Summary
Relational Quantum Mechanics (RQM), proposed by Carlo Rovelli in 1994, interprets the quantum state not as an absolute reality, but as a relation between physical systems. It solves the measurement problem by stating that physical quantities only have values relative to a specific observer (another physical system), eliminating the need for a privileged observer or observer-independent state. [1, 2, 3]
Core Principles of RQM
- Relational Reality: Properties of a system (S) are only meaningful in relation to another system (O) with which (S) interacts.
- No Absolute Observer: All physical systems are equivalent, meaning there is no special, objective, or “conscious” observer needed to collapse a wavefunction.
- Information-Theoretic Basis: RQM focuses on the information systems have about each other. A “fact” is generated when two systems interact, updating the state in relation to each other.
- Sparse Event Ontology: Quantum events (or “facts”) happen only during interactions, not at all times.
- Relative Facts: Different observers can give different accounts of the same set of events, yet both are accurate, similar to how Einstein’s relativity makes velocity relative to a frame of reference. [1, 2, 3, 4, 5]
Key Implications
- Solving the Measurement Problem: Because the quantum state is relative, the “collapse” of a wavefunction is not an objective event occurring for everyone simultaneously, but a change in information regarding a system’s interaction with another, making it specific to that interaction.
- Against Strong Realism: RQM rejects the idea that a physical system has a set of objective, observer-independent properties at all times.
- Connection to General Relativity: RQM suggests that quantum relationalism parallels the relational nature of spacetime in general relativity, where locations are defined only relative to other physical entities. [1, 2, 3, 4, 5]
Rovelli’s approach has been linked to the many-worlds interpretation in terms of acknowledging multiple perspectives but focuses on the information interaction rather than the split of worlds. [1, 2, 3]
Connects a ton to some realizations I had, tho I dont understand the “against strong realism” point yet (and whether it’s real or hallucinated) , need to dig deeper.
Ah lol, chapter-06 also goes into it.
the human essence is the ensemble of social relations.
refuses to reify things as static building blocks sitting behind the relations.