ABSTRACT
The nineteenth century is known as the Age of Invention. When we consider its inventions of communication, it could also be known as the Age of the Image and the Echo.
With the notable exception of the telegraph-at once the first electronic medium, the first industrial use of electricity, and the most abstract of any communication mode before or since (Morse Code is an abstraction of writing, itself an abstraction of speech, in turn an abstraction of what it describes)—all the major communication inventions of the last century worked by capturing or reflecting a literal energy configuration from the real world. The still images of the photograph fix the impressions made by light after it bounces off objects. The telephone turns sound waves into analogous, physically similar, electronic patterns. The phonograph recording is literally a record of sound waves woven into the contours of a durable physical medium. Motion pictures are individual photographic images presented to the eye so quickly that they give the illusion of motion —in effect, reconstituting the motion of the real world. And in the twentieth century, first radio and then television carried on in this analog tradition. Only the computer at last changed this course, trafficking in digital expressions of text as abstract as Morse Code-though, unlike Morse Code, invisible to the user. And the computer is now increasingly moving to digital processing and display not only of text but icons, sounds, and images.
