Closure Theory (CT) Guide: An Orientation to the CT–ACORN Framework

General Relativity showed that gravity is geometry. Closure Theory (CT) begins from the same philosophical foundation but explores a more general possibility: that curvature itself possesses an intrinsic dual structure. This structure is not an initial postulate; it was discovered from an initial "thought experiment". Within the resulting framework, now referred to as "Closure Theory", mass, charge, fields and observable geometry are investigated as emergent consequences of a common dual-curvature architecture rather than independent primitive ingredients of nature. This guide provides an accessible introduction to the CT--ACORN framework developed throughout the Closure Theory research programme. Rather than presenting detailed derivations, it introduces the conceptual architecture of the theory, including: the dual curvature fibre, the "Intrinsic" (T), "dynamic-relativistic" (t)- and "Observable" (o) - Domain organisation, the Transformation (([TR])) and Projection (([PR])) operators, the ACORN formalism, the principal recoveries obtained within the programme, and the long-term objective of recovering gravitation, electromagnetism and relativistic dynamics from a common geometric foundation. The guide is intended as the recommended entry point for readers approaching Closure Theory for the first time before progressing to the more detailed technical papers and explanatory booklets. Among the central ideas presented is the proposal that dual curvature fibres generate unique observable geodesic patterns. If this programme proves successful, it would provide a common geometric language linking microscopic matter structure with macroscopic spacetime geometry. This document therefore serves as an orientation guide to the CT--ACORN framework and to the broader Closure Theory research programme. The aim of Closure Theory is not simply to describe nature with geometry, but to investigate whether nature itself is geometry. Curvature is not directly observed. Like electric and magnetic fields, it is inferred from its observable consequences. General Relativity teaches us that gravity is the manifestation of spacetime curvature. Closure Theory begins from this successful geometric viewpoint and asks a single further question: might curvature itself possess an intrinsic dual structure?