natural hist museum nautilus shell carved sloane DSC 5361

Carved Nautilus shell, Natural History Museum, London. Originally from the collection of Sir Hans Sloane, carved by Johannes Belkien, late 1600s. The coil follows the golden ratio (or Fibonacci spiral composed of successive quarter circles in boxes whose lengths decrease by a factor of 0.168), a natural fractal considered by the ancient Greeks to be a mathematical embodiment of perfection.