November 23 is Fibonacci Day, an annual holiday that honors one of the most influential mathematicians of the Middle Ages – Leonardo Bonacci.
Also known as Leonardo of Pisa, he is popularly known as Leonardo Fibonacci. Fibonacci is a contraction of filo Bonacci, meaning the son of Bonaccio.
November 23 is celebrated as Fibonacci day because when the date is written in the mm/dd format (11/23), the digits in the date form a Fibonacci sequence: 1,1,2,3. A Fibonacci sequence is a series of numbers where a number is the sum of the two numbers before it. For example: 1, 1, 2, 3…is a Fibonacci sequence. Here, 2 is the sum of the two numbers before it (1+1). Similarly, 3 is the sum of the two numbers before it (1+2).
The Fibonacci sequence, one of the biggest accomplishments of Leonardo of Pisa came from a simple puzzle about rabbit population. In his book Liber acaci, Fibonacci posed this puzzle: if there are a pair of newly born rabbit – male and female – in the field and if they are able to produce another pair of rabbits in their second month of life, how many pairs of rabbits will be there after a year?
Born in 1170 in Pisa, Italy, Fibonacci was also responsible for making the Hindu-Arabic numerals popular in Europe. In Liber acaci he advocated the use of these numerals, explained the use of zero, provided ways to convert between currencies and different measurements, and described how to calculate interest.
Did You Know…
…that the ratio of two successive numbers in the Fibonacci sequence is very close to the Golden Ratio? The Golden Ratio is approximately equal to 1.6. Objects whose length and breadth exhibit the Golden Ratio are thought to be the most pleasing to the eye.
