science & techThe Public Domain Review1900 · Germany

Max Brückner catalogued star-shaped polyhedra, and one shape later inspired an Escher print

the gist

A stellated polyhedron is made by extending the faces of a regular solid until they meet again, which creates spikes on each face. Max Brückner, a German geometer, documented a large collection of these stellated and uniform polyhedra in his 1900 book Polygons and Polyhedra. One shape in his collection is a compound of three octahedra, which are eight-faced solids, interlocked around a shared centre. M. C. Escher made that shape the subject of his 1948 print Stars, which shows it as a cage floating in space with two chameleons inside.

how it works

Extending the faces of a solid until they intersect again produces new points, so a shape with spikes emerges. Compound shapes are made when several identical solids share the same centre and interpenetrate.

so what

Brückner's catalogue is a key reference that shows how geometers explore shapes beyond everyday solids. Escher's use of the shape shows how pure mathematics can become visual art.

Image: The Public Domain Review