Celestial Matters

An Alternate History Science Fiction / Fantasy novel by Richard Garfinkle, published in 1996.

Unlike our world, the universe of Celestial Matters obeys Ptolemaic astronomy, Aristotelian physics and Chinese Taoist alchemy. The earth is the center of the universe, with all the planets as well as the sun and moon revolving around it, set in a fixed sphere of stars. The timeline of this world also diverged from ours; the empire of Alexander the Great never collapsed, but grew and encompassed half the world.

A war has been raging between the Delian League and the Middle Kingdom for over a thousand years, both sides possessing different technology, but evenly matched with neither side being able to best the other. The protagonist, a Delian scientist named Aias, is heading Project Sunthief, an ambitious project that might finally bring about an end to the war. If all goes according to plan, the Delian League will fly a ship made from moonrock into space, take a piece of the sun and then use it as a weapon of mass destruction against the Middle Kingdom, obliterating their capital city and winning the war.

This novel provides examples of:

 * Alchemy Is Magic: Aristotelian and Chinese Taoist alchemy as well. Taoist alchemy is used by the Middle Kingdom, but the Delian League base their technology off Aristotelian physics and don't really understand how the Middle Kingdom technology works.
 * Alternate History: Alexander the Great ended up conquering pretty much all of Europe and then went into a thousand year war with the Orient.
 * Fantastic Nuke: The whole purpose of Project Sunthief. The piece of the sun that the Delian League plans to use against the Middle Kingdom is, in essence. a fusion bomb.
 * Forever War: The war between the Delian League and the Middle Kingdom has been going on for a thousand years.
 * Just Following Orders: There is a pivotal moment when a character has to decide whether to follow his orders or to obey his conscience.