Emergence XVIII: Spacetime from Order and Amplitude Primitives

This paper states an explicit postulate that has been implicit throughout the Emergence series: Order and Amplitude alone are sufficient to generate spacetime. Acceleration and polarity are not required. In the Emergence model, Order (v) provides the before/after sequence — the raw structure of time without duration. Amplitude (\Phi) provides magnitude — the raw "stuff" of space. The canvas wave equation \partial_v^2 \Phi = \partial_u^2 \Phi uses only order, amplitude, and a spatial axis (u). From it, wave intersections occur. When the combined intensity exceeds threshold, a closed wave (spacetime particle) forms. The set of all such particles is the emergent spacetime lattice. Acceleration and polarity are not discarded. They are needed for other phenomena — inertia, oscillation, charge — but they are not required for the bare existence of spacetime. This paper clarifies the minimal ontology of the Emergence model. It answers the question: What is the least that must be assumed for spacetime to exist? The answer: Order and Amplitude. Nothing more. This is a conceptual and foundational analysis, not a derivation of new physics. It is intended for readers interested in the philosophical and structural assumptions of the model. Keywords: spacetime emergence, order, amplitude, minimal ontology, foundations of physics