In June of 1939, 37-year-old Werner Heisenberg went on a tour of America for a cosmic-ray symposium, and everywhere he went everyone wanted to know why, why, why was he staying in Germany?
Heisenberg was no obvious anti-Semite, in fact, he had lost most of his friends, mentors and students to Hitler’s anti-Semitism and had just fought a symbolic war against the regime that wanted to label all theoretical Physics and physicists “Jewish filth”, and as Enrico Fermi’s wife Laura put it to him, “anyone must be crazy to stay in Germany”.
Heisenberg hemmed and hawed about it, and basically left it at, “we ought even to insist that everyone brave what storms there are in his own country”. A month later, her took a nearly empty boat back to Germany, a month after that on September 1, 1939, Hitler attacked Poland and started world war 2.
By September 25th, Heisenberg agreed to join the “Uranium club” and try to make a nuclear bomb for Hitler. So, once again, why? To answer this question, I think we need to look into how Heisenberg became famous in the first place and how he passively dealt with the Nazis before 1939.
Table of Contents
Werner Heisenberg’s Early Life
“Heisenberg is without doubt, one of the most gifted men in theoretical physics, and nobody can resist his cleverness and charm… the problem is whether to mix [politics] up with scientific questions.”
– Max Born October 18, 1948
I would like to start in Fall of 1922, 11 years before Hitler came to power when 20-year-old grad student Werner Heisenberg went to Gottingen to take a class from the delightful Max Born on new quantum theories.
Even though the class was attended by Heisenberg’s friend Wolfgang Pauli and a visiting scientist from Italy named Enrico Fermi, Born was most impressed with Heisenberg and offered him a post-doc position which he started in 1923. Two years later, in 1925, Heisenberg told Born that “he had written a crazy paper and did not dare send it for publication.”
Born, “began to think about it day and night,” then, one morning, Born recalled, “I suddenly saw the light: Heisenberg’s symbolic multiplication was nothing but the matrix calculus, well known to me since my student days.” Although Heisenberg complained, “I don’t even know what a matrix is”, he quickly learned and for the next 6 months Heisenberg, Born, and a fellow student named Pasqual Jordan created Matrix theory.
Then, mere months later a 39-year-old Austrian named Erwin Schrodinger published his wave model which, he said was partially motivated because he, “felt discouraged, not to say repelled, by [Heisenberg’s] method of transcendental algebra.” Threatened, Heisenberg wrote Wolfgang Pauli, “the more I reflect on… Schrodinger’s theory, the more disgusting I find it… I consider [it to be] crap.” (It turns out both methods work).
In the fall of 1926, Niels Bohr invited Heisenberg to Copenhagen to try to solve this dilemma. While in Copenhagen Pauli sent Heisenberg a strange result: in theory the more he could accurately measure the position of a particle, the less accurately he could measure the momentum (mass times speed).
Heisenberg used the “new laws” of quantum mechanics to derive this relation, now called the uncertainty relation. This was even more hated by Schrodinger and soon all the international and local colloquia were taken over by this debate.
By February of 1928, 26-year-old Heisenberg was so famous that he was appointed as the head of the physics department at the University of Leipzig and then he and Pauli created quantum field theory.
The Dark Era for Scientists In Germany
Then, in October 1929, the American stock market fell off a cliff and the faltering economy dragged the whole world into a global depression, especially in Germany. Desperate, many Germans started supporting either the Communist party or a group of racists led by a buffoonish moron named Adolf Hitler.
Heisenberg didn’t like either group, and started to focus on his philosophy that was born in his days of the German boy scouts, called the pathfinders, which was a pseudo-religious paramilitary group dedicated to revitalizing German honor and a rebirth of the chivalry of medieval knights.
This wasn’t a passing childhood phase as even in 1945, 43year old Heisenberg tried to justify his behavior to an Allied scientist named Gouldsmit where Gouldsmit complained to a friend that Heisenberg was spouting, “some abstract parallel or relationship between Christian ethics, a knighthood in the middle ages and the Nazi doctrine.” Not surprisingly, the pathfinders morphed into the Hitler youth movement in the 1930s.
