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 by the two opposite points, as in the case of Prince Rupert's problem. If the aspect ratio is not constrained, the rectangle with the largest area that fits within a cube is the one that has two opposite edges of the cube as two of its sides, and two face diagonals as the other two sides. Alternatively, one may ask for the largest formula_4-dimensional hypercube that may be drawn within an formula_5-dimensional unit hypercube. The answer is always an algebraic number. For instance, the problem for formula_6 asks for the largest cube within a four-dimensional hypercube. After Martin Gardner posed