The Consciousness Index (CI): A Physically Grounded Scalar Measure of Conscious Degree, Structure, and Evolutionary Potential

BFUT Paper 20 established the Hierarchical Channel Accessibility framework connecting the Spaticle field physics of the BFUT programme to sensing, consciousness, and evolution, and introduced the Consciousness Index (CI) as a natural scalar measure implied by that framework. The present paper, BFUT Paper 21, provides the full derivation, calibration, and validation of CI across a dataset of 100 species spanning the complete range of known biological and physical complexity. The CI framework is structured around two distinct but related measures. The Intrinsic Consciousness Index (CI0) measures the internal capability of a system: the degree to which it can perceive, integrate, and act on information about itself and its environment, independent of external conditions. The Effective Consciousness Index (CI) is defined as CI0 multiplied by the survival factor S, which represents the real-world viability of the system: how effectively the system sustains its consciousness in actual conditions. This two-level structure separates what a system can do from how well it sustains what it can do. The CI0 formula is: CI0 = CIfloor + C x Omega (V) x (1 + 0. 38A) x N¹. 3 x K¹. 2. CIfloor is a strictly positive constant enforcing the principle from Vijay's Law (Layer 2) that no physical system has zero consciousness. C is a derived scale constant calibrated so that the modern average human nervous system produces CI0 = 100. Omega (V) is an asymmetric size-dependent integration efficiency function that penalises excessive brain volume above the biological optimum without penalising small or efficient systems. A is the channel capacity, the average of five independently scored interaction channels. N is the network integration density, a weighted composite of structural connectivity, dynamic coordination, and hierarchical processing depth. K is the control depth, a weighted composite of autonomy, memory depth, and adaptive flexibility. The calibrated dataset of 100 species spans from the human nervous system (CI0 = 100) through non-human animals (CI0 range approximately 14 to 124), insect colonies (CI0 range approximately 23 to 35), plants and fungi (CI0 range approximately 12 to 37), down to bacteria (CI0 = 30), viruses (CI0 = 18), and the floor systems including single cells and simple invertebrates (CI0 range 5 to 14). The survival factor S reduces effective CI for vulnerable and non-autonomous systems, with virus CI falling to approximately 2. 8 and octopus CI falling to approximately 59 despite a high CI0 of 96. The paper states five falsifiable predictions from the framework and connects CI explicitly to the physical foundations in Papers 17 and 20 and to the six-layer framework of Vijay's Law. Part of the Big Flare-Up Theory (BFUT) research programme.