Robots and Empire

Blurb

Robots and Empire is a science fiction novel written by the American author Isaac Asimov and published by Doubleday Books in 1985. It is part of Asimov's Robot series, which consists of many short stories and several novels.
Robots and Empire is part of Asimov's consolidation of his three major series of science fiction stories and novels: his Robot series, his Galactic Empire series and his Foundation series..
In the novel, Asimov depicts the transition from his earlier Milky Way Galaxy, inhabited by both human beings and positronic robots, to his Galactic Empire. The galaxy of his earlier trilogy of Robot novels is dominated by the blended human/robotic societies of the fifty "Spacer" planets, dispersed over a wide part of the Galaxy. While the Earth is much more populous than all of the Spacer planets combined, its people are looked down upon by the Spacers and treated as second-class citizens. For a long time, the Spacers have forbidden immigration of people from the Earth. But Asimov's later Galactic Empire is populated by many quadrillions of human beings on hundreds of thousands of habitable planets; and by very few robots.