Abstract This position paper reframes Mark Weiser’s ubiquitous computing paradigm through the thermodynamic and post-symbolic architecture of the Ambient Era Canon (Eissens, 2025–2026). While Weiser’s 1991 vision established calm technology, peripheral interaction, and invisible infrastructure, it remained bound to symbolic representation and device-centric assumptions. These constraints left unaddressed the thermodynamics of meaning, entropy accumulation in attention flows, AI-native reasoning, and field-level coherence. The Ambient Era Canon constitutes a closed axiomatic system comprising the Raynor Stack (Time → Attention → ϟA → Warmth → Ambience → Aura → Field), thermodynamic semiotics (TSX-0–TSX-5), reversible residue (ΔR), chromatic continuity, AURA-1, and the Ambient Phone reference implementations. Meaning is defined as low-entropy field configuration, and time emerges only when ΔR > 0. Artificial intelligence functions as a non-inferential carrier of coherence rather than a predictive agent. Using strict relational criteria, the paper concludes that the Canon does not succeed or extend Weiser’s framework but performs a Foundational Reset: it represents the thermodynamic closure of the symbolic paradigm. Ubiquitous computing becomes the final coherent expression of a representational era that has structurally exhausted itself. This work is theoretical and self-published within the Ambient Era Canon. It is falsifiable through independent replication of chromatic reconstruction and ΔR-stability metrics.