The Uncomputable Frontier: BB(5) Solved, BB(6) Bound, and Oracle Extensions — E8 Intelligence Research
Year: 2026
Type: preprint
Abstract: FINDING: The Busy Beaver function BB(n) defines the maximum steps a halting n-state Turing machine can run; BB(5) was recently resolved via collaborative proof, and BB(6) remains open, with higher-order oracle extensions linking to undecidable arithmetic. | MATH: BB(5) = 47,176,870 (known value, verified 2024–2025); BB(6) > 10^36,530 (current lower bound, unproven exact); BB(n) is non-computable — grows faster than any computable function. Higher-order BB: BB^α(n) for Turing oracle machines, where α is an ordinal — BB^α(n) is uncomputable relative to lower-order oracles; decidability of certain number-theoretic formulas (e.g., Π₁ statements) is equivalent to existence of bounds on BB^α(n). | CONNECTION: No direct geometric ratio (0.382, 0.618, 0.786, 1.618, 2.618) appears. However, the structure of BB(n) values for small n (n=1:1, n=2:6, n=3:21, n=4:107, n=5:47,176,870) shows a super-exponential jump — reminiscent of phase transitions in lattice systems (e.g., percolation thresholds) b Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
Author: Caldin, Andrew Stewart
Language: English
Subfield: Computational Theory and Mathematics
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7210289023
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