Anyway, back in 1932, despite the fact that Hitler only won 37% of the vote, President Hindenburg and the Parliament were so scared of communists that they made Hitler chancellor. After the communists were blamed for a fire in February of 1933, Germany declared martial law and by the end of March, Hitler was able to pass a law to enact any law he wished.
On April 7th, Hitler wrote a new law that all communists and people of “non-Aryan” descent had to be fired with an exception for World War 1 veterans: doctors, lawyers, musicians, and, most importantly to Heisenberg, university professors.
Max Born (who was Jewish) ran off to the Italian alps, and Heisenberg turned to the elder statesman Max Planck for advice. Heisenberg then learned that Planck had actually personally talked to Hitler but had gotten nowhere convincing him to keep Jewish scientists in Germany.
Many people noted how despondent Planck was after the conversation, but Heisenberg seemed to have gotten a different vibe (Planck was apparently convinced that Hitler was so pathetic he was not long for power) and Heisenberg wrote Born, “Planck has spoken…with [Hitler] and received the assurance that the government will do nothing beyond the new …law … I would ask you not to make any decisions yet, but wait and see how our country looks in the fall.”
Born agreed to try to delay, but by the next month, Wolfgang Pauli, who also had a Jewish background but was safely working in Switzerland, found Born a job in Cambridge, and Born stopped waiting for Hitler to relent or be removed from power.
At the same time, Heisenberg’s rival, Erwin Schrödinger, who was not Jewish, decided that it would be fun to go to England which was taken as a rebuke of Hitler, leaving Heisenberg feeling like the most important supporter of theoretical physics left in Germany.
By the way, Schrödinger never publicly denounced Hitler, moved back to his native Austria in 1936, and, in 1938 published a disturbing pro-Nazi article to try to suck up to the regime as they rolled into town. Although Schrodinger became scared when he was fired for “political instability” and escaped to Ireland, he never publicly denounced his own repulsive words.
Anyway, back in Fall of 1933 Heisenberg learned that he was being awarded 1932’s Nobel Prize in Physics (a year late) and he wrote Born that he was embarrassed to earn without him.
There was then talk of giving Heisenberg Born’s old job and in early 1934, Heisenberg wrote his other mentor from Gottingen, James Frank, who had emigrated to Copenhagen, “I fear that a long time will pass before such a time of scientific enthusiasm will be possible once again in Germany. But I want to hold out here.
That I will do everything in my power for our Gottingen, you may be sure.” However, by the spring of 1934, a Nobel Prize-winning ass named Johannes Stark, who was a very early promoter of Hitler, and an obsessive anti-Semite, became chair of the German Research Foundation, and “At his first action, Stark ceased research funding for all theoretical work and even restricted what experimental work go funded to ‘Aryan’ topics.”
Heisenberg continued to be able to conduct research through other sources but was denied the position at Gottingen. It was around this time that Heisenberg realized that the Nazis weren’t going to just disappear as he had previously hoped and mulled over volunteering for an “army sports camp” to “acquaint [myself] a little more with this politics,” but he didn’t get around to it and the next year it became a moot point as he was drafted as an Army reservist.
Also, in May of 1935, Heisenberg heard that four Jewish professors at Leipzig were to be fired despite their exemptions for being World War 1 vets. Heisenberg and five other professors formally voiced their objections at a faculty meeting, (Heisenberg said it was, inconsistent, “with the intention of the law”) which went nowhere and, although Heisenberg wasn’t sacked, he was more and more the focus of vitriol, especially from Stark.
On September 15, 1935, Hitler used an annual rally in Nuremberg to announce new, stricter laws specifically attacking German Jews from almost all employment and removing the limitation on World War 1 vets as well as many other racist edicts! Heisenberg decided that it was pointless to object to anything anymore and that only science had value, writing his mother, “The world out there is really ugly, but the work is beautiful.”
