From the Wigner thought experiment they have postulated an unusual theory on the ultimate destiny of life in the universe.

The Friends have a complex scheme, which does not include a simple military return-and-rescue – the 1,500-year technology gap makes this 'risible'. One of the crew of the Cauchy returns with the Friends, Miriam Berg. The Qax had destroyed the Solar System gate, but a lashed-up human ship (a great chunk of soil including Stonehenge, crewed by a group called the Friends of Wigner) passes through the returning gate, travelling back to the unconquered humanity of 1,500 years ago. The project, towed by the spaceship Cauchy, returns a wormhole gate, appearing to offer time travel due to the time 'difference' between the exits of the wormhole (relativistic time dilation), with one end having remained in the Solar System and the other travelling at near lightspeed for a century. Ī human-built device, the Interface project, returns to the Solar System after 1,500 years. Humans have encountered a few other races, including the astoundingly advanced Xeelee, and been conquered once before – by the Squeem – but successfully recovered. Set thousands of years in the future ( AD 5407), the human race has been conquered by the Qax, a truly alien turbulent-liquid form of life, who now rule over the few star systems of human space – adopting processes from human history to effectively oppress the resentful race.

It largely sets the stage for the magnum opus of the Xeelee Sequence, Ring (as opposed to Vacuum Diagrams, Flux, or Raft, which concern themselves with side stories). The second book in the Xeelee Sequence, Timelike Infinity introduces a universe of powerful alien species and technologies that manages to maintain a realistic edge because of Baxter's physics background.

Timelike Infinity is a 1992 science fiction book by British author Stephen Baxter.

Timelike infinity