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Oppenheimer, (Julius) Robert - SCIENCE AND THE SECOND WORLD WAR (1939–45)

bomb atomic developed project

[op enhiymer] (1904–67) US theoretical physicist: contributed to quantum mechanics and the development of the atomic bomb.

 

SCIENCE AND THE SECOND WORLD WAR (1939–45)

The Second World War initiated projects of great importance both to the outcome of the war and to improvement of everyday life afterwards. Innovations directly attributable to the pressures of the war effort include radar, which was begun before 1939 in England and Germany with the British team led by ; air and sea transport has benefited since and the microwave oven is a side product. Radio astronomy was shaped by radar equipment and methods. Operations research (a mathematical modelling technique) grew out of the radar programme and protection against submarine warfare. Penicillin, the first antibiotic, discovered by in 1928, was developed for clinical use by 1944 . Penicillin and related antibiotics have dominated the treatment of many infections since. Computers were initially developed in the USA to calculate artillery trajectories, and in the UK by and others for decrypting the German ‘Enigma’ code messages. This decrypting programme (‘Ultra’) was notably successful and, by diminishing the effects of the Battle of the Atlantic and the (air) Battle of Britain, was critical in deciding the outcome of the entire war. Thereafter, computerized control has proved central to calculation in business, and developments include home entertainment and the control of space flight.

The German V-2 missile (the first ballistic missile) was developed by for warfare; he later headed the NASA space probe programme in the USA. Pesticides (notably DDT, due to ), curbed typhus during and after the war but their later use to control agricultural insect pests caused environmental problems; the work of and others led to limitations in their use. During the war a new class of poison gases was developed in Germany and made on a large scale. These are the intensely toxic organophosphorus esters (‘nerve gases’) such as Sarin (the lethal dose for humans is below 1 mg). Although not used in the war (the reasons are unclear) related compounds have been much used since, as insecticides in agriculture.

Turbojet aircraft engines were developed by in England and in Germany by P von Ohain (1911– ), and were first used in British military aircraft in 1941. After the war, jet propulsion largely replaced propellers in powering aircraft.

The Manhattan Project, which led to the atomic bomb and nuclear power, was work of massive scale and significance. At the time, its financial cost and the scientific and technical effort were vast, as were the military, political, energy-generating and environmental consequences. As those working on the project foresaw, the world was grossly changed after a controlled fission reactor, and later weapons based on both fission (the A-bomb) and fusion (the H-bomb), became practical realities from 1945. If the First World War was a chemist’s war, the Second was a physicist’s war.

Some novel schemes were only partial successes: for the Allied invasion of France in 1944, PLUTO, a fuel pipeline under the Channel, was partly successful; the huge transportable harbours (eg Mulberry) were valuable; the idea of a floating airfield of ice (refrigerated and reinforced with wood pulp), code-named Habakkuk, proved a false trail.

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Oppenheimer was born into a wealthy New York family and was educated at Harvard and Göttingen. In 1929 he took up posts at both the University of California at Berkeley and California Institute of Technology, having studied under whilst travelling in Europe. When the Manhattan Project (to develop an atomic bomb) was set up in 1942, Oppenheimer was asked to become director of the Los Alamos laboratories where much of the work was done. Having carried out this role with great skill, leading to the rapid development of the bomb, he attempted to remain a Government adviser on nuclear weapons, but was forced to resign in 1953. He became director of the Institute for Advanced Study at Princeton in 1947 and remained there after his retirement in 1966.

Oppenheimer’s early success in research began in 1930 when he analysed relativistic quantum mechanics and theory of the electron (1928). He showed that a positively charged anti-particle with the same mass as the electron should exist, and this positron was first seen by in 1932. During the 1930s Oppenheimer built up a formidable team of young theoretical physicists around him, the first time that the subject had been studied intensely outside Europe. In 1939, working on stellar structure, he showed that any massive star, when its thermonuclear energy is exhausted, will collapse to form a black hole, which has mass but from which light cannot escape.

After 1942 as director of Los Alamos he concentrated on gathering scientists and generating an atmosphere of urgency, skilfully handling the interface between his military superior, General Groves, and the unorthodox research scientists under him.

Oppenheimer’s wife and brother were left-wing sympathizers and possibly communists, and he ran into difficulties in 1943 when Groves demanded the name of a communist agent who had approached Oppenheimer; after much delay he finally gave it. The first atomic test explosion took place in July 1945, and two atomic bombs ended the war with Japan a month later.

After the war Oppenheimer initially continued his important role in atomic energy, but he opposed the development of the hydrogen (fusion) bomb. In 1953 his political background and his support for the Super Program (the hydrogen bomb project) were questioned, and President Eisenhower removed his security clearance, ending his Government service. However, the Fermi Award was conferred on him by President Johnson in 1963, implying that doubts about his integrity had been resolved.

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