drop zone in the snow-covered landscape and was forced to abort the mission. After turning around, it ran into icing conditions near the Norwegian coast, causing the glider’s towrope to snap. The bomber pilot radioed base that the glider had crashed into the sea. The second bomber, meanwhile, came in low over the North Sea to avoid the clouds, planning to climb once it reached clear skies over Norway. But ten miles inland, the bomber and glider crashed into a mountain. The six- man bomber crew and three of the commandos were killed. Several other commandos were severely injured. When German troops located the wreckage early in the morning, they found fourteen survivors and, in the wreckage of the glider, ski equipment and tents, machine and tommy guns, radios, food and explosives. After taking the survivors to headquarters, the Germans interrogated them just long enough to get their names, rank and service number. That evening they shot and killed all fourteen. It was obvious from the explosives on board that they were on a sabotage mission, but the exact target wasn’t known—until the next day, when the Germans found the second glider. It hadn’t crashed in the sea as first thought. It had crashed on land. The officers who interrogated the first survivors had been reprimanded for their hasty execution of the saboteurs. 80 This time they grilled them, and tortured several at length, forcing them to divulge their target—before they killed them. CHAPTER TEN CHICAGO

FERMI PLANNED TO TEST his latest prototype reactor in a forest twenty miles southwest of Chicago. His calculations convinced him that a runaway chain reaction spewing deadly radiation was an impossibility. Nevertheless, the distance from the city provided an extra measure of protection. Unfortunately, a labor strike delayed work on the reactor building. Worried about losing more ground to Heisenberg, Fermi was unwilling to wait, so he suggested an alternate location: a squash court inside the abandoned University of Chicago football stadium. Given the chance, albeit remote, of a catastrophic accident, Fermi and his Manhattan Project bosses knew the university president was not likely to approve, so they neglected to inform him of their plans. 81 The day of the test, December 2, 1942, was bitterly cold. Inside the stadium underneath the west stands, Fermi, bundled in his coat and hat, picked up where he left off in New York. The stakes this time could not have been higher. The United States was at war, and American soldiers were dying on the battlefield. The U.S. State Department had just confirmed rumors of a Nazi extermination campaign against Jews in Nazi-occupied Europe. 82 An estimated two million men, women and children had been killed, and Enrico and Laura were desperately worried about the fate of her brother, sisters and father whom they had left behind in Rome. For Fermi, building a working nuclear reactor was no longer an academic exercise; it was a first step in producing a plutonium bomb and potentially winning the war. Fermi’s Met Lab associates and some 30 high school dropouts waiting for their draft notices had spent weeks hauling tons of graphite blocks and bricks containing uranium slugs into the stadium and assembling the reactor. 83 As technicians made their final preparations, Fermi and his half-frozen colleagues watched from a balcony overlooking the unheated squash court. Below, George Weil, a young Met Lab scientist, waited for Fermi’s signal to remove the cadmium rods which were soaking up neutrons preventing a chain reaction. Fermi had built 30 prototypes preparing for this moment. He was confident this one would work. Not quite so certain, his fellow onlookers watched in tense silence. Among them was his Columbia University colleague Leo Szilard. Several months earlier Szilard had received a vaguely worded telegram from a scientist who knew Heisenberg. The telegram, sent from neutral Switzerland, has been lost, but Szilard had briefed the director of the Chicago Met Lab on its content, and he wrote a memo stating: “that the Germans have succeeded in making the chain reaction work. Our rough guess is that they may have had the reaction working for two or three months.” The memo warned, “there is a real danger of bombardment by the Germans within the next few months using bombs designed to spread radioactive material in lethal quantities.” 84 Fermi and his fellow scientists, no doubt, knew about the memo. An atom bomb in the Nazi arsenal, even a “dirty bomb” that killed by spreading radioactive material, could alter the balance of military power in Europe and throughout the world for generations. On Fermi’s signal, George Weil removed all but one of the rods from the reactor. After checking his calculations, Fermi signaled Weil to begin inching out the last one. Inside the reactor, split nuclei spewed out thousands, then millions of neutrons. A counter similar to a Geiger counter emitted an arrhythmic clicking noise that rapidly transformed into a steady static. As the spectators held their breath, Fermi remained calm, stopping every few minutes to compare the readings to his estimates. Over the next hour the clicking intensified as the shivering spectators stomped their feet to keep warm. When the intensity grew too great for the neutron counter, a chart recorder took over, its pen plotting a slowly rising line on a rotating cylinder of graph paper. Then, suddenly, the line angled sharply upward. 85 Fermi held up his hand, confirming what everyone already knew. The reactor had gone critical. One or more neutrons from each split U235 nucleus had managed to find and split another U235 nucleus. The chain reaction was self-perpetuating. It was 3:49 in the afternoon. Fermi let the reaction run for four minutes before reinserting the rods and shutting it down. The relieved spectators uncorked a bottle of Chianti. Everyone signed the bottle’s straw covering. Those barely decipherable signatures are the only record of who was there that day. “For some time we had known that we were about to unlock a giant,” Project physicist Eugene Wigner would later write, “still we could not escape an eerie feeling when we knew we had actually done it.” 86 Leo Szilard was frightened. “I shook hands with Fermi, and I said I thought this day would go down as a black day in the history of mankind.” 87 The reactor, a massive structure 20 feet tall, 25 feet wide containing 770,000 pounds of graphite and 93,000 pounds of uranium, generated only half a watt of energy, barely enough to light a flashlight bulb, but enough to keep the Allies within striking distance of Heisenberg in the race for the bomb. 88 As Fermi wrapped up the Chicago experiment, civilian death tolls in Europe mounted. The Germans had systematically targeted civilians in Poland, in bombing raids on British cities during “the London blitz” and in the Nazi death camps. The United States Air Force had initially held back, limiting its targets to German military and industrial facilities. But in 1943 the gloves came off, and it expanded its industrial targets to include worker housing around those facilities. “We must face the fact that modern warfare as conducted in the Nazi manner is a dirty business,” President Roosevelt told the American people. “We don’t like it . . . but we are going to fight it with everything we’ve got.” As the “dirty business” continued, it prepared the way for even more killing. It made what was once “unthinkable,” a weapon of mass destruction like an atom bomb, “thinkable.” 89 No nation had ever wielded such a powerful weapon. How much energy would it generate? How wide a swath of destruction would it leave? One mile? Two miles? How many lives would it take? No one could be sure. The science of nuclear-fission was still in its infancy. There were no precedents. “Most experience in life can be comprehended by prior experiences,” the physicist Norris Bradbury would later write, “but the atom bomb did not fit any preconceptions possessed by anybody.” 90 The largest explosion ever to hit a populated area came from an accidental blast in Canada during World War I. Oppenheimer used that explosion to estimate the damage from an atom bomb. 91 On December 6, 1917, a French munitions ship, the SS Mount Blanc , sailed into the harbor in Nova Scotia. From there it planned to join a convoy of ships sailing to a port in France. Onboard were 2,300 tons of picric acid, a powerful explosive, 200 tons of TNT, and numerous drums of high-octane fuel. 92 At 9:04 that morning, while negotiating a narrow passage into the harbor, the Mount Blanc collided with a Norwegian ship, setting off a powerful blast that destroyed two square miles of the north end of the city and ignited dozens of fires. The explosion killed more than 1,500 people instantly and injured thousands more. Hospitals filled to overflowing. Freight cars two miles away were blown off their tracks. Telephone and telegraph facilities were downed for 30 miles around the city. The Toronto Daily Star reported: “Screams of suffering children stabbed the heart.” It appeared “as if some giant scythe had blown down [the] neighborhood and then spat fire on it.” 93 It took more than two thousand tons of high-energy chemical explosives to level those two square miles of Halifax waterfront. How would an atom bomb compare? The volume of chemical explosives onboard the Mount Blanc far exceeded the anticipated volume of U235 or plutonium in an atom bomb. But U235 and plutonium would carry a far greater punch. Chemical explosives release at most five electron volts of energy per atom. The split uranium nuclei in an atomic bomb would yield 200 million electron volts. 94 CHAPTER ELEVEN CONSTRUCTION

THE MET LAB SCIENTISTS had negotiated the first hurdle in the race for the bomb. With the nation ill-prepared for war, millions of tons of steel, copper, concrete and other materiel that would otherwise have been used to build ships and planes and tanks were diverted to building the bomb. President Truman would later call the decision to build the atom bomb “the greatest scientific gamble in history.” 95 Ever since Archimedes designed the first catapult for use against the Romans, warring nations had looked to scientists and engineers to build ever more lethal weapons. The atom bomb would be unlike any device ever invented. If it worked, if it could be built in time to use during the war, it would be the greatest leap in destructive power in the history of warfare, dwarfing all other weapons. Armed with such a weapon, a single bomber could strike a blow that previously would have required 2,000 bombers dropping more than 150 thousand 500-pound bombs. 96 The United States had gotten a late start, but it was now fully committed to beating the Germans. Everyone understood that whoever got to the finish line first could not only win the war, but also reverse a defeat. In the longer run, if Hitler obtained an atom bomb, he could extend Nazi power across the globe. The world would be dominated by his Nazi social policies of forced sterilization, euthanasia and genocide—policies designed to create a racially pure state—for years, perhaps centuries. In the future, every Jew in the world would be at risk of death. It would be a horror show. THE HILLS AND VALLEYS of eastern Tennessee echoed with the sound of bulldozers and jackhammers racing to clear land for U235 separation plants. It was the spring of 1943. In an 80,000-acre area later named Oak Ridge, railroad workers rushed to lay tracks for the hundreds of railcars hauling thousands of tons of uranium ore for processing. Fermi needed 93,000 pounds of natural uranium containing a mix of U238 and U235 atoms to generate half a watt of energy. If all went as planned, Oppenheimer would use just 135 pounds of nearly pure U235 atoms to trigger an atomic explosion. To harvest those 135 pounds Manhattan Project engineers would have to process thousands of tons of uranium ore. It would be a monumental undertaking, and there was no proven method for doing it. Manhattan Project officials had to gamble on two technologies that had never been used for the purpose. The separation plants were enormous. The machinery for the first technology, gaseous diffusion, would fill a six-story plant that stretched half a mile and encompassed 2,000,000 square feet. The giant magnets for the second technology, mass spectrometry, would cover an area larger than twenty football fields. (In June 1944, with the gaseous diffusion plagued by problems, Oppenheimer and General Groves would authorize a crash effort to build yet another separation plant, this one using thermal diffusion technology.) 97 After the war, the adjectives “mammoth,” “monumental,” “enormous,” and “giant” would all be used to describe the fuel processing plants, but none seemed adequate. While workers at Oak Ridge rushed to build U235 processing plants, across the country surveyors on a desolate, windswept tract of real estate half the size of Rhode Island raced to map a site for the production of plutonium. This new town, Hanford, Washington, would serve three nuclear reactors and chemical separation plants. The separation plants were so large the army of workers building them named them “Queen Marys” after the giant flagship of Cunard ocean liners. General Groves contracted with dozens of companies to build the facilities at Oak Ridge and Hanford, imposing impossible deadlines that forced them to design and build simultaneously, and then begin operations even before construction was completed. General Groves would later admit, “Never in history has anyone embarking on an important undertaking had so little certainty about how to proceed as we had then.” 98 CHAPTER TWELVE HEAVY WATER III

THREE MONTHS HAD PASSED since the failed mission to sabotage the Norwegian heavy water plant. In that time the Germans had beefed up security, adding more troops, machine guns, searchlights and even a minefield around the plant. The British had improved their operation as well. Two Norwegian engineers, who had built the Norsk Hydro plant, were now working with the Allies in England. Armed with the plant blueprints, they had constructed a mockup of the electrolysis area where the heavy water was distilled, so that six Norwegian saboteurs could practice laying dummy explosive charges in the dark. This time there would be no gliders. The advance team that had been in place, living off the land since the first ill-fated attempt, would mark the drop zone, and the saboteurs would parachute in. On the first attempt, the plane carrying the saboteurs could not find the advance team’s beacon and had to return to Scotland. On a moonless night weeks later, their luck changed. The saboteurs parachuted onto a snow- packed mountain plateau, a barren landscape inhabited only by reindeer. Fighting gale-force winds, they managed to find the supplies they had parachuted in and meet up with the advance team. 99 After days of skiing, the whole group finally sighted their target. The imposing, seven-story Norsk Hydro plant sat on a ledge at the bottom of a steep bluff. Alongside, several large pipes carried water from the lake above to the gorge below. Their intelligence briefs had been spot on. The guards, the machine guns, etc. were exactly where they expected. Just after the 10 p.m. shift change, the eight saboteurs began their assault. In a heroic feat of mountaineering, they eluded the German guards by descending into the gorge, crossing a frozen river and climbing the 500-foot rock face on the other side. From there, they cut through a wire fence and crawled through a cable-intake opening into the plant. There the demolition team went to work, laying explosive charges, setting the fuses and retracing their steps. They had less than a minute to get away before the explosives went off. 100 Miraculously, all the saboteurs escaped uninjured. British intelligence estimated it would take twelve months for the Germans to get the plant up and running again. CHAPTER THIRTEEN LOS ALAMOS

