BERTLMANN'S SOCKS AND THE NATURE OF REALITY [chapter]

J. S. Bell
2001 John S Bell on the Foundations of Quantum Mechanics  
R6sum6.-Les corr6lations dfEinstein, Podolsky et Rosen, sont assez semblables 5 beaucoup de ph6nomGnes banals de la vie quotidienne. I1 est donc un peu difficile pour le profane de comprendre au premier abord pourquoi un tel £lot de paroles a coul6 2 ce sujet. I1 faut rappeler que les grands th6oriciens de la m6canique quantique 6taient convaincus qu'il fallait abandonner l'id6e d'une r6alit6 objective sur le plan microphysique. Les corrglations en question, vues dans l'optique de l1hypothSse
more » ... causalit6 locale (absence d'action 5 distance), 6taient un argument de taille pour une telle r6alit6. Les physiciens quantiques ont d6velopp6 des contre-arguments (ni trSs clairs ni trGs convaincants 5 mon avis) et les opposants sont rest6s sur leurs positions. Depuis il a 6t6 possible de pousser l'analyse un peu plus loin, en considgrant surtout des situations voisines de celles envisag6es par Einstein, Podolsky et Rosen. On trouve des corr6lations qui ne sont pas du tout banales. Ce n'est plus ais6 de croire, avec Einstein, que les previsions de la mscanique quantique sont r6conciliables avec la causalit6 locale et la r6alit6 objective du monde microphysi.que. Abstract.-The Einstein-Podolsky-Rosen correlations are very like many ordinary occurrences of everyday life. So it is a little difficult for the man in the street to understand immediately why there has been so much fuss about them. It must be recalled that the founding fathers of quantum mechanics had convinced themselves that it was necessary to abandon the idea of an objective reality at the microphysical level. But the correlations in question, together with the idea of local causality, were a formidable argument for such a reality. The founding fathers offered counter-arguments (neither very clear nor very convincing in my opinion) and each side held to its position. Since then it has been possible to push the analysis a little further, considering especially situations just alittle different from those considered before. Then correlations appear, according to quantum mechanics, which are not at all like those of everyday life. As a result it is not now easy to believe, with Einstein, that quantum mechanical predictions are reconcilable with the notion of a Lorentz invariant objectively real microphysical world.
doi:10.1142/9789812386540_0015 fatcat:7oti3lgkmnh4rkvr7u6aeihq6m