Today more than half the world's population resides in a city, an all-time high that's trending upward. Some 38 cities are estimated to contain more than 10 million people, designating them "megacities." Unfurling outward, climbing higher, converging into one another, metropolises from Mumbai to Mexico City are competing for space in a way few midcentury architects could have forseen, but not Charles and Ray Eames.

Already legends in the field of architecture and design, in 1977 the husband and wife team adapted a book by a Dutch educator into a short documentary, Powers of Ten. The film—in case you missed science class that day—shows the human environment slowly receding as the camera zooms out over a park in Chicago into outerspace. In a matter of seconds, the Eamseses put the city in a radically new perspective.

Though the film does not predict the rise of massive urban conglomerations, it was an early glimpse of the city as the sum of its parts—a kind of precursor to Google Maps. The Eamseses enabled a generation of aspiring designers to visualize a metropolitan area as sweeping as the issues confronting it.

Eames and Llisa Demetrios, Charles and Ray's grandchildren, will discuss Power of Ten's legacy at Dwell on Design in Los Angeles next month.