Genius in the Shadows

by William Lanouette

  But it was more personal than that: Groves’s authoritarian, anti-Semitic views cast Szilard as a pushy Jewish busybody; Szilard’s openness and glee at “baiting brass hats” cast Groves as a rigid militarist, who also seemed not too bright. Groves considered Szilard the only “villain” in the Manhattan Project, while Szilard considered Groves its biggest fool.29

  Right away Groves warned the senior men on the project about the need to maintain tight security. Compton, Fermi, Szilard, and other scientists listened, nodded, and resumed their debates about reactor designs. After that first meeting, Charles D. Coryell, a Met Lab chemist, was walking toward the door with Groves. Glancing back at the large window in the conference room, Coryell wondered aloud about their own security.

  “General, what would you think if someone threw a hand grenade through that window?”

  “It’d be a damn good thing,” Groves snapped. “There’s too much hot air in here.”30

  Groves had chided the academics at their first meeting when he pointed out that while he didn’t have a Ph.D, he had “ten years of formal education after I entered college. . . . That would be the equivalent of about two Ph.D.s, wouldn’t it?” Besides, Groves said, his assistant, Colonel Nichols, did have one. The scientists listened in silence, exchanging a few embarrassed smiles. Szilard fumed, and as soon as Groves walked from the conference room, he turned to his colleagues.

  “You see what I told you?” he said. “How can you work with people like that?”31

  At his first meeting with Groves, Szilard pushed hard for his bismuth cooling scheme. Groves pushed back, and two days later Compton had a “directive” from the general. Szilard could build his bismuth-cooled reactor, but only if he acted as a “consultant” to the Met Lab’s chief engineer, Thomas V. Moore. Moreover, the reactor must be ready for operation by June 15, 1943. If not, Compton said, it “will cease to be of the greatest urgency” for the project.32

  This dispute over building a bismuth-cooled reactor involved much more than a technical challenge. It was the first head-on clash between Szilard and the evolving military-political-industrial complex that controlled the effort he alone had first led. Szilard, Wigner, Anderson, and even Fermi saw the choice of a reactor-cooling system as a dispute between physics and engineering, between their three-year-old Columbia team and the fresh consultants from Du Pont, Stone & Webster, and the Army Corps of Engineers. Here the physicists, led by Szilard, would draw the line.

  “It is almost fall, but the weather is nice and clear, and there are a lot of fights that do not disturb me too much because basically I don’t care which way it will turn out,” Szilard wrote to Trude on October 11. He may not have cared which cooling system—water or bismuth—was used, for he was soon at work on reports about both. But he was under stress and complained about feeling “terribly awfully tired and [I] often go to bed around 8:00 p.m.”33 To Szilard, the fights with the engineers had more to do with authority than with technology.

  Groves thought so, too. The few hours he had spent in conference with Szilard and the reports he had gleaned from others raised suspicions. “Groves thought Szilard was the perfect spy,” said Samuel K. Allison, a Met Lab colleague. “Not much was known about his background,” and his movements were erratic.34 Recalled John Marshall, Jr., Szilard’s colleague at Columbia and Chicago, “He was always moving around . . . and he questioned army orders.” Soon after they met, Groves became concerned about Szilard’s “reliability.” This enemy alien with the German accent and the very unmilitary bearing made Groves, the consummate military engineer, uneasy.

  Szilard, too, was uneasy, about engineers in general. He complained to Compton one day that they knew nothing about designing and building a nuclear reactor. They were fine at putting up bridges, he said, but this was something special. Something new. Moreover, Szilard’s own delight with tinkering made him think that he could design a reactor on his own.

  “If you don’t get rid of those engineers, I’m going to quit” said Szilard.

  “You have just resigned” Compton told Szilard, venting the pressure he felt as mediator between his scientific colleagues and the army. Quietly, Szilard stood up and walked back to his office. There Compton found him a few minutes later.

  “I didn’t mean it, Leo,” he said. “We still need you.”35

  To Trude, Szilard reported that “Wigner and I are fighting on the same side; if we are out of luck, we will get what we want.”36 Wigner also resented dealing with the engineers as equals.

