A Fire Upon The Deep (Zones of Thought)

Set thousands of years in the future, Vernor Vinge's 1992 space opera takes place in a galaxy divided into four concentric Zones of Thought, from the Unthinking Depths around the core through the Slow Zone and the Beyond to the Transcend, where superintelligent Powers dwell. A mind's potential depends on where it is. When the warring Straumli Realm turns an ancient Transcendent artifact into a weapon, it unleashes a force that destroys thousands of worlds. Fleeing that threat, a ship carrying cryogenically frozen children, the only survivors of a destroyed lab, crash lands on a world of the Tines, an alien race whose culture is harsh and medieval. The novel shared the 1993 Hugo Award with Connie Willis's Doomsday Book.

Benjamin Humphrey called it spectacular in scale and detail, and singled out its original zones of thought concept, in which each part of the galaxy has its own laws of physics. Brandon Sanderson counts it among his all-time favorite science fiction books.