G. Tarozzi

Quantum Mechanics Reality and Separability

1

Experimental tests of the properties of the quantum-mechanical wave function

SummaryA new experimental proposal on the wave-particle dualism is discussed, unifying the two different classes of experiments recently advanced to detect the physical properties of quantum waves of producing interference or stimulated emission.

Is nondistributivity for microsystems empirically founded

SummarySome authors have proposed nondistributive logic as a way out of the difficulties usually met in trying to describe typical quantum phenomena (e.g. the double-slit experiment). We show, however, that, if one takes serously the wave-corpuscle dualism, which was after all the central fact around which quantum theory was developed, ordinary (distributive) logic can fully account for the empirical observations. We, furthermore, point out that there are unavoidable physical difficulties connected with the adoption of a nondistributive corpuscolar approach.RiassuntoAlcuni autori hanno proposto una «logica non distributiva» come soluzione delle difficoltà sollevate da certi fenomeni quantici, come l’esperimento della doppia fenditura. Si mostra invece che, se si prende seriamente il dualismo onda-corpuscolo, che fu dopo tutto il fatto centrale attorno al quale si sviluppò la teoria quantistica, la logica ordinaria può pienamente spiegare le osservazioni sperimentali. Inoltre si fa notare che vi sono ineliminabili difficoltà fisiche connesse con l’adozione di un approccio non distributivo corpuscolare.РезюмеНекоторые авторы предполагют недистрибутивную логику как способ для того, чтобы обоити трудности, обычно встречающиеся при попытке описания типичных квантовых явлений (например, эксперимент с двумя эелями). Однако, мы показываем, что если принять корпускулярно-волновой дуализм, который, в конце концов, является центрльным фактом, вокрут которого развивалась квантовая теория, то обычная (дистрибутувная) логика может полностью объяснить эмпирические наблюдения. Мы отмечаем, что имеются неизбежные физические трудности, связанные с выбором недистрибутивного корпусклярного подхода.

Nonlocal theories satisfying bell’s inequality

SummaryBell’s inequality is well known to be a necessary consequence of Einstein locality. We show, however, that the two best-knownnonlocal theories (Newtonian dynamics and the de Broglie-Bohm nonlocal hidden-variable model) always satisfy Bell’s inequality. The domain of validity of the latter is, therefore, much broader than hitherto believed and the only known theory capable of violating it is the quantummechanical treatment of correlated spins.RiassuntoCome è ben noto la diseguaglianza di Bell è una conseguenza necessaria della località di Einstein. Si mostra tuttavia che le due teorienon locali più note (la dinamica newtoniana ed il modello a variabili nascoste di de Broglie e Bohm) soddisfano sempre la diseguaglianza di Bell. II dominio di validità di quest’ultima è perciò molto più ampio di quanto si credesse finora e la sola teoria capace di violarla è la trattazione quantomeccanica degli spin correlati.

From Ghost to Real Waves: A Proposed Solution to the Wave-Particle Dilemma

The most controversial epistemological problem of the foundations of quantum mechanics arises in connection with the interpretation of the fundamental theoretical term of quantal formalism,i .e. the wave-function or state-vector ∣ ψ >, which is at the origin of the problem of the wave-particle duality.

Parthood and Composition in Quantum Mechanics

The paper deals with parts and wholes in quantum theory. It addresses a much neglected question, namely of what mereological theory are quantum systems a model of. It argues that they are at least a model of the so called Closed Extensional Mereology. It then goes on to address the question of whether quantum theory favors a particular answer to what is known as the special composition question, i.e. what are the sufficient and necessary conditions a set of entities has to meet in order to have a mereological sum. It is suggested that quantum mechanics by itself falls short to yield a definitive answer to that question and different possible suggestions are explored. One of them is that quantum theory, together with some mild assumptions, such as the one that maintains that there are no uninstantiatedproperties, delivers at least a sufficient condition for having a mereological sum. This condition turns out to be that the quantum system is in an entangled state.

Why quantum mechanics is incompatible with Einstein locality

Abstract Recently de Muynck and van Stekelenborg have challenged our proof of Bells theorem. We answer their criticism by showing that in our argument the reduction postulate is not needed and that the locality assumption plays instead an essential role.

Quantum measurements and macrophysical reality: Epistemological implications of a proposed paradox

After an outline of the macrorealistic solutions to the difficulties of the measurement theory, a new paradox is proposed and then discussed in the light of three different interpretations of quantum mechanics.

On the Different Forms of Quantum Acausality

Four empirical formulations of the causality principle, due respectively to Laplace, Kant, John S. Mill and Hume, are discussed in relation to the philosophy of quantum mechanics, showing how they are all violated by the basic principles of the Copenhagen interpretation, whereas they are perfectly compatible, with the only exception of Laplacean determinism, with a realistic reinterpretation of the present theory.

Probability and Determinism in Quantum Theory

At a variance with a popular opinion according to which the basic feature of modern physics would be reducible to its transition from classical determinism to quantum-mechanical indeterminism, I propose, rather, to put in evidence how the main peculiarity of quantum theory is constituted by an ambigous formal coexistence between a deterministic and a probabilistic description. In particular, I shall show that such an unsolved dualism can be considered an essential interpretative key to the main philosophical problems of this last theory.