The Rovelli relational interpretation of quantum mechanics is based on the assumption that the notion of observer-independent state of a physical system is to be rejected. In RQM the primary target of the theory is the analysis of the whole network of relations that may be established among quantum subsystems, and the shift to a relational perspective is supposed to address in a satisfactory way the general problem of the interpretation of quantum mechanics. Here I discuss two basic issues, that (...) I take to be serious open problems of the interpretation. First, I wish to show—mainly through an analysis of the so-called third person problem—that it is far from clear what a relativization of states to observers exactly achieves and in what sense such an approach really advances our understanding of the peculiar features of quantum phenomena. Second, I argue that the claim, according to which RQM is able to preserve locality, is at best dubious. I conclude that further work needs to be done before RQM may aspire to become a satisfactory interpretational framework for the main foundational issues in quantum mechanics. (shrink)

Counterfactual definiteness is supposed to underlie the Bell theorem. An old controversy exists among those who reject the theorem implications by rejecting counterfactual definiteness and those who claim that, since it is a direct consequence of locality, it cannot be independently rejected. We propose a different approach for solving this contentious issue by realizing that counterfactual definiteness is an unnecessary and inconsistent assumption. Counterfactual definiteness is not equivalent to realism or determinism neither it follows from locality. It merely reduces to (...) an incongruent application of counterfactual reasoning. Being incompatible with falsifiability, it constitutes an unjustified assumption that goes against the scientific method rigor. Correct formulations of the Bell theorem’s bases show it is absent either as a fundamental hypothesis or as a consequence of something else. Most importantly, we present a coherent Bell inequality derivation carefully devised to show explicitly and convincingly the absence of incompatible experiments or counterfactual reasoning. Thus, even admitting that counterfactual definiteness could be a consistent assumption, the necessary conclusion is that it is irrelevant for the inequality formulation and can be safely ignored when discussing Bell’s inequality philosophical and physical implications. (shrink)

According to Husserl, the epochè must be left incomplete. It is to be performed step by step, thus defining various layers of “reduction.” In phenomenology at least two such layers can be distinguished: the life-world reduction, and the transcendental reduction. Quantum physics was born from a particular variety of the life-world reduction: reduction to observables according to Heisenberg, and reduction to classical-like properties of experimental devices according to Bohr. But QBism has challenged this limited version of the phenomenological reduction advocated (...) by the Copenhagen interpretation. QBists claim that quantum states are “expectations about experiences of pointer readings,” rather than expectations about pointer positions. Their focus on lived experience, not just on macroscopic variables, is tantamount to performing the transcendental reduction instead of stopping at the relatively superficial layer of the life-world reduction. I will show that quantum physics indeed gives us several reasons to go the whole way down to the deepest variety of phenomenological reduction, may be even farther than the standard QBist view: not only reduction to experience, or to “pure consciousness,” but also reduction to the “living present.”. (shrink)

According to Husserl, the epochè (or suspension of judgment) must be left incomplete. It is to be performed step by step, thus defining various layers of “reduction.” In phenomenology at least two such layers can be distinguished: the life-world reduction, and the transcendental reduction. Quantum physics was born from a particular variety of the life-world reduction: reduction to observables according to Heisenberg, and reduction to classical-like properties of experimental devices according to Bohr. But QBism has challenged this limited version of (...) the phenomenological reduction advocated by the Copenhagen interpretation. QBists claim that quantum states are “expectations about experiences of pointer readings,” rather than expectations about pointer positions. Their focus on lived experience, not just on macroscopic variables, is tantamount to performing the transcendental reduction instead of stopping at the relatively superficial layer of the life-world reduction. I will show that quantum physics indeed gives us several reasons to go the whole way down to the deepest variety of phenomenological reduction, may be even farther than the standard QBist view: not only reduction to experience, or to “pure consciousness,” but also reduction to the “living present.”. (shrink)