Kamil Furman
Jagiellonian University
Relational Quantum Mechanics (RQM) is an interpretation of quantum theory developed recently by Carlo Rovelli (Rovelli 1996, 2018, 2022). Compared to other interpretations, it does not change the formalism of the theory or introduce ad hoc rules, but tries to change the ontology by reinterpreting the concepts that make up the quantum formalism. According to RQM, variables do not have their values in an absolute way, but only relative to another system. Variables take on values when two systems interact. RQM is intended to be an answer to a number of conceptual problems in quantum mechanics, with the measurement problem at the forefront.
Several objections can be raised against this interpretation, for example the vagueness of the concepts it uses or a questionable solution to the measurement problem provided by RQM. I would like to argue that RQM leads to undesirable consequences regarding the temporal persistence of objects, resulting in the ontology of many-worlds. The fact that a quantity pertaining to the system can have two different values relative to two other systems is in tension with the basic intuitions according to which given values at a given moment can have an influence (e.g. causal) on future events. Attempts to reconcile these basic intuitions with the picture emerging from the RQM lead to a many-worlds interpretation. This is problematic for Rovelli, as he himself has criticized such solutions and believes that his interpretation has no such flavour. I also want to suggest that, in general, any interpretation based on Everett’s notion of the relative quantum state leads to some version of multiverse.
Rovelli, C. (1996), “Relational Quantum Mechanics”, [in:] International Journal of Theoretical Physics 35.
— (2018), “The Sky is Blue…”, [in:] ‘’Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376.
— (2022), ‘’The Relational Interpretation”, [in:] ‘’The Oxford Handbook of the History of Quantum Interpretations’’.
Chair: Niklas Parwez
Time: September 11th, 14:10 – 14:40
Location: SR 1.004
SOPhiA 2026 