Bohr and Heisenberg
The partnership that changed physics — and the world — is at the heart of the Lantern’s production of COPENHAGEN.
When Niels Bohr met Werner Heisenberg in June 1922, they did not seem a natural pair. Bohr was 37 and already a Nobel Prize winner. Born, raised, and living in Copenhagen, Denmark, Bohr was the son of a close and prosperous academic family. He spoke carefully, concerned always with how communication can help or hinder relationships and the expression of scientific ideas. He was a giant in the world of physics, regularly engaging in discussion and debate with figures like Einstein, who called Bohr’s model of the atom “one of the great discoveries.”
Heisenberg was just 21 and still a doctoral student. Though he had already made waves with his extraordinary theoretical leaps and mathematical prowess, he was doing poorly in his experimental lab work and would only barely obtain his PhD the following year when his lab professor gave him a failing grade. He was also the son of an academic, but his childhood in Munich was marred by the devastation of World War I, when he and his family faced food and fuel shortages. This experience gave him a fierce love of Germany and a romantic desire to return his country to the more idyllic times before the war. He was independent, audacious, and optimistic.
Bohr was visiting the University of Göttingen to give a series of lectures on atomic physics, which Heisenberg attended. When he disagreed with assertions in the revered scientific leader’s speech, Heisenberg stood up and criticized Bohr in front of all the other attendees. But rather than being appalled by or dismissive of this public challenge, Bohr invited Heisenberg on a walk. They talked, argued, and traded theories over the grounds of the university, and a partnership was born. By 1924, they were working together for months at a time at Bohr’s institute in Copenhagen.
The careful Bohr may have seen something of himself in the brash Heisenberg: he too began his career by criticizing an established scientist, pointing out errors in his mentor’s papers. Both had backgrounds in the arts and philosophy; Heisenberg played piano, while Bohr was interested in language. And both were willing to make enormous theoretical leaps that flew in the face of established science; Bohr’s 1913 model of the atom — which won him the Nobel prize in 1922 — discarded classical laws, and Heisenberg’s first paper violated the established principles of both quantum and classical physics.
The partnership initiated by that first contentious meeting would change the face of theoretical physics forever. Bohr and Heisenberg worked together most closely from 1924 to 1927, largely at Bohr’s Institute of Theoretical Physics in Copenhagen, which he founded with the dream of providing a space for international scientific collaboration. Scientists from all over the world came to Copenhagen to work with Bohr, and perhaps the most fruitful collaboration was the one with Heisenberg. Their work complemented each other’s, and in just three years, much of the progress toward the new era of theoretical physics was made. Bohr and his protege, not yet 30, had produced the Copenhagen Interpretation, the dominant understanding of quantum physics. This fertile collaboration also birthed a long friendship — one that would be tested and irrevocably changed in 1941.
Bohr and Heisenberg continued to collaborate throughout the 1930s, meeting at conferences, visiting each other, and keeping up correspondence. The outbreak of war in 1939 changed that, however. Heisenberg chose to stay in Germany while the Bohrs remained in Denmark. Germany invaded and occupied Denmark in 1940, and all chance at collaboration was shut down. When Heisenberg visited Copenhagen in 1941, Germany was winning the war in Europe and many occupied countries were resisting the rule of the Third Reich.
Onstage January 11 through February 18, 2018 at Lantern Theater Company, Copenhagen examines the mysterious 1941 meeting of Bohr and Heisenberg in the Danish city, seeking the truth of why Heisenberg visited his friend and colleague in the middle of a war. Both men spoke about it after the fact; Bohr reported the details to British and American intelligence forces, and Heisenberg spent much of the rest of his life explaining it to the press and in print. Others in their orbit offered different explanations of the meeting.
This much is known: Heisenberg came to Copenhagen in September 1941 with permission from Germany, and he and Bohr met at least once at Bohr’s home. Both accounts agree that Heisenberg broached the subject of nuclear weapons, that he felt certain they were feasible, though not without terrific technical effort. Both men agree that Bohr became agitated, and cut the talk off. Beyond that, accounts vary. Heisenberg had to be cagey due to German surveillance, making his motives especially hard to divine. Did he come to warn Bohr that Germany was attempting a bomb, to persuade Bohr to convince the Allies not to make a bomb, or — most troublingly — to extract information from his old friend on the state of the Allied nuclear program? Heisenberg reached out to Bohr after the war, hoping to get their stories straight, but was never successful. Unsent drafts of letters from Bohr’s private collection show that he was dissatisfied by Heisenberg’s recollections of the meeting in a 1956 book.
The meeting and its fallout took their toll: their friendship continued, with birthday greetings and general notes exchanged throughout their remaining years, but the close collaboration never recovered. Each continued their luminous scientific careers after the war; Bohr returned to the head of his Institute in 1945, and Heisenberg took over the Max Planck Institute for Physics in Germany, helping to rehabilitate and rebuild the German scientific field after the war, as he’d always hoped to do. Bohr died in 1962 and Heisenberg in 1976, taking the facts of the Copenhagen meeting with them.
Copenhagen is onstage at the Lantern January 11 through February 18, 2018. Visit our website for tickets and information.
