Explanation of the Phi ratio and Golden ratio:
In nature (from seeds and petals to the structure of the human body), in architecture, in the universe, we find everywhere the phi-spirals and ratio of the Golden Mean as the ideal geometric ratio for growth, conservation of energy and beauty.
Golden / Divine Rectangle:
The rectangle has a vertical length of 1 and a horizontal length of 1.618.
By making a square in the rectangle with a vertical line, you create another golden rectangle on the right. This subdivision repeats itself spirally inwards and you can repeat this endlessly. The golden angle (approx. 137.5 °) is an angle that divides the golden ratio according to a circle.
You will find this spiralization everywhere. The spiral is the natural flow shape of water as it passes down the drain. It is also the natural flow shape of the air in tornadoes and hurricanes. In addition, the Nautilus shell as a good example. The Golden Ratio occurs countless times in the human body, in the proportions of the bones and the length of arms and legs, for example. For example, the Golden Ratio is also the ratio of the distance from the navel to the toe and from the navel to the crown.
Cristobal Vila beautifully illustrates the principle of Phi and the Golden Ratio in his short film Nature by Numbers: https://www.youtube.com/watch?v=kkGeOWYOFoA