Spirals in Nature
Low pressure system over Iceland.
Image from NASA, taken on .
[image source http://visibleearth.nasa.gov/view_rec.php?id=6204]
Cyclones
in general have the shape of
equiangular spiral.
A cut-away view of the
Nautilus
shell.
Photo by “Chris 73”.
image source
In general, Spiral-shaped growths in nature are mathematicaly
equiangular spirals.
A garden snail, showing equiangular spiral.
More photos of seashells at
Beautiful Seashells Exhibition.
Romanesco broccoli, exhibiting equiangular spiral and fractal geometry.
[Photo by Dror Bar-Natan http://www.math.toronto.edu/%7Edrorbn/Gallery/Plants/index.html]
A Hawaiian ferm, exhibiting
Archimedes' Spiral.
[Photo by Dror Bar-Natan http://www.math.toronto.edu/%7Edrorbn/Gallery/Plants/index.html]
Man-Made Spirals
Great Mosque of Samarra, exhibiting Archimedean Spiral.
The neck of a unfinished violin.
[image source]
Such a spiral in ornament is called a volute.
See Also
Math of Seashell Shapes
.
Archimedes' spiral,
Clothoid,
Lituus,
equiangular spiral.