Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [174]
With seventeen the minimum age for admission and his parents unable to finance his university studies, Bell looked for work and fortuitously found it as an assistant technician in the laboratory of the physics department at Queen's University. Before long, the two senior physicists recognised Bell's abilities and allowed him to attend the first-year lectures whenever his duties permitted. His enthusiasm and obvious talent were rewarded with a small scholarship, and this, together with the money he was able to set aside, meant that he returned after his year as a technician as a fully-fledged physics student. With the sacrifices that he and his parents had made, Bell was focused and driven. He proved to be an exceptional student and in 1948 obtained a degree in experimental physics. A year later he gained another in mathematical physics.
Bell admitted that he 'had a very bad conscience about having lived off my parents for so long, and thought I should get a job'.19 With his two degrees and glowing references, he went to England to work for the United Kingdom Atomic Energy Research Establishment. In 1954 Bell married a fellow physicist, Mary Ross. In 1960, having gained a PhD from Birmingham University, he and his wife moved to CERN, the Conseil Européen pour la Recherche Nucléaire, near Geneva, Switzerland. For a man who would make his name as a quantum theorist, Bell's job was designing particle accelerators. He was proud to call himself a quantum engineer.
Bell first came across von Neumann's proof in 1949, his last year as a student in Belfast, when he read Max Born's new book, Natural Philosophy of Cause and Chance. 'I was very impressed that somebody – von Neumann – had actually proved that you couldn't interpret quantum mechanics as some sort of statistical mechanics', he later recalled.20 But Bell did not read von Neumann's book as it was written in German and he did not know the language. Instead he accepted Born's word for the soundness of von Neumann's proof. According to Born, von Neumann had put quantum mechanics on an axiomatic basis by deriving it from a few postulates of a 'very plausible and general character', such that the 'formalism of quantum mechanics is uniquely determined by these axioms'.21 In particular, Born said, it meant that 'no concealed parameters can be introduced with the help of which the indeterministic description could be transformed into a deterministic one'.22 Implicitly, Born was arguing in favour of the Copenhagen interpretation, because 'if a future theory should be deterministic, it cannot be a modification of the present one but must be essentially different'.23 Born's message was that quantum mechanics is complete, therefore it cannot be modified.
It was 1955 before von Neumann's book was published in English, but by then Bell had read Bohm's papers on hidden variables. 'I saw that von Neumann must have been just wrong', he said later.24 Yet Pauli and Heisenberg branded Bohm's hidden variables alternative as 'metaphysical' and 'ideological'.25 The ready acceptance of von Neumann's impossibility proof proved only one thing to Bell, a 'lack of imagination'.26 Nevertheless, it had allowed Bohr and the advocates of the Copenhagen interpretation to consolidate their position even while some of them suspected that vonNeumann might be wrong. Even though he later dismissed Bohm's work, Pauli in his published lectures on wave mechanics wrote that 'no proof of the impossibility of extending [i.e. completing quantum theory by hidden variables] has been given'.27
For 25 years, hidden variable theories had been ruled impossible by the authority of von Neumann. However, if such a theory could be constructed