THEY BEGAN ARRIVING AT the small train platform in Lamy, New Mexico in April 1943, four years after the discovery of atomic energy. They were predominantly single men, graduate students, but also some families. From Lamy, they made their way to 109 East Palace Avenue in Santa Fe where Dorothy McKibben, a 45-year-old widow hired by Oppenheimer, provided the newcomers with passes and arranged transportation to “the Hill,” a secret site on a plateau more than 7000 feet above sea level. Los Alamos, the hub for America’s atom bomb program, would eventually grow to 6,000 scientists and support personnel. With Oppenheimer looking on, each new group of scientists filed into a large wood-paneled room that had served as the reading room for the Los Alamos Ranch School. General Groves had purchased the school the previous year, and it had issued its last diplomas at the end of a shortened school year just four months earlier. Now called Project Y or Los Alamos, the top-secret laboratory did not appear on any maps. To the United States Postal Service it was simply P.O. Box 1663, Santa Fe, New Mexico. Inside the hall, Robert Serber, Oppenheimer’s associate from U.C. Berkeley, greeted the new arrivals. Shouting to make himself heard over the noise of hammering and sawing, he began, “The object of the project is to produce a practical military weapon in the form of a bomb in which the energy is released by a fast neutron chain reaction . . .” 101 The young recruits looked at each other. They’d been told that their work might shorten the war and save American lives. Few, if any, had imagined they would be building an atomic bomb. They would design two types of bombs, Serber explained: one fueled by a critical mass of U235 weighing 33 pounds (that number would later quadruple); another, containing an 11-pound mass of plutonium atoms. Serber then moved on to “the part of the job about which we know least at present,” how to detonate the bomb. Oppenheimer’s team planned to use the same gun-type detonator for both bombs. Simply put, the detonator would fire a projectile of plutonium or U235 down a cannon barrel at a target made of that same plutonium or U235. The two would merge to form a critical mass, the minimal amount of material necessary to sustain a chain reaction. The chain reaction would trigger an explosion. 102 In his Chicago nuclear reactor, Enrico Fermi had slowed neutrons down to generate a chain reaction, but slowed neutrons would not work in a bomb. For a bomb, Oppenheimer would need super-fast, turbo-charged neutrons, and plenty of them. As he raced to catch up to Heisenberg, Los Alamos’s scientific director knew there was no margin for error. The difference between success and failure—and perhaps the outcome of the war—would be determined in roughly a millionth of a second, the time it would take to split 80 generations of nuclei. The formation of the critical mass would trigger a frenzy of careening neutrons. Twenty, then 30 and 40 generations of nuclei would split, generating heat of 100,000, then 200,000 degrees Fahrenheit. Pressure inside the bomb would build. The chain reaction would continue, splitting 50, then 60 and 70 generations. The heat would intensify: 300,000, 400,000 degrees. 103 And then, if everything went as designed, the bomb would explode. But, if things did not go as planned; if the chain reaction lasted longer than 80 generations, the swelling explosion would drive the atoms in the critical mass apart. Neutrons could then escape through the gaps; the chain reaction would peter out, and the searing heat, now equivalent to that in the interior of the sun, would incinerate the bomb. 104 There would be an explosion, more like a fizzle, equivalent to several tons of TNT, but nothing comparable to an atomic explosion. The challenges were staggering. And Oppenheimer got off to a shaky start. Directing the bomb project required far more than a brilliant mind. It required extraordinary stamina, patience, cool under fire, and an ability to manage and motivate others. On paper, Oppenheimer did not seem a good fit. “He was such a smart-aleck,” commented Robert Wilson, a former student, “and didn’t suffer fools gladly.” 105 He was frail. He had suffered bouts of severe depression when he was younger. And he carried the burden of a political past he couldn’t shake.

IN JUNE 1943 WHILE in Berkeley on business, Oppenheimer got in touch with an old flame, Dr. Jean Tatlock, a pediatric psychiatrist and a former member of the Communist Party. She was unhappy and had written several letters begging to see him. Oppenheimer must have known that Colonel Pash’s men would be watching, but he arranged nonetheless to meet her. Every move was observed and duly reported: the two had drinks. 10:50 p.m. Oppenheimer and Tatlock drove back to her apartment. 11:30 p.m. the lights went out. 8:30 a.m., Oppenheimer exited the building. Two weeks after that meeting, Colonel Boris Pash wrote his superiors at the Pentagon recommending that Oppenheimer be denied his security clearance and fired. By the summer of ’43 the stress of the Tatlock affair, the constant surveillance and the six-day workweeks had taken a toll at work and at home. Oppenheimer began pinning top-secret documents in his pockets to ensure that he didn’t misplace them. His wife Kitty had not adapted well to the fenced-in life at Los Alamos and was drinking heavily. Depressed and exhausted, Oppenheimer confided to a friend that he was at the end of his rope and thinking of quitting. The friend’s response: “There isn’t anybody else who can do it.” 106 Not until General Groves brushed aside Pash’s recommendation and granted Oppenheimer his security clearance, did Oppenheimer’s mood improve. Oppenheimer rose to the challenge. “He knew and understood everything that went on in the laboratory whether it was chemistry or theoretical physics or machine shop,” wrote Manhattan Project scientist Hans Bethe. 107 And he was determined that others know as well. Early on, General Groves had imposed strict security measures, insisting that information be compartmentalized, that the chemists, metallurgists, theoretical physicists and others be told only what they needed to know to do their jobs. Oppenheimer had objected, arguing that he needed everyone contributing and sharing their ideas. In a rare retreat, General Groves acquiesced. In time, Oppenheimer became a decisive and even inspirational leader known to everyone on the mesa, from telephone operators to Nobel Prize- winners simply as “Oppie.” Doubters became ardent supporters. “When I was with him, I was a larger person,” said Robert Wilson, who had previously called him a smart- aleck. “I became very much of an Oppenheimer person and just idolized him . . . I changed around completely.” 108 “He never needed to show off or shout,” commented a young telephone operator. “He could have demanded priority one with his telephone calls but never did. He never really needed to be as kind as he was.” 109

THE BRAIN TRUST ASSEMBLED by Oppenheimer for The Manhattan Project included a large number of current and future Nobel Prize-winners. Their mission would require every bit of that intellectual horsepower. In 1943, Los Alamos had only a gram of U235 and only microscopic amounts of plutonium. Unable to conduct experimental atomic explosions, the scientists had to work everything out theoretically. 110 In the atmosphere, stray neutrons zip along at speeds in excess of 15,000,000 miles an hour. 111 How fast would they travel in a solid mass of U235 or plutonium? When the intense heat turned the solid to liquid, how fast would they travel then? And how fast, when the liquid turned to gas? How long would it take to split 80 generations of atoms? The answers to those questions begged more questions. Most importantly, what was the exact volume of U235 and plutonium, the critical mass, necessary to sustain a nuclear chain reaction? How pure did the U235 have to be? Under normal conditions, engineers would have waited until they knew the answers before deciding how many nuclear reactors to build at Hanford, how many uranium separation plants at Oak Ridge. A 500-pound critical mass would require a much larger bomb casing and far more processing capacity than a 50-pound, a lot more electricity, a larger power plant. The size of the critical mass would factor into manpower decisions: how many engineers, carpenters, pipefitters and electricians to hire; the number of worker houses, barracks, hospitals, grocery stores to build. But these were not normal times. “With time as the controlling factor we could not afford to wait to be sure of anything,” wrote General Groves. 112 Instead, the Manhattan Project rushed ahead based on educated guesses, building two, then three different kinds of uranium separation plants and two different kinds of bombs. Redundancy was their best hedge against failure. If one technology did not work, there would be another as backup. The scientists did everything they could to chop fractions of a millionth of a second off the estimated chain reaction time. They surrounded the critical mass with a reflector to bounce escaped neutrons back into the mass. They added a supplemental source of neutrons, an “initiator,” that sprayed additional neutrons into the critical mass. But no matter how much progress the Los Alamos scientists made; no matter how many research hours they put in; they could not shake the fear that they were losing ground to their nemesis Heisenberg. 113 Werner Heisenberg never set foot on the Los Alamos mesa, yet Hitler’s chief atom- bomb-maker was a constant presence. One afternoon, after workers installed a public address system in the top-secret technical area, an anonymous caller asked the Los Alamos operator to page one of the scientists. The operator tried two or three times, and was puzzled when each announcement drew bursts of laughter. “Dr. Werner Heisenberg, please report to the office. Dr. Heisenberg please report to the office.” CHAPTER FOURTEEN HUNTING HEISENBERG

1943-02-09 BBC RADIO

ROBERT ROBINSON REPORTS: The triumphant conclusion of the battle of Stalingrad and the capture of eight more German generals and 45,000 other prisoners in the past two days has overshadowed the rest of the news from Russia. Our allies have kept up their great advance on the southern front.

THE MOMENTUM OF WAR WAS SHIFTING in the Allies’ favor. The German Sixth Army in Stalingrad and the vaunted Afrika Korps commanded by General Erwin Rommel in North Africa had both been defeated. But what should have been good news left many senior Manhattan Project scientists more anxious. What would Adolf Hitler do if cornered? Citing “recent reports from newspapers and secret service,” Manhattan Project physicist Edward Teller, Heisenberg’s former graduate student, warned Oppenheimer, “it is possible that the Germans will have by the end of the year, enough material to make a large number of bombs.” 114 Another émigré scientist urged General Groves to “warn the American people in an official broadcast that the United States might be hit by an atomic bomb.” 115 Groves declined, electing to send a message directly to Heisenberg instead, an airmail special delivery from the RAF. In December 1943, waves of British long-range Lancaster bombers swept across the skies above the Institute of Theoretical Physics in Leipzig where Heisenberg conducted his research. Their bombs destroyed the Institute’s top floors and Heisenberg’s scientific papers along with them. They damaged the home of Heisenberg’s in-laws where he and two of his children were staying. But they failed in their primary mission: “the killing of scientific personnel employed therein.” 116 Heisenberg was in another part of town when the bombing started. In a memoir written after the war, Heisenberg describes running to his in-laws’ home and stepping in liquid phosphorous from incendiary bombs that ignited his shoes. “I quickly stepped into a puddle and so saved my precious footwear.” At the house he discovered it had been “badly hit; doors and shutters were blown in, and to my horror I discovered that there was no sign of life inside.” 117 Racing through what was left of the front door and up to the attic, he found his mother-in-law desperately trying to beat out the flames of burning timbers. His children were safe with neighbors. His wife Elisabeth was out of town. Allied bombers followed the Leipzig attack with a raid on Otto Hahn’s nuclear fission lab outside Berlin. Hahn also escaped injury. Germany’s atomic research laboratories were spread across the country in several different universities. After the raids, Germany dismantled the labs and moved their whole atomic research program to secret locations. As a consequence, the little bit of intelligence that had trickled in to General Groves’ office concerning Heisenberg “virtually ceased.” And, as historian Thomas Powers wrote, “in the soil of silence . . . grew the seeds of fear.” 118

IN SEPTEMBER ’43, GENERAL GROVES, his hands already full managing construction at Oak Ridge, Hanford and Los Alamos, took on another job: gathering intelligence on German nuclear fission research. He accepted the assignment, in part, to calm the nerves of his émigré scientists. 119 According to one of the general’s aides, Heisenberg had become such a distraction that “Groves had difficulty keeping the scientists’ minds on [their] work.” 120 Ironically, British scientists, those most likely to be targeted by Hitler’s first bombs, were far less troubled. British intelligence knew that the Germans had accelerated heavy water production in Norway. But they had not discovered any giant uranium processing complexes similar to Oak Ridge. A source in Berlin, who had been monitoring Heisenberg’s comings and goings, reported no mysterious travels or long absences from Berlin. 121 And a review of German scientific journals turned up several atomic research papers that would certainly have been censored had the Germans been working on a bomb. All considered, British intelligence concluded that Heisenberg was most likely not a serious threat. United States analysts disagreed. The British had failed to account for 51 of the 60 German scientists known to be working in the field of nuclear fission. U.S. analysts took the publication of nuclear fission related research as a cautionary sign: the Germans were trying to “deceive us about the extent and progress of his program, and so cause us to relax the pressure on our own.” General Groves concluded, “We couldn’t take the chance.” 122 Now his own intelligence chief, General Groves turned to Oppenheimer for advice. Oppenheimer did as British scientists had done two years earlier with their analysts. He gave General Groves a list of eminent scientists likely to be working on the bomb. He gave him the rough parameters of what bomb-making and uranium processing facilities might look like. They’d be larger than a city block, draw large amounts of electric power and be located a long distance from the Soviet border and out of range of British bombers. Plutonium reactors would be “operating . . . where water [to cool the plants] is plentiful and where the flow from the plant passes either through open country or through country inhabited by an ‘inferior race’ whom they do not mind killing off.” 123 Armed with that information, U.S. and Royal Air Force reconnaissance flights prowled German skies looking for Heisenberg’s uranium and plutonium processing plants. Specially equipped A-26 Invader bombers sniffed the air for radioactive gases produced by nuclear reactors. And Allied agents sampled German rivers searching for radioactive water. These were dangerous missions. The A-26 crews often had to fly within easy range of German anti-aircraft fire. Weeks of reconnaissance turned up nothing, but Manhattan Project officials were still not convinced. Maybe Heisenberg didn’t need a large industrial plant like Oak Ridge to separate out U235. “[Heisenberg] might have come up with a way to do it in his kitchen,” Oppenheimer warned. 124 Perhaps Heisenberg found a different way to produce plutonium and didn’t need to build large nuclear reactors. WHAT INTELLIGENCE AMERICA DID possess came chiefly from scientists fleeing Nazi-occupied Europe, men like the Danish physicist Niels Bohr, the man who had identified U235 as the source of atomic energy. Bohr, whose mother was Jewish, had returned to his home in Copenhagen after his stint at Princeton University. When the Nazis invaded in 1940, they chose not to roil the waters by arresting Danish Jews. But that changed in 1943, and Bohr, with the help of British intelligence, escaped to England. On December 30, 1943, General Groves showed up at Los Alamos with a special guest traveling under the name Nicholas Baker. Oppenheimer immediately recognized the distinguished Dane, Niels Bohr. Bohr had enjoyed a near twenty-year father-son relationship with Heisenberg. They had first met in the summer of 1922 in Göttingen where Bohr was a guest lecturer and Heisenberg one of his students. Bohr took a liking to the brilliant young German. In the decade that followed, the period when Heisenberg produced his greatest work, Bohr was his collaborator and chief critic. The two had vacationed together at Bohr’s ski cottage and gone on long sailing trips together. Heisenberg had played with Bohr’s children, taking them on pony rides. 125 The war had severed Heisenberg’s relations with many friends on the Allied side. None of those lost friendships pained him more than the loss of Bohr’s friendship. After the war began, Heisenberg wrote his mentor an affectionate farewell: “Since I don’t know whether and when our destiny will lead us together again, I will once again thank you for . . . everything you have done for me.” 126 Niels Bohr and Werner Heisenberg (Niels Bohr Archive, Copenhagen, courtesy AIP Emilio Segrè Visual Archives)

Two years later, in September 1941, unwilling to trust in destiny, Heisenberg scheduled a lecture in Nazi-occupied Copenhagen and used the occasion to reach out to his old friend. Bohr reluctantly agreed to meet, inviting his former protégé to dinner. The get-together began on a sour note when Bohr asked Heisenberg about a comment he had reportedly made at a recent luncheon defending Germany’s destruction of Poland. Heisenberg responded that Poland was a tragic case and tried to excuse his countrymen, pointing out that Germany had not been as brutal in France. 127 What Heisenberg’s true intentions were in coming to Copenhagen would be much debated after the war. Heisenberg would say he came to warn Bohr that Germany was working on a bomb and to search for a way that scientists could join together to halt its development. Bohr believed that Heisenberg’s visit was anything but humanitarian, that he had come solely to pump him for information about the Allies’ bomb program. 128 When General Groves solicited Oppenheimer’s take on the meeting, Oppenheimer, still distrustful of Heisenberg, sided with Bohr. During their dinner in Copenhagen Heisenberg had sketched a cylinder with a line sticking out to illustrate what he was working on. Bohr thought it was a bomb and brought the drawing with him to Los Alamos. Oppenheimer and colleagues saw instead a nuclear reactor and control rods. 129 Either way, Bohr’s story provided direct confirmation that Germany had a nuclear research program; that, at the very least, it was building a nuclear reactor and that Heisenberg was deeply involved. After Bohr left Los Alamos, General Groves pulled Oppenheimer aside and told him about a recent intelligence report. Groves cautioned that the source might not be trustworthy, but according to the report, Germany was not building an atom bomb. The two men looked at each other. Oppenheimer shrugged and said nothing, but his message was clear: it didn’t matter whether the report was true. Oppenheimer and Groves were going to finish what they had started. 130 CHAPTER FIFTEEN HEAVY WATER IV