How Heisenberg Ended Up Working for Hitler
Also, in 1935, Arnold Sommerfeld, who was Heisenberg’s Ph.D. advisor, retired and promoted Heisenberg as his successor, and, at first, it seemed like Heisenberg would get the position, but in December, Johannes Stark gave a speech where he denounced how it could be possible that, “Heisenberg, the spirit of Einstein’s spirit, is now to be rewarded with a call to a chair.”
The appointment was postponed, and Heisenberg wrote his mother, “I can wait; this complete idiocy cannot last forever.” But the idiocy just seemed to grow, and become an attack on all theoretical physics! Meanwhile, in the summer of 1936, Heisenberg went to Bavaria to complete eight weeks of military training, which he adored, writing his mother, “It is nice not to have to think for a change, but only to obey… the duty agrees with me in every respect.”
By the end of 1936, Heisenberg was back at work and got together with other scientists to create a petition on the need for theoretical physics which was signed by nearly physicist remaining, seventy-five in total, including many Nazi party members. It seemed like Heisenberg had won, and by March, 1937, he was told that he could have Sommerfeld’s spot if he still wanted it.
Heisenberg accepted but with a small delay as he had just met a young woman named Elizabeth (Li) Schumacher in January and was busy arranging their marriage for April (he worked fast). This gave Stark time to renew his attacks and by July 15, 1937, Stark published an attack ad titled “White Jews in Science” that called Heisenberg (and, for good measure, Max Planck and Arnold Sommerfeld), “bacterial carriers of the Jewish spirit who must be eliminated just as the Jews themselves.”
Incensed, Heisenberg wrote to Heinrich Himmler directly demanding an investigation into the accusations and an apology. Yes, that Heinrich Himmler, Hitler’s number 2 guy and according to Wikipedia, was “one of the most powerful men in Nazi Germany and a main architect of the Holocaust.”
This didn’t work the way Heisenberg wanted as Heisenberg didn’t like meeting with the SS (he even had his mother call up Himmler’s mother to ask Himmler to take it easy on her boy)! Heisenberg wrote Arnold Sommerfeld that he would have to leave Germany, “if the defense of my honor is refused” as he had, “no desire to live in Germany as a second-class citizen” (Heisenberg didn’t seem to notice the irony of staying in Germany where *other people* were second-class citizens or slaves or worse or wonder why being called Jewish was an insult to his honor).
Anyway, in July of 1938, a powerful Aerospace engineer named Ludwig Prandtl, spoke up for Heisenberg, “not because of Heisenberg as a person, but because of his concern for German Physics” and less than two weeks later Heisenberg heard the good news that Himmler would support Heisenberg as long as Heisenberg didn’t get too “political” and that quantum mechanics and relativity could be taught in school. Heisenberg was victorious, and now had a very powerful ally in Himmler. Heisenberg Can’t Separate Politics and Science
Strangely enough, this whole escapade actually made Heisenberg into a willing tool of the Nazis. He had made a Faustian bargain: he would support the regime no matter what as long as he was a 1st class citizen and was allowed to study theoretical physics. Heisenberg felt he had to “ignore politics” in order to “save German science” and decided to not worry about the moral implications of working for Nazis or the ramifications of his science research.
Even as the Nazis started to systematically starve and abuse (and eventually slaughter) millions. He ignored the adage, “you cannot sup with the devil even with a long spoon”.
Just 9 days after getting the “good news” from Himmler, Heisenberg’s new morality was put to the test as Heisenberg found himself in uniform with thousands of other Germans getting ready to attack Czechoslovakia for Hitler.
Luckily for Heisenberg, Hitler signed the “Munich treaty” with Italy, France and England where Hitler got part of Czechoslovakia if Hitler special pinky promised to stop there and British Prime Minister Chamberlain proclaimed “peace for our time”.
By October, Heisenberg was back at his desk in Leipzig and continued his work with Himmler to try to get Sommerfeld’s position. Then in November 9, 1938, all of Germany erupted in mob violence specifically against the Jewish population.
Discrimination Against the Jews
Two days before, a Jewish teenager living in Paris had shot and killed a Nazi diplomat in revenge for how his parents and other Jews had been treated by the Nazi regime. Hitler decided it was a grand Jewish conspiracy and Himmler and Goebbels then arranged a “spontaneous” protest and soon mobs of SS were burning, looting, killing, and desecrating graves and synagogues.