  “What do you want me to do?” Wigner asked when they called on him to cooperate.

  “Well,” one engineer said, “all we want you to do is to answer our questions.”

  “Oh,” Wigner replied, his sarcasm barely masked by his polite manner, “if you know what questions to ask, you will find the answers to any question which you might ask and which I can answer in my files. All I have to do, then, is give you the key to my files, which I shall be very glad to do.”37

  On Monday morning, October 26, Szilard was in Compton’s office again, this time at Compton’s request. Szilard assumed they would discuss how to design and build a reactor cooling system, but Compton announced that no arrangement would work with Szilard involved. His very presence at Chicago made it difficult to organize a collaboration of physicists and engineers. Compton suggested that Szilard transfer back to Columbia, to work there in loose connection with the Met Lab. “Finally,” Szilard recorded in notes he made, “he asked me to arrange matters so as to leave the Metallurgical Laboratory within forty-eight hours so as to make it easier for him to reorganize the technological division. . . .”

  His work from New York would be of little value to the project, Szilard protested, and any salary would be little more than “a pension.” Instead, Szilard insisted, he would prefer to apply for patents on his chain-reaction inventions and receive a royalty from the government.38 Compton was surprised by this counterproposal. He cabled Groves that morning: “HAVE GIVEN SZILARD TILL WEDNESDAY TO REMOVE BASE OF OPERATIONS TO NEW YORK. ACTION BASED ON EFFICIENT OPERATION OF ORGANIZATION NOT ON RELIABILITY. ANTICIPATE PROBABLE RESIGNATION. SUGGEST ARMY FOLLOW HIS MOTIONS BUT NO DRASTIC ACTION NOW;”39

  Two days later, Compton offered a compromise. Szilard could form an independent organization to build a bismuth-cooled reactor at the Illinois Institute of Technology in Chicago. Again Szilard refused. If his presence caused trouble or led to friction, this would continue on the Met Lab’s Technical Committee.40 Fearing resignations by Wigner and others over Szilard’s removal, Compton cabled Groves again: “SZILARD SITUATION STABILIZED WITH HIM REMAINING CHICAGO OUT OF CONTACT WITH ENGINEERS. SUGGEST YOU NOT ACT WITHOUT FURTHER CONSULTATION CONANT AND MYSELF.”41

  But Groves had ideas of his own and the same day drafted a secret letter to be signed by Secretary of War Henry L. Stimson.

  WAR DEPARTMENT

  October 28, 1942.

  The Honorable,

  The Attorney General.

  Dear Mr. Attorney General,

  The United States will be forced without delay to dispense with the services of Leo Szilard of Chicago, who is working on one of the most secret War Department projects.

  It is considered essential to the prosecution of the war that Mr. Szilard, who is an enemy alien, be interned for the duration of the war.

  It is requested that an order of internment be issued against Mr. Szilard and that he be apprehended and turned over to representatives of this department for internment.

  Sincerely yours,

  Secretary of War.42

  Stimson refused to sign, which so angered Groves that he vowed to discover new reasons for Szilard’s imprisonment and assigned a special agent to watch him. “Few enemies were causing us as much trouble . . .” as Szilard, Groves later recalled.43

  At week’s end, Szilard was eager to leave town, but as an enemy alien he could not travel without army permission. Compton had approved a brief vacation for Szilard, but now Groves had to decide if
he could take it. Groves was to be in Chicago in three days.44

  Waiting for the general to arrive, Szilard wrote Trude:

  A lot has happened here in the meantime. On Monday they tried “to push me out of the project.” It seemed, and for a while it was almost certain, that I would be “retired” and would be back in New York in one week. After that a “storm” broke out that raged for two days, so that everybody (including me) was flabbergasted. Naturally I liked it very much! Now we have a terribly funny situation that I am quite comfortable with but which is not helpful to our work from a professional point of view. This, however, cannot be helped and will continue for some time. All the younger people who are important, no matter if they come from Columbia, Princeton, or Chicago, have behaved terribly decently and have given them “hell.” I have cheered up accordingly; have resigned from all duties . . . and enjoy life. Also, I wanted to go on vacation right away, but I was asked to wait with that for another week.

