It’s the sunflower time of year, as the flowers spangle yards and roadsides and meadows in gold.
But have you ever studied those gorgeous orbs up close? As sunflowers go to seed, the flower heads reveal a spiral shape.
That graceful pattern tells of a connection between mathematics and nature discovered a long time ago. It’s called the Fibonacci Sequence.
In the early 1200s Italian mathematician Leonardo Pisano, also known as Fibonacci, presented a series of numbers. Each one is the sum of the two previous ones, so the sequence starts: 1, 1, 2,3, 5, 8, 13, and continues into infinity. Fibonacci was famous in his lifetime but then forgotten for nearly four centuries, until a French mathematician gave his name to the sequence and reintroduced it to the world.
Hidden within the sequence is the “golden ratio.” It illustrates the spiral patterns not only in sunflowers but also the arrangement of leaves and branches on some plants, bracts of a pinecone, shape of a snail shell, spiral galaxies and even proportions of the human body.
Biologists and others recognize the golden ratio in nature, and artists and architects apply it in design.
Why does this pattern occur so often? There may not be a single, simple answer. But it may have to do with fitting in the most seeds, gathering the most sunlight, or other evolutionary benefit.
Nature isn’t always tidy, and spirals aren’t everywhere. But when the Fibonacci sequence does appear, its elegant symmetry will astound.
This Earth Note was written by Rose Houk and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
