On his own initiative, Esau had stockpiled all uranium available in Germany. When the Joachimsthal mines in Czechoslovakia came under German control, Esau immediately requested samples of radium from the mines. He had worked hard, he had shown his mettle, his persistence, and his vision. But instead the Ministry of Armaments had decided to start its own nuclear research program behind Esau’s back.
They appointed Dr. Kurt Diebner to do their work. Diebner had been whining for years to get something like this, and now he had stolen it from Esau. Abraham Esau was ordered to cease his own atomic research and to stop questioning orders. They told him to surrender his carefully stockpiled reserves of uranium to Diebner. He had no choice in the matter.
But now, three years later, the roller coaster of political machinations had left Esau in a position to step up, to become the new Plenipotentiary. Now he oversaw Diebner’s work, which, with his group of physicists at Göttingen, was the second prong of German nuclear research. Esau despised Diebner, with his thick black glasses, sloping forehead, and ponderous speech. Diebner had once accused Esau of stealing his work, claiming that he himself had been working on the problem since 1938… which was absolutely absurd, since Hahn hadn’t even discovered nuclear fission until the year after that.
Diebner’s team seemed the most productive of the three, but Esau knew that was only because Diebner had confiscated the cyclotron from Frédéric and Irene Joliot-Curie in Paris, when the Nazis had overrun France. Diebner had taken Joliot-Curie’s work; he had copied the Frenchman’s ideas and implemented them himself. Whose ideas would he steal next?
The third and most impressive arm of nuclear research was led at the Kaiser-Wilhelm Institute in Dahlem, a suburb of Berlin. Its most prominent member was Dr. Werner Heisenberg, the scientist who had developed the famous quantum Principle of Uncertainty, for which he’d won the Nobel Prize in 1932.
Heisenberg was the darling of the theoreticians. His fame was greater than any of the others, yet he was quiet, firm, not as much a prima donna as so many of the other researchers. Heisenberg kept his voice low, his words clipped, his thoughts very clear. Esau didn’t care for Heisenberg personally, though he respected the man.
A few months earlier, when Abraham Esau had called a conference to discuss nuclear physics work with the Nazi high command, he invited many important people in the party, as well as a great number of prominent German physicists. The idea was for the first day to be an overview, a sales pitch to the leaders of government about what exactly the research teams were working on, with subsequent days devoted to in-depth secret discussions and papers among the nuclear physicists themselves.
Goering had curtly declined Esau’s invitation, as had most of the others. Not until much later did Esau realize that his own secretary had bungled her job and mailed the wrong schedules, inviting the government and military representatives to a long agenda of technical papers with nonsensical titles, making no mention of the general overview. No wonder so few of the important ones had showed up.
Still, the room was crowded. The physicists milled around, uneasy in such a large crowd. A handful of men in military uniforms sat at a long table and in wooden chairs near the wall.
Esau ignored the physicists and spent his time making sure the officials remained comfortable, that they had coffee to drink, that someone attended to them immediately if they had questions. Perhaps, even though their superiors had not bothered to come, Esau could impress upon them what his section was doing for the war effort, what this strange nuclear physics was about. But how was he to explain atomic fission to people who did not even know what an atom was?
“Gentlemen,” Esau said. He paused, waiting for those gathered in the room to fall silent and turn their attention to him. Self-consciously, he straightened his tie. The physicists, dressed in street clothes rather than uniforms, continued to rustle about; they had no interest in what Esau would say, since they already knew more about the subject than he did himself. Let them act snobbish, Esau thought— they wouldn’t get far in their research without his support.
“Gentlemen,” he said again, focusing especially on the ranking man there, Air Marshal Erhard Milch of the Luftwaffe. “You are familiar with presentations of enhanced explosives and new ways to fashion artillery—but I guarantee that you have never before heard how German science can unleash an entirely new destructive power, one as limitless as the universe itself. It is a power that springs from the most fundamental particle of all matter—the center of the atom itself.”
Esau held up a clenched fist. “In 1938 our esteemed Otto Hahn discovered how the nucleus of the uranium atom can be split, releasing the energy contained within.” He held up a second clenched fist against the first, put them in front of him, then violently snapped them apart. “This suggests the possibility of a superbomb, a weapon based on atomic energy.
“Upon learning of this, I myself stockpiled all of Germany’s uranium resources, because the uranium nucleus is the only one that exhibits this phenomenon of fission. But alas, it is not even that simple, because only a very special type of uranium is susceptible. This type of uranium, an isotope with an atomic weight of 235 instead of the more usual 238, is exceedingly rare. Out of every thousand grams of purified uranium, only seven are of the proper type, and even then, the uranium-235 is completely mixed with the rest. We are developing techniques to separate it out.”
Esau was losing his audience. He saw them scowling, skeptical; this was not what they wanted to hear. He did not want to discuss the many failures so far, but to emphasize the possible results.
“Lest you be discouraged, let me point out that a single bomb made with uranium-235 would be more powerful than a thousand of the best bombs we have available now. The successful completion of this project will more than compensate for the difficulties. Because of this, we believe nuclear investigations should be given the highest priority from the Armaments Ministry and Education Ministry. We can win the war as soon as we overcome this obstacle of separating out the special uranium.”
“And what is so difficult about that?” Air Marshal Milch said. He remained seated. He clearly knew that he outranked everyone in the room. Insignia decorated his shoulders and his breast. His cheeks were chubby, his eyes small and dark. He puffed on a deep brown cigarette, as if to flaunt that he could obtain good Turkish tobacco even with rationing. “German chemical workers pride themselves that they can process any material.”
Esau nodded soberly, though it was a stupid question. “It is not so simple, Herr Marshal. We cannot use a chemical process because there is no chemical difference between the isotopes—they are both uranium, as far as the chemistry goes. We must find a physical method. We are working with devices such as cyclotrons, a new instrument called the ultracentrifuge, another called the ‘isotope sluice.’
“The actual difference between the good uranium and the bad uranium, if I may call it that, is infinitesimally small. Let me use this comparison: imagine you are on top of the Cologne Cathedral, looking down upon a crowd. You are given the task of finding the one man who has an odd number of eyelashes in his left eyelid… and you have only a pair of dirty binoculars to work with. That is the magnitude of our task.”