The Great War is over and humans have spread across the solar system, but mathematician Alex Ligon's complex computer model has just predicted that humanity is inexplicably doomed within a century. At the same time, scientist Milly Wu has identified what appears to be an extraterrestrial signal, and the idiosyncratic genius Bat searches for weapons from the Great War to add to his collection, finding much more than he bargained for. Their stories and others are intertwined in this tightly plotted and thoroughly engaging follow-up to Sheffield's Cold as Ice.

Nebula Award winner Sheffield distinguishes himself as a writer of intelligence, humor, and a pleasing balance of hard science and interesting, engaging characters. Fans will be particularly delighted to renew their acquaintance with Bat, but readers new to Sheffield's work should take the plunge enthusiastically--this novel easily and gracefully stands alone as a story of people, science, and the puzzles that both can produce. --Roz Genessee


From Publishers Weekly
Fans of tangled plots, detailed settings and taut adventure will have a great time with Nebula Award-winner Sheffield's follow-up to Cold as Ice (1992). Earth and settlements on our moon and on Mars languish following the Great War, while colonies in the Asteroid Belt and on the moons of Jupiter and Saturn are now thriving centers for business and research. Alex Ligon, heir to Ligon Industries, has turned his back on the family business to pursue mathematical modeling of development in the solar system. As Alex frets over his latest model, which shows humanity mysteriously dying out within a century, his family manipulates him into visiting Bat, a brilliant but antisocial hacker who owns the lease on Saturn's moon Pandora, where the Ligons want to place a new processing facility. Eager to acquire a cosmically devastating weapon left over from the Great War of which he's heard rumor, Bat agrees to meet with Alex out of curiosity over the mathematician's population model and a possible connection between it and the weapon. In the meantime, a man who may be the key to Bat's hypothetical superweapon is on his way to Ganymede, and SETI investigator Milly Wu has discovered the first real signal from an alien intelligence. Sheffield ties all the threads together a little too neatly by the end, but there's plenty of yarn left over for another sequel. The world he creates here seems imminently possible, and his characters, especially Milly and Bat, are portrayed with humor as well as the intellectual rigor demanded by a hard SF plot. Copyright 2002 Cahners Business Information, Inc.


From Library Journal
Decades after the Great War almost destroyed humanity, the human race has recovered somewhat and has settled and prospered in the southern half of Earth, on Mars, and on the moons of Jupiter and Saturn. As scientist Alex Ligon stumbles upon a mathematical model that predicts the end of the human race, neophyte scientist Milly Wu discovers signals from outside the solar system, and reclusive genius Rustum Battachariya finds a powerful weapon left over from the Great War. Sheffield's sequel to Cold as Ice brings the future of space colonization to life in a visionary tale of aliens and artifacts that combines sf adventure, wry humor, and spot-on science. For most sf collections. Copyright 2002 Cahners Business Information, Inc.


From Booklist
The sequel to Cold as Ice (1992) operates at the same high level of quality, though with 10 years' worth of other strong books to Sheffield's credit, that won't much surprise his steady readers. It opens with the solar system a little farther along in recovering from the Great War, and it interweaves three subplots involving three different characters. Alex Ligon, heir to a multiplanetary fortune, develops a population-expansion model that suggests the human race is doomed. Milly Wu, newly arrived at the SETI project base, believes she has detected the signals of intelligent aliens. And eccentric and reclusive mathematician Rustum Battachariya, who collects Great War hardware the way some people nowadays collect World War II relics, stumbles on something rather more dangerous: a weapon that can destroy the sun. Following these three characters, Sheffield leads us through the book with his usual wit, impeccable science, and command of the language. It is hard to think of anybody who is writing hard sf these days substantially better than he is. Roland Green
Copyright © American Library Association. All rights reserved


Review
“Sheffield leads us through the book with his usual wit, impeccable science, and command of the language. It is hard to think of anybody who is writing hard sf these days substantially better than he is.” –Booklist



Book Description
The Solar System is finally recovering from the Great War – a war that devastated the planets and nearly wiped out the human race – and the population of the outer moons, orbiting Jupiter and Saturn, is growing.

On one of those moons, Alex Ligon, scion of a great interplanetary trading family has developed a wonderfully accurate new population model, and cannot wait until the newly reconstituted "Seine," the interlinked network of computers that spans the planets and moons and asteroids, comes back on line. But when it does, and he extends his perfect model a century into the future, it predicts the complete destruction of the human race.

