latter include everything from black matter, time dilation, the theory of relativity, and Big Crunch theory of the universe. Reymont, the constable, regularly persists as a hyper-masculinized police officer, while first officer Ingrid basically acts as a buffer between Reymont and Captain Telander. These three characters are responsible for the majority of all decision-making on the ship, but Reymont is the only one who makes regular chapter-to-chapter appearances. In between these interactions, there are numerous romantic entanglements. In the final, ending parts, much of the novel deals with the crewmembers' reactions to being the last remnants of humanity, and the prospect of being confined with their colleagues indefinitely. Though they were prepared to "lose" twenty Earth years during their journey and spend five on board the ship, the knowledge that they are being carried further and further into the future has various effects on the psychology of the characters. The novel describes the changing and extreme time dilation effects as well as events from the perspective of both the ship and an external observer. Incidental to the main themes is the political situation on the Earth from which the protagonists set out: a future where the nations of the world entrusted Sweden with overseeing disarmament and found themselves living under the rule of the Swedish Empire. This sub-theme reflects the great interest which Anderson, an American of Danish origin, took in Scandinavian history and culture. In later parts of the book, characters compare their desperate situation to that of semi-mythical characters of Scandinavian legend, with the relevant poetry occasionally quoted. In addition, there is a fist fight between an American astronaut and a Swedish astronaut about who built the best empire, as well as other nationalistic rhetoric. See also Tau Zero Foundation – Successor to the NASA Breakthrough Propulsion Physics Program, named after Tau Zero References External links Tau Zero at Worlds Without End 1970 American novels 1970 science fiction novels American science fiction novels Novels by Poul Anderson Works originally published in Galaxy Science Fiction Hard science fiction Doubleday (publisher) books Novels about the end of the universe Novels about time travel Fiction about nebulae