The golden ratio was first observed in nature and studied by geometricians in ancient Greece. From here, it spiralled into numerous loosely connected fields. In doing so, it became a template for Renaissance thought. “The Golden Ratio started to become available to artists in theoretical treatises that were not overly mathematical, that they could actually use,” as Luca Pacioli’s Divina proportione of 1509 put it.
As a child trying to get your head around this magic number, you were probably guided towards pictures of seashells, sunflowers and spiral galaxies.