Spin by Robert Charles Wilson
Set in the near future, Spin begins with the sudden and mysterious enveloping of the Earth in an artificial membrane that blocks out the sky, including the stars and moon. The membrane selectively filters incoming electromagnetic radiation, blocking out the view of anything beyond minimal low Earth orbit. However, the membrane displays a faux-sun on its inner surface, maintaining a relatively normal day-night cycle for the inhabitants of Earth.
The novel is told in the first person, from the viewpoint of Tyler Dupree. Tyler is a close childhood friend of Jason and Diane Lawton, twins of E. D. Lawton (a wealthy industrialist). As children, Jason, Diane, and Tyler witness the dramatic arrival of the "Spin", as the phenomenon comes to be known, when the stars suddenly disappear one night. Initial experiments by the world’s governments show that the membrane is permeable, allowing space probes to pass through, but that time on Earth has been dramatically slowed to a rate of roughly 100 million years per Earth year, or about 3 years outside for every second inside. Thus, it is deduced, within the time of one generation on Earth the rest of the solar system will age 4 billion years and Earth will be destroyed by the expanding Sun.
The story follows four primary protagonists, each of whom respond to the Spin and to the knowledge that humanity is doomed in distinct ways. E.D. Lawton founds a low Earth orbit satellite company (using high-altitude balloon technology) and profits spectacularly. Jason becomes a scientist with his father's political and financial backing, and devotes himself to trying to understand the "Spin" and who or what is behind it. Diane joins a religious cult who views the Spin as part of God's plan for the end times. And Tyler, the narrator, becomes a medical doctor who immerses himself in his work, but suffers through a series of existential crises related to the Spin and its obviously alien purposes.
When huge technological constructs are detected outside the Spin, hovering in orbit above the Earth’s poles (in seeming defiance of orbital physics), it becomes clear that the Spin can not possibly be some peculiar natural phenomenon, but the act of some unknown agency. The possible beings behind the Spin are dubbed, appropriately enough, "The Hypotheticals", and attempts are started at discovering who they are, why they are covering the Earth in the Spin membrane, and how to disable the membrane before it's too late.
The first attempt is to destroy one of the pole-floating devices with a thermonuclear explosion. The attempt briefly causes the Spin to become partially transparent, which incites mass panic as the population of Earth is suddenly able to see the astounding speed at which stars are "spinning" in the sky (due to the time differential). Soon after, the Spin membrane goes back to normal, and there seems to be no further effects; the floating pole device is undamaged.
The second attempt to stave off extinction happens when the world powers decide to terraform Mars, something possible now thanks to the vast rate at which time progresses outside Earth. Several automated rockets seed Mars with biological material, to begin the terraforming. Human colonists are then sent to Mars to start a new civilization. Though only a matter of weeks pass on Earth, millennia have passed for the Martian colonists, who have flourished into an entirely separate and ancient culture that has developed science far ahead of Earth's. After 100,000 years, the Martian government sends the scholar Wun Ngo Wen to Earth, just as Mars is engulfed by its own Spin membrane.
Wun provides Earth with the technology to send Von Neumann machines out of the Spin membrane that will self replicate and expand throughout the galaxy in search for information about the Spin’s creators and broadcast it back to Earth and Mars. However, within a few years of Earth time, the signals become weaker, contradictory or corrupted. Wun also brings a collection of advanced medical technology, including a drug that brings about an upgrade in human beings known as the "Fourth Age".
The final explanation behind the Spin is that it was created by self-replicating machines similar to those humans sent out, but a far more advanced self-conscious galaxy-spanning collective entity that is billions of years old; the “Hypotheticals”. The earlier corruption of the Earthly information-seeking machines was caused by them being both materially consumed by the more ancient network of self-replicating machines, as well as technologically assimilated by it. Before it's fully absorbed by the Hypotheticals, the human-created network returns evidence that other planets outside the Solar system have been contained by similar Spins, but ultimately it is the technological assimilation of one network by the other that allows humans to indirectly detect the Spin-creator network and infer its objectives, at least as far as humanity is concerned. What is inferred is that the Spin-creator network puts planets with sentient species into a state of almost suspended animation as soon as it detects they've entered a phase of unsustainable growth that will destroy them and their home planet due to resource depletion. While these planets are suspended, the machines construct huge wormhole-based gates connecting planets of similar conditions to those that were suspended, in a long chain of interconnected planets of similar environment and habitability. This is supposed to compensate for the inefficiencies of space travel as a mean of propagation, saving those sentient species from their own self-destruction by providing them greatly expanded means of development.
At approximately 4 Billion AD, a few years after the Hypotheticals have shut down the time-warping properties of the Spin membrane (although not the membrane itself, since the Sun, having already expanded by then, would kill life on Earth were the Spin completely disabled), Earth's governments start to hunt down humans who have gone through the Fourth Age treatment, fearing the potentially culturally disrupting effect of Martian biotechnology. Jason is long dead, but Diane, being a Fourth, must hide. Tyler, who is with her, also undergoes the process of becoming a Fourth, and by the end of the book both run away from the governmental persecution by leaving Earth, going through the wormhole gate to the next Earth-like world in the sequence.
The first half of the story is told in the form of notes and memories written by Tyler during his Fourth treatment, which encompasses the "in the present" chapters of the first half of the book, as well as a substantial part of the second half.
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