Quantum Mechanics in Terms of Realism

Leshang Pang, Dylan Bianchi

How are quantum mechanics and realism related? This paper will discuss whether or not the Copenhagen Interpretation of quantum mechanics and the doctrine of philosophical realism are compatible. To answer this question, this paper will first introduce quantum mechanics and the Copenhagen Interpretation in terms of the particle in the box experiment. Then, philosophical realism will be introduced and defined. Finally, the relationship between the Copenhagen Interpretation and philosophical realism will be evaluated. Several points of the Copenhagen Interpretation appear to contradict philosophical realism; thus, it can be concluded that the Copenhagen Interpretation is not compatible with philosophical realism.

G. C. Ghirardi

Hans Primas

Juha T. Saatsi

Matthias Egg (2021) argues that scientific realism can be reconciled with quantum mechanics and its foundational underdetermination by focusing realist commitments on 'effective' ontology. I argue in general terms that Egg's effective realism is ontologically overly promiscuous. I illustrate the issue in relation to both Newtonian mechanics and quantum mechanics.

Claudio Garola, Sandro Sozzo

Most physicists uphold that the tests of the Bell-Clauser, Horne, Shimony and Holt (BCHSH) inequalities confirm quantum mechanics (QM) and refute local realism. Some scholars, however, criticize this conviction, yet maintaining that QM conflicts with local realism. At variance with both viewpoints one of the authors has recently worked out an extended semantic realism (ESR) model which shows that, if quantum probabilities are interpreted as conditional rather than absolute probabilities, a picture of the microworld can be constructed that is simultaneously consistent with local realism and QM. We show here that the BCHSH inequalities must be replaced, within the ESR model, by more general inequalities. These depend on parameters (detection probabilities) which may be such that the inequalities are never violated by quantum expectation values. The condition that no violation occurs implies the existence of upper bounds on detection probabilities, which makes the ESR model falsifiable. These results admit an intuitive explanation in terms of unfair sampling but basically differ from the seemingly similar results obtained by other approaches in which the efficiency problem is discussed in order to vindicate some kind of local realism.

Stanley Gudder