The GOLDEN RATIO SPIRAL is inside a GOLDEN RECTANGLE (see picture), which is a rectangle that can be divided into a square and another rectangle such that the ratio between the dimensions of the new rectangle equals that of the original rectangle. Look at the golden rectangle with dimensions of 1 and φ. It is divided into a square of side 1 unit and a rectangle with dimensions φ - 1 and 1 units. Since the ratio of the dimension of the original rectangle equals the ratio of the dimensions of the newer rectangle, we have 1/φ = (φ - 1)/1. This gives φ a value of (1 + √5)/2 ≈ 1.618034. This number is the GOLDEN RATIO (also known as the "golden mean"), and is referred to by the Greek letter phi, φ. When we divide the golden rectangle into a square and a rectangle, the ratio of the dimensions of the smaller rectangle is the same as that of the original rectangle. Therefore, the smaller rectangle is a golden rectangle too, so we can split it into a square another smaller golden rectangle. We can do this over and over indefinitely, forming the figure known as the GOLDEN SPIRAL (see picture)!