“Around Earth, there grew up colony worlds circling neighboring stars and these colony worlds were far richer in robots than was Earth itself. There was more use for robots on raw, new worlds. Earth, in fact, retreated, wished no more robots, and rebelled against them.” “What happened?” asked Pelorat. “The Outer Worlds were the stronger. With the help of their robots, the children defeated and controlled Earth—the Mother. Pardon me, but I can’t help slipping into quotation. But there were those from Earth who fled their world—with better ships and stronger modes of hyperspatial travel. They fled to far distant stars and worlds, far beyond the closer worlds earlier colonized. New colonies were founded—without robots—in which human beings could live freely. Those were the Times of Flight, so-called, and the day upon which the first Earthmen reached the Sayshell Sector—this very planet, in fact—is the Day of Flight, celebrated annually for many thousands of years.”” (from “Foundation’s Edge (English Edition)” by Isaac Asimov)