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.