Today Fibonacci Day

is celebrated all over the world 

, the day dedicated to

one of the most important mathematicians in history:

Leonardo Pisano, known as Fibonacci , who introduced

Arabic numerals

and the use of 

0

in Italy and throughout the West 

.

The date for the celebration does not seem random: 

November 23 

in the Anglo-Saxon world is

11-23,

or 

the first four numbers of the mathematical sequence theorized by the Italian genius in which each number is the result of the sum of the previous two

.

The Fibonacci sequence is still applied in the

development of barcodes

and contributed to population studies and finance.

In these days, two 

educational activities are dedicated to Fibonacci as part of the Rome Science Festival

, scheduled until November 27: "How did the numbers get there?"

and “Wow Fibonacci”.

And on the occasion of

Fibonacci Day

, the "Futuro Remoto" festival

kicks off at the

Città della Scienza in Naples with an exhibition dedicated to the

Pisan mathematician

and

educational workshops to play with numbers starting from the famous sequence.

Leonardo Pisano

was born around

1170 

and became acquainted 

with Arabic mathematics

thanks to his work at the Pisan merchant colony of Bugia in Algeria.

His "

Liber Abbaci"

, written on his return from his travels, is responsible 

for the diffusion of the Arabic numerals in the western world and of the zero 

which supplanted the use of the Roman ones, widespread up to that moment. 

His is also the 

golden number. 

Denoted by the Greek letter

φ

(phi), the golden section is, like π, a number whose decimal expansion continues indefinitely, never repeating itself without a general pattern.

The decimal expansion of π begins with 3.14159 

that of φ with 1.61803

.

The connection between the Fibonacci numbers and the golden section was verified in the 19th century: 

if each Fibonacci number is divided by the previous one, as one proceeds in the sequence the result obtained tends to φ (

1.618) 

i.e. it progressively approaches the section gold, reality present in many 

natural realities

.

The example of the 

shell of the Nautilus mollusc is famous

which takes its shape perfectly:

Wikipedia/Gedoghedo

Shell of the Nautilus mollusk

The

history of art

is full of expressions of the golden section: from the facade of the

Parthenon in Athens

to many works by

Leonardo da Vinci, 

as made known to the general public

also thanks to the thanks to

Dan Brown's book "The Da Vinci Code", 

which relates the study of the mathematician to some works of the Tuscan genius.

The influences of the golden section even reached the

music of Bach, Debussy, Stockhausen, Xenakis.