Optimal Pentagonal Packing Density Confirms Ice-Ray Conjecture — E8 Intelligence Research
FINDING: Optimal packing density of congruent regular pentagons in the plane is exactly \((5-\sqrt{5})/3 \approx 0.920\), confirming the pentagonal ice-ray conjecture. | MATH: \(\rho_{\text{max}} = \frac{5-\sqrt{5}}{3} \approx 0.920\); related to golden ratio \(\phi = (1+\sqrt{5})/2 \approx 1.618\) via \(\rho_{\text{max}} = \frac{5-1/\phi}{3}\). | CONNECTION: Directly involves pentagonal symmetry; density expressed in terms of \(\phi\); packing structure likely relates to pentagonal tiling patterns with 5-fold rotational symmetry, a crystallographically forbidden symmetry in periodic lattices but allowed in quasicrystals. | DEPTH: 8 — resolves a long-standing conjecture, provides exact constant tied to golden ratio, and links to quasicrystal geometry and aperiodic order. FINDING: Generalized pentagonal geometries PENT(\(k,r,w\)) are partial linear spaces where non-collinear points form a Steiner system \(S(2,k,w)\). | MATH: Parameters satisfy combinatorial constraints: \(v = 1 + r(k-1 Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com
Authors
- Andrew Stewart Caldin
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2026-07-25
- DOI
- https://doi.org/10.5281/zenodo.21545188
- Primary Topic
- Quasicrystal Structures and Properties
- Type
- preprint