Soviet nuclear physicist, an outspoken advocate of human rights, civil liberties, and reform in the Soviet Union as well as for rapprochement with non-communist nations. In 1975 he was awarded the Nobel Prize for Peace.
Sakharov was the son of a physicist, and his exceptional scientific promise was recognised early. He won a doctorate at the age of 26 and was admitted as a full member of the Soviet Academy of Sciences at age 32. By that time he had worked for several years with Igor Tamm as a theoretical physicist to develop the Soviet Union's first hydrogen bomb and had also devised, with Tamm, the theoretical basis for controlled thermonuclear fusion. As a pre-eminent Soviet scientist, he was accorded luxuries and honours.
After years of attempts at less public persuasion, Sakharov in 1961 went on record against Premier Nikita S. Khrushchev's plan to test a 100-megaton hydrogen bomb in the atmosphere, fearing the effects of widespread radioactive fallout. Three years later Sakharov successfully mobilised opposition to the spurious doctrines of the still-powerful Stalin-era biologist T.D. Lysenko.
In 1968 he published in the West his essay"Progress, Coexistence, and Intellectual Freedom," in which he called for nuclear arms reductions, predicted and endorsed the eventual integration of communist and capitalist systems in a form of democratic socialism, and criticised the increasing repression of Soviet dissidents. In 1971 he married the human-rights activist Yelena G. Bonner.
Sakharov and Bonner continued to be at odds with the Soviet government. Speaking out against Soviet political repression at home and hostile relations abroad, he was isolated and became the target of official censure and harassment.
In December 1979, with his denunciation of the Soviet invasion of Afghanistan and his call for a world boycott of the Moscow Olympic Games, he was silenced. In January 1980 the Soviet government stripped him of his honours and exiled him to the closed city of Gorky (now Nizhny Novgorod).
In 1984 Bonner was convicted of anti-Soviet activities and was likewise confined to Gorky. In December 1986 the Soviet government under Mikhail Gorbachev released Sakharov and Bonner from their exile and let them return to Moscow.
Elected to the Congress of People's Deputies in April 1989, Sakharov had his honours restored and saw many of the causes for which he had fought and suffered become official policy under Gorbachev.
Sakharov's memoirs, translated by Richard Lourie, were published in 1990.