AFTER THE DARING COMMANDO attack, British intelligence estimated it would take the Germans twelve months to repair the Norsk Hydro plant. But it was up and running again in just six, prompting the Allies to plan a third attack. 131 This time it was an American operation. As the Eighth Air Force squadron of B-17’s approached the Norwegian coast, it was 22 minutes early. The workers at the plant had not yet taken their lunch break. They were not in the basement cafeteria, safe from the Allied bombs soon to be headed their way. To kill time the squadron commander turned back towards the North Sea executing a wide 360-degree turn. By the time they returned, the Germans were ready. One bomber was shot down by ground fire; another was hit and the crew forced to parachute into the sea. 132 One hundred and seventy-six planes made it inland to Vemork and the Norsk Hydro plant where they were joined by 29 B-24 bombers. Together they dropped more than 700 bombs. None of them scored a direct hit. The company’s power plant was damaged, but the “high concentration” plant where the heavy water was produced went untouched. The local residents paid the steepest price: 21 Norwegian civilians killed. 133 Once again, the Germans were quick to make repairs. In February 1944, just seven weeks after that third attack, a shortwave operator with the Norwegian resistance sent an urgent message to England’s Special Operations Executive. SOE ran Britain’s sabotage operations in Europe. The Norsk Hydro plant was back in business and preparing to send the Germans a 15-ton shipment of heavy water. Thirty-nine barrels of the precious liquid would be loaded into two freight cars and transported by rail to a nearby port where the cars would be transferred to a rail-ferry for the next leg of the journey across Lake Tinnsjø. 134 The Norwegian heavy water shipments were the weakest link in Heisenberg’s atomic supply chain. The Germans knew it, and the Allies knew it. With such a large shipment at risk, the Germans took extraordinary precautions. The plant already had armed guards, anti-aircraft guns, land mines and machine guns. The Germans added still more troops and sealed off every possible entry except the main gate. They brought in a special army detachment backed by a regiment of SS police to guard the railroad tracks and ride the freight cars transporting the heavy water to the port. A squadron of spotter aircraft was positioned at a nearby airfield to assist with aerial reconnaissance. 135 Several troops were assigned to the port to guard the ferry. The Norwegian resistance fighters had no good options. The plant itself was too well guarded, as was the train. The best option was to sink the ferry. Plant managers, who were working with the resistance, scheduled the crossing for a Sunday morning when they anticipated there would be the fewest passengers. Some of them and some crewmembers would likely die in the icy waters. It was a terrible price to pay. And the Germans might make it a lot worse. In the past, the Gestapo had executed civilians in retaliation for killing German soldiers. In one instance, they had destroyed an entire town: “Every house and building burned down, every boat in the harbor sunk, every animal killed, and the entire community . . . sent to various concentration camps.” 136 A resistance shortwave operator wired London: “Doubt whether the effect of the operation is worth the reprisals. As we cannot decide how important the operation is, we request a reply soonest.” Within hours London wired back: “The matter has been considered and it’s decided it is very important to destroy STOP Hope it can be done without great misfortune.” 137 The stage was set for a fourth attack on the Norwegian heavy water. On a frigid Sunday morning, the Hydro, a rail ferry with 53 passengers and crew, started its journey across Lake Tinnsjø. Below deck, hidden in the bilge near the bow, were nineteen pounds of plastic explosives attached to an alarm clock. Resistance saboteurs had set the timer to go off 45 minutes after the scheduled departure, when the ferry would be over the deepest part of the lake. 138 The alarm went off as planned. The explosives ripped through the hull. Twenty-six passengers and crew perished in the freezing waters. 139 CHAPTER SIXTEEN KIDNAP

WHILE NORWAY GRIEVED, Colonel Carl Eifler began putting together a team of operatives for a special mission: kidnapping Werner Heisenberg. Proposals to “deny Germany [Heisenberg’s] brain” had been kicking around since October 1942, when the U.S. passed up an opportunity to seize Heisenberg during a visit to Switzerland. Sixteen months later, at the request of General Groves, the Office of Strategic Services, the OSS, precursor to the CIA, resurrected the idea. Eifler, the former head of a guerrilla unit battling the Japanese in Burma, was, according to one OSS operative, “the toughest, deadliest hombre in the whole OSS.” 140 The OSS gave Eifler a budget of $100,000 ($1.3 million adjusted for inflation) and unprecedented authority, notifying OSS officials: “the Director considers Eifler’s mission one of the highest priority and importance . . . The Eifler mission ‘must be made to work.’” 141 His first task would be to track down Heisenberg, whose lab had been relocated after it was bombed. Oppenheimer provided a photo of Heisenberg taken during his 1939 trip to the United States. 142 In a plot worthy of a James Bond novel, Eifler planned to sneak into Germany from neutral Switzerland with a team of twelve operatives, kidnap Heisenberg and drag him back across the Swiss border. From there, Eifler and Heisenberg would board a small plane, fly to the Mediterranean and parachute into the sea where they would be picked up by an American submarine. 143 (Eifler would have preferred to fly Heisenberg to a base in England, but the British SOE did not approve of the OSS running operations in northern Europe, thus the submarine.) He spent months preparing. Oppenheimer assisted with information about Heisenberg’s known associates, their “traits, appearance and habits,” anything he could use to locate Heisenberg. Eifler traveled from Britain to Italy, then to North Africa and India building a cover story. The mission was so secret not even his fellow operatives could know what he was up to. Claiming to be head of a “Strategic Trial Unit,” he demonstrated exploding pencils and other OSS clandestine warfare gadgets to key Allied personnel. 144 He was so convincing that British agents shared information about their “toys and gadgets,” like suppositories for smuggling microfilm. When their superiors got word that clandestine tradecraft had been compromised, they were furious, and the kidnap plot was scrubbed. 145 CHAPTER SEVENTEEN DARK DAYS

BACK IN THE UNITED STATES Oppenheimer and Groves faced endless setbacks. The uranium processing plants in Oak Ridge were hobbled by technical problems. At the current rate, it would take until the end of 1945 to produce enough U235 for just one bomb. 146 The nuclear reactors in Hanford were producing plutonium, but tests revealed a problem: the plutonium contained impurities which would trigger a premature chain reaction. The searing heat would cause the projectile mass and the target mass to melt before they could fully assemble. 147 The bomb would fizzle out. The Manhattan Project had invested more than five billion in today’s dollars building Hanford. 148 More than 130,000 workers had spent 126,000,000 man-hours constructing 540 buildings, 600 miles of roads and 158 miles of railroad track. The plutonium bomb had been a colossal gamble. And now it seemed a colossally bad bet, a disaster of the first order! 149 July 1944 ushered in what would become the Manhattan Project’s darkest days. Twenty-two months after the launch of “the greatest scientific gamble in history” both bombs were dead in the water, and Robert Oppenheimer faced the very real possibility that he would fail. Los Alamos would lose the race for the bomb. Nazi rule with all its horrors would continue to spread. Physicist Isidor Rabi recalls the sense of gloom that pervaded a meeting at the height of the crisis. “Who were the German scientists? We knew them all. What were they doing? We finally arrived at the conclusion that they could be exactly up to us, or perhaps further. We felt very solemn.” 150 D-day had come and gone. Allied armies had stormed the beaches of Normandy in the largest seaborne invasion in history and were beginning a long, bloody march to Berlin. Armed with an atom bomb, Hitler could reverse whatever gains the Allies might make. He might even force a negotiated settlement to the war. Isolated atop a mesa in the New Mexico desert thousands of miles from the fighting, Oppenheimer and crew felt as if the entire weight of the Allied cause rested on their shoulders. “The only way we could lose the war,” one concluded, “was if we failed our jobs.” 151 Desperate, Oppenheimer reorganized Los Alamos around a single mission: developing a faster detonator for plutonium. Scientists and engineers, electronics and explosives experts, chemists and metallurgists not accustomed to working together all pooled their knowledge and expertise. 152 Time was their enemy. Each day of delay meant thousands more Allied servicemen and civilians would die. Each delay ratcheted up the fear that Hitler would build the atom bomb first, that he would target London, Moscow . . . and perhaps New York. His repeated boasts of a “wunderwaffe” only heightened those anxieties: “Very soon I shall use my triumphal weapons, and then the war will end gloriously . . . This is the weapon of the future, and with it Germany’s future is likewise assured.” 153 Then, in October 1944, two news agencies, Reuters and the International News Service, quoted reports from Swedish scientists that appeared to confirm his boasts.

10-03-44 INTERNATIONAL NEWS SERVICE

Nazis Have Atom Bomb, Stockholm Report Declares

Reports reaching neutral scientists . . . said the Germans already have made atom bombs experimentally in considerable numbers. Mysterious explosions seen 80 miles distant from Bornholm [Denmark] were caused by atom bombs. 154

Reuters quoted an eyewitness who described the results of one of those tests: “The countryside for hundreds of yards around was completely flattened as if it was sheared by a knife.” 155 CHAPTER EIGHTEEN ALSOS

AUGUST, 1944.

WORLD WAR II NEWSREEL

MUSIC: The Marseilles

NARRATOR: As Allied troops sweep onwards toward Paris a three-word announcement from the capital brings the great news “Paris is liberated.” 156

While Parisians celebrated and Oppenheimer struggled to design a new plutonium detonator, Alsos, a top-secret American intelligence unit, rolled into the City of Lights. Its mission: to locate Germany’s atom bomb facilities, seize its uranium and capture its atomic scientists before the Soviets could nab them. The scientist leading the mission was a man Heisenberg knew well, the man in the white, double-breasted suit in that 1939 University of Michigan photograph. He was Dutch-born physicist Sam Goudsmit, his close friend and his host in Ann Arbor just before the war. Samuel Goudsmit (AIP Emilio Segrè Visual Archives, Crane-Randall Collection, Goudsmit Collection)

The mission’s military commander was a man Oppenheimer knew all too well: Colonel Boris Pash, the fervent anti-Communist counter- intelligence officer who had hounded him so mercilessly at Los Alamos. His “thorough competence and great drive had made a lasting impression” on General Groves, who appointed him to head the mission. 157 True to his reputation, Pash was among the first Allied troops to enter Paris. Driving in an open jeep, he and his men weaved in and out of a column of French tanks dodging sniper fire as they went. Goudsmit arrived in Paris a week after Pash. A nuclear physicist with a penchant for problem solving, he was well suited for intelligence work. While in college, he had taken a forensics course taught by a local police chemist and studied Egyptology, learning how to decipher hieroglyphics. 158 “Sam has a sixth sense when it comes to bringing order to jumbled facts,” one physicist friend wrote. “He thinks like a detective. He is a detective.” 159 Goudsmit’s gumshoe skills would be a boon to the mission, but it was his web of personal relationships with Heisenberg and other European physicists that made him indispensable. In a letter volunteering for the assignment he had written, “I have very close personal contacts with most of the physicists in Italy, France, Belgium, Holland and even Germany. I think there are even some German physicists who still believe I am their friend,” a reference, no doubt, to Heisenberg. 160 Goudsmit mailed his letter on June 25, 1943, three months after receiving a letter from his parents, whom he had last seen in Holland before the war. It bore a Portuguese postmark, but it had been written inside the barbed wire fences of Auschwitz, the notorious Nazi death camp. Pash and Goudsmit stayed in Paris for three months, pursuing intelligence leads while waiting for Allied troops to drive the Germans out of France. Their first stop was the laboratory of Frédéric and Irène Joliot-Curie, two pioneers in nuclear fission research. Soon after German troops marched into Paris in June 1940, German physicists rushed to their laboratory intending to dismantle their American-made cyclotron, and ship it to Berlin. Rather than surrender theirs, the quick-thinking Joliot-Curies offered a compromise: they agreed to share it. 161 If anybody knew what the Germans were up to, Goudsmit figured it was the Joliot-Curies. Unfortunately, they had little useful information. Broadening their search, Goudsmit and Pash raided the deserted offices of German electronics and chemical firms. A discarded piece of carbon paper at one company gave them the names and addresses of French employees. Two months’ worth of telephone messages and the sign-in book in the lobby yielded names, affiliations, times and dates of visitors. Goudsmit and Pash tracked down several employees and visitors, looking for clues to anything related to atomic energy. All to no avail. Their detective work eventually led them to a Herr Petersen, a Paris- based German chemist who worked for Auer, a large German chemical company. Peterson had fled the city, leaving behind documents about a radioactive metal called thorium. Just before the liberation of Paris he had sent a large shipment of thorium via rail to Auer offices in Berlin. “This really scared us,” says Goudsmit. It scared them because thorium could be used in an atom bomb. 162 Checking industrial uses for thorium, Goudsmit discovered that very few companies used the chemical and then only in very small quantities. He found no reason for such a large shipment . . . except building an atom bomb. “The thorium mystery became an obsession,” says Goudsmit. 163 He and Pash managed to track Herr Petersen to Eupen, a small town on the German-Belgian border. The French army administered that area. Allied protocols required that American soldiers get clearance to operate there. But Pash and his team ignored the rules, climbed in their jeeps and drove the 250 miles to Eupen. There they took the startled chemist and a suitcase full of documents into custody. He was the Alsos mission’s first prisoner. Back in their suite in Paris, Pash and Goudsmit spent several hours interrogating Petersen, but he claimed to know nothing about the thorium. Frustrated and disappointed, Goudsmit combed through the contents of Petersen’s suitcase. He found a ticket from a Berlin streetcar and a recent bill for a hotel in Hechingen, a small village in southern Germany. The name rang a bell. After Heisenberg’s laboratory in Leipzig was bombed, he had relocated to southern Germany, and Allied intelligence had identified Hechingen as the probable new location of his lab. “It seemed a tight case,” Goudsmit would later write. “It connected the . . . thorium from France with the secret project in Hechingen with the foremost [German] chemical firm, the Auer Company.” 164 But Goudsmit’s “tight case” soon sprung leaks. Petersen’s mother lived in Hechingen, and he had gone there to visit her. The thorium? Looking to the company’s future after the war, Auer planned to market thoriated toothpaste for “sparkling brilliant teeth.” An American company, makers of Pepsodent toothpaste, had boosted sales with a whitening agent it called irium. “The Pepsodent Show starring Bob Hope” advertised the benefits of irium every week on Armed Forces Radio. If irium worked for Pepsodent, why not thorium for Auer? 165 But Goudsmit’s efforts did yield one perhaps significant piece of intelligence. A letter from Petersen’s mother referred to the town of Hechingen as a “restricted area.” Why was it restricted? What were the Germans hiding? Goudsmit passed the information along to General Groves and British intelligence. While in Paris, Goudsmit also came across a course catalogue for the Reich University of Strasbourg. A model of German higher education, it was staffed primarily by Nazi loyalists including some atomic physicists. Goudsmit and Pash were eager to get to Strasbourg and interrogate those men. Unfortunately, the city on the French-German border was still under German control, so they had to wait for it to be liberated. The two used the time to take a side trip to two newly liberated cities. In Brussels, Goudsmit raided the offices of Union Minière, a large mining company that held most of the world’s known uranium deposits. The company’s books showed that since 1940 it had shipped more than a thousand tons of uranium products to Germany, far more than German firms would need for normal commerce and a sure sign they were attempting to harness atomic energy. 166 From there, Goudsmit moved on to the Dutch city of Eindhoven, home of a plant suspected of supplying nuclear research equipment to the Nazis. It turned out that Goudsmit and a young physicist working at the plant had a friend in common. Goudsmit asked if the friend had any news about Goudsmit’s parents. The young man confirmed the Germans had deported them along with other Jews. Back in Paris, as he wandered the streets, peering in shop windows, Goudsmit could not stop thinking about his parents. When he was growing up in The Hague, his mother owned a stylish French hat shop, Au Louvre. He loved hearing her talk about designing hats, about the challenges of predicting next year’s fashions and, of course, about Paris, the world’s fashion capital. The young Sam Goudsmit hoped to go into the millinery business himself one day. “Even now, when I think of Parisian streets and buildings,” he told a reporter, “I can hear my mother’s voice telling me about them.” 167

