Contested Microtubule Quantum Coherence: Decoherence Timescales Constrain Orch-OR Neural Computation — E8 Intelligence Research

FINDING: Microtubule quantum coherence experiments (Penrose-Hameroff Orch-OR framework) probe whether tubulin dimers sustain quantum superpositions long enough to influence neural computation — evidence remains contested, with decoherence timescales the central constraint. | MATH: Key quantities: tubulin dimer ~8 nm lattice spacing; microtubule = 13 protofilaments arranged in a helical B-lattice (13-start helix, ~3-start and ~5-start helical families). Decoherence time estimates: Tegmark (2000) τ_D ~ 10⁻¹³–10⁻²⁰ s (thermal decoherence, prohibitive); Hagan-Cusson-Hameroff (2002) revised to τ_D ~ 10⁻⁴–10⁻³ s via Debye screening and kink soliton shielding. Quantum beat frequency ω = ΔE/ℏ; coherence length λ ~ ℏ/√(2m k_B T). Fröhlich condensation: polar modes above threshold T_c obey Bose-Einstein-like occupation n(ω) ∝ 1/(e^(ℏω/k_BT) − 1) with metabolic pumping. | CONNECTION: The 13-protofilament microtubule is a crystallographic lattice with helical symmetry — 13-fold rotational + transl Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com