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The golden ratio is a scientific nugget that has, for at least two thousand years, belonged as much to mysticism as to mathematics.

It is just a number – 1.618 – but to its devotees the ratio expresses aesthetic perfection, and can be found wherever there is beauty.

For example, they argue that of all the rectangles in the world the most pleasing to the eye has a ratio of length to width of 1.618.