FRENCH TROOPS LIBERATED THE CITY of Strasbourg on November 23, 1944. Days later Colonel Pash and an advance team of Alsos soldiers made a dash for the university where they took four German physicists into custody. 168 Goudsmit followed a week later. With German artillery still shelling the city, he and his men spent two days and candle-lit nights poring over the papers of the captured scientists. In a letter to his wife he described the agony he felt knowing that he would be responsible for sending fellow scientists to prison. “I am too soft for this game,” he told her. 169 Goudsmit was shocked by how much information the prisoners’ papers revealed about their research. One set of experiments, in particular, attracted his attention. A biologist, Eugene von Haagen, developed vaccines for influenza, yellow fever and other diseases. His laboratory was filled with cages for mice, guinea pigs and monkeys. 170 But he also had a second lab, this one located in a nearby prison, where he tested a vaccine for spotted fever. Haagen had fled Strasbourg, but a copy of a letter to a Nazi SS officer revealed the nature of that research. “Of the one hundred prisoners you sent me, eighteen died in transport,” von Haagen complained. “Only twelve are in condition suitable for my experiments.” He then requested another hundred before closing with “Heil Hitler.” 171 As fate would have it, Goudsmit was billeted in Haagens’ apartment and slept in his son’s bed. “All his toys were still there, his electric train, a movie projector, an old microscope” along with mementos of his time as a Hitler Youth, Goudsmit wrote his wife. 172 In liberated Paris, Goudsmit had managed occasionally to escape the war by wandering the streets alone with his thoughts. In Strasbourg, the horrors were present night and day. In the mornings, as he made his way from the von Haagens’ apartment to the Alsos office, he had to thread his way through weary soldiers crying and trembling from shell shock. It was too much for the genial college professor. The stress of the war, and the waning hope that his parents might somehow have survived, left him emotionally drained. Back at the apartment he became inconsolable. He “just went off his rocker,” an Alsos friend reported. “He was furious at the Germans, weeping and thrashing about.” It took a half-hour for a colleague to calm him down. 173 A short while later Goudsmit flew back to Ann Arbor for a brief, much-needed rest.

THE DOCUMENTS GOUDSMIT DISCOVERED in Strasbourg were an intelligence jackpot. For the first time the Alsos mission had a window into the inner workings of Germany’s atomic research program, notes from secret meetings, postcards, memos from one scientist to another and a personal letter addressed to “Lieber Werner” (Heisenberg) sharing gossip about life in Strasbourg. 174 Letterheads included the addresses and telephone numbers of the laboratories where the scientists worked. Goudsmit was shocked that the Germans made little effort to censor their communications. It took Goudsmit and colleagues several days to sift through all the documents. In the end they found no evidence of a massive industrial facility like Oak Ridge or Hanford, but they did confirm that Heisenberg headed a team of scientists working to build a nuclear reactor. Other teams were working to separate U235 from uranium ore and to produce heavy water. The cache of papers also revealed that the German Army, independent of Heisenberg, was building its own nuclear reactor. The scientist in charge was Kurt Diebner, an able physicist and a loyal Nazi. 175 There was no love lost between the Diebner and Heisenberg groups. 176 Goudsmit would later learn that Heisenberg had wasted a year trying to perfect his own prototype while Diebner had made considerable progress. Heisenberg eventually abandoned his reactor design and adopted Diebner’s. 177 But despite Diebner’s superior performance, his group still had to stand in line behind Heisenberg to receive scarce heavy water and uranium supplies. Heisenberg was a world-renowned Nobel Laureate; Diebner, a talented experimental physicist, but a comparative nobody. 178 After reviewing all the documents, Goudsmit felt confident that the Germans were far behind the United States in the race for the bomb. The news reports that the Germans had already developed the atom bomb were either mistaken or German propaganda. Goudsmit arranged to have his findings hand-delivered to General Groves in Washington. 179 But the results were not what Goudsmit had expected. The general remained skeptical. Locating Heisenberg had been too easy; the documents with addresses and telephone numbers, too revealing. General Groves worried that they had been planted for the Allies to find, that they were Nazi disinformation. CHAPTER NINETEEN RESTRICTED AREA

GENERAL GROVES HAD REASON to be suspicious. Goudsmit and his Alsos intelligence team had moved on from their thorium toothpaste adventure. General Groves had not. The Alsos investigation had left some critical questions unanswered: why was the town of Hechingen “a restricted area”? What were the Nazis hiding? To find answers, RAF reconnaissance flights swept hundreds of square miles near Hechingen. The specially equipped Spitfires carried two cameras, one on each wing, which filmed overlapping images. Back in England, interpreters from Britain’s Air Scientific Unit studied the photos through stereoscopes which married the two images, producing what looked like a three-dimensional picture. The interpreters spent countless hours looking for uranium processing plants and nuclear reactors. They had been briefed to search for a large industrial facility using enormous amounts of electricity. With so much territory to search, the interpreters used Germany’s electric power grid as a guide. They looked for large electric transformer stations and followed the high-voltage power lines radiating from them. It was painstaking, mind- numbing work, but it paid off. The photo interpreters discovered more than a dozen medium-sized industrial plants under construction, stretching for twenty miles along a valley close to Hechingen. Each had a small factory building with storage tanks and what looked like a grid of pipes alongside. 180 The interpreters observed workers from nearby slave-labor camps building rail spurs and stringing power lines. They could see large quantities of material being brought in by truck and rail. Every reconnaissance mission brought new evidence of what was obviously an urgent, top-priority program. But it was a second piece of intelligence that bumped the program to the top of General Groves’ watch list: Werner Heisenberg had been spotted in the area. As the interpreters grew more familiar with the imagery they noticed that the dozen or so plants were all strung along the same geologic contour. Armed with that additional bit of information, the Interpretation Unit sent an officer to Britain’s Geologic Museum. There, a curator searched through volumes of old records and discovered that German geologists had explored the area before the war looking for oil-bearing shale. Germany was desperately short on gasoline. Allied intelligence concluded that the pipes alongside the plants were used to “cook the oil out of the shale.” What the reconnaissance had discovered was a crash program to refill Germany’s gas tanks. 181 Allied intelligence later learned that the German term “restricted area” which they interpreted to mean “top secret, keep out” didn’t mean that at all. It was simply a warning that the town, already flooded with displaced people from war-ravaged areas, was no longer open to refugees. CHAPTER TWENTY BATTLE OF THE BULGE

ON DECEMBER 16, 1944, Goudsmit, fresh from his visit home, was back in Paris with Pash waiting for Allied troops to occupy southern Germany, so they could get to Hechingen and to Heisenberg’s lab. Meanwhile, 185 miles to the northwest in the Ardennes forest, British and American troops were relaxing, looking forward to a peaceful Christmas holiday. The Germans were on the run. It seemed only a matter of time before the Allies would roll into Berlin, and the war would be over. But at dawn, the roar of German artillery and the clanging of German tank treads shattered the calm. Bad weather had grounded Allied reconnaissance flights, and the Allies were caught completely by surprise. Twenty-five German divisions launched a ferocious attack.

NEWSREEL: BATTLE OF THE BULGE

NARRATOR: In one day the enemy smashed though the defenses of the American First Army on a 45-mile front and was fighting deep into Luxembourg and Belgium.

Marshaling what was left of the mighty German Wehrmacht, Hitler had launched a brilliant, but desperate attempt to encircle and crush U.S. and British forces and seize their fuel supplies. It nearly worked. But the skies cleared, and Allied air superiority and reinforcements eventually carried the day. The Allies had let their guard down and paid an enormous price. The Battle of the Bulge, as it was later called, cost 19,000 American lives. It was America’s bloodiest battle of the war. Heisenberg was in Zurich preparing to give a lecture and doing some Christmas shopping when he heard the news of the attack. Paul Scherrer, a physicist at the city’s Federal Technical College, had invited him to give the lecture. 182 Scherrer was a friend of Goudsmit and, unbeknownst to Heisenberg, an important intelligence source for the Allies. A few days after the lecture, Heisenberg attended a dinner party hosted by Scherrer. Heisenberg had asked that politics not be discussed, but with news of the German attack filling newspapers and radio broadcasts the topic was impossible to avoid. After dinner the guests split up into separate rooms. A young Dutch physicist later reported that he overheard Scherrer’s wife in the next room grilling Heisenberg about Nazi crimes against the Jews. “What do you say to these atrocities?” she demanded. 183 Heisenberg claimed that he knew nothing about the murder of Jews in Holland and France. No one believed him. The young physicist accused Heisenberg of supporting the Nazi regime. “I’m not a Nazi,” Heisenberg answered angrily, “but a German.” 184 Later, pressed to admit that Germany would likely lose the war, Heisenberg replied, “Yes, but it would have been so good if we had won.” 185 Years of life under Nazi rule had taught Heisenberg the dangers of speaking his mind. “We all had to disguise our words and actions as best we could,” Elisabeth Heisenberg wrote later. “Even among acquaintances and casual friends we were guarded, and we spoke only in innuendoes.” 186 Heisenberg also knew that neutral Switzerland was a hotbed of Allied and Nazi spies. But that night in Zurich Heisenberg’s emotions got the better of him. That night he spoke the truth, and he spoke it publicly for everyone to hear. He wanted Germany to win the war and feared it would not. His former friends on the Allied side heard, the Gestapo heard and in future years historians trying to understand his motives would hear. When his comment made its way back to Goudsmit, it only strengthened his contempt for his former friend. 187 When the SS in Berlin got wind of the remark, it prepared to charge Heisenberg with treason. Such defeatist comments were punishable by death. But once again Heisenberg had a friend in a high place. The friend promised to reprimand Heisenberg, and the incident was swept under the rug. 188 THE AFTERSHOCKS FROM THE Battle of the Bulge reached all the way to the United States and Hanford, Washington. American commanders in Belgium had let their guard down and been taken by surprise. General Groves would not allow that to happen here. Gambling that Oppenheimer would solve the plutonium detonator problem, Groves ordered Du Pont, the company that built and operated the Hanford reactors, to accelerate plutonium production. Standard protocol required that the plutonium from the nuclear reactors be stored in cooling ponds for 120 days, so that the most radioactive elements would have time to decay before further handling. 189 General Groves ordered that storage time cut in half, and then cut it again. The handling was done via remote control. Nevertheless, DuPont executives worried about the radiation hazard and worker safety. What effect, if any, the speeded-up schedule had on the workers or communities downwind is not known. At Los Alamos, Oppenheimer and his scientists were already working six-day weeks to develop a plutonium detonator. Hanford’s accelerated schedule pushed everyone to their limit. The relentless pressure day after day left Los Alamos’s chain-smoking scientific director emotionally drained and physically exhausted. By the spring of 1945, the already frail Oppenheimer had lost 30 pounds and weighed a mere 150. Worried about Oppenheimer’s health, General Groves violated his own security regulations and invited Oppenheimer’s brother Frank, a former member of the Communist Party, to come to Los Alamos for moral support. CHAPTER TWENTY-ONE HUNTING HEISENBERG II

1945-03-08 BBC FREDDY GRISEWOOD

The Allies are across the Rhine. Troops under General Hodges established a beachhead on the east bank south of Bonn on yesterday afternoon. A Reuter report from the First American Army says that the crossing was made at Remagen, which is about 25 miles south of Cologne.

