We live in a visual age, an age of images--iconic, instant, and influential--that have crystallized our conception of the large, the small, and the complex, of both inner and outer space. Some, like Robert Hooke's first microscopic views of the natural world, arose because of new technical capabilities. Others, like the first graphs, were breathtakingly simple but perennially useful. The first stunning picture of Earth from space stimulated an environmental...