Posted on | October 12, 2013 | 78 Comments
Time travel science fiction tends to come in two flavors: conventional time travel, in which the heroes journey into the future or the past, and the parallel worlds type of story where there are multiple alternate time lines which can be travelled to. Keith Laumer did both; in Dinosaur Beach, his hero is a member of the Timesweepers, a group trying to clean up the messes left by previous time travelers, while in Imperium, Brion Bayard fights an alternate version of himself who threatens the destruction of the Imperium. Larry Niven, on the other hand, treats time travel as an impossibility in Flight of the Horse to comic effect, while its sequel Rainbow Mars is considerably darker.
Authors don’t always explain the details of how their heroes wind up in the past or the future. We never do find out how Asimov’s retired tailor from Pebble in the Sky winds up in a post-nuclear Earth, or how the feckless protagonist of Ward Moore’s Bring the Jubilee fumbles his way back to the Battle of Gettysburg to cost the South the Battle of Gettysburg – and the war. In contrast, Dan Davis in Hainlein’s The Door into Summer uses cold-sleep twice and an experimental time machine to make his life turn out the way it should have after his unfaithful fiance shanghais him into the future. Elsewhen, Lazarus Long travels back to pre-WWI America to meet his family in Time Enough for Love with nearly fatal results, but as the filk song concludes, “Nothing wrecks this Oedipus!”
On the other hand, some authors rejected the very notion that you could change the past. Alfred Bester’s nearly-forgotten classic “The Men Who Murdered Mohammed” (collected in Virtual Unrealities: The Short Fiction of Alfred Bester) introduces what has come to be known as the concept of “quantum time” and its consequences for would-be meddlers. Fortunately, Poul Anderson and H. Beam Piper paid no attention to this and created separate law enforcement agencies to guard the time stream: Time Patrol and the previously mentioned Paracops of The Complete Paratime.
More recently, Harry Harrison and Harry Turtledove address the notion of present-time people going back to aid the Confederacy in A Rebel In Time and The Guns of the South, while Connie Willis’ considerably more depressing Doomsday Book sends a graduate student back to medieval England just in time for the Black Death. On a lighter note, there’s Leo Frankowski’s The Cross-Time Engineer, in which Conrad Schwartz winds up in 13th century Poland and resolves to save it from the Mongols. Its spiritual ancestor, of course, is L. Sprague DeCamp’s Lest Darkness Fall, in which Martin Padway takes it on himself to save the Western Roman Empire and its Gothic rulers from Justinian and Belisarius – and itself. Connie Willis can also do humorous time travel, as can be seen in To Say Nothing of the Dog.
Feel free to suggest your own favorites in the comments!