Manifold

Manifold is a science fiction novel by the British writer Stephen Baxter, published in 2000.

The book is built around one of the oldest questions in the genre, which is why the universe appears to contain nobody but us, and Baxter approaches it from two directions. Malenfant's strand is a voyage and a set of choices about how much of himself he is prepared to spend on the answer, and it becomes a study of a man who cannot stop. On Earth, the Japanese scientist Nemoto is working on evidence that the Moon, Venus and Mars were once capable of supporting life and are not now, which turns the question from a matter of distance into a matter of history, since something appears to have happened to the neighbourhood before humanity arrived. Baxter is less interested in the machinery of the gateway than in what the evidence implies, and the novel keeps arriving at the same uncomfortable conclusion, which is that a galaxy which looks empty may have been emptied. He writes this kind of story on a scale that is unusual even by the standards of hard science fiction, and the trilogy that followed explored the same premise from other directions.