Raft

Raft is a 1991 hard science fiction book by British writer Stephen Baxter. Raft is both Baxter's debut novel and the first book in the Xeelee Sequence, although the Xeelee are not present. Raft was nominated for the Arthur C. Clarke Award in 1992. Setting The novel is an elaborated version of his 1989 short story of the same title. The story follows a group of humans who have accidentally entered an alternate universe where the gravitational force is far stronger than our own, a "billion" times as strong. Planets do not exist, as they would immediately collapse under their own gravity; stars are only a mile across and have extremely brief life-spans, becoming cooled kernels a hundred yards wide with a surface gravity of five g. Human bodies possess a "respectable" gravity field in and of themselves. "Gravitic chemistry" also exists, where gravity is the dominant force on an atomic scale. Plot summary The few thousand humans survive in a nebula of relatively breathable air, existing in divided communities. The society is highly stratified, with the elite living on the "Raft" (the remains of the starship that contains almost all the high technology), workers/miners living on various "Belt" worlds (where they mine burned-out star kernels), and the "Boneys", a nomadic band of "unmentionables" who live on worlds created out of corpses.