Spiral aloe, Kangaroo Island, Australia
© Michael Melford/Alamy
Fibonacci Day - Nature's secret code
On Fibonacci Day, mathematicians and scientists honor one of their own: Leonardo Bonacci, better known as Fibonacci. The medieval mathematician popularized the Hindu-Arabic numeral system, with its use of zero, decimal points, and 10 numbers instead of the ponderous Roman numeral system. He's most famous, however, for his sequence of numbers: 0, 1, 1, 2, 3, 5, 8... By adding the first two numbers, you arrive at the third, and adding the previous two numbers, you arrive at the next number, and so on. Disregarding the zero, the first four numbers correspond to today's date, 11/23.
The Fibonacci sequence is also related to a mathematical phenomenon called the golden ratio, an irrational number that begins 1.61803 but whose terms go on forever after the decimal point. It is found in nature, including the spiral shapes of nautilus shells, sunflower seeds, pinecones, and the leaves of the spiral aloe plant in today's image. It is also found in the relationship between adjacent numbers in the Fibonacci sequence. As successive Fibonacci numbers above 5 are divided by the previous number, the answer gets ever closer to the golden ratio. These mysterious numbers intertwine in nature, creating beautiful patterns in unexpected places.