Index Entry
Invisible:
“As a consequence of its uniquely unopposed diametric vertexing–ergo permitted-- diametric exit, only the tetrahedron among all the symmetric polyhedra can turn itself inside-out pulsatingly and can do so in eight different ways (see 624.00624 and in each instance, as it does so, one-half of its combined concave-convex unity ‘twoness’ is always inherently invisible.”
