PFUSRC-113 The Origin of Temperature — Flow-Variable Activity Density and the Hot-Cold Markers of Topological Structure

Temperature ranks among the most fundamental yet profoundly misinterpreted physical concepts. Mainstream statistical physics defines temperature as the average kinetic energy of molecular thermal motion; this phenomenological definition suffices to describe thermal macroscopic behaviors but fails to answer core ontological questions: the fundamental origin of temperature, the inherent existence of upper and lower temperature limits, and the structural logic behind differentiated temperature distributions across cosmic objects. Built upon the axiomatic system of PFUSRC’s 11-dimensional triple coaxial 45° bicone topology, this paper puts forward an ontological redefinition: temperature is a measurable marker reflecting the local activity density of four-dimensional flow variables projected onto the 3D observable spacetime layer, rather than an independent fundamental physical quantity. It serves as a perceptual hot-cold signal generated during the self-sustaining circulation of the topological Mother Universe at specific spatial positions and evolutionary stages. Two core topological states of flow variables determine thermal manifestations: the expansive Flowing State corresponds to high temperature, while the compressed convergent Latent State corresponds to low temperature. The fixed temperature gradient of the bicone forms an intrinsic geometric necessity: the upper expansion cone maintains high-temperature zones, the central waist ring acts as a temperature transition equilibrium surface, and the lower convergence cone forms low-temperature regions approaching absolute zero. The upper and lower bounds of temperature are strictly bounded by topological structural limits: absolute zero corresponds to fully flattened flow variables (the unreachable Bitter-Cold Frontier), while Planck temperature marks the critical activity density threshold triggering topological phase transition of the bicone skeleton. Macroscopic celestial bodies such as stars are cross-scale projections of the bicone structure, inherently presenting a “hot outer surface, low-temperature hollow core” temperature distribution, consistent with helioseismic observational evidence. Volcanic crater cooling phenomena directly verify the expansion-latching thermal cycle of the upper cone. The bicone topology carries adaptive self-regulation of temperature gradients to maintain steady-state circulation; stable thermal gradients are the vital sign of a self-sustaining living topological system. This paper concludes that temperature is not an intrinsic state of matter, but a structural marker of cosmic topology. All temperature measurements essentially sample the flow-variable activity state by anchoring the observer’s coordinate within the high-dimensional bicone manifold.