Abstract In this article I elaborate on the approach to relational quantum mechanics suggested by Adlam and Rovelli (2023). I suggest that this approach fills an important gap in the spectrum of relational approaches, because it posits that the relational aspects of quantum mechanics are both inherent and dynamical. I compare this approach to Orthodox RQM, arguing that it has a number of advantages, and I show how some possible objections can be resolved.
Abstract In this article I elaborate on the approach to relational quantum mechanics suggested by Adlam and Rovelli (2023). I suggest that this approach fills an important gap in the spectrum of relational approaches, because it posits that the relational aspects of quantum mechanics are both inherent and dynamical. I compare this approach to Orthodox RQM, arguing that it has a number of advantages, and I show how some possible objections can be resolved.
Abstract The following paper explores the metaphysical significance of Relational Quantum Mechanics (RQM). For this, I will first outline Rovelli’s philosophical framework, and then offer a reconstruction of Rovelli’s seminal argument in favour of RQM. I will then explore some healthy lines of philosophical work that may be undertaken to strengthen RQM. First, I will frame RQM in the debate between realist and antirealist readings of QM and defend the general claim that RQM is compatible with realism. Then, I discuss the main ontological interpretations of RQM, which I classify as “dispositional”, “transcendental” and “structural”, and argue that all of them remain committed to substantialist assumptions that limit the radicality of Rovelli’s proposal. Finally, I analyse recent developments on RQM’s ontology and suggest that preserving its ontological originality requires an assessment on the concept of “pattern”.
Relational quantum mechanics (RQM) is an interesting alternative to the standard responses to the measurement problem in quantum mechanics. But it suffers from a distinctive kind of epistemic solipsism: an observer can’t in principle know anything beyond their immediate present experience. This makes RQM self-undermining: it takes away the evidence we have for believing in quantum mechanics in the first place. Recently, Adlam and Rovelli have proposed a solution to this problem in the form of a new postulate they call cross-perspective links. Here I argue that this postulate does indeed solve the skeptical problem, but it also removes those aspects of RQM that make it distinctively relational. Nevertheless, the result of equipping RQM with cross-perspective links is an interesting interpretation in its own right.
The relational interpretation of quantum mechanics (RQM), introduced in its present form by Carlo Rovelli in 1996, involves a number of significant departures from other QM interpretations widely discussed in the literature. We begin here by summarizing these unique RQM features, with a focus on those that suggest altered insights into the nature of the randomness exhibited in QM phenomena. One of these RQM features is the assumption that all objects in the universe are quantum objects, regardless of their material complexity. And, the interaction of any two objects can result in new relational quantum states of each of the objects with the other as reference. But such new states do not replace relational states corresponding to previous interactions with other reference objects. In particular, such earlier relational states that include a variable considered to be random do not collapse to define a determined value of the variable, but instead simply take on that specific value in the state relative to the new reference. The concept of randomness associated with quantum state variables in RQM thus differs from that in other QM interpretations. Rather than take the usual pedantic approach of elaborate side-by-side comparisons between the RQM and other common QM interpretations, we illustrate these differences by describing in some detail the well-known "dual-slit" experiment in terms of RQM concepts, pointing out the important advantages over other interpretations along the way. Of course, we suggest no change in dual-slit experiment results, but believe that the interpretative modifications are helpful and profound.
In a recent paper, Rovelli responds to our critical assessment of Relational Quantum Mechanics (RQM). His main argument is that our assessment lacks merit, because we fail to understand, or cope with, the premises of his theory; instead, he argues, we judge his proposal, blinded by the preconceptions inherent to ``our camp''. Here, we explicitly show that our assessment judges RQM on its own terms, together with the basic requirements of precision, clarity, logical soundness and empirical suitability. Under those circumstances, we prove false Rovelli's claim that RQM provides a satisfactory, realistic, non-solipsistic description of the world. Moreover, his reply serves us to further exhibit the serious problems of the RQM proposal, as well as the failures of its author to understanding the basic conceptual difficulties of quantum theory.
This paper discusses perspectivism and relationalism in the two versions of Relational Quantum Mechanics (RQM): that initiated by Rovelli ( Int. J. Theor. Phys. , 35 (8), 1637–1678 1996) and the other, by Adlam and Rovelli ( Philos. Phys. , 1 (1) 2023). To this end, we offer a substantial discussion of this interpretation. We investigate the issue of the disagreement of results between different observers; distinguish four senses of agreement: strong, weak, very weak, and perspectival; and argue that the old version guarantees only the very weak and perspectival agreement, whereas the new version guarantees the weak agreement as well. The problem that individuals in RQM need to be propertyless when they do not interact is also investigated. Concerning the issue of probabilities in RQM, we argue that to express probabilities involving events relative to different systems, a new kind of probability spaces needs to be devised. The final problem that we identify concerns underspecified dynamics; we argue that some additional postulates are indispensable to make RQM’s dynamics fully specified. The last two points lead to the conclusion that, contrary to declarations of RQM proponents, this interpretation requires some modifications of quantum formalism and not merely conceptual changes. Finally, concerning the problem of testimony, while the new version of RQM was devised to solve it, we argue that in the old version, this problem can be alleviated to the extent that perspectivism permits.
This article uses the existing literature on the panpsychist combination problem as a starting point to think about how to address a structurally similar combination problem in relational quantum mechanics. I note some similarities and differences between the two problems, and I consider various proposed solutions to the panpsychist problem, assessing the prospects for a similar solution in the context of RQM. I argue that overall the prospects for solving RQM's combination problem look better for RQM with cross-perspective links than for orthodox versions of RQM.