The head of the American Consul in Leipzig described it as, “the most violent debacle the city had probably ever witnessed” and how the consulate was inundated with desperate beaten, and bloody people begging for help where, “most of these visitors being desperate women, as their husbands and sons had been taken off to concentration camps”.
Heisenberg knew of much of this and wrote his mother how he was, “still completely in shock from the last nights.” However, Heisenberg, like the majority of his countrymen, decided to stay silent. Instead, Heisenberg looked for a country house for his wife and two going on three children.
In the calm of the country, Heisenberg went back to his campaign for a position with Himmler! The international political community acted like Heisenberg, shock, and dismay followed by… not much of consequence, but for ordinary people inside and outside of Germany, it was becoming clear that Hitler and his regime were evil.
Hitler downplayed his role in “the night of broken glass” or Kristallnacht, but he learned that he could do what he wanted with little repercussions and Kristallnacht is often considered the starting date of the holocaust.
The Experiments Made During the War
Now, finally, we get to nuclear fission. Less than two months after Kristallnacht, on January 6th, 1939, the German Chemist Otto Hahn and his assistant published their startling results that when uranium was bombarded with neutrons sometimes the heavy uranium nucleus split in what is called nuclear fission, into smaller elements.
By February 11, Hahn’s longtime partner Lise Meitner (who had discovered what was happening with Hahn’s experiment and described it to Hahn), and her handsome nephew Otto Frisch, published the physics of nuclear fission, and how the new configuration would have slightly less mass, and correspondingly, energy from E=mc2.
They published separately because both had Jewish backgrounds (Lise had only recently escaped Germany). However, as Frisch noted in his autobiography, “in all this excitement, we had missed the most important point: the chain reaction.” By March 1939, Frederic Joliot and his wife Irene Curie (daughter of Marie Curie), published that the nuclear fission produced more neutrons that it absorbed and therefore could cause other uranium have a nuclear reaction in a chain reaction.
Although it still seemed unlikely, a nuclear bomb was possible. And by the end of April, the New York Times published an article that “Scientists say [that a] bit of Uranium could wreck New York.” Just a few weeks later, Heisenberg was on his way to the United States for a symposium as I described in the introduction.
When Heisenberg returned to Germany, he regaled his family with stories of an explosive that could destroy New York (I guess he read the New York Times article) and his theory that whoever possessed this first could blackmail the whole world.
This became more disturbing, when, not surprisingly to anyone except for Neville Chamberlain, Hitler violated his treaty with England and France, made a secret pact with Russia, and attacked Poland on September 1st. Heisenberg waited, ready, for his call to the front.
However, on September 25th, he was asked to go on a very different mission and found he was called to Berlin to join an “Uranium club” with an old friend and former student of his named Carl Frederick von Weizsäcker to determine if an atomic bomb was possible.
After the war, Weizsäcker recalled that Heisenberg wasn’t hard to convince, and told him, “Hitler will lose this war. It is like the end game in chess, with one castle less than the others. He will lose his war. Consequently, much of Germany will be destroyed … [but] the value of science will still be there and it is necessary that science should live through the war, and we must do something for that.”
However, Hitler was far more successful in the West than Heisenberg expected and within 9 months they had overrun Belgium, the Netherlands, and Luxenberg and signed an armistice with France!
Heisenberg was floored, but decided that Europe was weak and Europeans had to decide between Hitler and Stalin and, as he told a friend in 1943, “it had always been the historic mission of Germany to defend the West and its culture against the onslaught of eastern hordes and the present conflict was one more example… perhaps, a Europe under German leadership might be the lesser evil.”
When that friend objected especially because of the Nazis “Mad and cruel anti-Semitism” Heisenberg said he thought things would “change for the better once the war was over” and, besides, most of the cruelty was focused on the East not in good Nordic places! (Vomit).
Note that while Heisenberg was convinced that Germany was going to win, he *still* worked on nuclear research, and complained about lack of funding as he continued to look for validation of theoretical physics worth to the regime, although he didn’t seem to feel in a particular rush.
