chapter six

A Secret Project

1938–1939

It was not surprising that Niels Bohr was the first to learn of nuclear fission from Otto Robert Frisch. By then Bohr was fifty-four years old, a Nobel laureate, and considered the foremost physicist in the world. He was very excited about this discovery by his longtime friend Lise Meitner and her nephew.

In December 1938, during a lecture in Copenhagen, which was later printed in Niels Bohr’s Times: In Physics, Philosophy, and Polity, he said, “With present technical means it is, however, impossible to purify the rare uranium isotope in sufficient quantity to realize the chain reaction.” As it happened, not far from him, in Stockholm, Lise Meitner was also making a discovery that December that would lead to what he had until then believed to be impossible.

Bohr was preparing to attend the fifth Washington Conference on Theoretical Physics, to be held the following month. His mind had been churning since hearing the news and continued to do so throughout the nine-day transatlantic journey to the United States. He arrived in New York on January 16, 1939, nearly two weeks after the Fermis had docked there. In fact, it was Enrico Fermi who met him at the pier.

By the time he took to the conference podium to share his news, Bohr was positively bubbling over with enthusiasm. He had prepared his remarks on a stack of papers that he held in front of him, but then, looking out at his audience, he swept his notes aside and began to speak freely, as if in front of one of his classes. Fission, he told the audience, referred to the moment when the nucleus of an atom split into two fragments.

As Bohr relayed the information to his colleagues, all of them could feel the electricity running through the auditorium. Although some of the information had been leaked prior to Bohr’s talk, hearing the news from Bohr’s own lips allowed the news to be received with enthusiasm and not even the smallest amount of skepticism. Still, they wanted Bohr to end his speech as soon as possible. It was impolite to get up and leave in the middle of a talk, but they wanted to rush to their own laboratories and check the experiments themselves. Once they did, the theory of nuclear fission would become widely accepted.

A few of these scientists wondered why they had not observed the phenomenon before. Others boasted of having come close to the solution themselves; whether or not that was true, they agreed that they should have stayed with the experiments a little longer.

It was a startling moment, not only for Lise Meitner’s breakthrough but also for nuclear science in general. Many of the scientists in attendance, much like Lise Meitner, would come to the realization that nuclear fission could form a self-sustaining chain reaction—which in turn, if properly utilized, could form a bomb.

Enrico Fermi was in attendance at the Washington conference. Colleges and universities across the United States were hiring professors who were fleeing the racial persecution in Europe, and Fermi, having received the Nobel Prize in Physics in 1938, had been quickly offered jobs at five different universities; he accepted a teaching post at Columbia University in New York City. The university felt it was a real coup to land a man like Fermi, and he did not disappoint.

Soon after the conference ended, Fermi urged his supervisors at Columbia University to repeat the tests that had been conducted in Europe. If they were successful, he told them, they should begin to study the possibilities of a long-range chain reaction. The Columbia laboratory was led by Fermi along with Leo Szilard, a Hungarian émigré. Both of them had fled Europe because of the Nazis, and now it was their job to determine whether or not a chain reaction was possible, and how that could be used against the enemies.

Fermi succeeded in performing a small experiment related to nuclear fission by showing that uranium bombarded by neutrons emitted more neutrons than it absorbed. The Columbia group released a statement saying, “This new process gives the largest conversion of mass into energy that has yet been obtained by terrestrial methods.” The words were a little outlandish and pompous, given that in Europe Fritz Strassmann and Otto Hahn had been conducting those same experiments for months. But then, Fermi was an extravagant man.

From this point on, scientists pursued studies and experiments on fission with abandon, and hundreds of papers were written and published, outlining the methods for fission without regard for who would be at the receiving end of that knowledge. Countries around the world began thinking that fission might be used for military purposes.

Although Americans’ larger aim was to create a nuclear bomb, they had to tackle the questions that came first: They needed to understand how the finer details of nuclear fission worked and whether or not they could control it. Once they got a handle on those things, they could move forward.

Scientists studied these concepts and continued to publish their results. Publication was the natural outcome of years of research, hours of hard and dedicated work, sometimes tedious, at other times exciting. These articles could be read by anyone. Soon, a voluntary ban against publishing research was instituted by the British as well as by those working in the United States. However, the French team, led by the Joliot-Curies, refused to adhere to any ban. They had difficulty accepting the fact that the Nazis might be considering the possibility of constructing a bomb and might be looking to their work for inspiration. And so they continued publishing.

