The Century-Long Pause in Fundamental Physics

The debate is painted as one of physics's deepest unresolved puzzles. After 95 years the field cannot resolve which interpretation is correct, and there is no possibility of empirical resolution because all interpretations make the same predictions. The puzzle is much smaller once you separate two questions about it: a mathematical model reproduces measurements, while a physical theory says what in the world makes them come out that way. If QM were a physical theory, the persistence of the disagreement would be intolerable. If QM is a mathematical model (a probability calculus on a wave-mechanical system), the situation is unremarkable. Einstein's "God does not play dice" was a complaint of exactly this shape: not that the calculus failed, but that a probability calculus was being treated as physical theory when it described measurements rather than what was being measured. The persistence of the disagreement is itself evidence of which kind of object QM is in the field's working posture.

The two postures look identical when both reproduce the same data. They diverge when you ask what changes if the data is reproduced equally well by an alternative formalism. For a mathematical model, nothing changes; pick whichever is computationally easier. For a physical theory, that is a serious problem requiring resolution, because two different ontologies cannot both be how the world actually is.

The interpretations problem is the visible symptom of a broader pattern. Since 1928, fundamental physics has confirmed a large catalogue of particles and interactions, but the underlying ontology has not changed: spacetime as fixed by general relativity (1915), and relativistic matter as a wave-like spinor field on that spacetime fixed by the Dirac equation (1928). Everything since (QED, the Standard Model, GUTs, SUSY, string theory, LQG, twistor theory, SMEFT) added gauge fields, scalar fields, and other content inside that ontology. No widely accepted, empirically confirmed new ontology has displaced it in the intervening century. Later confirmations, including the Higgs and CKM mixing, added structure inside the inherited ontology rather than replacing it. The question is whether today's impasses (the QM-GR junction, the gauge group, the generation count, the hypercharges, the measurement problem, the cosmological constant) share a cause: physics learned to extend successful calculational formalisms faster than it learned to renew their ontology.