Mark Scrivener Poetry Blog No 50 Shell on the Shelf

SHELL ON THE SHELF

The shell shows its remarkable geometry in its spiral- a shape which has been described as the spiral of growth. To quote from Wikipedia-

A logarithmic spiral, equiangular spiral or growth spiral is a self-similar spiral curve which often appears in nature. The logarithmic spiral was first described by Descartes and later extensively investigated by Jacob Bernoulli, who called it Spira mirabilis, "the marvellous spiral".

Spira mirabilis, Latin for "miraculous spiral", is another name for the logarithmic spiral. Although this curve had already been named by other mathematicians, the specific name ("miraculous" or "marvellous" spiral) was given to this curve by Jacob Bernoulli, because he was fascinated by one of its unique mathematical properties: the size of the spiral increases but its shape is unaltered with each successive curve, a property known as self-similarity. Possibly as a result of this unique property, the spira mirabilis has evolved in nature, appearing in certain growing forms such as nautilus shells and sunflower heads. Jacob Bernoulli wanted such a spiral engraved on his headstone along with the phrase "Eadem mutata resurgo" ("Although changed, I shall arise the same."), but, by error, an Archimedean spiral was placed there instead.

SHELL ON THE SHELF

A sand-snail shell rests on the shelf,

with time-traced whorls of growing’s curve,

a swirl of logarithmic spiral.

And so it sits in still completedness,

far from the vast, wave-rippled ocean,

so purely formed, brown and alone,

far from its forming, slow creation,

where curves of water, time and life

were gradually gathered into stone.