If scale is the proportional arbiter of worlds of differing measure, it is also a sign of difference itself, calibrating the degree of dimensional discontinuity between those worlds. Many artists of the past century have focused their attention on just such discontinuities, striving to eliminate, or bring into question, the perceptual veil that allows us to speak of a separate “world” of art. The highly polished paint surface associated with the great 19th-century fine-arts academies, in which the physical presence of pigment all but vanishes under a seamless film of representational illusion, gave way to rougher brushwork that proclaimed and celebrated the literal depths of paint on canvas. Likewise, art that directly examined the idea of scale as a proportional intermediary began to appear early in this century. The scale of Marcel Duchamp’s readymade snow shovel is 1:1 by definition, an incursion into the dimensional space of the viewer, emphasized by the deliberate lack of a pedestal.

With the mural-size paintings of the Abstract Expressionists and the rigorous geometries of Minimalist sculpture, the viewer is subsumed into the spatial coordinates of the artwork itself. Scale becomes less a matter of proportional relationship than of sheer size and physical concordance with one’s own bodily presence. Indeed, in the past four decades, scale—as a critical element in the confrontation of art with the viewer’s body, the earth, and beyond—has become subject matter itself. As artists such as Joseph Beuys, Christo, Walter De Maria, Robert Morris, and James Turrell have extended the scope of art to encompass entire streets, cities, deserts, and distant stars, the proportional, ecological, and perceptual relationship of the viewer to the work of art—and through art to the world—rises to the most challenging scale imaginable.