Phi - The Golden Key

Phi: 1.618 is the ratio the universe uses to multiply and divide itself at all scales…

In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. The figure on the right illustrates the geometric relationship. Expressed algebraically, for quantities a and b with a > b > 0,

a + b a = a b   = def   φ , {\displaystyle {\frac {a+b}{a}}={\frac {a}{b}}\ {\stackrel {\text{def}}{=}}\ \varphi ,}

where the Greek letter phi ( φ {\displaystyle \varphi } φ or φ {\displaystyle \phi } φ) represents the golden ratio. Its value is:

φ = 1 + 5 2 = 1.6180339887 … . {\displaystyle \varphi ={\frac {1+{\sqrt {5}}}{2}}=1.6180339887\ldots .}

The golden ratio is also called the golden mean or golden section (Latin: sectio aurea). Other names include extreme and mean ratio, medial section, divine proportion, divine section (Latin: sectio divina), golden proportion, golden cut, and golden number.