On another moon, the Search for Extraterrestrial Intelligence goes on, undaunted by generations of failure. And to her amazement, Millie Wu, a young genius newly recruited to the project, has found a signal . . . a signal that is coming from outside the solar system.

And in his new retreat on a minor moon of Saturn, the cranky genius Rustam Battacharyia is still collecting weapons from the Great War. He thinks he may have stumbled on an unexpected new one...but he’ll need to disarm it before it destroys the Sun.



About the Author
Charles Sheffield is a mathematician and theoretical physicist by training. His doctoral work was on Einstein's Special Theory of Relativity. Currently Dr. Sheffield works as chief scientist for the Earth Satellite Corporation, a Washington, D.C.–based firm that specializes in the analysis of data gathered from space.

The author of thirty previous science fiction novels, including Cold as Ice and The Ganymede Club from Tor, Sheffield lives in Silver Spring, Maryland, with his wife, author Nancy Kress.

FROM THE PUBLISHER

"Dark as Day is set in the universe Sheffield created for his brilliant novel Cold as Ice. It is a universe where humanity is still limited to our solar system, and was nearly wiped out entirely in an interplanetary war that ended some thirty years before Dark as Day begins. But not quite destroyed." "In this sequel, Charles Sheffield returns to the human-settled solar system in the years after the Great War. That interplanetary war is over now, but there are still horrifyingly dangerous weapons caches to threaten human survival. The solar system is finally recovering, though. The Earth is returning to habitability, at least in the Southern Hemisphere. The Northern Hemisphere, target of dreadful biological weapons, remains uninhabitable. Mars has a small population, and the asteroids and the moons of Jupiter and Saturn are thriving centers of trade and research." "On one of those moons, Alex Ligon, scion of a great interstellar trading family, has turned his back on his family business in favor of the mathematics of statistical modeling. He has developed a wonderfully accurate new population model and cannot wait until the newly reconstituted "Seine," the interlinked network of computers that spans the planets and moons and asteroids, comes back on-line. But when it does, and he extends his perfect model a century into the future, it predicts the complete destruction of the human race." On another moon, the search for extraterrestrial intelligence goes on, undaunted by generations of failure. And to her amazement, Millie Wu, a young genius newly recruited to the project, has found a signal.. a signal that is coming from outside the solar system. Deciphering this transmission will be the greatest challenge ever presented to the Puzzle Network.

FROM THE CRITICS

Publishers Weekly

Fans of tangled plots, detailed settings and taut adventure will have a great time with Nebula Award-winner Sheffield's follow-up to Cold as Ice (1992). Earth and settlements on our moon and on Mars languish following the Great War, while colonies in the Asteroid Belt and on the moons of Jupiter and Saturn are now thriving centers for business and research. Alex Ligon, heir to Ligon Industries, has turned his back on the family business to pursue mathematical modeling of development in the solar system. As Alex frets over his latest model, which shows humanity mysteriously dying out within a century, his family manipulates him into visiting Bat, a brilliant but antisocial hacker who owns the lease on Saturn's moon Pandora, where the Ligons want to place a new processing facility. Eager to acquire a cosmically devastating weapon left over from the Great War of which he's heard rumor, Bat agrees to meet with Alex out of curiosity over the mathematician's population model and a possible connection between it and the weapon. In the meantime, a man who may be the key to Bat's hypothetical superweapon is on his way to Ganymede, and SETI investigator Milly Wu has discovered the first real signal from an alien intelligence. Sheffield ties all the threads together a little too neatly by the end, but there's plenty of yarn left over for another sequel. The world he creates here seems imminently possible, and his characters, especially Milly and Bat, are portrayed with humor as well as the intellectual rigor demanded by a hard SF plot. (Mar. 14) Copyright 2001 Cahners Business Information.

Library Journal

Decades after the Great War almost destroyed humanity, the human race has recovered somewhat and has settled and prospered in the southern half of Earth, on Mars, and on the moons of Jupiter and Saturn. As scientist Alex Ligon stumbles upon a mathematical model that predicts the end of the human race, neophyte scientist Milly Wu discovers signals from outside the solar system, and reclusive genius Rustum Battachariya finds a powerful weapon left over from the Great War. Sheffield's sequel to Cold as Ice brings the future of space colonization to life in a visionary tale of aliens and artifacts that combines sf adventure, wry humor, and spot-on science. For most sf collections. Copyright 2002 Cahners Business Information.

Kirkus Reviews