Collapse Models, Relativity, and Discrete Spacetime

Chretien Versteegh

General relativity and quantum mechanics rely on fundamentally incompatible conceptions of spacetime: the former treats spacetime as a smooth, dynamical entity, while the latter presupposes a fixed background on which quantum states evolve. This work introduces the Collapse Spacetime Model (CSM), a foundational framework in which spacetime itself is not fundamental but emerges from discrete ontological transition events (OTEs)—objective, irreversible acts of actualization that generate localized spacetime structure. Within CSM, quantum state reduction is reinterpreted as one particular manifestation of a more general ontological transition, rather than as an anomaly within unitary dynamics. A central refinement, the Multiplicity of Spacetime Hypothesis (MSH), proposes that physical systems construct their own partial spacetimes, with the classical spacetime continuum arising from stable intersections among these locally generated structures. Constants such as the speed of light are interpreted as invariant structural ratios of spacetime co-generation, rather than as fundamental properties of matter or signals. The model aligns conceptually with causal set theory, emergent network geometry, and collapse-based approaches, while offering a unified ontological account of spacetime emergence, time’s passage, and the relational origin of geometry. CSM reframes physical reality as a becoming universe, providing a coherent foundation for quantum gravity, cosmology, and the philosophy of time, while deliberately postponing detailed dynamical and mathematical formalization to future work.

Shan Gao

Jérôme Martin, Vincent Vennin

Daniel Bedingham

A picture of dynamical collapse of the wave function which is relativistic and time symmetric is presented. The part of the model which exhibits these features is the set of collapse outcomes. These play the role of matter distributed in space and time. It is argued that the dynamically collapsing quantum state, which is both foliation dependent and follows a time-asymmetric dynamics, is not fundamental: it represents a state of information about the past matter distribution for the purpose of estimating the future matter distribution. It is also argued from the point of view of collapse models that both special and general relativistic considerations point towards a discrete spacetime structure and that gravity may not need to be quantised to give a theory that is consistent with quantum matter.

Joshua Sandeman

Relational Actualism I introduces a discrete framework for fundamental physics in which spacetime is modeled as a finite causal graph evolving through irreversible event formation. Building on causal set theory, the framework defines a sequential growth process governed by the Benincasa–Dowker–Glaser (BDG) action and a local conservation law, the Local Ledger Condition. Unlike standard formulations of quantum theory and relativity, the theory treats actualization itself as primitive and does not assume a continuum spacetime, wavefunction, or collapse rule. The paper establishes the core kernel of the theory—its axioms, growth rule, acceptance criterion, and active support surface—and identifies open targets including quantum-statistical frequency laws, covariance closure, and macroscopic spacetime structure.