Leonardo Fibonacci
Leonardo Fibonacci was born around AD1175, in Pisa, Italy. His father, Guilielmo
Bonacci, was a customs officer for the North African city of Bugia (later called
Bougie and now called Bejaia). His father being a merchant, young Fibonacci was
able to travel freely around the Byzantine Empire, letting him be able to learn
mathematics of the scholars and the popular calculating schemes at the time.
"When my father, who had been appointed by his country as public notary in
the customs at Bugia acting for the Pisan merchants going there, was in charge,
he summoned me to him while I was still a child, and having an eye to usefulness
and future convenience, desired me to stay there and receive instruction in the
school of accounting. There, when I had been introduced to the art of the
Indians' nine symbols through remarkable teaching, knowledge of the art
very soon pleased me above all else and I came to understand it, for whatever
was studied by the art in Egypt, Syria, Greece, Sicily, and Provence, in all its
various forms."
-Liber Abaci (1202) by Leonardo Fibonacci-
Fibonacci was known by many names. He sometimes used the name Bigollo, which
means good-for-nothing or traveler. He was mostly known as Leonardo of Pisa, or
Leonardo Pisano in Italian. Fibonacci, as known today was derived by shortening
the Latin "Filius Bonacci", which means "the son of Bonaccio".
Fibonacci has had many accomplishments in his life. In 1202 he published his
first book Liber Abaci. This was his first of four books that he wrote. Liber
Abaci used the Hindu-Arabic numbering system which introduced the Indian numbers
0 through 9 to the European Culture. In the book it is apparent that Fibonacci
was highly influenced by the Muslim and Arab culture by righting things from
right to left instead of left to right. Also he wrote the numbers in descending
order and wrote the fractions before the number such as ½ 3 instead of 3 ½.
The Fibonacci sequence began as a problem that Fibonacci investigated in 1202.
Fibonacci investigated how fast rabbits would breed in ideal circumstances,
seeing as that the rabbits would not die and that each pair of rabbits would not
give birth to more than one pair of rabbits each month. The first pair of
rabbits give birth 2 a pair of other rabbits, they don't mature till after the
first month. Then that pair of rabbits gives birth to another pair of rabbits,
and they don't mature until after the first month. This sequence keeps repeating
on and on forever.
The Fibonacci sequence is: 1,1,2,3,5,8,13,21,34,55,……….. .
With the Fibonacci sequence, and his introduction of the Arabian numbers to the
European culture, gave the Europeans a newer and faster way to do calculations
instead of the Roman Numerals which had too many letters that represented
numbers other numbers in different ways. In 1962 The Fibonacci Society was
founded to recognize Leonardo Fibonacci. The Fibonacci Quarterly appeared in
1963, it was devoted to studying mathematics related to the Fibonacci sequence.
Leonardo Fibonacci was a great mathematician. Besides his great discovery of the
Fibonacci sequence, Fibonacci did many other great things. He proved many number
theories such as "there is no x, y such that x2+y2 and x2-y2 are both
squares, and x4-y4 cannot be a square."-Leonardo Fibonacci-. He also
defined the concept of a congruum. He said that it is a number of the form
ab(a+b)(a-b), if a+b is even, and 4 times this if a+b is odd. Any way you look
at it, Leonardo Fibonacci died around AD1240 in Pisa, Italy. He was one of the
greatest mathematicians there has ever been.
Leonardo
Fibonacci
His
life
Leonardo Fibonacci was a great mathematician
who lived in 12th century Italy. Very little is known about him; even his birth
and death dates are shrouded in mystery. He is presumed to have lived in Pisa
from ca. 1175 - ca. 1250, around the time of St. Francis of Assisi (ca. 1182-
ca. 1226). He called himself Fibonacci, which is short for filius Bonacci (meaning “son of Bonaccio”- it may also be a
nickname meaning “lucky son”) Perhaps he is better called “Leonardo of
Pisa” , altough he sometimes wrote “Leonardo Bigollo”, with bigollo meaning “a traveler” .
I will stick to Fibonacci or Leonardo, to make things simpler.
His legend
Fibonacci is most recognized for the sequence that bears his name, but
first I will tell you about Fibonacci and the Arabic number system.
Fibonacci was one of the first people to introduce the Arabic numbers:
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 0 and “.”
Until this time, most people used the roman numeral
system, which works like this:
I
=
1
V
=
5
X
=
10
L
=
50
C
=
100
D
=
500
M
=
1000
13 would be written XIII, but 99 would read
LXXXXVIIII or 50+10+10+10+10+5+ 1+1+1+1!!! In this manner, addition and
subtraction were very difficult, and I don’t want to think about
multiplication and division!
Leonardo also created the Fibonacci series, altough it was named this by
Edouard Lucas, a French mathematician (1842-1891).
The series goes as follows:
1,1,2,3,5,8,13,21,34,55,89,144,etc... Each number is
created by the addition of the two before it! This sequence is also found in
nature, on such things as leaves and petels, and in the arangement of seeds in a
seedpod (sunflowers are a good example).
This series of numbers is also the answer to a problem in one of the many
books he wrote:
A pair of rabits are put into a field. It is not posible for the rabbits
to escape the field, and they never die. If rabbits take one month to mature,
and then produce a new pair every following month, how many pairs of rabbits
will there be in each month?
The answer would be Fibonacci’s sequence(
1,1,2,3,5,8,13,21,34, etc, etc...)
His Books
Fibonacci wrote several works of math, four books and a letter to a
“Master Theodorus”. They are:
* Liber Abbaci-1228 (the Book of the Abacus)
*Practica geometriae-1220 (Practial Geometry)
*Flos-1225
*Liber quardratorum-1225 (The Book of Squares)
*A Letter to Master Theodorus- ca. 1225