  The life of a horse is funny. What is new with you?45

  Around the university campus, Szilard made friends with some biologists, whom he joined for their afternoon coffee break, drinking from glass beakers as they sat around a lab table. “They said there are only two kinds of scientist among the biologists,” Szilard reported to Trude. “‘Sons of a bitch’ and ‘bastards’; the former are those who write a paper and put in things that are not so, and the latter are those who point it out.” (Szilard loved this distinction and cited it often once he became a biologist.)46

  When Groves met with Compton, he must have complained again about Szilard’s “reliability,” because two days later Szilard turned over details about his life and work to help with “a more thorough investigation of my background in connection with the work of our project.” He listed Einstein, Wigner, Benjamin Liebowitz, and Edward Teller as references.47 To Trude, Szilard reported that Teller had problems of his own—a hernia—and asked for a medical book he knew about for nurses. Meanwhile, Szilard reported, “Teller got hold of another popular book and immediately looked up ‘hernia’ and found this: ‘With the latest advances in asepsis and anaesthesia and the influx into the nursing profession of vivacious and pretty girls an operation for hernia must be considered as one of the lighter forms of amusements.’ No further anatomic details were given.”48

  Szilard was also amused to find himself writing to Compton and describing his own “attempts at secrecy from March 1939 to June 1940” He, the inventor of atomic secrecy, was now suspected of not being secretive enough. To Groves, Compton cited Szilard’s early efforts to keep scientific secrets from Germany, his research in nuclear physics, his advancement of the US program, and his “important part in originating the ideas of the processes that we are now developing.” Compton also felt obliged to remind Groves that Szilard had become a German citizen under the Weimar Republic and had first come to the United States on an immigrant visa before the Nazi takeover.49

  Winter’s chill gripped Chicago by mid-November, making the site for the first reactor especially inhospitable. Stagg Field was a medieval-style monument to Chicago’s past glory as a football power, and this season the west stands stood mute against the gray sky, its ranks of empty seats overgrown with weeds. Below the sloping stands, the concrete walls of an abandoned squash court trapped and held the cold. There, bypassed and ignored by the university community, the Met Lab constructed its chain-reacting pile. (Another site, in the Argonne Forest west of the city, had been picked as a safer location, but a carpenters’ strike interfered with construction there, and the existing structure was used. Once the physicists gave assurances that a chain reaction would not explode, Compton picked the closer site—right in the middle of the campus.)

  His decision to build the first reactor at Stagg Field was not made until Saturday, November 14, and the following Monday morning, Walter Zinn, Herbert Anderson, and others began work by laying out a square balloon cloth—custom-made by Goodyear—in the squash court and setting down the first layer of graphite bricks for the nuclear pile. If the uranium-graphite pile did not work as planned, the physicists thought, then perhaps the neutrons could be encouraged to collide by surrounding the whole system with helium in the balloon. The scientists kept warm by the vigorous work of carrying and stacking graphite blocks, but the armed guards on duty danced from foot to foot in order to fight the damp chill. Zinn thought that graphite, a pure form of coal, might burn to heat the place. But when small fires were lit in steel oil drums, they fouled the dark room with smoke. Next, ornamental gas-fired imitation logs were hooked up, but these consumed the court’s oxygen and produced eye-stinging fumes. Finally, when rummaging through the empty halls beneath the stands, Zinn found his solution in a dusty locker: a heap of full-length raccoon coats from the university’s big-league football era. “For a time,” remembers Zinn, “we had the best-dressed collegiate-style guards in the business.”50

  The brick stacking was slow and dirty work seven days a week. The scientists slipped and slid on the graphite dust, at times so blackened by the task that only their bright eyes and teeth gleamed in the dark chamber. More and more uranium spheres were set into the pile of graphite, with cadmium strips inserted to absorb any neutrons that might set off a chain reaction prematurely. As the pile grew, layer by dusty layer, Szilard sat at his desk in Eckhart Hall scribbling calculations for the next reactor— one designed to produce plutonium for the bomb. He refined his bismuth cooling system and devised a new way to assemble uranium fuel.51 But no matter how absorbed he was in his work, Szilard hopped up from his desk every few hours and rushed out to buy the latest editions of the papers.

