PHI: The Golden Ratio or Golden Section - a unique Ratio (or relationship between parts) that seems to be preferred by Nature as the best geometry for growth, energy conservation, elegance and has some fundamental relationships to the platonic solids and the Mandelbrot set. It was formally discovered by the Greeks and incorporated into their art and architecture, but it has been shown to occur even in prehistoric art, possibly as a function of Man's natural affinity for it's beauty.
The Golden ratio is a number found by dividing a line into two parts so that the longer part divided by the smaller part is also equal to the whole length divided by the longer part. It is symbolized using phi, after the Greek alphabet. In an equation form, it looks like this: a/b = (a+b)/a = 1.618033988749894842 As with pi, the digits go on and on, theoretically into infinity. Phi is usually rounded off to 1.618.
They are geometrical forms which are said to act as a template from which all life springs. They are named after the ancient Greek philosopher Plato. To the Greeks, these solids symbolized fire, earth, air, spirit (or ether) and water.