Steven Pinker -- How the Mind Works - Hampshire High Italian ...

216 HOW THE MIND WORKSroom, the rear wall slanted away from left to right, but it had crajzy anglesthat made its left side just short enough to cancel its expansion in perspective,and its right side just tall enough to cancel its contraction.Through a peephole on the opposite side, the wall projected a rectangle.The visual system hates coincidences: it assumes that a regular imagecomes from something that really is regular and that it doesn't just lookthat way because of the fortuitous alignment of an irregular shape. Amesdid align an irregular shape to give a regular image, and he reinforced hiscunning trick with crooked windows and floor tiles. When a child standsin the near corner and her mother stands in the far one, the child projectsa larger retinal image. The brain takes depth into account whenassessing size; that's why a looming toddler never seems to dominate herdistant parent in everyday life. But now the viewer's sense of depth is avictim of its distaste for coincidence. Every inch of the wall appears thesame distance away, so the retinal images of the bodies are interpreted atface value, and Junior towers over Mom. When they change places bywalking along the rear wall, Junior shrinks to lapdog size and Mombecomes Wilt Chamberlain. Ames' room has been built in several museumsof science, such as the Exploratorium in San Francisco, and you cansee (or be seen in) this astonishing illusion for yourself.Now, a picture is nothing but a more convenient way of arrangingmatter so that it projects a pattern identical to real objects. The mimickingmatter sits on a flat surface, rather than in a dollhouse or suspendedby wires, and it is formed by smearing pigments rather than by cuttingshapes out of wood. The shapes of the smears can be determined withoutthe twisted ingenuity of an Ames. The trick was stated succinctly byLeonardo da Vinci: "Perspective is nothing else than seeing a placebehind a pane of glass, quite transparent, on the surface of which theobjects behind the glass are drawn." If the painter sights the scene from