`  ==Themes and Similarities to Other Works of Science Fiction==  ``The concept of a spacecraft being propelled by relativistic forces is also seen in the novel Earth by David Brin, published fifteen years earlier.``  What does this mean? Are they referring to the Rockhopper's drive, which appears to be some sort of fusion powered ion drive? OK, still theoretical, but not really relativistic. Or is it a reference to Janus' propulsion system, which is unexplained but appears to drag nearby objects along with it. In which case, this idea is at least as old as Arthur C Clarke's 'Rendezvous With Rama' (18 years before Brin's book), and probably even older. What is meant by a 'relativistic drive' anyway? Gravitational drive might be a better description (and is just about as meaningful!).  Thinking about it, 'Rendezvous With Rama' is a better comparison; Reynolds just takes it a step further - what if the exploration team never got away from Rama?   `