Fibonacci Spiral photographs . Italian 12th century mathematician Fibonacci designed a spiral used on following numbers added to each other. Pictures by Paul Pickard Fibonacci golden spiral, the golden ration fibonacci spiral photography

**Leonardo Pisano** is better known by his nickname **Fibonacci.** He was the son of Guilielmo and a member of the Bonacci family. Fibonacci himself sometimes used the name Bigollo, which may mean good-for-nothing or a traveller.

The Fibonacci sequence is one of the most famous formulas in mathematics.

Each number in the sequence is the sum of the two numbers that precede it. So, the sequence goes: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, and so on. The mathematical equation describing it is Xn+2= Xn+1 + XnIn technical analysis, a Fibonacci retracement is created by taking two extreme points on a stock chart and dividing the vertical distance by the key Fibonacci ratios of 23.6%, 38.2%, 50%, 61.8%, and 100%.