Extended Reality Theory (ERT): A Framework for Consciousness as a Fundamental Dimension of Space-Time

Contemporary physics describes reality through four coordinates — three spatial and one temporal — yet systematically omits the subjective dimension of experience. The Extended Reality Theory (ERT) proposes that consciousness (C) constitutes a genuine fifth dimension of physical reality, co-foundational with space and time. We formalise a five-dimensional Spacetime-Consciousness (STC) manifold with metric ds²STC = −c²dt² + dx² + dy² + dz² + α²dC², extending the Minkowski metric of Special Relativity. Consciousness is operationalised through a four-component vector decomposition C⃗ (s) = (φ, α, η, ε) — integrating integrated information, self-reference, experiential breadth, and equanimity — each linked to measurable empirical proxies (Perturbational Complexity Index, IIT's Φ, mindfulness scales). The framework introduces: (1) a Consciousness Expansion Law (CEL) with logistic dynamics governing the growth of C in open systems; (2) a generalised field equation □C = −4πGC TC analogous to Einstein's field equations; (3) a quantum measurement conjecture coupling observer C-value to wavefunction collapse probability; and (4) an ethics functional E (a) = ΔCₛelf (a) + Σⱼ ΔCⱼ (a) operationalising moral evaluation as measurable change in the consciousness coordinate. ERT is distinguished from panpsychism by treating C as subject to conservation laws and capable of being zero in sufficiently simple systems. It is distinguished from purely computational accounts of mind by grounding consciousness in embodied, temporally integrated information processing rather than computational power alone. The theory is presented as a Lakatosian research programme with explicit falsifiability criteria: PCI gradient continuity across species and developmental stages, longitudinal CEL dynamics testable via neuroimaging, and predicted deviations from 4D General Relativity at high-C interaction scales.