  Finally, on the night of December 1, the fifty-seventh and last layer of graphite bricks was set.52 Compton dismissed some colleagues’ fears that the first nuclear reactor might somehow run wild, its atom-splitting neutrons exploding in a burst of heat and radioactivity. Szilard, too, doubted that this pile would misbehave, but he brooded nonetheless and seemed withdrawn from his friends.53 That night, he walked to Culver Hall, a science laboratory on campus, where he knew that the physiological psychologist Heinrich Kluver often worked late.

  “Come to dinner with me,” Szilard said, and Kluver, who enjoyed Szilard’s speculative conversations, accepted. As they walked through the bitter-cold night to a nearby restaurant, Szilard admitted that he had already eaten but would have a second dinner “just in case.”

  “Just in case what?” Kluver asked Szilard over dinner.

  “In case an important experiment doesn’t succeed,” said Szilard with a typical air of mystery. He was not specific but did say that he and other scientists knew that something “might just fail to work; indeed, that seems to be the most likely outcome.” However, another more remote possibility prompted Szilard’s second meal that night. If their experiment “works too well,” there might be an explosion. Did Szilard distrust the conclusions of his own colleagues? asked Kluver.

  “Not at all,” said Szilard. “But even the greatest theoretical physicists cannot be absolutely certain. So I felt that a second dinner was in order.”

  54 Cold weather hung on that night, and by dawn on December 2 the temperature was 10 degrees Fahrenheit. A strong, raw wind rattled the city. The elevated trains and the trolleys were jammed, the result of gasoline rationing, which had begun the day before. Newspaper headlines reported an air battle over Tunisia. The US State Department announced on this day that 2 million Jews had already perished under Hitler and 5 million more were in danger.55

  Still wondering if the Fermi-Szilard graphite pile would work, a group of visiting Manhattan Project executives, led by Warren K. Lewis of MIT, sat in Eckhart Hall that morning debating the merits of a heavy-water reactor. But under the stands at Stagg Field, the pile stood ready for the test. From a balcony overlooking the squash court Fermi ordered the cadmium control rods pulled from the black carbon pile. One by one. Until a single rod was left to absorb neutrons. Fermi eyed the neutron counter and flicked his slide rule. Every
thing was ready.

  “I’m hungry,” Fermi said. “Let’s go to lunch,” and back in went all the rods.

  The break eased a spell of anxiety and anticipation, so that everyone seemed more relaxed as they filed back into the gloomy court that afternoon. By 2:20 P.M. Fermi’s Columbia colleague George Weil stood before the balcony, facing the pile. When only one cadmium control rod kept the neutrons in check, Fermi called, “All right, George,” to the floor below, and Weil pulled it to a predetermined point. The team watched in silence, checking dials. Fermi manipulated his slide rule. Szilard stood at his elbow, watching in silence. Thirty tense and busy minutes later, Fermi had Weil pull out the rod another foot, and the Geiger counters surged. Anderson remembered the final moments this way.

  When the cadmium rod was pulled out to the position [Fermi] asked for next, the increase in neutron intensity was noticeably quickened. At first you could hear the sound of the neutron counter, clickety-clack, clickety-clack. Then the clicks came more and more rapidly, and after a while they began to merge into a roar; the counter couldn’t follow any more. That was the moment to switch to a chart recorder. But when the switch was made, everyone watched in the sudden silence the mounting deflection of the recorder’s pen. It was an awesome silence. Everyone realized the significance of that switch; we were in the high [neutron] intensity regime and the [Geiger] counters were unable to cope with the situation any more. Again and again, the scale of the recorder had to be changed to accommodate the neutron intensity which was increasing more and more rapidly. Suddenly Fermi raised his hand: “The pile has gone critical,” he announced. No one present had any doubt about it. Then everyone began to wonder why he didn’t shut the pile off. But Fermi was completely calm. He waited another minute, then another, and then when it seemed that the anxiety was too much to bear, he ordered, “Zip in!” Zinn released his rope [dropping a control rod], and there was a sigh of relief when the [neutron count] dropped abruptly and obediently. . . .56