In 1935, Frédéric Joliot-Curie, while delivering a lecture, included the following paragraph: “If, turning towards the past, we cast a glance at the progress achieved by science at an ever-increasing pace, we are entitled to think that scientists, building up or shattering elements at will, will be able to bring about transmutations of an explosive type, true chemical-chain reactions. If such transmutations do succeed in spreading in matter, the enormous liberation of usable energy can be imagined. But unfortunately, if the contagion spreads to all the elements of our planet, the consequences of unleashing such a cataclysm can only be viewed with apprehension.”

Not surprisingly, while listening to Niels Bohr at the Washington conference, some in the audience immediately began to speculate about what kind of weaponry such a discovery could offer. For the military, this could be quite a coup. Up until that point, the notion of a bomb based on the principle of a chain reaction was still an abstract concept in the minds of a few who believed it could never come to fruition—at least not during their lifetimes.

But the discovery of nuclear fission discussed at the Washington conference, and the possibility of it being used for weapons, came at the right moment. There were already hints of war, and it was widely believed that Hitler and his regime would be using methods of warfare previously unheard of. One had to fight fire with fire, but there were questions to contend with: If a chain reaction could be achieved, could it also be sustained, or would the reaction speed up and release energy without assistance, basically uncontrolled? Would it shut itself off whenever it wanted to? Could scientists basically control it?

By the summer of 1939, the Americans believed that Germany had already started its own research program, wanting to be the first to develop an atomic weapon, with the British following close behind. Work was also under way in the Soviet Union, where the possibility of an atomic bomb had been discussed and a proposal appeared in 1940. (The Soviet scientific community had discussed the possibility of an atomic bomb throughout the 1930s, going so far as to make a concrete proposal in 1940, but they initiated their program only during World War II, in 1942.)

Although American scientists believed that a fission chain reaction was possible, they were also aware that many obstacles stood in their way. For starters, not every atom could be split in two, though uranium could, especially rare-form uranium-235, which accounted for only 0.72 percent of the naturally occurring element. It was already difficult to separate a large enough amount of identical uranium isotopes for a laboratory reaction; to do it on an industrial scale seemed almost impossible.

Szilard had listened carefully to all that was said at the conference, and he left with two things on his mind: the realization that there was military potential for a nuclear weapon; and the knowledge that the Germans were already very much aware of that potential and were likely working on a bomb.

Szilard realized that the United States and its laboratories had become the beneficiaries of much of the knowledge brought forth by the exiled European scientists. But he was also aware that many other scientists had stayed behind, and they were still working in Germany—for Adolf Hitler. They might have already come up with plans to hand over to Hitler a weapon the likes of which the world had never seen.

Szilard didn’t know whether people would listen to him or his ideas. Small in stature and rather round, he liked to sit in a wide chair when deep in thought and cross his hands over his protruding belly. Some thought he had a flair for the dramatic, a reputation he didn’t particularly like. But in this case, he was correct in thinking that this was an important matter that needed to be studied with special attention. He was sure that many of the new discoveries had to be kept secret, for fear that they would land in the wrong hands. In fact, he was the one who spearheaded the voluntary publication ban.

Fermi had this to say about Szilard: “He is certainly a very peculiar man, extremely intelligent.… He is extremely brilliant and… he seems to enjoy startling people.… Contrary to perhaps what is the most common belief about secrecy, secrecy was not started by generals, was not started by security officers, but was started by physicists. And the man who is mostly responsible for this certainly extremely novel idea for physicists was Szilard.”

It was necessary, he decided, to bring the president into the equation. But Szilard knew where he stood in the great scheme of things. He was not the most famous of the scientists who had come to America. While at times that fact pained him, he realized that this was not the time for petty thoughts. He asked some of his colleagues and friends, including Einstein, to help write a letter to President Roosevelt explaining the possibilities of what they were looking into.

Einstein had become one of the most recognizable scientists, thanks in part to his theory of relativity, which, in truth, few could really understand. Aside from his own celebrity status, Einstein had also elevated the status of physics itself. Americans had immediately fallen in love with this man, who was seen by all as a shy genius, a bit of a scatterbrain who could laugh at himself, and highly unpretentious. They loved those who were associated with him, too, assuming that geniuses ran in packs.

Initially, Einstein had not wanted anything to do with atomic projects. But with the discovery of nuclear fission, he realized that chain reactions could be used with devastating results. Although the general implications of an atomic bomb were already hinted at, Einstein agreed the president must be told of the physicists’ concerns.

