No CrossRef data available.
Article contents
A Burning Question: Einstein's Paradox of Correlations
Published online by Cambridge University Press: 02 April 2024
Extract
In 1927 at the fifth Solvay Council, that reunited all the aristocracy of theoretical physics, Einstein, regarding with solicitude the new-born “quantum mechanics” of Louis de Broglie, Schrödinger, Heisenberg and Dirac, discerned with his usual sagacity an indelible mark that was destined to become, with time, a subject of passionate discussion among those whose vocation is to adulate this enigmatic and capricious personality.
In 1926 Born had given the prophetic stroke to the portrait. Turning to probability as to the official factotum of the reconciliation of the continuous and the discontinuous-here, the associated wave and particle-he transmuted the waves of de Broglie and Schr6dinger into an undulatory calculus o f probabilities, deducing, from a surprising principle, consequences that were even more surprising but always verified through experiment. Parting from the idea that the intensity of the wave is the probability of the detection of the particle at a given point and time, Born replaced the classic principle of addition of partial probabilities with his “principle of the addition of partial amplitudes” that are, as in classical optics, represented by “complex” dimensions, with one real part and one imaginary part. In general, the square of the module of the sum of amplitudes will be the probability. This expression contains, of course, the terms “square” and “rectangular.” The first, if they were alone, would give the former law; as for the second, they express the existence of phenomena of interference that are at the origin of the thousand and one well verified paradoxes of the “new mechanics “-the one thousand and first being the one under consideration here.
- Type
- Research Article
- Information
- Copyright
- Copyright © 1980 Fédération Internationale des Sociétés de Philosophie / International Federation of Philosophical Societies (FISP)
References
1 T.S. Kuhn, The Structure of Scientific Revolutions, Chicago, University of Chicago Press, 1962. P. Duhem, La Théorie physique, son objet, sa structure, Ri vière, 1906 and 1913, Part II, Ch. IV and VI. Duhem was a precursor of the theory of Kuhn's paradigms.
2 Einstein: Philosopher, Scientist, P.A. Schilpp, ed.; Evanston, Illinois, The Library of Living Philosophers, pp. 83 and 683.
3 The word "test" re-entered French through English, from Old French, where it had exactly the same meaning.
4 The most precise verifications of "direct" correlation between "future measurements" due to Friedman and Clauser (1972); Clauser (1976); and Fry and Thompson (1976) concern the linear polarizations of two photons issued from a "cascade." A striking verification of "inverse" correlation between "past preparations" due to Pflegor and Mandel (1967-1968) concerns the im possibility of "retrodicting" from which of the two lasers each photon detected in the zone of interference came.
5 A controversial point of history is to know whether or not in 1905 Einstein was acquainted with Michelson's experiment. The argumentation mentions in a general way the experiments in optical kinematics, the earliest of which was the one of Arago (1818) that inspired Fresnel with his formula of the "dragging along of the ether". In 1930 Hadamard demonstrated how to deduce the formulas of Lorentz-Poincaré from Fresnel's formula and from a postulate of the theory of groups.
6 P. Eberhard, Nuovo Cimento, 46B, 1978, p. 392.
7 These formulas were already known to Larmor in 1898 and also, almost exactly, to Voigt in 1887.
8 Specialists distinguish the T-reversal of Wigner from the T-symmetry of Rachah. We will not go into these fine points.
9 E.P. Wigner, Symmetries and Reflections, M.I.T. Press, 1967, pp. 171-184.
10 R. Descartes, Lettres, Adam-Tannery, ed., Vol. I, Letter 525, p. 222; and Vol. III, Letter 302, p. 663.
11 H. Schmidt, the physicist, is not to be confused with the West German Chancellor. See Found. Phys. 8, p. 464; Bull. Amer. Phys, Soc. 24, p. 38 (1978); Proc. Intern. Conf., "Cybernetics and Society," I.E.E.E., 1977, p. 535.
12 H. Bergson, L'Evolution créatrice, Ch. I.
13 Honni soit qui mal y pense! Out with the charlatans and muddled heads who only reason by "woolly" approximation! As for myself, it was by meditating on the implications of the internal symmetries of relativity, calculation of probabilities and quantum mechanics that I became convinced that there is some truth in what is called "parapsychology." It was only afterward that I investigated and was persuaded of the seriousness of some research…
14 E. Capra, The Tao of Physics, Shambala, Berkeley, 1957.
15 E.E. Witmer, Amer. Journ. Phys, 35, 40, 1967; A. Cochran, Found. Phys., I, p. 235, 1971.
16 B. d'Espagnat, A la recherche du réel, Gauthier Villars, 1979. See pp. 114-120.
17 Lord Kelvin, Phil. Mag., 2, 1, 1901.