The Divine Proportion : ɸ (phi) = The Golden Number = 1,618

Leonardo Guilielmi   (nicknamed Fibonnaci) lived from 1170 to 1250.  His theorum in mathematics, is still extremely relevant today. 

Basically, while trying to sort out the number of rabbits that mated in a year, he discovered a sequence of numbers, that are profoundly consistent in man, nature and animals.  Imagine, a series of numbers that literally can be seen throughout nature.
Here is the beginning of the fibonnacci sequence:
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233…and this continues.
Each number + the next number, = the third number!  That is the fibonnacci sequence.
Fibonacci numbers can be seen throughout nature. For example, here are 13 petals on a black eyed susanL

The first 100 digits of phi are :

1,618 033 988 749 894 848 204 586 834 365 638 117 720 309 179 805 762 862 135 448 622 705 260 462 189 024 497 072 072 041

ɸ is the positive solution of the equation : x²-x = 1
it is equal to : (1+√5)/2


In the Fibonacci sequence of numbers, each number is the sum of the previous two numbers, starting with 0 and 1. 
F(n) = F(n-1) + F(n-2)

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610 etc.

Link between Fibonacci sequence & phi : the ratio of two successive terms of the Fibonacci sequence is approaching the phi number when n is big.

>> is this the key of Nature harmony in the universe ???

http://www.etereaestudios.com

In summary, the beauty of the thing lies in the hidden links between addition and ratio of terms.

For those who are sensitive to the sacred aspects of life, we can notice :

Bible :

Exodus, Chapter 16 V18 (Moses is in the Desert with the Israelites, and his people are asking him to pray God for getting food : they are told the next morning they will find food on the sand of the desert)

     "18 And when they measured it by the omer, he who gathered much did not have too much, and he who gathered little did not have too little. Each one gathered as much as he needed."

Which is certainly a beautiful way to mention and to reach, respectively, harmony.

Quran :
16:18 If you count GOD's blessings, you cannot possibly encompass them. GOD is Forgiver, Most Merciful.