A question of reality (Vol. 51, No. 5)

Spooky action at a distance: Bell’s Theorem in sketch form (Figure 12 in the paper). Credit: Reinhold Bertlmann (1988). Original presented to Bell on the occasion of his 60th birthday by R. Bertlmann

John Stewart Bell’s eponymous theorem and inequalities set out, mathematically, the contrast between quantum mechanical theories and local realism. They are used in quantum information, which has evolving applications in security, cryptography and quantum computing.

The distinguished quantum physicist John Stewart Bell (1928-1990) is best known for the eponymous theorem that proved current understanding of quantum mechanics to be incompatible with local hidden variable theories. Thirty years after his death, his long-standing collaborator Reinhold Bertlmann of the University of Vienna, Austria, has reviewed his thinking in a paper for EPJ H, ‘Real or Not Real: That is the question’. In this historical and personal account, Bertlmann aims to introduce his readers to Bell’s concepts of reality and contrast them with some of his own ideas of virtuality.

R. Bertlmann, Real or Not Real: that is the question, Eur. Phys. J. H 45, 205–236 (2020)