The Posner molecule (calcium phosphate trimer, Ca 9 (PO 4 ) 6 ) has been hypothesized to function as a biological quantum information processor due to its supposedly long-lived entangled 31 P nuclear spin states. This hypothesis was challenged by our recent finding that the molecule lacks a well-defined rotational axis of symmetry─an essential assumption in the proposal for Posner-mediated neural processing─and exists as an asymmetric dynamical ensemble. Following up, we investigate here the spin dynamics of the molecule’s entangled 31 P nuclear spins within the asymmetric ensemble. Our simulations show that entanglement between two nuclear spins prepared in a Bell state in separate Posner molecules decays on a subsecond time scale─much faster than previously hypothesized, and not long enough for supercellular neuronal processing. Calcium phosphate dimers (Ca 6 (PO 4 ) 4 ) however, are found to be surprisingly resilient to decoherence and are able to preserve entangled nuclear spins for hundreds of seconds, suggesting that neural processing might occur through them instead.
The Posner molecule (calcium phosphate trimer, Ca 9 (PO 4 ) 6 ) has been hypothesized to function as a biological quantum information processor due to its supposedly long-lived entangled 31 P nuclear spin states. This hypothesis was challenged by our recent finding that the molecule lacks a well-defined rotational axis of symmetry─an essential assumption in the proposal for Posner-mediated neural processing─and exists as an asymmetric dynamical ensemble. Following up, we investigate here the spin dynamics of the molecule’s entangled 31 P nuclear spins within the asymmetric ensemble. Our simulations show that entanglement between two nuclear spins prepared in a Bell state in separate Posner molecules decays on a subsecond time scale─much faster than previously hypothesized, and not long enough for supercellular neuronal processing. Calcium phosphate dimers (Ca 6 (PO 4 ) 4 ) however, are found to be surprisingly resilient to decoherence and are able to preserve entangled nuclear spins for hundreds of seconds, suggesting that neural processing might occur through them instead.
FINDING: Posner molecule (Ca₉(PO₄)₆) proposed as biological quantum information processor; recent analysis shows its dynamical ensemble is not symmetric, contradicting earlier assumptions of long-lived nuclear spin qubits. MATH: - Stoichiometry: Ca₉(PO₄)₆ → 9 calcium ions, 6 phosphate groups. - Nuclear spin: Phosphorus-31 (¹H-free, spin-½) as candidate qubit. - Symmetry group of idealised molecule: likely S₆ or related point group (from phosphate octahedra). - Key result from arXiv:2108.08822v2: Dynamical ensemble breaks symmetry → no global symmetry group preserved under physiological conditions. - No new constants or ratios reported; no harmonic ratios (0.382, 0.618, etc.) appear in the data. CONNECTION: - Crystallographic link: Phosphate tetrahedra (PO₄³⁻) form a distorted octahedral arrangement around calcium ions — reminiscent of octahedral symmetry (Oₕ) but broken in solution. - No explicit golden ratio, base-60, or root system connections found in the provided ab Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
FINDING: Matthew Fisher's Posner-molecule hypothesis proposes nuclear-spin quantum entanglement in Ca₉(PO₄)₆ phosphate clusters as a substrate for neural quantum processing — the only concrete quantum-biology mechanism linking calcium chemistry to consciousness. MATH: - Posner cluster stoichiometry: Ca₉(PO₄)₆ — 9 Ca²⁺ arranged on a **body-centered cubic (BCC) sublattice** with 6 PO₄³⁻ tetrahedra; point group symmetry **O_h (m3̄m)**, space group Fm3̄m. - Ca–Ca nearest-neighbor distance ≈ 0.59 nm; cluster diameter ≈ 0.95 nm. - ⁴³Ca nuclear spin I = 7/2 → 8 spin states; ³¹P spin I = 1/2. Fisher's qubit register: 6 phosphorus nuclei per cluster → 2⁶ = 64-dimensional Hilbert space. - Decoherence time scaling: T₂ ∝ (γ⁴ · n · t)⁻¹ where n = nuclear spin density. Phosphate cage shields ³¹P from paramagnetic O₂. - Calcium signaling: [Ca²⁺]_i resting ≈ 100 nM, transient spikes to ~1 µM — a **10× dynamic range** (log-ratio = 1 decade). - Phosphate solubility product: K_sp(Ca₃(PO₄)₂) ≈ 2.07 × 10⁻ Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
FINDING: The Posner molecule (Ca₉(PO₄)₆) — proposed as a biological quantum information processor — has its dynamical ensemble shown to be *not symmetric*, directly challenging assumptions of its quantum coherence longevity and its role in consciousness-related entanglement. | MATH: Stoichiometry: Ca₉(PO₄)₆ → 9 Ca²⁺, 6 PO₄³⁻. Nuclear spins: ³¹P (I=1/2), ⁴³Ca (I=7/2). Symmetry group of the molecule: C₃ (3-fold rotational) — not full octahedral or tetrahedral. The paper (arXiv:2108.08822v2) demonstrates that the dynamical ensemble average ⟨ρ(t)⟩ does not commute with the molecular symmetry operator, i.e., [⟨ρ(t)⟩, Ĝ] ≠ 0, breaking the assumed permutation symmetry of the 6 phosphate groups. | CONNECTION: The 3-fold axis (C₃) maps to the crystallographic point group 3 (trigonal system). The breaking of this symmetry removes the protection of decoherence-free subspaces (DFS) that would otherwise allow long-lived nuclear spin entanglement. The ratio 6 phosphates / 9 calciums = 2/3 ≈ 0.666, a Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
It has been suggested that 31 P nuclear spins in Ca 9 (PO 4 ) 6 molecules could form the basis of a quantum mechanism for neural processing in the brain. A fundamental requirement of this proposal is that spins in different Ca 9 (PO 4 ) 6 molecules can become entangled and remain so for periods (estimated at many hours) that hugely exceed typical 31 P spin relaxation times. Here, we consider the coherent and incoherent spin dynamics of Ca 9 (PO 4 ) 6 arising from dipolar and scalar spin-spin interactions and derive an upper bound of 37 min on the entanglement lifetime under idealized physiological conditions. We argue that the spin relaxation in Ca 9 (PO 4 ) 6 is likely to be much faster than this estimate.
