Cube of Space letters with six cardinal directions (up, down, east, west, north, south). The verse in chapter 5 associates 12 hebrew letters with either 12 diagonal directional 'arms' or 12 diagonal boundaries (different translations contradict each other), which some interpret as referring to the 12 edges of an octahedron, though Paul Foster Case interpreted these as the 12 edges of a cube. In the most authoritative English translation of the Sepher Yetzirah, scholar Aryeh Kaplan interprets this verse (Chapter 5, Verse 2) as describing a cube. (Sefer Yetzirah Page 203) While occult author Kevin Townley explains a cosmology with an octahedron within
Prince Rupert's cube for the largest square that lies within a unit cube. More generally, show how to find the largest rectangle of a given aspect ratio that lies within a unit cube. As they show, the optimal rectangle must always pass through the center of the cube, with its vertices on edges of the cube. Based on this, they show, depending on the desired aspect ratio, that the optimal rectangle must either lie on a plane that cuts diagonally through four corners of the cube, or it must be formed by an isosceles right triangle on one corner of the cube and