Einstein warned President Roosevelt that building a superbomb was now very much a possibility. Most scientists feared that the Germans might already be working on such a thing and believed that the United States had to beat them at their game. It would be devastating if the Germans succeeded first.

“Certain aspects of the situation which have arisen,” Einstein advised the president, “seem to call for watchfulness and, if necessary, quick action on the part of the Administration.”

Einstein urged the president to maintain contact with nuclear physicists through a confidante who could do the following:

a) to approach Government Departments, keep them informed of the further development, and put forward recommendations for Government action, giving particular attention to the problem of securing a supply of uranium ore for the United States;

b) to speed up the experimental work, which is at present being carried on within the limits of the budgets of University laboratories, by providing funds, if such funds be required, through his contacts with private persons who are willing to make contributions for this cause, and perhaps also by obtaining the co-operation of industrial laboratories which have the necessary equipment.

In fall 1939, Alexander Sachs, an economist who worked as President Roosevelt’s adviser, brought Einstein’s letter to the president. This letter would eventually trigger the Manhattan Project in 1942. Sachs convinced President Roosevelt that the United States, much like other countries, needed to explore the possibility of a fission weapon. President Roosevelt agreed, and the Advisory Committee on Uranium was quickly formed. Money was set aside for buying uranium, and contracts were awarded to various schools across the country, including Columbia, Cornell, and Johns Hopkins, in Baltimore, Maryland, as well as organizations such as the Carnegie Institution for Science, for advanced scientific studies of uranium.

It was from these universities and their laboratories that scientists would eventually be recruited for the Manhattan Project. These men and women, who had been studying nuclear science and anything related to it, were believed to possess the skills and knowledge that the country needed. It was that knowledge that was important, regardless of a scientist’s gender. Many employers would not have considered women for work a man could do, but some of the sharpest minds in the new field belonged to women, and they were needed.

And so, instigated by the belief that the Germans were building atomic bombs, many women scientists made their way to the laboratories. Those who joined the project saw this as their patriotic duty; it was their job to help the government, to help stop a madman who could kill millions of people with the push of a button. They were eager to serve in whatever capacity necessary.

Three main sites would eventually be chosen. To provide fuel for the bomb, Oak Ridge, Tennessee, was selected as the site to enrich uranium, and Hanford, Washington, as the site produce the plutonium. At a third site, scientists would design and build the bomb. This spot needed a certain amount of isolation but also easy transportation. There had to be abundant water available, and mountains had to surround the site. It would be only a small facility, officials initially thought: a small laboratory where a few scientists would hash out the final details of the bomb’s design. But, as it turned out, Los Alamos, New Mexico, defied everyone’s expectations.

Neither Fermi, Szilard, nor any of the Hungarian scientists would take the lead at any of these facilities. Following the attack on Pearl Harbor on December 7, 1941, they were classified as enemy aliens and thus could not be put in charge of such secret affairs, though they still could work on them. And so they continued to study and research at a feverish pace.

Through it all, James Franck, who had joined the Metallurgical Laboratory at the University of Chicago, urged officials to come up with guidelines for the weapons, should they come to fruition. They should be used only under extreme circumstances, Franck said, and only as a last resort. But few gave much thought to what he was proposing. Their focus was on finishing the bomb as soon as possible.

But then something spectacular happened. A new element arrived on the block, an element that could shift things completely and help in the production of the weapon. Scientists learned that uranium-238 could absorb neutrons, thus becoming uranium-239. This, in turn, emitted beta particles, becoming the first human-made element, eventually called neptunium-239. Neptunium-239 also went through a process of exhibiting beta decay, which changed into plutonium-239. And just like uranium, plutonium was found to have the power to fission, or split in two. When bombarded by neutrons, plutonium also released huge amounts of energy. It was a stunning discovery, as scientists now had two paths to building the atomic bomb.

By this point, it was 1941 and Lise Meitner was still in Sweden, away from the Nazis, not knowing that her discovery of fission had laid the groundwork for this secret military operation. The women who would arrived in Oak Ridge, in Hanford, in Los Alamos, and in the various laboratories across the country followed in Lise’s footsteps and saw her as their guide, a woman who had helped steer their careers. To them she was a benevolent, brilliant, groundbreaking inspiration, much as Marie Curie had once been to Lise. Once Lise learned of the intentions of the Manhattan Project and found out how her discovery was being used, she would be repulsed. She would not be the only one to feel that way.