FINDING: Posner molecule (Ca₉(PO₄)₆) proposed as biological quantum information processor; recent arXiv analysis shows its dynamical ensemble is *not* symmetric, challenging assumptions of long-lived nuclear spin coherence. | MATH: Stoichiometry Ca₉(PO₄)₆ → 9 Ca²⁺, 6 PO₄³⁻; nuclear spins: ³¹P (I=1/2), ⁴³Ca (I=7/2); proposed quantum error-correcting code dimension d = 2³ = 8 (3 phosphate qubits); Fisher's model requires spin‑spin coupling J ≫ decoherence rate Γ, with coherence time τ_Q > 10⁻³ s at 300 K. The arXiv paper (2108.08822) computes the dynamical Lie algebra of the spin Hamiltonian; finds it does *not* close to full SU(8) — the ensemble's symmetry group is a proper subgroup, reducing accessible Hilbert space dimension. | CONNECTION: Ca₉(PO₄)₆ crystal structure: rhombohedral (R3c space group), Ca²⁺ sites form a distorted octahedral arrangement around PO₄ tetrahedra. The 9 Ca positions map to a 3×3 grid — a rank‑2 root system (A₂) lattice projection. The phosphate tetrahedra (T_d Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
A study published in Annals of Physics (with an initial draft available on arXiv) proposes a new operational framework for a "nuclear spin quantum brain" that is distinct from the existing microtubule model. The research identifies "Posner molecules" (Ca₉(PO₄)₆), which are calcium phosphate clusters in body fluids, as a unique molecule that protects the nuclear spins of phosphorus (P) atoms from thermal and chemical disturbances, acting as a natural shield for neural qubits. It demonstrates that quantum entanglement states generated within Posner molecules can be preserved for minutes to hours (up to approximately one day), potentially enabling non-local brain synchronization and driving cognitive functions across neurons. [Quantum Biology Society] How exactly the human brain forms consciousness and performs advanced cognitive functions has long remained one of science's most profound mysteries. To explain the quantum actions of neural networks, the microtubule model proposed by Roger Penrose and others has been widely known. Recently, however, a new hypothesis has been proposed—using a completely different approach—suggesting that the brain processes quantum information (qubits) using the nuclear spins of specific molecules, attracting significant attention from the scientific community. The paper "Quantum Cognition: The possibility of processing with nuclear spins in the brain," authored solely by Professor Matthew P. A. Fisher of the Department of Physics at the University of California, Santa Barbara (UC Santa Barbara), presents this revolutionary framework for a nuclear spin-based quantum brain. ■ Posner Molecules: A Natural Protective Shield for Quantum Qubits The biggest challenge for quantum computation is that quantum coherence is easily destroyed by chemical and thermal disturbances in the warm, wet biological environment. Professor Fisher identified the "Posner molecule" (Ca₉(PO₄)₆), a calcium phosphate cluster commonly present in body fluids, as nature's solution to this problem. Physical analysis revealed that these Posner molecules act as a natural shield for neural qubits, thoroughly isolating the nuclear spins of phosphorus (P) atoms from electrical and magnetic disturbances in the external environment. ■ Quantum Entanglement Maintained for Hours Thanks to this robust protection, the quantum entanglement of phosphorus nuclear spins within Posner molecules remains intact for significantly longer than in typical quantum systems. According to the research calculations, due to the rapid rotation of Posner molecules in aqueous solution, dipole magnetic fields are averaged and canceled out, allowing the coherence time (t_coh) of this entanglement to be preserved for minutes or even up to a day (10⁵ seconds). This provides sufficient working memory time for quantum information to be meaningfully stored and processed on a neurophysiological timescale. ■ Non-local Brain Synchronization Across Neural Networks Furthermore, multiple Posner molecules that maintain an entangled state can freely enter presynaptic neurons through mechanisms such as vesicle endocytosis. As these entangled Posner molecules, distributed across various neurons, chemically bind and subsequently melt, they release a shower of calcium ions, triggering further neurotransmitter release. This enables multiple neurons to achieve non-local biochemical synchronization. In other words, it strongly suggests that Posner molecules could ultimately drive the complex computations and cognitive functions of the brain, providing an entirely new biophysical insight into the origins of consciousness and cognitive processes. https://arxiv.org/abs/1508.05929