IN LATE APRIL 1945 the German armies were in full retreat. Soviet forces were advancing on Berlin. French forces were already in southern Germany and fast approaching the towns of Haigerloch and Hechingen where Heisenberg’s laboratory was located. After all the effort they had put in, Pash and Goudsmit were determined not to lose their number one target to the French. With an assist from borrowed U.S. Army troops, Colonel Pash and an Alsos caravan of two armored cars, jeeps and assorted vehicles set off to collect their prize. As was now standard practice, Goudsmit and his scientists followed a few days later. Goudsmit thought the procedure was adopted to protect the scientists’ lives. He was mistaken. It was adopted by order of General Groves to assure that none of the scientists were captured and forced to reveal atomic secrets. 190 As Pash and his troops rolled into the small town of Haigerloch, white sheets and pillowcases hung from its windows signaling surrender. Alsos agents immediately set about interrogating the residents, who claimed to know nothing about any scientific experiments. They did, however, point out a cliff overlooking the town where they had witnessed some unusual activity. Just below the top, carved into the face of the cliff 80 feet above the ground, was a concrete entrance to a cave. The entrance would have been invisible to aerial reconnaissance and virtually impossible to target with a bomb. His curiosity piqued, Pash “persuaded” a local resident granted special access to unlock the cave door and there, inside a ten-foot-wide concrete hole in the floor, was what he had come halfway across Europe to find: a metal cylinder, Heisenberg’s nuclear reactor. The reactor’s lid hung from the cave ceiling with some 600 uranium cubes dangling like Christmas ornaments on chains from its underside. Once the lid was lowered, the reactor could be sealed and heavy water pumped in. A primitive prototype of a nuclear reactor, it was all Heisenberg had to show for six years of work. 191 He had hoped to use it as a bargaining chip to win favorable treatment from the Allies after Germany’s defeat. But, as Alsos soon learned, the reactor had never sustained a nuclear chain reaction. It had never gone critical. America’s scientists had entered the race convinced that German science was the best in the world. The Germans believed it. The President of the United States believed it. Fear of German scientific superiority had driven President Roosevelt to authorize building the atom bomb. It kept General Groves, Oppenheimer, Fermi and Goudsmit awake at night as they raced to catch up to Heisenberg. Now, it seemed, it was all a myth. Werner Heisenberg, Germany’s most brilliant physicist, the man Allied intelligence called “the brain,” had not come close to building an atom bomb. He hadn’t even built a working nuclear reactor. Wasting no time, Pash left Goudsmit with the reactor and drove ten miles to Hechingen where Heisenberg and his group of 50 scientists had their offices inside an old textile mill. Heisenberg wasn’t there when Pash arrived, but he’d left behind on his desk a framed photo of himself. He had carried it with him in August 1939, when he sailed from New York back to Germany, his memento of happier times. Taken at the University of Michigan, it showed him and the man he had once considered a close friend, Samuel Goudsmit, staring into the camera and smiling. Goudsmit’s fellow soldiers took advantage of the situation and ribbed him about it for months. 192 CHAPTER TWENTY-TWO CAPTURE

DURING THE WANING DAYS of the war in Europe, Colonel Pash rounded up nine of the German scientists on his most wanted list. Only Heisenberg remained free. With the German army in disarray and offering only sporadic resistance, Pash and his men tracked Heisenberg to his family’s cabin in the mountain town of Urfeld 150 miles from Hechingen. Heisenberg had ridden there by bicycle, traveling only at night to elude SS troops executing suspected deserters and Allied fighter planes strafing vehicles on the road. Heisenberg was sitting calmly on the veranda, looking out at the lake, when Pash and his men, out of breath from the steep climb, trudged up the road to his cabin. 193 On seeing the American uniforms, he said simply, “I’ve been expecting you,” and invited them in to meet his stunned wife and children. 194 In the cabin, Pash’s soldiers found another photo of Heisenberg and Goudsmit, this one from the 1920s when Goudsmit was a student in Göttingen. “Sam Goudsmit is waiting for you at headquarters in Heidelberg,” they told him. 195 Heisenberg seemed pleased, but concerned about his family’s welfare. Not wanting to appear to be collaborating with the enemy, he asked Pash to treat him roughly, and Pash played his part. In the nearby village, his men handcuffed Heisenberg and forced him into an Army jeep. 196 Twenty-seven years after losing World War I, Germany had lost another. Millions of Germans had been killed. Much of the country had been turned to rubble. Yet at the moment of capture Heisenberg felt only relief, “like an utterly exhausted swimmer setting foot on firm land.” 197 Heisenberg didn’t know it, but that swimmer had come within a hair’s breadth of not making it. In November 1944, after inviting Heisenberg to lecture in Zurich, Paul Scherrer cabled Goudsmit who notified the OSS. The OSS assigned one of its top agents, Moe Berg, to attend the lecture. A man with a colorful history, Berg had studied seven languages at Princeton and played fifteen years of professional baseball, ending his career as catcher with the Boston Red Sox. Often described as “the brainiest player in major league baseball,” 198 he had passed the bar exam in the off-season and years later been recruited by the OSS. Berg arrived in Paris just before the Battle of the Bulge for a week of OSS briefings by Sam Goudsmit and others. It’s not known exactly what was said during Berg’s briefings, but Berg, an inveterate note taker, left a fragmentary scrap of paper reading— “gun in my pocket” and on the next line “nothing spelled out but—Heisenberg must be rendered hors de combat ,” a French phrase meaning “out of the battle.” 199 On December 18, 1944 Berg and another OSS officer arrived early for a 4:15 seminar at the University of Zurich lecture hall on Ramstrasse. Encountering no security, they left their hats and coats at the door and took seats in the second row. Only about twenty people were in the audience. Heisenberg stood at the blackboard in front of the room and began to speak. Berg had been briefed on nuclear fission, but this speech on something called S-matrix theory seemed to have little to do with fission. Berg listened intently trying to decide if Heisenberg should live or die. Well into the lecture, Berg began taking notes: “thinish” . . . “Irish look” . . . “Heavy eyebrows, emphasize movement of that part of bony structure over the eyes” . . . “Sinister eyes” . . . “Continuous seeming quizzical smile as he talks.” 200 After the war, Berg told a friend he would have shot Heisenberg there and then had he believed he was building a bomb. But S-matrix theory, “sinister eyes” and “quizzical smile” were not sufficient evidence for a death sentence. Berg issued Heisenberg a reprieve. The “exhausted swimmer” was allowed to reach “firm land,” unaware how close he had come to drowning. 201 It was Heisenberg’s second Allied reprieve. After the Strasbourg documents confirmed the location of his laboratory in Hechingen, General Groves set in motion plans to have the lab bombed. Goudsmit convinced the General that Heisenberg was not a threat, and the mission was scrubbed. CHAPTER TWENTY-THREE THE HUNT IS OVER

1945-05-01 BBC RADIO

This is London calling. Here is a news flash. The German radio has just announced that Hitler is dead. I repeat that. The German radio has just announced that Hitler is dead.

SAM GOUDSMIT’S SEARCH FOR WERNER HEISENBERG ended in Heidelberg, Germany on May 6, 1945, a week after German dictator Adolf Hitler committed suicide. In the preceding months Goudsmit had met with a dozen or more German scientists, helping to decide whether they would be interned or freed. As he waited for Heisenberg to be ushered into his office, he knew that the fate of his nemesis had already been decided. Heisenberg was simply too valuable an asset to risk his being kidnapped and forced to work for the Soviets. Goudsmit would have to take him into custody. It had been almost six years since the two had last seen each other. There was so much to say that the two ended up saying very little. Goudsmit asked Heisenberg, as he had in 1939, if he wanted to come to the United States. And once again he answered no. He would be needed in Germany after the war. And then Heisenberg proudly asked Goudsmit if he wanted to see his prototype nuclear reactor. “He was still too impressed by his own importance,” Goudsmit later wrote. Goudsmit didn’t even bother to ask Germany’s chief atomic theoretician about his work. “I merely thanked him for his offer and left him secure in the belief that his work was ahead of ours.” 202 In his brief report on the interrogation Goudsmit said simply, “Heisenberg is actively anti-Nazi, but strongly nationalistic.” 203 In his account of the meeting Heisenberg completely misinterpreted Goudsmit’s comments. “The conversations with Goudsmit . . . were as amicable as though the last six years had never taken place, and I myself haven’t felt this well for years, both emotionally and physically,” he wrote his wife. 204 It’s hard to imagine how he could have been so far off the mark. The letter was never mailed. She discovered it after his death among his papers. The day after the meeting, Germany surrendered, and the full horror of Nazi atrocities finally became public—atrocities that certainly would have been much worse had Germany developed an atom bomb. Newsreels from the period showed ditches filled with rotting bodies piled one on top of another and prisoners not yet dead, waiting to die.

WORLD WAR II NEWSREEL

NARRATOR: For the first time America can believe what they thought was impossible propaganda. Here is documentary evidence of sheer mass murder. 205

Among the dead were Enrico Fermi’s father-in-law, an admiral in the Italian navy . . . and Goudsmit’s parents. With typical German efficiency, the Nazis had recorded the date of their murder. It was February 11, 1943, Isaac Goudsmit’s seventieth birthday. 206 Werner Heisenberg knew Goudsmit’s parents. He had met them in 1925 at Goudsmit’s home in the Netherlands. When the Gestapo arrested them, a friend alerted Heisenberg, hoping he would intercede. Heisenberg responded by sending a letter to Nazi authorities in Holland saying that Goudsmit had always been a friend of the German people and “He would be very sorry if . . . [Goudsmit’s] parents would experience any difficulties in Holland.” 207 Goudsmit considered the letter woefully inadequate and could not forgive Heisenberg. Nor would he forgive himself. He wrote very movingly about his own failure to save his parents in his memoir on the Alsos mission: “Maybe I could have saved them . . . If I had hurried a little more, if I had not put off one visit to the immigration office for one week, if I had written those necessary letters a little faster, surely I could have rescued them from the Nazis in time. Now I wept with a heavy feeling of guilt in me.” 208 CHAPTER TWENTY-FOUR PLUTONIUM

MANHATTAN PROJECT SCIENTISTS, ENGINEERS and their corporate partners had overcome myriad obstacles since they began their journey. After the war, Pentagon officials would calculate that they had filed several thousand patent applications for new devices, new methodologies, new technology to clear a path to the atom bomb. None of those obstacles posed a greater challenge than detonating a plutonium bomb. The gun type detonator that triggered the U235 bomb wouldn’t work with plutonium. The thousandth of a second required for the projectile and target to assemble was too slow. Fortunately, Oppenheimer had a backup. Some of his scientists had been experimenting with an idea for a faster detonation technology called “implosion.” It was a long shot, so it had gotten little attention. Now it was Oppenheimer’s only option. It had to work. It was far more complex than the U235 detonator: a high-performance racing machine versus a Model T. Thirty-two high-energy explosive charges encompassing the outer shell of the spherical bomb would fire at precisely the same moment. Inside the bomb, the shockwaves from those explosions would compress a grapefruit-sized plutonium sphere into a dense, golf-ball- sized critical mass. The compressed mass would, in turn, squeeze an initiator, which would spew out millions of neutrons, accelerating the nuclear chain reaction and leading to an explosion. The dynamics of the implosion had to work to perfection. If not, the plutonium mass would deform like a squeezed balloon. Neutrons would escape, and the chain reaction would fizzle out. 209 In the fall of 1944, Oppenheimer and General Groves pulled out all the stops, racing to develop the new detonator. They asked Fermi, who was at the Met Lab in Chicago, to relocate to Los Alamos. They scoured the country looking to recruit additional mathematicians and explosives experts. General Groves relaxed the tight security at Los Alamos so that British scientists, whom he had previously barred from the top-secret site, could be brought in. And he arranged to have 600 members of the Army’s Special Engineering Detachment reassigned to help with the exhaustive testing that went into designing the bomb. 210 Finally, after months of experimentation, they came up with plans for a working detonator. If all went well, the plutonium bomb would be even more powerful than the U235 bomb. 211 But manufacturing the precision components proved more difficult than anticipated. The first shipment of parts for the explosive mechanism failed at an alarming rate, and a second contractor supplying the firing circuits was late on its deliveries. 212

THE CONVOY, THREE LARGE panel trucks sandwiched between a lead and rear escort car, arrived early in the morning. Each vehicle had two guards “armed with shotguns, revolvers and a submachine gun.” 213 Their destination: a vault dug deep in the side of a mountain in Hanford, Washington. As the armed guards watched, soldiers emerged from the vault carrying dozens of wooden boxes and set them gently on racks inside the trucks. Each box contained a stainless-steel flask. In that flask, 80 grams of a bluish-green slurry: plutonium. From Hanford the five-vehicle convoy traveled 700 miles to Fort Douglas in Salt Lake City. There they met a second convoy of soldiers who transferred the precious cargo to their trucks. The first returned to Hanford; the second headed for Los Alamos. Neither convoy knew the full particulars of the journey, where it originated and where it ended. As Hanford’s three giant nuclear reactors disgorged more and more plutonium, the convoys grew more frequent. 214 By July 1945 they were delivering almost enough plutonium to produce three bombs a month. Oppenheimer’s long struggle to develop the implosion detonator was almost over. Would it work? Oppenheimer was confident that the U235 bomb with its relatively simple detonator would. But the plutonium bomb with its precision firing system was always a serious concern. As far back as January 1944 Oppenheimer and Groves had begun discussing ways of testing the bomb. 215 That test was finally scheduled for July 16, 1945. CHAPTER TWENTY-FIVE JAPAN

THE WAR IN EUROPE was over. But the battle against Japan continued.

1945-02-20 CAN RADIO REPORT ON IWO JIMA

It’s almost unbelievable. Everything on Iwo Jima is either underground or buried in the side of a volcano. The Marines have had to dig the Japs out of every sunken pillbox, blockhouse and cave that escape a direct hit. And there were lots of them. And there will be lots more before this is over no matter how many tons of shells we pour in here.

