For questions about "Zones of Thought", the universe of three novels and a short story by Vernor Vinge, first seen in long form in "A Fire Upon the Deep". The laws of physics vary as a function of location, from the center of the galaxy that does not permit intelligence to transcendent intelligence on the rim.

The Zones of Thought universe is the setting of three novels by Vernor Vinge: A Fire upon the Deep, A Deepness in the Sky and The Children of the Sky, as well as a short story, “The Blabber”. In this universe, the laws of physics vary on a galactic scale. The further one is from the center of the galaxy, the more complex thought is possible. Life is impossible near the center, while transcendent intelligences and faster-than-light travel are possible on the outskirts.

The Zones

The region around the Milky Way galaxy is divided into four major zones

  • The Transcend A region where magical technologies are possible and the inhabitants are sufficiently far advanced beyond mere human equivalent intelligence that people in the lower zones can treat them effectively as gods.

    The Transcend lies far from the major galactic mass distributions and presumably includes all of deep inter-galactic space.

  • The Beyond A region where faster than light travel and communication are possible, but intelligence seems to be limited to not much more than human equivalent. Many technologies are possible in the beyond that are not possible that are the Slow Zone; these include artificial intelligence, indefinite anti-aging support, effective anti-gravity and others. The physics of the beyond varies so that these things are easier in the "high Beyond" (near the Transcend) than in the "middle Beyond" and especially the "low Beyond" (near the Slow Zone).

    The Beyond occupies a deep layer between the Slow Zone and the Transcend.

  • The Slow Zone A region where faster than light travel and communications are not possible. Nor are many other technologies that are possible in the Beyond.

    The Slow Zone forms a layer outside of the Unthinking Depths; in the plane of the galaxy it occupies about a quarter of the radius and a similar thickness of the central galactic disk. Earth is deep in the Slow Zone.

  • The Unthinking Depths Little is known about this region, except that it will not support human-equivalent intelligence.

    The Unthinking Depths occupy the densest part of the galaxy--the central bulge, the innermost half of the disk, and regions immediately around them.


  • A Fire Upon The Deep (novel, 1992) Takes place mostly in the Beyond.
  • A Deepness in the Sky (novel, 1999) Takes place in the Slow Zone.
  • The Blabber (novella, 1988) The first story set in the universe, it takes place after A Fire Upon The Deep and Children of the Sky and is related to them (if it forms part of a self-consistent chronology, anyway). First published in Threats...and Other Promises
  • Children of the Sky (novel, 2011) Sequel to A Fire Upon The Deep, it takes place on a planet formerly at the bottom of the Beyond, now inside the Slow Zone.