Proof Engine Verification (PARTIALLY VERIFIED): The adult human brain has approximately 86 billion neurons and an average of 7,000 synapses per neuron, resulting in a total synaptic count exceeding 6 × 10^14.

Automated fact-verification of the claim: "The adult human brain has approximately 86 billion neurons and an average of 7,000 synapses per neuron, resulting in a total synaptic count exceeding 6 × 10^14." Verdict: PARTIALLY VERIFIED Key Findings SC1 PROVED: The adult human brain contains approximately 86 billion neurons, confirmed by two independent verified sources: Herculano-Houzel 2009 (peer-reviewed, PMC) and UCLA Brain Research Institute (B1, B2). SC2 NOT SUPPORTED (as stated): The 7,000 synapses/neuron figure comes from research specifically on neocortical neurons (~20 billion of the 86 billion total). The primary source (BioNumbers/Drachman 2005, B3) explicitly states "20 billion neocortical neurons, with an average of 7,000 synaptic connections each" — not all neurons brain-wide. SC3 ARITHMETIC IS CORRECT, BUT PREMISES ARE INVALID: 86 × 10⁹ × 7,000 = 6.02 × 10¹⁴ > 6 × 10¹⁴ (true arithmetically). However, because SC2 does not apply to all 86 billion neurons, the product is not a valid estimate of the brain-wide total. PRIMARY LITERATURE GIVES ~1–3 × 10¹⁴ TOTAL SYNAPSES: UCLA BRI cites ~100 trillion (1 × 10¹⁴); Pakkenberg et al. 2003 reports ~1.5 × 10¹⁴ for the neocortex alone. No primary peer-reviewed source was found supporting 6 × 10¹⁴ as a whole-brain figure. Files proof.py — Re-runnable Python verification script proof.md — Structured proof report proof_audit.md — Full verification audit trail proof_narrative.md — Plain-language summary proof.json — Machine-readable structured data Generated by Proof Engine v0.10.0.