The Relational Universe: Interaction and the Transition of the Possible to the Actual

We argue that quantum randomness is a logical necessity arising from the nature of intrinsically

relational properties—properties lacking definite states outside specific contexts of causal interaction.

This motivates Relational Actualism (RAQM), an ontological framework classifying physical properties

as invariant, classical, or intrinsically relational. RAQMgrounds wave function actualization in physical

interaction rather than observer-relative facts. The actualization criterion is physically grounded

and mathematically precise: an interaction constitutes an actualization event when it produces an

irreversible increase in the entanglement entropy of the system with its asymptotic environment,

generating a robust, redundant causal record. In weakly coupled QFT, a sufficient condition is the

exchange of a real, on-shell excitation (pμ pμ = m2c2). This criterion is basis-independent, nonperturbative,

and requires no new fundamental constants. To reconcile a globally consistent wave

function with special relativity, the Tomonaga-Schwinger equation establishes a foliation-independent

global update mechanism. We derive a consistency condition demonstrating that RAQM’s actualization

map preserves identical observable statistics at spacelike-separated points regardless of hypersurface

choice—a derived result, not a postulate—strictly forbidding superluminal signaling via algebraic

microcausality. The no-signaling result applies rigorously to the non-selective (outcome-averaged)

actualization map; conditioned branches are treated explicitly. Three specific, discriminating empirical

predictions are stated: a finite actualization propagation velocity bounded by the Lieb-Robinson

speed, an environment-dependent transition duration scaling as ℏ/ΔEenv, and a sharp reversibility

threshold at the actualization criterion. RAQM is distinguished from Relational Quantum Mechanics

(which relativizes facts), dynamical collapse models (which ground collapse in stochastic gravitational

thresholds rather than causal interaction), decoherence-only models (which leave the outcome problem

open), and Everettian Many-Worlds (which denies definite events). Classical behavior emerges

dynamically when continuous actualization events eliminate all unconstrained degrees of freedom.

The companion papers RAGC and RACI extend these results to gravity, cosmology, and biological

complexity; RAHC [Sandeman, 2026e] extends the framework further to the emergence of agentic

intelligence, formalizing the recursive coarse-graining hierarchy that generates successive levels

of causal closure from the microscopic DAG; key theorems in those papers have been formally

verified in Lean 4/Mathlib. A second Lean 4 file (RA_AQFT_Proofs_v10.lean) formalises the

finite-dimensional AQFT proof program and proves the frame-independence and Rindler stationarity

theorems; see the note on formal verification in the companion paper RAGC [Sandeman, 2026b].