The Japanese were on the defensive, but still refusing to give ground. Their forces in the Pacific launched wave after wave of assaults against invading U.S. Marines on specks of land that few Americans had ever heard of— islands with names like Tarawa, Saipan and Iwo Jima. And when all was lost, instead of surrendering, they committed suicide. CHAPTER TWENTY-SIX FARM HALL

IN JULY 1945, AFTER a month-long stay in Belgium and France, Heisenberg and nine other captured German scientists were taken to Farm Hall, a Georgian country house near Cambridge, England. Adjusting to their new lives, the “guests” of the British signed pledges agreeing not to try to escape and settled into a daily routine—breakfast at 9:00 a.m., lunch at 1:00 p.m., tea at 4:00 p.m. and dinner at 7:45 p.m. 216 In between, they whiled away the hours walking in the rose garden tended by German POWs, playing volleyball and tennis, reading books from the estate’s well-stocked library, listening to the radio, playing bridge and attending scientific lectures conducted by their colleagues. The English officer in charge even arranged to bring in a piano so that Heisenberg could give recitals. 217 He could perform some of Beethoven’s most difficult sonatas with technical perfection, commented one critic, but his performances were “almost completely devoid of passion.” 218 Incarceration kept the German scientists out of Soviet hands while the British decided what to do with them. But their stay at Farm Hall served another even more important purpose. It allowed British intelligence to eavesdrop on their conversations. Unbeknownst to Heisenberg and colleagues, Farm Hall was a British safe house with microphones hidden in the bedrooms, dining room and living room. A bilingual team of British military monitored their conversations day and night and preserved those of intelligence value on reusable shellacked metal disks. 219 The disks recorded the “guests” debating what the Americans would do with their nuclear fission research. “I am convinced they [the British and Americans] have used these last three months mainly to imitate our experiment,” one argued. 220 The scientists were anxious about the future, but also trying to distance themselves from the past. One Nazi party member admitted to his colleagues that he took “the line of least resistance.” Another boasted about how he had rebelled against the Nazis: “I had no picture of Hitler in my institute. They kept on coming and saying we should buy a picture of Hitler. I always said no.” 221 Heisenberg, who had refused to join the Nazi party, recounted his efforts to intercede on behalf of friends and colleagues arrested by the Nazis: “He had already been killed” . . . “It was no good, and he was shot” . . . “I couldn’t even find out . . . whether he was alive or dead.” Historian David C. Cassidy notes that Heisenberg made about ten such humanitarian gestures, but “when Heisenberg did act, he did so as he had in past situations—offering too little, too late.” 222 Only one of the detainees accepted responsibility for his countrymen’s atrocities: “We went to Poland and not only murdered the Jews in Poland, but for instance, the SS drove up to a girls’ school, fetched out the top class and shot them simply because the girls were high school girls and the intelligentsia were to be wiped out. Just imagine if they had arrived in Hechingen, drove up to the girls’ school and shot all the girls! That’s what we did.” 223 By the end of July 1945, Heisenberg and colleagues had been held for more than two months with little news from home. They knew only that their country was in turmoil controlled by occupying armies, the economy in shambles, food and fuel in short supply. Everyone feared for the welfare of his family. (Heisenberg didn’t know it, but his wife and five children were better situated than most. Colonel Pash had been looking out for them, making several trips to their cabin to bring groceries and other supplies.) 224

SAM GOUDSMIT AND A SMALL CONTINGENT of Alsos personnel traveled to Berlin in July 1945 to see the laboratory where Heisenberg had done much of his research. A sign on the door at the Kaiser Wilhelm Institute for Physics in Berlin read Director of Intelligence of the U.S. Control Council. Inside, the American officer who greeted them seemed surprised by their interest. The Russians, he explained, had cleaned the place out. He invited them to have a look. 225 In the yard behind the lab Goudsmit and his colleagues found broken lab equipment, blocks of pressed uranium oxide and old notebooks. After wandering through the building, they went down into the basement and then the sub-basement. There they discovered a bunker fortified with six-foot- thick reinforced concrete walls and what was left of Heisenberg’s laboratory. The Russians had scavenged what they could, but to Goudsmit it “looked as if it had once been excellently equipped.” 226 In the center was a large circular pit that once contained a heavy water reactor vessel. Metal containers and frames that suspended uranium cubes inside the vessel were scattered on the floor. The winch that held the reactor was gone, but the track that guided it was still attached to the ceiling, and remnants of a sophisticated ventilation system still hung on the walls. Airtight steel doors opened to surrounding rooms which had served as laboratories and living quarters for the skeleton crew that sheltered there during Allied bombing raids. 227 Goudsmit, who had apparently seen one of Fermi’s early reactors, was struck by how much more sophisticated Heisenberg’s operation seemed. The Germans had so many advantages over the Americans at the start. Goudsmit couldn’t understand why they had made so little progress. CHAPTER TWENTY-SEVEN HIROSHIMA

THE CITY’S RESIDENTS WERE ON EDGE. They had seen neighboring towns decimated by mass raids of American B-29 bombers. “B-san,” they called them, Japanese for “Mr. B.” But their city had not been touched. Rumor had it that the Americans had something special in mind for Hiroshima. Not wanting to find out, thousands of residents had taken part in planned evacuations reducing the city population to 245,000 from a peak of 380,000. Those who stayed behind had heard the minute-long blasts of the air- raid sirens many times. They heard them at night, when large numbers of Mr. B’s flew in from the coast to a rendezvous point northeast of the city, before heading off to bomb other cities. They heard them in the morning, when a single American weather observation plane flew over. 228 But then, just before 7:30 a.m. on August 6, 1945 Japanese radar operators spotted three blips on their radar screens and sounded the sirens. The B-29 Super Fortresses crossed the Japanese coastline and headed to a spot fifteen miles east of Hiroshima. Assuming they were part of a reconnaissance mission targeting some other city, the operators sounded the all-clear. 229 But then, just after 8:12 a.m., the three blips changed direction, heading straight for Hiroshima. At 8:15 a.m. the bomb bay doors on the lead plane snapped opened and released its payload, a single ten-foot-long bomb. 230 Forty-three seconds later the energy from a nuclear explosion heated the air to several million degrees centigrade producing a giant fireball. A flash of light hundreds of times brighter than the sun illuminated the morning sky. Silent pressure waves of superheated air accelerated outwards away from the blast. The waves incinerated and shattered structures and killed almost every living being in their path. By the time the roar of the explosion, traveling at the speed of sound, caught up, several square miles of the city had been turned to rubble and flames. 231 Within seconds the once bustling factory town had disappeared into a black hole cut off from all communication with the outside world. The Hiroshima radio station ceased broadcasting. The city’s main telegraph line went dead. At the headquarters of the Japanese General Staff in Tokyo, commanders tried repeatedly to telephone the Army Control Center in Hiroshima, but no luck. Soon, confusing reports from small train stations several miles from the city started pouring in to the railroad’s telegraph center. There had been an enormous explosion. The military commanders knew from the radar that only three Allied bombers had been in the area, hardly enough to take out an entire city. They knew the army had no large stores of explosives in Hiroshima. There was nothing to explain the mysterious sudden and total silence. Desperate for an explanation, headquarters ordered a young army officer to fly to Hiroshima and report back. Three hours later, while still 100 miles from the city, he and his pilot spotted a smoke cloud blanketing the area where the city should be. Only after they landed did they appreciate the full extent of the destruction. The officer radioed back: the whole city was on fire or in ruins. 232 The veteran commanders were stunned. In all their years of military service they had never experienced anything like it. Later estimates would put the number of people killed in the initial blast at 80,000. Another 50,000 to 60,000 would die in the months that followed. 233

OPPENHEIMER WAS IN HIS LOS ALAMOS office when word came. He’d sent John Manley, one of his assistants, to Washington with instructions to call the second there was confirmation. The teletype at Manhattan Project offices in D.C. finally began clicking late in the night of August 5 Washington time, but General Groves wouldn’t allow Manley to call Oppenheimer until shortly before 11:00 a.m. the next day when the White House made the official announcement. Sixteen hours after the explosion of mankind’s first atomic bomb the Japanese finally learned what had hit them. 234 Moments after Oppenheimer got the news, the Los Alamos public address system relayed it to the scientists in the Technical Area, among them Enrico Fermi: “Attention please, attention please. One of our units has successfully been dropped on Japan.” 235 That evening Oppenheimer stood in the auditorium pumping his clasped hands over his head like a prizefighter as the crowd stomped and cheered. His only regret, he said, was that the bomb wasn’t built in time to use against the Germans. Later, on his way home from a party, he encountered a distraught co-worker vomiting in the bushes. The nuclear age had begun. So too had a time of reckoning. 236

ON AUGUST 6 SAM GOUDSMIT was combing through the ruins of Himmler’s headquarters in Berlin, when an Alsos officer ran up to him. He told him he had just fifteen minutes to get to the airport for a flight to Frankfurt. There, at the Alsos office, he received only a vague, unsatisfactory explanation for the sudden orders. Later, over dinner with friends, he learned that a plutonium bomb had been successfully tested in the New Mexico desert. After an evening of catching up, he drove one of his friends to her hotel. The sleepy sergeant manning the desk was listening to a dance band on the radio, and as Goudsmit turned to leave, an announcer interrupted the program with a special bulletin: the United States had dropped an atomic bomb on Hiroshima. 237

SHORTLY BEFORE DINNER ON August 6, Major Rittner, the officer in charge at Farm Hall, called Otto Hahn, the man who had split the atom, into his office and told him that the Americans had dropped an atomic bomb on Hiroshima. “Hahn was completely shattered by the news,” Rittner reported, “and said he felt personally responsible for the deaths of hundreds of thousands of people, as it was his original discovery which had made the bomb possible.” 238 Hahn then broke the news to Heisenberg and the others who gathered around the radio to hear the 7 p.m. BBC broadcast.

1945-8-6 BBC RADIO BROADCAST

Scientists, British and American, have made the atomic bomb at last. The first one was dropped on a Japanese city this morning. It was designed for a detonation equal to 20,000 tons of high explosives.

Long convinced of their own superiority, the Germans couldn’t believe that the Americans had managed to accomplish what they could not. “How have they actually done it?” Heisenberg asked. “I find it is a disgrace, if we cannot at least work out how they did it,” he told the others. 239 Responding to a colleague’s question about how much U235 was needed to make the Hiroshima bomb, he at first said “one ton” (sixteen times the actual amount), but later admitted, “Quite honestly, I never worked it out, as I never believed you could get pure [uranium] 235.” 240 Hahn lashed out at Heisenberg: “If the Americans have a uranium bomb then you’re all second-raters . . . You might as well pack up.” 241 “I quite agree,” Heisenberg replied. 242 Meanwhile, Walter Gerlach, Germany’s chief coordinator of nuclear research, worried how his countrymen back in Germany would react. “We will be looked upon as the ones who have sabotaged everything. We won’t remain alive long there.” 243 “The impact on the ten scientists was shattering,” Goudsmit writes. “Their whole world collapsed. At one stroke all their self-confidence was gone . . . their hope for a bright future for German science was only so much illusion.” 244 To account for their failure, the Farm Hall detainees put together a statement for the British press, saying that wartime conditions made it impossible to build a bomb. Instead, they focused on producing a “uranium engine,” a nuclear reactor to drive machinery. One member of the Farm Hall group, Carl-Friedrich Von Weizsäcker, declared that he and his colleagues were morally superior to the Americans. “I believe the reason we didn’t do it was because all the physicists didn’t want to do it, on principles.” German scientists would make that claim frequently after the war. Already worrying about their place in history, Von Weizsäcker continued, “History will record that the Americans and the English made a bomb, and that at the same time the Germans, under the Hitler regime, produced a workable engine.” 245 In the heat of the moment he seemed to forget that the Germans had not succeeded in building a “workable” uranium engine and that such an “engine” could produce plutonium for an atomic bomb.

Three days after the bombing of Hiroshima, the BBC broadcast a report of a second bomb targeting Nagasaki, Japan. The bomb triggered a chain reaction that consumed just one gram of plutonium. The energy from that single gram, one-third the weight of a penny, leveled a good part of the city with a blast even more powerful than that of Hiroshima, a blast equivalent to 168,000 conventional 500-pound bombs striking the same aiming point at the same precise moment. 246

WAR DEPARTMENT NEWSREEL

The bomb had been purposely exploded high so that the greatest part of its radioactive material was dissipated in the stratosphere. For the valley area of little more than three square miles blast and fire reduced the industrial plants and surrounding buildings to blackened rubble. The cloud rose to 60,000 feet in less than five minutes and there it stayed, a boiling turbulent mass expanding until it reached some two miles across.

WORLD WAR II NEWSREEL

Buildings vaporized, so too did the clothes on people’s backs. Was it a bomb that should never have been dropped? Some people thought so. Others argued that it shortened the war and kept the subsequent peace. 247

Estimates of the number of Japanese killed by the two bombs range as high as 250,000. Two hundred fifty thousand in a war that claimed 60 million lives, the vast majority of them civilians. The Japanese surrendered shortly after Nagasaki, fulfilling a promise that Oppenheimer had made to all of his Los Alamos recruits: that their work would shorten the war and save American lives.

WORLD WAR II NEWSREEL

PRESIDENT TRUMAN: We have spent two billion dollars on the greatest scientific gamble in history. And we have won. But the greatest marvel is not the size of the enterprise, its secrecy or its cost, but the achievement of scientific brains in making it work.

President Truman called the development of the atom bomb, “the greatest achievement of organized science in history.” 248 The Manhattan Project scientists, engineers and private contractors had done what few believed possible: they had built three new towns—Oak Ridge, Hanford and Los Alamos—and a behemoth industrial plant as large as that of all of America’s automobile manufacturers put together. 249 They had transformed Fermi’s historic nuclear chain reaction, a reaction yielding only enough energy to light a flashlight bulb, into the most powerful weapon mankind had ever known. And they had done it in just over a thousand days. Optimists hoped the bomb would change the calculus of future conflicts, making war among nuclear-armed adversaries too horrific to contemplate. Pessimists feared it would trigger a global arms race that would bring that dreaded war closer to reality. CHAPTER TWENTY-EIGHT PEACE

AFTER THE WAR, ENRICO FERMI went on to a distinguished career at the University of Chicago and to the job he loved the most, teaching. Six of his students would go on to become Nobel Prize-winners themselves. 250 He initially opposed development of the hydrogen bomb, a bomb 450 times more powerful than the Nagasaki bomb, but then reversed himself during the Korean War when the Soviet Union began building one. To his critics who opposed building the bombs, Fermi offered no apologies. “It is no good trying to stop knowledge from going forward,” he said. “Whatever nature has in store for mankind, unpleasant as it may be, men must accept, for ignorance is never better than knowledge.” 251 Robert Oppenheimer also returned to academia. For almost twenty years he served as director of the Institute for Advanced Study in Princeton, New Jersey. Showered with accolades, he became a national hero, appearing on the covers of Time and Life magazines, and an advisor to presidents. Later, as the full horror of Hiroshima and Nagasaki sank in, and the nuclear arms race took off, he became a leading advocate for arms control. But his opposition to building a hydrogen bomb and a bitter feud with a commissioner on the Atomic Energy Commission (AEC), the agency overseeing peacetime development of atomic technology, won him some formidable enemies. And, in a twist of fate worthy of a Greek tragedy, those adversaries punished him for his postwar efforts. In 1954, at the height of the McCarthy era red scare, the AEC struck a humiliating blow. Dredging up Oppenheimer’s pre-war Communist ties, they voted to strip him of his top-security clearance. Werner Heisenberg, meanwhile, returned to a war-ravaged Germany and the university town of Göttingen where he first met Goudsmit, Fermi and Oppenheimer. He held several prestigious positions, all the while trying to restore Germany’s physics program to world prominence. Those who knew him described him as often depressed. Never again did his star burn as brightly as it had before the war. 252 Samuel Goudsmit, now at Northwestern University, published ALSOS , his World War II memoir on the Alsos mission. The memoir drew from classified documents including the Farm Hall transcripts which would not become public for almost a half century, so it helped shape the views of journalists and historians all during the post war era. In it, he cited reasons he believed Germany’s atom bomb program had failed. The attacks on the Norsk Hydro heavy water plant were obviously critical. But beyond that, he zeroed in on Nazi dogma: the hiring of party loyalists for important managerial positions, exiling of Jewish scholars, bureaucratic infighting and the blind hero worship of the program’s chief architect, Werner Heisenberg. 253 “Werner Heisenberg . . . was the foremost atomic physicist in Germany,” Goudsmit wrote. “No good young German scientist would think of questioning the word of the master.” 254 Not similarly constrained, and still bitter over his parents’ murder, Goudsmit saved much of his criticism for his former friend, arguing that Heisenberg had only a superficial understanding of how a reactor or an atom bomb works. 255 Goudsmit’s memoir triggered an exchange of angry letters between the two men. In the end, after Heisenberg produced German war records, Goudsmit conceded that some of his criticism had been inaccurate and that he had underestimated Heisenberg’s knowledge. The two ultimately agreed to a truce. 256 Goudsmit’s criticism of the German bomb program fell short on one other point. It failed to take note of a critical meeting between Heisenberg and Albert Speer, Hitler’s Minister of War Production, in the spring of 1942.

