Experimental test of local observer independence

Quantum mechanics has been interpreted by influential scientists as a theory assessing observer-dependent relational properties/reference frames (Smerlak and Rovelli 2007; Yang 2018). Relational formulations of quantum mechanics have been experimentally supported by recent papers that contradict the tenet of local realism: "the properties of the physical world are independent from the observer" (The BIG Bell Test Collaboration 2018; Proietti 2019).

Here a philosophical concept from our medioeval past comes into play. In the question 19 of the second quodlibet (ed. Ockham 1991), William of Ockham asks whether the propositon "hoc est corpus meum" ("this is my body") is literally true as uttered by the priest at mass. According to Ockham, to every spoken proposition corresponds some mental proposition. When the priest utters the first words: "hoc est...", the body of Christ does not exist yet in the Eucharist, because the words "hoc est" are not themselves determinate enough to fix the meaning intended by the speaker. Indeed, the priest's utterance in the middle of the phrase is true as mental proposition, but it is not yet true as spoken proposition, because the words "corpus meum" have not yet been pronounced.
A mental proposition is true at the beginning and at the end, because it exists as a whole all at once. This means that a mental proposition can be termed "ens permanens" (a permanent entity). In turn, a spoken proposition exists just successively and not all at once, so that it is true at the end but not at the beginning of the utterance. This means that a spoken proposition can be termed "ens successivum" (a successive entity).

Therefore, the proposition is true not at the beginning, rather at the end of the utterance. In terms of relational quantum mechanics, we may state that reality itself is different at the beginning and at the end of the utterance, or, in non-linguistic terms, reality itself is different at the beginning and at the end of the experimental procedures to detect quantum phenomena. To provide an example, at the beginning of the experiments that assess quantum entanglement, it is not certain whether the quantum state detected at the end will exist or not.

Therefore, quantum reality might stand for an ens successivum (successive entity) such that only a proper part of it exists at any given time. This means that the role of time, underrated and almost dispised in quantum mechanics, must be kept into account: a deep difference does exist in a quantum state before and after the intervention of the observer.
A further leap is required to proceed towards a novel approach to quantum mechanics: from relationism to interactionism.

1) Ockham W. 1991. Quodlibetal questions. Eds. Freddoso AJ, Kelley FE. Yale University Press, New Haven & London.

2) Proietti M, Pickston A,  Graffitti F, Barrow P, Kundys D, et al. 2019. Experimental test of local observer independence. Science Advances, Vol. 5, no. 9, eaaw9832, DOI: 10.1126/sciadv.aaw9832.

3) Smerlak, M.; Rovelli, C. Relational EPR. Found. Phys.2007, 37, 427–445.

4) The BIG Bell Test Collaboration. Challenging local realism with human choices. Nature. 2018, 557, 212–216.

5) Yang, J.M. A Relational Formulation of Quantum Mechanics. Sci. Rep.2018, 8, 13305.

Arturo Tozzi
M.D., Pediatrician, ASL Na2Nord, Italy

phD, Computational Intelligence Lab, University of Manitoba, Canada

Adjunct Assistant Professor in Physics, University of North Texas, USA

Tozziarturo@libero.it