Bohr's 1950 open letter called for an open world

Person: Niels Bohr
Lived: 1885–1962
Field: Physics
From: Danish

The story

During the Second World War Niels Bohr escaped from occupied Denmark and worked as a consultant to the British and American atomic bomb projects, visiting Los Alamos several times. He recognised early that nuclear weapons would change relations between nations. In April 1944 he received a letter from the Soviet physicist Peter Kapitza inviting him to the Soviet Union, which convinced him that the Soviets knew about the Allied project and would try to catch up.

Bohr concluded that the only safe course was openness. He met Winston Churchill on 16 May 1944 and found that, as he put it, they did not speak the same language. His friend Felix Frankfurter, a Supreme Court justice, arranged a meeting with Franklin Roosevelt on 26 August 1944, where Bohr argued for sharing information about the project with the Soviet Union to avoid a dangerous arms race. In September the two leaders rejected the idea, and even asked for steps to be taken to make sure Bohr leaked nothing.

Bohr did not give up. On 9 June 1950, after the Soviet Union had tested its first nuclear weapon, he addressed an open letter to the United Nations calling for international cooperation on nuclear energy. Later that year he published a version titled For An Open World in the Bulletin of the Atomic Scientists. His central argument was that the free exchange of information and ideas between countries was the only lasting basis for security.

His ideas helped shape the institutions that followed. In the 1950s the International Atomic Energy Agency was created along lines Bohr had suggested. He supported the creation of CERN, chaired the Danish Atomic Energy Commission and helped found the Risø research establishment for peaceful nuclear research. In 1957 he became the first recipient of the Atoms for Peace Award.

His Nobel biography records that in his later years Bohr devoted his work to the peaceful uses of atomic physics and to the political problems raised by nuclear weapons, advocating full openness between nations. The open letter remains the clearest statement of that belief.

Why it matters

Bohr's call for openness influenced the creation of the International Atomic Energy Agency, which still inspects nuclear facilities and promotes the peaceful use of nuclear energy worldwide.