The divine proportion is also called the golden mean or abbreviated by the greek letter phi. The actual value is (1 + root(5))/2 or about 1.618 (the number actually never ends and is irrational, because root(5) is irrational).\n\nAs an application, say we have a line of length 1. If you had another line of length 1.618, the ratio between the two would essentially be the golden mean.\n\nThis ratio occurs almost everywhere in nature. Shells form golden spirals, the ratio from tail to dorsal fin and dorsal fin to head on a dolphin is about the golden mean, same for foot to waist and waist to head in humans. So on and so on. It also has been a dominant design principle for much of civilization. The parthenon, for instance is composed of many golden rectangles and books are often designed so that the box of text forms a golden rectangle. There is something about it that is inherently pleasing to the eye.
What is 'Divine Proportion'?