The golden number is the mathematical representative of perfection in nature. It has been studied since antiquity and many Greek constructions and artistic works have this number as a basis. The golden number is represented by the Greek letter phi and is obtained by the proportion 
= 1.61803399... But why is this number so important? Why does he represent perfection, the beauty of nature? The answer is simple: because it appears almost everywhere in nature and in the things we consider most beautiful.
In the 13th century, Italian mathematician Leonardo Fibonacci was studying the growth of a population of rabbits and asked himself the question. respect of how many rabbits would you have at the end of a year, if there was only one pair at the beginning of the year and if no rabbits died in that year. time course. He was surprised to find that from the third month onwards, the number of rabbits in the following month was equal to the sum of the previous two months. And that way he would have 144 rabbits by the end of the year. Fibonacci was so intrigued by this relationship that he began to study this sequence (1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144,...) in nature and found it in the petals of roses, in the stems of trees and in the spiral shells of the nautilus, a mollusc marine; As this mollusk grows, its shell grows following the golden ratio, in a logarithmic spiral.
The golden number is an irrational number and can be obtained from a straight line segment. 
any. Consider a point C, dividing this segment into two smaller segments. 
and 
so the ratio of the segment length divided by segment length is equal to the ratio of the length of divided by the length of . This ratio corresponds to the divine proportion, so called, as some scholars believed that the number Φ present some message from God, since it is present in different places in nature. Even in humans, we can find the golden ratio if, for example, we divide a person's height by the measurement of their navel to the ground.
The number of gold also appears a lot in arts and geometry. In several works by Leonardo Da Vinci it is possible to find the divine proportion, the painting by Mona Lisa being one of the most famous examples. The Greeks, in the Pythagorean school, represented the golden number through the pentagram, which contains the golden proportion in all segments.
by Franciely Guedes
Graduated in Mathematics
