Leonardo Pisano Bigollo (c. 1170 – c. 1250) – aka Leonardo of Pisa or sometimes just Fibonacci – was one of the most famous mathematicians in the Middle Ages. He initiated the spread of the Hindu–Arabic numeral system to Europe, in his book Liber Abaci (Book of Calculation), published in the year 1202. This number system is based on 10 different glyphs or symbols, including a zero. It’s the system we use every day: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.
Fibonacci also laid the groundwork for our modern-day mathematical understanding of certain shapes in nature, including Nautilus shells. In his book, Fibonacci introduced what’s now called the Fibonacci number or sequence, which can be described as follows.
Suppose you place two baby rabbits in a garden. The pair, at one month old, is too young to reproduce. Suppose that in their second month, and every month after that, they produce two more rabbits. If each new pair of rabbits does the same, the number of pairs each month increases according to the following sequence, starting with 0 and 1. This sequence begins 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987. Each number is the sum of the two previous numbers.
See a movie that demonstrates how to construct a Fibonacci spiral.
1999 article mathematician Keith Devlin: New mathematical constant discovered
Fibonacci Flimflam via Lock Haven University
Who was Fibonacci? via University of Surrey
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