The life of our city is rich in poetic and marvelous subjects. We are enveloped and steeped as though in an atmosphere of the marvelous; but we do not notice it. —Charles Baudelaire, 1846
Urban landscapes are embodiments of human aspirations and dreams. They represent the spirit of an age and personify the minds and hearts of the people who inhabit them. Archaeological excavations of ancient cities, such as the magnificently preserved ruins of Pompeii and Herculaneum, bring to life our distant past. If we could peer into the future, we would want to know what our cities will look like to understand who we will become.
Cities capture our imagination in fascinating ways. Art and folklore are chock-full of mythical and imaginary cities, from the sunken lost city of Atlantis and El Dorado’s city of gold to Fritz Lang’s dystopian film Metropolis and, more recently, the Escheresque architecture of the folding cityscapes in the movie Inception. Yet we need not turn to fiction or travel far in space or time to experience the wonder. Even the most desolately functional urban environments can be sprinkled with nuggets of magic and surprise, with illusion “Easter eggs” that challenge our perception of what’s real.
Our everyday cities are not all that they may seem. Oftentimes it’s a matter of perspective.
Several artists use anamorphosis, a type of perspective that relies on a particular vantage point. Phantom stairways to heaven and other geometric figures haunt the observer. Move a few steps to the side, however, and only fragmented shapes remain. These artworks are dramatic examples of the perceptual organization principle that Gestalt psychologists called good continuation: we tend to group visual elements that suggest an unbroken or continued line. Neuroscientist Charles D. Gilbert and his colleagues at the Rockefeller University found a neural basis. Neurons in the primary visual cortex are tuned to specific edge orientations; they prefer, say, horizontal line segments or vertical ones. Your brain can integrate information well beyond the boundaries of single neurons, however. It turns out that neurons with similar orientation preferences are connected via horizontal fibers that travel long distances in the primary visual cortex. These long-range connections among similar types of neurons allow your mind’s eye to “see” the ladder instead of disjointed shapes.
Projection mapping is a recent technique for artistic expression, which provides the illusion of movement in stationary objects such as large buildings. The 3-D aspects of the end product are equally remarkable. By adding shading and subtle size changes to the projected objects, the artists induce a powerful feeling of depth and volume that our visual neurons can’t resist. This piece, produced by Urbanscreen and projected on the Galerie der Gegenwart at the Hamburger Kunsthalle art museum in Germany, is entitled How It Would Be if a House Was Dreaming. Watch the video at www.urbanscreen.com/usc/41.
Honey, I Shrunk the Stadium
We turn from the massive to the minute. Miniature faking via digital postprocessing can turn a crowded stadium into a game of foosball. In this technique, a small selected portion of the image remains sharp, whereas the other regions are blurred to various degrees, simulating the shallow depth of field of close-up photography. The resultant image looks like the photograph of a miniature scale model, rather than an actual scene.
An Invisibility Cloak of Paint
Some illusions make objects appear, such as floating ladders and squares. Others make objects disappear. Sara Watson, then a student at University of Central Lancashire in England, devised a spectacular vanishing act as part of her drawing and image-making course. She gave an old Skoda a new paint job that made it invisible by allowing it to blend in with the background like a chameleon. Urban camouflage at its finest.