Sky Scraper

Skew lines are two lines that do not intersect and are not parallel. Equivalently, they are lines that are not coplanar. Lines that are coplanar either intersect or are parallel, so skew lines exist only in three or more dimensions.

Photograph copyright (c) Trevi Bennett 2012

Perspective Lines

Perspective (from Latin perspicere, to see through) is an approximate representation, on a flat surface, of an image as it is seen by the eye. The two most characteristic features of perspective are that objects are drawn: Smaller as their distance from the observer increases and Foreshortened: the size of an object’s dimensions along the line of sight are relatively shorter than dimensions across the line of sight.

Photograph copyright (c) Trevi Bennett 2012

Three-dimensional Space

The understanding of three-dimensional space in humans is thought to be learned during infancy using unconscious inference, and is closely related to hand-eye coordination. The visual ability to perceive the world in three dimensions is called depth perception. 3-dimensional shapes on a 2-dimensional surface embedded in 4-dimensional space-time.

Charcoal on paper copyright (c) Trevi Bennett 2012