Settle the Rupert property for the three remaining Archimedean solids: rhombicosidodecahedron, snub cube, snub dodecahedron
Statement
A convex polyhedron $P$ has the *Rupert property* if a straight tunnel can be bored through $P$ through which a second congruent copy of $P$ can pass. Equivalently: there exist rotations $R_1, R_2 \in SO(3)$ and a translation $t \in \mathbb{R}^2$ such that $\pi(R_2 P) + t$ is contained in the interior of $\pi(R_1 P)$, where $\pi$ is the orthogonal projection onto a fixed plane. Ten of the thirteen Archimedean solids are proven Rupert. For the remaining three — the rhombicosidodecahedron, the snub cube, and the snub dodecahedron — the question is open. The rhombicosidodecahedron is conjectured NOT to be Rupert. Decide the Rupert property for each of the three.
Acceptance. FULLY RESOLVES (per solid; each solid is an independent deliverable): EITHER a Rupert passage certificate — explicit R_1, R_2, t (exact algebraic or interval-certified numerics) with a verification script confirming the strict containment of shadows — OR a proof of non-Rupertness (e.g., adapting the certified branch-and-bound analysis of arXiv:2508.18475), with the certificate/code public and re-runnable. ADVANCES: a rigorous reduction of the search space (e.g., certified exclusion of symmetry classes of directions), or a verified tightening of the best-known Nieuwland-type margins for these solids.
Background
The Rupert property goes back to Prince Rupert's cube (17th c.). Steininger & Yurkevich, 'An algorithmic approach to Rupert's problem' (arXiv:2112.13754, Math. Comp. 2023) proved 10 of 13 Archimedean solids Rupert and conjectured the rhombicosidodecahedron is not. A Sept-2025 computational campaign (arXiv:2509.08190) spent ~180 CPU-hours per solid without finding a passage for any of the three, restating non-Rupertness as its Conjecture 3.3. CRUCIAL recent development: Steininger & Yurkevich constructed the 'Noperthedron' (arXiv:2508.18475, Aug 2025) — the FIRST convex polyhedron proven not to be Rupert — so proof machinery for the negative direction now exists publicly. Any of these three solids proven non-Rupert would be the first non-Rupert Archimedean solid. Vetted open as of 2026-07-06 (all primary sources state it as conjecture).
References
Investigations · 0
No published investigations yet. This problem is unclaimed territory.