However, once the war seemed lost, Heisenberg worked harder to produce a reactor (first step before a bomb), as he went back to feeling, as he did in 1939, that German science embodied in his personal success, and they needed a ticket to negotiating with the new rulers.
Heisenberg’s actions were not a secret, and the majority of Allies felt that, as the scientific head of the mission to “investigate enemy research” said, “no one but Professor Werner Heisenberg …could be the brains of a German uranium project. Every physicist in the world knew that.”
When Heisenberg was captured in 1945, they labeled him in their communications as “the leader of the German atomic weapons program,” and it was fear of Heisenberg in particular that drove the scientists and politicians in the Manhattan Project to devote so much energy and money to developing the atomic bomb.
This brings us to one of the biggest mysteries in Physics. In the fall of 1941, Werner Heisenberg went to Nazi-occupied Denmark, and according to Niels Bohr and many other contemporaries, Heisenberg started spouting truly offensive garbage about how great Germany was and how happy everyone should be about their inevitable victory and then, according to Bohr, “I also remember quite clearly our conversation in my room at the Institute … that under your leadership, everything was being done in Germany to develop atomic weapons and that you … had spent the past two years working more or less exclusively on such preparations.”
Which leads to the mystery, why would Heisenberg tell Bohr about the bomb? You can bet that Robert Oppenheimer and Enrico Fermi weren’t going on vacation and telling people about their work leading the Manhattan Project.
Did Bohr remember the event correctly? Was Heisenberg warning Bohr? Trying to recruit Bohr? Trying to scope out the competition? Trying to get absolution? Bohr could never figure it out. It seemed so ironic: the uncertainty of time, of memory, of morality, around the actions of the creator of the uncertainty principle! That would make a fabulous play. [Hint: it is fabulous].
I assumed, like most others, that it would always remain… uncertain. But in researching the history I think I might have solved it, and that story is next time on the lightning tamers!
 As relayed in Rose, P Heisenberg and the Nazi Atomic Bomb Project (1998) p. 267
 Found in Pais, A Niels Bohr’s Times (1991) p. 278
 Found in Pais, A Niels Bohr’s Times (1991) p. 278
 Schrodinger, E (1926) found in Miller, A 137: Jung, Pauli, and the Pursuit of a Scientific(2010) p. 96
 Schrodinger, E (1926) found in Miller, A 137: Jung, Pauli, and the Pursuit of a Scientific (2010) p. 96
 Schrodinger, E (1926) found in Miller, A 137: Jung, Pauli, and the Pursuit of a Scientific (2010) p. 96
Goudsmit to Irving (August 4, 1966) Found in Rose, P Heisenberg and the Nazi Atomic Bomb Project (1998) p. 243
 Max Planck to Von Laue (1933) Cassidy, D Beyond Uncertainty (2010)
 Hillman, B et all The Man Who Stalked Einstein (2015) p. 146
 Heisenberg to his mother (July 12, 1934) found in Cassidy, D Beyond Uncertainty (2010) p. 335
 Found in Ball, F Serving the Reich (2014) P. 72
 Heisenberg to his mother (Oct 5, 1935) found in Cassidy, D Beyond Uncertainty (2010) p. 355
 Stark opening of the Philipp Lenard Institute (February 1936) found in Cassidy, D Beyond Uncertainty (2010) p. 378
 Heisenberg to his mother (Feb 15, 1936) found in Cassidy, D Beyond Uncertainty (2010) p. 381
 Heisenberg to his mother (Aug 28, 1936) found in Cassidy, D Beyond Uncertainty (2010) p. 391
 Found in Ball, F Serving the Reich (2014) P. 100
 According to Hillman, B The Man who Stalked Einstein (2015) P. 175
 Found in Walker, M Nazi Science (2013) p. 132
 David H Buffum, American Consul (Nov 21, 1938) found in Nazi Conspiracy and Aggression (1946) P. 1041
 Recalled in Rose, P Heisenberg and the Nazi Atomic Bomb Project (1998) p.268