HITLER’S SURPRISE INVASION of the Soviet Union had ground to a halt on the outskirts of Moscow. Winter had set in. The German troops had no gloves, boots or heavy clothing, and many were freezing to death. The “blitzkrieg” war had turned into a war of attrition, which the Germans were ill prepared to fight. 257 To marshal his resources, the Führer ordered a review of all weapons under development. Those that would not be ready for use within nine months would be cancelled. 258 In response, Albert Speer, the architect in charge of war production, summoned Heisenberg and other weapons developers to a meeting in Berlin. On June 4, 1942 Speer, his military advisors and Heisenberg and other weapons developers all crowded into a university lecture hall. Standing at a small podium in the front of the room, the first speaker made his case for funding a new type of mine detector. Heisenberg spoke second. He told the assembled officials that he had just tested his latest reactor design and was on a path “to explosives that are more than a million times more effective than those currently available.” 259 Speer was impressed. He offered Heisenberg up to two million Reichmarks to continue his research. He even volunteered to exempt several hundred soldiers with scientific backgrounds from military service so that they could work on the bomb. 260 In the audience, Heisenberg’s rival Kurt Diebner, the head of the army’s atomic bomb program, was no doubt thrilled. Earlier in the year he had offered an upbeat assessment of his own research, arguing that the development of an atomic bomb was “technically feasible” and should be aggressively pursued. 261 But rather than jump at Speer’s offer, Heisenberg backed off. Emphasizing the technological hurdles and the extraordinary resources required, he told Speer it would be several years. Instead of the millions offered him, Heisenberg asked for a modest 350,000 Reichmarks to continue work on “a uranium engine” (a nuclear reactor). He argued the engine could be used to generate electricity and to power U-boats. 262 But aiding the war effort was not his primary motive. Heisenberg was determined to protect the future of theoretical physics in Germany. Nazi anti-Semitic policies had filled German universities with professors who rejected theoretical physics as “Jewish science.” Work on the engine would keep his young scientists safe from military service, so that they could reclaim those classrooms after the war. Speer approved Heisenberg’s funding request, and Heisenberg put the money to work building a new laboratory in Berlin to replace one in Leipzig that had been damaged in a fire. Curiously, Heisenberg did not make it clear that a nuclear reactor could produce plutonium for an atomic bomb. Why, is a matter of much speculation. He may have feared the Führer’s wrath should he fail to deliver. Or he may have wanted to deny Hitler use of such a devastating weapon. Heisenberg never explained his decision. His only comment: “we wanted to keep things as small as possible.” 263 Later, he would claim he played no role in the demise of Germany’s atom bomb program saying, somewhat disingenuously, “I was pleased to be spared the responsibility of making a decision.” 264 Following the Berlin meeting, Minister Speer met with Adolf Hitler to review the results. Nuclear fission was item sixteen on a long list of issues and received only a brief mention. It was the only time in all his meetings with the Führer during the war that Speer ever discussed the issue. According to Speer, “The idea [of an atom bomb] quite obviously strained his intellectual capacity.” 265 Adolf Hitler had alarmed the Allies during the war with his repeated threats of super weapons. The Germans did indeed develop some impressive “wunderwaffen.” Among them, the V2, the first long-range ballistic missile, and the first jet planes. The V2s terrorized the cities of London and Antwerp and killed several thousand people, but they did not seriously impact the outcome of the war. 266 As for the atom bomb, it never made it to Hitler’s list of “wonder weapons.” The race to build the atom bomb, the world’s first weapon of mass destruction, was over before it started. It ended with that meeting in Berlin in June 1942. Six months later, when Heisenberg’s former friend Enrico Fermi triggered the first sustained nuclear chain reaction in Chicago, Manhattan Project scientists had the racetrack all to themselves, but they didn’t know it.

AFTER THE WAR, SEVERAL of Heisenberg’s colleagues insisted, as they had in their Farm Hall press release, that they never wanted to build Hitler an atom bomb. Author Robert Jungk repeated the claim in his highly controversial 1956 book Brighter Than a Thousand Suns . In it, he went a step further, arguing that the Germans were morally superior to the Allies, “that the German nuclear physicists . . . obeyed the voice of conscience and attempted to prevent the construction of atom bombs, while their professional colleagues in the democracies . . . concentrated their whole energies on production of the new weapon.” 267 Heisenberg refused to be interviewed for the book, and he never claimed to have sabotaged the atom bomb program. 268 Jungk would later reverse himself, saying the scientists had misled him, and he regretted “spreading the myth of passive resistance.” 269 Nevertheless, suspicion that Heisenberg had worked to deny Hitler the bomb persisted long after the war. Post-war accounts tended to place Germany’s premier physicist at one extreme or the other: either a saboteur, and therefore a traitor to the fatherland, or a second-rate nuclear engineer. 270 Nothing Heisenberg said could change those narratives, and he eventually stopped trying. For the final decades of his life, he remained silent about the war. Werner Heisenberg died in 1976 at the age of 74. In an obituary, Samuel Goudsmit, now the editor-in-chief of the prestigious journal Physical Review , called him “one of the greatest physicists of our time.” On a personal note, Goudsmit conceded that he had been too harsh in blaming Heisenberg for failing to save his parents from the Nazi death camp: “I doubt that I, or most of the physicists I know would have done better under the same circumstances.” Goudsmit’s obituary on Heisenberg concluded: “He was . . . a deep thinker, a fine human being and also a courageous person. He defended his science under dangerous circumstances . . . Many of us hoped that he would have been more outspoken in condemning the Nazi regime.” 271 ACKNOWLEDGMENTS

I am indebted to the many scholars named in my bibliography. My thanks in particular to Richard Rhodes whose book The Making of the Atomic Bomb , fired my interest in the subject in the first place, and who gave generously of his time and insights, sitting for an interview early on when I envisioned “Chasing Heisenberg” as a documentary rather than a book. Great thanks, too, to Dr. Brian Schwartz, professor of Physics and co-director of the New Media Lab at the City University of New York, who read sections of the manuscript and expanded my understanding of the physics behind the bomb. I’m grateful to those who spent time on the phone with me: David C. Cassidy, author of Uncertainty: The Life and Science of Werner Heisenberg , who broadened my understanding of Germany’s premier atomic physicist; Olivia Fermi, who shared wonderful stories about her grandfather, including the fact he read Winnie the Pooh to improve his English; and Cindy Kelly, founder of the Atomic Heritage Foundation, who was my resource without equal when I needed a contact at Los Alamos, The Department of Energy or an expert on a point of physics; and the late David Wald, a cherished friend and colleague, who shared my interest in the bomb and was an invaluable sounding board. My friends Tom Seligson and John Merrow encouraged me to turn my documentary research into a book. They, along with John Tulenko and my brother Gordon, read many versions of the manuscripts, and offered suggestions, which invariably improved the work. Finally, I owe more than I can say to my wife Joanne Kaufman, a New York Times and Wall Street Journal columnist and my Editor-in-chief, who read my final manuscript. She kept me on track when I wandered off topic. And, when I insisted certain passages were perfectly clear, prevailed upon me to go back to the computer and make them more “perfectly clear.” BIBLIOGRAPHY

Adventures in the Atomic Age by Glenn Seaborg

ALSOS by Samuel Goudsmit

The Alsos Mission by Colonel Boris T. Pash

American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and Martin J Sherwin

Atom Bombs by John Coster-Mullen

Atom Journey Across the Subatomic Cosmos by Isaac Asimov

Atoms in the Family by Laura Fermi

Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb by David C. Cassidy

Brighter Than a Thousand Suns: A Personal History of the Atomic Scientists by Robert Jungk

Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence and Edward Teller by Gregg Herken

Critical Assembly: A Technical History of Los Alamos During the Oppenheimer Years 1943–1945 by Lillian Hoddeson, Paul W. Henriksen, Roger A. Meade & Catherine Westfall Day of Trinity by Lansing Lamont

E=mc 2 by David Bodanis

Fermi Remembered by James W. Cronin

From Hiroshima to the Moon by Daniel Lang

Heisenberg and the Nazi Atom Bomb Project: A Study in German Culture by Paul Lawrence Rose

Heisenberg’s War: The Secret History of the German Bomb by Thomas Powers

Hiroshima Diary: The Journal of a Japanese Physician August 6-September 30, 1945 by Michihiko Hachiya, M.D. Translated and edited by Warner Wells, M.D.

Hitler’s Gift: Scientists Who Fled Nazi Germany by Jean Medawar & David Pyke

Hitler’s Uranium Club: The Secret Recordings at Farm Hall by Jeremy Bernstein

Inner Exile: Recollections of a Life with Werner Heisenberg by Elisabeth Heisenberg

Inside The Third Reich Memoirs by Albert Speer

J. Robert Oppenheimer and the American Century by David C. Cassidy

Manhattan Project: The Untold Story of the Making of the Atomic Bomb by Stephane Groueff

Memoirs: A Twentieth-Century Journey in Science and Politics by Edward Teller with Judith Shoolery Nazi Science: Myth, Truth, and the German Atomic Bomb by Mark Walker

Now It Can Be Told: The Story of the Manhattan Project by General Leslie M. Groves

Physics and Beyond: Encounters and Conversations by Werner Heisenberg

Racing for the Bomb by Robert S. Norris

Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea by Jeffrey T. Richelson

Tales of Los Alamos: Life on the Mesa 1943-1945 by Bernice Brode

The Curve of Binding Energy by John McPhee

The First War of Physics: The Secret History of the Atom Bomb 1939-1949 by Jim Baggott

The General and the Bomb by William Lawren

The Glory and the Dream by William Manchester

The Griffin: The Greatest Untold Espionage Story of World War II by Arnold Kramish

The Joy of Insight, Passions of a Physicist (Kindle edition) by Victor Weisskopf

The Making of the Atomic Bomb by Richard Rhodes

The Rise and Fall of the Third Reich: A History of Nazi Germany by William L. Shirer

The World Set Free by H.G. Wells

Tuxedo Park: A Wall Street Tycoon and the Secret Palace of Science That Changed the Course of World War II by Jennet Conant

Uncertainty: The Life and Science of Werner Heisenberg by David C. Cassidy

Uranium Wars by Amir d. Aczel

Virus House by David Irving

War’s End: An Eyewitness Account of America’s Last Atomic Mission by Maj. Gen. Charles W. Sweeney, U.S.A.F. (Ret) with James A. Antoucci and Marion K. Antonucci

