Orphans of the Sky - Robert A Heinlein - Bog

Ancient myths told of a place called Earth, but the modern world knew it was nonsense. Science knew the Ship was all the Universe, and as long as the sacred Converter was fed, lights would glow and air would flow through the miles of metal corridors. Hugh never questioned these truths until a despised mutie showed him the Control Room and he learned the true nature of the Ship and its mission.