Hitler’s Physicists and the Bomb
WHY YOU SHOULD CARE
Because failure can be good for mankind.
Hindsight is a wonderful thing. “I would definitely have considered making atomic bombs for Hitler a crime,” wrote nuclear physicist and Nobel Prize winner Werner Heisenberg to the Dutch mathematician Bartel Leendert van der Waerden in 1948.
Yet Heisenberg’s friend Niels Bohr, another nuclear physicist and Nobel Prize winner, has a quite different memory of the 1941 conversation that Heisenberg was alluding to. “You spoke in vague terms that naturally gave me the strong impression every effort was being made under your leadership to develop atomic weapons in Germany,” Bohr wrote in a letter he ended up never sending. “You said there was no need to go into specifics because you were very familiar with them, and you’d been more or less exclusively occupied with that kind of developmental work for the past two years.”
With an almost indescribable combination of hubris and ignorance, they assumed they were way ahead of potential competition.
That draft letter only came to light at an auction a few years ago. It cast a shadow over Heisenberg, who’d been a pioneer in his field. Together with other physicists, Heisenberg made the famous 1957 “Göttinger 18” declaration against nuclear arms for West Germany’s army. But did Heisenberg actually have no qualms about developing the ultimate bomb for Hitler? Germany’s N24 television news channel is now showing the documentary “Hitler’s Scientists and the Race for the Atomic Bomb” as part of its series Zeitreise mit Stefan Aust (Time Travel with Stefan Aust). The documentary summarizes the confirmed facts about Germany’s nuclear fission attempts. Heisenberg does not come out of it well.
The first experiment with a nuclear reactor took place in the early summer of 1940 at Hamburg University, just as the German armed forces were advancing through Western Europe. But Paul Harteck and his team of nuclear chemists had insufficient uranium oxide to progress any further. They understood the chain reaction in theory but never achieved it in practice. However, the German Army Weapons Agency had by that time decided it was worth dedicating several teams of scientists to research the new super weapon. The German scientists were unconcerned that their wartime enemies were perhaps carrying out similar research. With an almost indescribable combination of hubris and ignorance, Heisenberg, Carl Friedrich von Weizsäcker and other German physicists simply assumed they were way ahead of any potential competition.
No wonder. Berlin was the global capital of theoretical physics up to and even after the First World War. The cream of students and junior scientists flocked to the Kaiser Wilhelm Institute in the well-heeled suburb of Dahlem, known as “Germany’s Oxford.” Attending a German university was considered mandatory for anyone who wanted to make a name for themselves in nuclear physics. The universities in Karlsruhe, Leipzig and Göttingen, in addition to Berlin, all had excellent reputations. Renowned professors and institute directors such as Albert Einstein, Max Planck and even Heisenberg were also a big attraction.
All that ended when the Nazis seized power in 1933 and banished allegedly “Jewish” physicists. Many outstanding junior researchers left Germany, among them the Hungarian Edward Teller, from Göttingen, and Hans Bethe, from Frankfurt. The latter was deemed a “half-Jew” under Nazi terminology. Both men went to the U.S., where they joined J. Robert Oppenheimer’s team dedicated to top-secret U.S. nuclear weapon research, known as the “Manhattan Project.”
Still, nuclear physics continued in Germany. Heisenberg summarized its intended goal in a December 1939 letter to the German Army Weapons Agency. “Enriching uranium-235 is the only means of ensuring a machine’s volume is small (around one cubic meter). Furthermore, it is the only way of manufacturing explosives with an explosive force that’s tens of times more powerful than the hitherto strongest explosives.” Heisenberg later participated fully in the developments. He belonged to the “uranium club” team and also considered how the military could use it. But while virtually limitless resources were available in the U.S., the German physicists were given insufficient resources by a Nazi leadership convinced of its own imminent victory.
Yet that’s probably not the reason why German scientists never came close to building a working bomb. Even when the physicists were detained and monitored in Britain’s Farm Hall following Germany’s defeat, they still hadn’t understood the essential theoretical principles of nuclear fission weapons. But they had attempted it. And what’s more, they hadn’t prevented it — as Heisenberg and Weizsäcker later claimed. In their defense, they presumably acted out of patriotism. But it’s a patriotism that would also have benefited Adolf Hitler.