Tuesday, May 14, 2013

The Icosasphere

Marianne Moore (1887-1972) has fun with the sounds of words -- including a number of math terms -- in her playful poem that celebrates inventive constructions from bird nests to a steel sphere-like icosahedron to the Pyramids of Egypt.

The Icosasphere       by Marianne Moore

“In Buckinghamshire hedgerows
the birds nesting in the merged green density,
weave little bits of string and moths and feathers and
thistledown,
in parabolic concentric curves" and,
working for concavity, leave spherical feats of rare efficiency;
whereas through lack of integration,

avid for someone's fortune,
three were slain and ten committed perjury,
six died, two killed themselves, and two paid fines for

risks they'd run.
But then there is the icosasphere
in which at last we have steel-cutting at its summit of economy,
since twenty triangles conjoined, can wrap one

ball or double-rounded shell
with almost no waste, so geometrically
neat, it's an icosahedron.  Would the engineers making one,
or Mr. J. O. Jackson tell us
how the Egyptians could have set up seventy-eight-foot solid

granite vertically?
We should like to know how that was done.

I have found "The Icosasphere" in my copy of The Complete Poems of Marianne Moore (Macmillan, 1982).   Its opening lines quote Edward McKnight Kauffer, a graphic artist and friend of Moore. "The Icosasphere" was a featured example in my 2006 article, "Mathematics in Poetry, available in the Journal of Online Mathematics and Its Applications.  Links to others of my poetry-math articles are available at my website.
The twenty-triangle sphere-like icosahedron (Moore's "icosasphere") is one of five Platonic solids -- that is,  the five possible regular, convex polyhedra. The faces are congruent, regular polygons, with the same number of faces meeting at each vertex. There are exactly five solids that meet these criteria -- and each is named according to its number of faces.
Other postings of Moore's work in this blog are found on 21 March 2013, 9 September 2010,  and -- celebrating baseball -- on 9 April 2010 (back when this blog was nearly new).