Consequence

A theoretical physicist trained in Cambridge and in Göttingen under Max Born, Oppenheimer built a school of theoretical physics at Berkeley in the 1930s and directed the Los Alamos laboratory that produced the atomic bombs used on Hiroshima and Nagasaki. After the war he chaired the Atomic Energy Commission’s General Advisory Committee, which in 1949 advised against a crash programme for the hydrogen bomb, and directed the Institute for Advanced Study. In 1954 the commission withdrew his security clearance after a hearing that turned on his loyalty and his opposition to the hydrogen bomb.

• 1946 · A Report on the International Control of Atomic Energy

  International control of dangerous capability

  The report, largely his work, argued that inspection and secrecy could not make atomic energy safe, and proposed an international authority that would own and run the dangerous stages of production.

• 1947 · Physics in the Contemporary World

  Knowledge that cannot be shed

  In a lecture at MIT he said that the physicists who built the bomb had acquired a knowledge of their own complicity that they could never lose.

• 1953 · Atomic Weapons and American Policy

  Candour over secrecy

  Secrecy about the arms race kept the public from judging a policy it would have to live with. He urged candour about the weapons and their consequences.

• 1953 · Science and the Common Understanding

  Partial views

  In his BBC Reith Lectures he took complementarity from quantum physics as a model for how different, incomplete descriptions can each be valid, and for the limits of any one expert’s view.

• 1954 · In the Matter of J. Robert Oppenheimer

  The pull of the technically sweet

  At his security hearing he described how scientists faced with an elegant technical possibility tend to build it first and argue about its use only after it works.

1. Who becomes responsible once this capability exists?
2. Once this exists, who controls it, and who answers for its use?
3. Is this being built because it should be, or because it can be?
4. What does the public need to know to judge it, and is secrecy keeping that from them?

Scientific expertise does not by itself confer political legitimacy. The lens centres the conscience of the people who build a technology and can neglect the people who live with its effects.