109 East Palace: Robert Oppenheimer and the Secret City of Los Alamos by Jennet Conant END NOTES

1 http://repository.aip.org/islandora/object/nbla:243957#page/1/mode/2up 2 David C. Cassidy, Beyond Uncertainty, Heisenberg, Quantum Physics, and the Bomb (Bellevue Literary Press, New York 2009) p. 363 3 David C. Cassidy, Uncertainty, The Life and Science of Werner Heisenberg (W.H.Freeman and Company 1992) p. 303 4 Repository AIP.org , Samuel A. Goudsmit papers, Box 46, Folder 148. Werner Heisenberg, Yearbook of the American Philosophical Society, 1976, p. 77 5 Werner Heisenberg, Physics and Beyond: Encounters and Conversations , (paperback) p. 165 6 Kai Bird and Martin J. Sherwin, American Prometheus, The Triumph and Tragedy of J. Robert Oppenheimer, (Vintage Books 2005 paperback), p. 65 7 Laura Fermi, Atoms in the Family, My Life with Enrico Fermi (The University of Chicago Press 1954 paperback), p. 32 8 The Sun , Magazine Section, New York, Sunday, September 28, 1919 9 Atoms in the Family , p. 89 10 Stephane Groueff, Manhattan Project , The Untold Story of the Making of the Atomic Bomb (Universe, Inc.) p. 25 11 Isaac Asimov, Atom: Journey Across the Subatomic Cosmos (Truman Talley Books/Plume/New York 1992) p. 167 12 Atoms in the Family , p. 86 13 The Making of the Atomic Bomb , p. 211 14 Ibid, p. 213 15 Atoms in the Family , p. 91–92 16 The Making of the Atomic Bomb , p. 217 17 Atoms in the Family, p. 98 18 Ibid, p. 101 19 Ibid, p. 115 20 Ibid, p. 118 21 https://www.nobelprize.org/nobel_prizes/physics/laureates/1938/ 22 Atoms in the Family , p. 115, 121, 123 23 Enrico Fermi Nobel Lecture , December 12, 1938, p. 417 24 Brighter Than a Thousand Suns , p. 62 25 The Making of the Atomic Bomb, p. 259–260 26 Walter Isaacson, Einstein: His Life and Universe , (Simon & Schuster, 2007), p. 139 27 Richard Rhodes filmed interview with the author, 2014. 28 The New York Times, January 31, 1939 29 The Making of the Atomic Bomb p. 286 30 The New York Times , August 12, 1945 31 The Making of the Atomic Bomb p. 294 32 Winston S. Churchill, (The Second World War , The Gathering Storm), (Houghton Mifflin, 1976) (paperback) p. 345 33 Jean Medawar & David Pyke, Hitler’s Gift, Scientists Who Fled Nazi Germany , (Richard Cohen Books 2000) p. 235 34 Elisabeth Heisenberg, Inner Exile: Recollections of A Life with Werner Heisenberg (Birkhäuser Boston 1984) p. 57 35 Thomas Powers, Heisenberg’s War: The Secret History of the German Bomb (Da Capo Press 1993) p. 4 36 Inner Exile p. 64 37 Heisenberg’s War, p. 256 38 David C. Cassidy, J. Robert Oppenheimer and the American Century (Pi Press 2005) p. 167 39 http://repository.aip.org/islandora/object/nbla:243957#page/2/mode/2up p. 75 40 Jim Baggott, The First War of Physics: The Secret History of the Atom Bomb 1939–1949 (Pegasus Books 2010), p. 10 41 J. Robert Oppenheimer, Atomicarchive.com 42 Ibid, p. 43 43 Gino Segrè and Bettina Hoerlin, The Pope of Physics: Enrico Fermi and the Birth of the Atomic Age (Henry Holt and Company 2016), p. 162 44 Physics and Beyond , p. 169 45 Ibid, p. 170 46 Samuel Goudsmit, ALSOS (American Institute of Physics Press 1996) p. 114 47 http://en.wikipedia.org/wiki/Invasion_of_Poland 48 Arnold Kramish, The Griffin: The Greatest Untold Espionage Story of World War II (Houghton Mifflin Company 1986), p. 59 49 Ibid, p. 59 50 The New York Times, “Vast Power Source in Atomic Energy Opened by Science,” May 5, 1940 51 The First War of Physics, p. 60–61 52 http://www.atomicarchive.com/Docs/Begin/MAUD.shtml (The Maud Report, 1941) 53 David C. Cassidy, J. Robert Oppenheimer and the American Century (Pi Press 2005) p. 218 54 Glenn T. Seaborg with Eric Seaborg, Adventures in the Atomic Age, From Watts to Washington (Farrar, Straus and Giroux 2001) p. 70 55 Ibid, p. 71 56 Paul Lawrence Rose, Heisenberg and the Nazi Atomic Bomb Project, A Study in German Culture (University of California Press 1998 paperback) p. 134 57 Ibid, p. 396 58 David Irving, The Virus House, Germany’s Atomic Research and Allied Counter-Measures (electronic version copyright 2002 Parforce UK Ltd) p. 157 59 Thomas Powers, Heisenberg’s War: The Secret History of the German Bomb (Da Capo Press 1993 paperback) , p. 195 60 From Hiroshima to the Moon , p. 226 61 Hitler’s Uranium Club , p. xxvi 62 Beyond Uncertainty, p. 311 63 https://archive.org/details/1940RadioNews 64 Seva Gunitsky, Fascism Spread in 1930’s America. It could Spread Again Today (Chicago Tribune 8/16/17) 65 Atoms in the Family , p. 170 66 Ibid, p. 171 67 Gino and Bettina Hoerlin, The Pope of Physics: Enrico Fermi and the Birth of the Atomic Age (Henry Holt And Company New York 2016) p. 175, 180 68 Adventures in the Atomic Age, p. 86 69 Ibid, p. 86–87 70 Hitler’s Gift p. 173 71 Leona Marshall Libby Interview, Voices of the Manhattan Project, Atomic Heritage Foundation 72 American Prometheus p. 185 73 The Making of the Atomic Bomb, p. 426 74 Ibid, p. 448–449 75 http://www.atomicheritage.org/history/oppenheimer-security-hearing 76 William Lawren, The General and the Bomb, A Biography of General Leslie R. Groves, Director of the Manhattan Project (Dodd, Mead & Company New York 1988) p. 100 77 Gregg Herken, Brotherhood of the Bomb (Henry Holt and Company LLC 2002), p. 55 78 The First War of Physics, p. 144 79 Virus House p. 124 80 Ibid, p. 158–162 81 The Making of the Atomic Bomb , p. 432 82 The New York Times, Wise Gets Confirmation: Checks with State Department on Nazis’ Extermination Campaign, November 25, 1942 83 The Making of the Atomic Bomb p. 433–436 84 The First War of Physics, p. 131 85 The Making of the Atomic Bomb , p. 440 86 Ibid, p. 440 87 Ibid, p. 440–442 88 Ibid, p. 436 89 Ibid, p. 475–476 90 The Making of the Atomic Bomb , p. 674 91 Laura M. MacDonald, Curse of The Narrows (Walker Publishing Company, Inc. 2005), p. 288 92 The First War of Physics , p. 95 93 The Toronto Daily Star , December 8, 1917 (p. 1 headline) 94 The First War of Physics , p. 259 95 Harry S. Truman Presidential Library, August 6, 1945 (Statement by the President Announcing the Use of the A-Bomb at Hiroshima) 96 John Coster-Mullen, Atom Bombs, The Top Secret Inside Story of Little Boy and Fat Man (2009), p. 41 97 The First War of Physics , p. 280 98 General Leslie R. Groves, Now It Can Be Told, The Story of the Manhattan Project (Da Capo Press 1983) p. 72 99 Virus House , p. 156 100 Ibid, p. 183–188 101 Robert Serber, The Los Alamos Primer: The First Lectures on How to Built an Atomic Bomb (University of California Press) 102 The Making of the Atomic Bomb , p. 462 103 AtomicBombMuseum.org 104 The Making of the Atomic Bomb , p. 323 105 American Prometheus , p. 209 106 Ibid, p. 231 107 The Making of the Atomic Bomb , p. 570 108 American Prometheus, p. 209 109 Ibid, p. 216 110 Lillian Hoddeson, Paul W. Henriksen, Roger A. Meade & Catherine Westfall, Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943–1945 (Cambridge University Press 2004) p. 77 111 Curve of Binding Energy, p. 192 112 General Leslie R. Groves, Now It Can Be Told, The Story of the Manhattan Project (Da Capo Press 1962 paperback) p. 72 113 ALSOS, p. 65 114 Jeffrey T. Richelson, Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea (W.W. Norton & Company 2006), p. 27 115 Now It Can Be Told, The Story of the Manhattan Project , p. 199 116 Daniel J. Kevles, Heisenberg’s Uncertainties (The New Yorker, 1993) 117 Physics and Beyond, p. 188 118 Heisenberg’s War, p. 60 119 Jeremy Bernstein, Hitler’s Uranium Club, The Secret Recordings at Farm Hall (Copernicus Books 1957), p. 44 120 Spying on the Bomb p. 29 121 Ibid, p. 32 122 Ibid, p. 43–45 123 Ibid, p. 33 124 Spying on the Bomb p.34 125 Inner Exile p. 77 126 Heisenberg’s War (hard cover) p. 22 127 Amir D. Aczel, Uranium Wars, The Scientific Rivalry That Created the Nuclear Age (Palgrave MacMillan 2009) p. 147 128 Heisenberg’s War , p. 255 129 Ibid, p. 127 130 Ibid, p. 257 131 Robert S. Norris, Racing for the Bomb, General Leslie R. Groves, The Manhattan Project’s Indispensable Man (Steerforth Press 2002), p. 284 132 The First War of Physics , p. 216 133 Neal Bascomb, The Winter Fortress, The Epic Mission to Sabotage Hitler’s Atomic Bomb , (Houghton Mifflin Harcourt 2016) p. 269 134 Virus House p. 241–242, 246 135 Ibid, p. 241–242 136 The Winter Fortress , p. 60 137 The Making of the Atomic Bomb p. 514 138 Virus House , p. 241 139 The Winter Fortress , p. 306 140 Racing for the Bomb , p. 291–292 141 Heisenberg’s War p. 267 142 Heisenberg’s War, p. 5 143 Ibid, p. 265 144 Ibid, p. 264, 267 145 Ibid, p. 313 146 Racing for the Bomb, p. 364 147 Implosion Becomes a Necessity (The Manhattan Project, an interactive history, U.S. Department of Energy, Office of History and Heritage Resources) 148 S.L. Sanger, Craig Wollner, Working on the Bomb: An Oral History of WWII (Continuing Education Press, School of Extended Studies, Portland State University 1995) 149 Racing for the Bomb , p. 221 150 American Prometheus p. 281 151 Ibid, p. 281 152 Critical Assembly, A Technical History of Los Alamos during the Oppenheimer Years, 1943–1945 153 The Winter Fortress , p. 311 154 Nazis Have Atom Bomb, Stockholm Report Declares , The Minneapolis Star, October 3, 1944, p. 7 155 Nazis’ New ‘V-2’ Bomb a Failure According to Report of Witness, The Ottawa Journal, October 5, 1944, p. 2 156 Paris Delivered , British Pathé Gazette Newsreel 157 Now It Can Be Told , p. 193 158 From Hiroshima to the Moon , p. 232 159 Ibid, p. 232 160 American Institute of Physics, Niels Bohr Archives, Samuel Goudsmit Papers, Box 25, Folder 03, Alsos – travel and other orders and receipts with some Goudsmit correspondence, 1942–1945 161 ALSOS , p. 34 162 Ibid, p. 56 163 Ibid, p. 56 164 Ibid, p. 58–60 165 Ibid, p. 65 166 Virus House , p. 293 167 From Hiroshima to the Moon , p. 230–231 168 Ibid, p. 225, 228 169 American Institute of Physics, Niels Bohr Archives, Sub Series A, ALSOS Mission Material, Box 25, Folder 05, letter to wife, December 10, 1944 170 Heisenberg’s War, p. 371 171 ALSOS , p. 75 172 Niels Bohr Archives, ALSOS Mission Material, Box 25, Folder 05, Letter to Wife, December 10, 1944 173 Heisenberg’s War, p. 371 174 ALSOS , p. 69 175 Ibid, p. 70 176 Hitler’s Uranium Club , p. xxv 177 Ibid, p. xxix 178 Virus House, p. 309 179 ALSOS, p. 71 180 Heisenberg’s War , p. 376 181 Ibid, p. 377 182 Spying on the Bomb , p. 37 183 Heisenberg’s War , p. 402 184 Ibid, p. 402 185 The First War of Physics , p. 278 186 Inner Exile , p. 3 187 Heisenberg’s War , p. 403 188 Uncertainty , p. 493 189 Racing for the Bomb p. 368 190 ALSOS , p. 98 191 Virus House , p. 321 192 ALSOS , p. 99 193 Colonel Boris T. Pash, The Alsos Mission (Award books 1969 paperback), p. 229 194 Now It Can Be Told , p. 243 195 The Alsos Mission , p. 239 196 Ibid, p. 239 197 Physics and Beyond, p. 191 198 Heisenberg’s War, p. 294 199 Ibid, p. 392 200 Ibid, p. 397–398 201 Ibid, p. 392–393 202 ALSOS , p. 112–113 203 Heisenberg’s War , p. 426 204 Inner Exile , p. 108 205 Universal Newsreel: Nazi Murder Mills (First Newsreel Pictures of Nazi Death Camps) 206 Heisenberg’s War , p. 326 207 Ibid, p. 326 208 ALSOS, p. 48 209 The Curve of Binding Energy , p. 81 210 Jennet Conant, Man of the Hour: James B. Conant, Warrior Scientist (Simon & Schuster 2017), p. 310 211 The Making of the Atomic Bomb , p. 543 212 The General and the Bomb , p. 203 213 Racing for the Bomb , p. 371 214 Ibid, p. 371 215 Lillian Hoddeson, Paul WE. Henriksen, Roger A. Meade & Catherine Westfall, Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943–1945 (Cambridge University Press 2004) p. 174 216 Hitler’s Uranium Club p. 319 217 Inner Exile , p. 113 218 Victor Weisskopf, The Joy of Insight: Passions of a Physicist (Plunkett Lake Press 2013) location 1037 219 Hitler’s Uranium Club , p. xviii 220 Ibid, p. 102 221 Ibid, p. 98 222 Uncertainty , p. 483 223 Hitler’s Uranium Club , p. 96, 98 224 Uncertainty p. 525 225 ALSOS , p. 125 226 Ibid, p. 126 227 Virus House , p. 275 228 John Hersey, Hiroshima (Vintage Books 1973), p. 2–4 229 Ibid, p. 5 230 Major General Charles W. Sweeney, U.S.A.F. (Ret.) with James Atonucci and Marion K. Antonucci, Wars End, An Eyewitness Account of America’s Last Atomic Mission (Avon Books 1997) p. 168 231 David Bodanis, E=MC2, A Biography of the World’s Most Famous Equation , (A Berkley Book 2001) p. 166–169 232 The Avalon Project: The Atomic Bombings of Hiroshima and Nagasaki: Chapter 7 – The Attacks (Yale Law School, Lillian Goldman Law Library) 233 David McCullough, Truman (Simon & Schuster 1992) p. 457 234 American Prometheus , p. 315 235 Ibid, p. 315 236 Ibid, p. 316, 319 237 ALSOS , p. 131 238 Heisenberg’s War, p. 437 239 Now it Can Be Told , p. 338 240 Hitler’s Gift p. 177 241 Hitler’s Uranium Club , p. 116 242 Ibid, p. 116 243 Ibid, p. 116, 125 244 ALSOS , p. 134–135 245 Beyond Uncertainty , p. 376–378 246 Atom Bombs , p. 41 247 Pathé Newsreel 248 Harry S. Truman Presidential Library, August 6, 1945 (Statement by the President Announcing the Use of the A-Bomb at Hiroshima) 249 The Making of the Atomic Bomb , p. 605 250 The Pope of Physics , p. 269 251 Atoms in the Family , p. 244 252 Uncertainty , p. 528 253 ALSOS , p. xxxv–xxxvi 254 ALSOS , p. xli 255 Ibid, p. xxii 256 Beyond Uncertainty , p. 381 257 The First War of Physics , p. 111 258 Heisenberg’s War , p. 133 259 The First War of Physics , p. 126 260 Ibid, p. 126–127 261 Heisenberg’s War , p. 137 262 Niels Bohr Library Archives, Samuel Goudsmit Papers, (Box 10, Folder 95, Heisenberg Werner: Correspondence 1940–1954) 263 Inner Exile , p. 74 264 Virus House , p. 134 265 Albert Speer, Inside the Third Reich Memoirs (Simon & Schuster Paperbacks 1970), p.227 266 Mark Walker, Nazi Science: Myth, Truth and the German Atomic Bomb (Perseus Publishing 1995), p. 196 267 Brighter than A Thousand Suns , p. 105 268 Heisenberg’s War , p. 459 269 Ibid, p. 100 270 Nazi Science: Myth, Truth and the German Atomic Bomb , p. 259 271 http://repository.aip.org/islandora/object/nbla:243957#page/4/mode/2up , p. 78–79 ABOUT THE AUTHOR

Michael Joseloff is a TV news and documentary producer, writer and director. A four-time Emmy award winner, he began his career at ABC News, then moved to PBS, where, for thirteen years, he was a producer at The MacNeil/Lehrer NewsHour . In 1995, he left to become an independent producer. His documentaries have aired on PBS and the major cable TV channels including The History Channel, A&E, Discovery, and CNBC. Joseloff’s interest in the atom bomb dates back to 1993, when he produced a segment for The NewsHour on the “father of the bomb,” J. Robert Oppenheimer.