All The Alternative Histories

Is there a catalogue of alternative histories anywhere? We know who the main writers are and what the main themes are. Roy Tully in SM Stirling's Conquistador (New York, 2004) summarizes two:

"'...I know the concept. South wins the Civil War, Hitler wins World War Two, that sort of thing. Been some pretty good movies that used it.'" (p. 177)

There are other obvious themes:

Alexander the Great lived longer (Poul Anderson, Greg Bear, SM Stirling);
different outcomes in 1066 (?);
no Reformation (Kingsley Amis, Philip Pullman);
a successful Spanish Armada (Keith Roberts);
Oliver Cromwell lived longer (a DC Comics Elseworld) -

-and less obvious:

aliens invaded Earth during World War II (Harry Turtledove);
Mars and Venus were terraformed long ago (SM Stirling);
someone discovered how to degauss the effects of cold iron (Poul Anderson).

Bring The Jubilee by Ward Moore begins as a Confederate States alternative history but ends as a causality violation time travel novel, thus showing the degree of overlap between these two sf themes. Did Bring The Jubilee influence Anderson's "Time Patrol"? Anderson could not remember. However, conceptually, Bring The Jubilee does belong in a sequence of precursors to the Time Patrol:

Mark Twain, A Connecticut Yankee...;
HG Wells, The Time Machine;
L Sprague de Camp, Lest Darkness Fall;
Moore, Bring The Jubilee;
Anderson, "The Little Monster" and "The Man who Came Early."

An involuntary time traveler prospers and makes changes that do not last;
the Time Traveler invents the Time Machine and his dinner guests discuss anachronisms on battlefields like Hastings;
a second involuntary time traveler prospers and makes lasting changes;
a time traveling historian unintentionally diverts the course of a decisive battle;
a third involuntary time traveler survives but a fourth comes to grief;
the Time Patrol is founded to prevent accidental or deliberate historical changes.

In Anderson's "The House of Sorrows" and also in the deleted timeline of his "Delenda Est," Christianity does not get started whereas, in his Westfall timeline, Christendom exists but is destroyed. In all three timelines, Europe remains divided into small warring states practicing polytheism. The difference is that the Westfallers eventually develop science.

A Conceptual Sequence

Seven works by six authors form not a linear series but certainly a conceptual sequence that could with profit be read in this order:

"Missing One's Coach: An Anachronism" (Anonymous)
A Connecticut Yankee In King Arthur's Court by Mark Twain
The Time Machine by HG Wells
Lest Darkness Fall by L Sprague de Camp
Bring The Jubilee by Ward Moore
Past Times by Poul Anderson
The Time Patrol series by Poul Anderson

Several other works, including three further novels by Anderson, are also closely connected. However, the listed seven are significantly sequential, culminating in one collection, one omnibus collection and one long novel by Anderson. These three volumes draw together strands introduced in the earlier works.

"Missing One's Coach" introduces the idea of a modern man transported backwards through time into a historical period. It might have been a dream but the idea is there. Pastwards travel is essential for time travel. Without it, the Time Traveler would have been unable to return.

Twain develops this idea of a modern man transported to an earlier period but seems not to realize, first, that it would have been difficult to introduce technological innovations in the Dark Ages and, secondly, that it would have been impossible to introduce at one stroke modern technology in such a period. Twain's successors, de Camp and Anderson, spell out this difficulty and impossibility.

Wells:

introduces the idea of a temporal vehicle or "time machine," which reappears in a more versatile form in the Time Patrol series;

discusses the appearance of a time traveler on a historical battlefield, an idea developed by Moore and Anderson;

 
hints at temporal paradoxes, examined in one novel each by de Camp and Moore and in a lengthy series by Anderson;

colorfully describes future periods as Anderson colorfully describes past periods;

as a pessimistic Victorian, describes the devolution of humanity whereas the optimistic American Anderson refers to its evolution;

shows the Time Traveler exploring the further future as an Anderson character does in "Flight to Forever."

For his first Time Patrol assignment, Manson Everard travels from the year in which The Time Machine was published to post-Roman Britain in order to prevent a "time criminal" from pulling a Connecticut Yankee stunt back then. Anderson's "The Man who Came Early," which should be included in future editions of Past Times, is a reply to Lest Darkness Fall whereas "The Little Monster," which is in Past Times, presents the de Campian view: a modern man can survive in the past. Thus, the conceptual sequence progresses and culminates with Anderson.

Time Travel Fiction II

The previous post differentiated two kinds of time travel stories. Poul Anderson alone excels at both. I will omit titles on the ground that the page viewer already knows them or can find out or can ask.

Causality Violation
Mark Twain: a classic novel of attempted historical causality violation.
HG Wells: the classic time travel story with only a hint of "...anachronism and utter confusion..."
L Sprague de Camp: a definitive novel of deliberate historical causality violation.
Ward Moore: a definitive novel of accidental historical causality violation.
Jack Finney: nostalgic time travel in several short stories and in two long, illustrated novels presenting an unfortunately confused account of causality violation.

Circular Causality
HG Wells: understated circular causality.
Robert Heinlein: three definitive statements of circular causality in futuristic settings.
Harry Harrison: humorous historical circular causality.
Tim Powers: hard fantasy circular causality.
Richard Matheson: a romantic novel with circular causality.
Audrey Niffeneger: the same sub-genre as Matheson.

Poul Anderson
Three novels of historical circular causality.
A long series about a time travel organization preventing historical causality violations sometimes by closing causal circles.

Dimensions

Copied from the Logic of Time Travel blog:

I am going back to basics with dimensions. Many page viewers will not need to read this post.

On the flat surface of a blank sheet of paper, there are two dimensions: horizontal and vertical. Each dimension has two directions. Horizontal: left and right. Vertical: up and down. Each dimension is at right angles to the other. Thus, it is possible to move up or down without moving left or right and vice versa.

We can let the horizontal dimension represent the temporal dimension. In that case, the vertical can represent either one of the three spatial dimensions or a second temporal dimension. In this post, it will represent the latter. A temporal dimension has a direction or "arrow" defined by causality, memory and entropy whereas a spatial dimension does not.

If the horizontal represents our familiar temporal dimension, then a horizontal straight line represents a history or "timeline" from beginning to end. Each point on the line represents a moment of time. To an observer located in one of these points, every point to the left is earlier or past and every point to the right is later or future whereas, to an external observer looking down on the sheet, the points coexist with each other simultaneously.

A second straight line drawn above and parallel to the first line can represent a second timeline existing later then the first timeline in the second temporal dimension which extends up the page. If a time traveler, reversing his arrow of time, "travels" leftwards, then he moves pastward in the first temporal dimension (T1). If he travels upwards, then he moves futureward in the second temporal dimension (T2).

The hero of Ward Moore's Bring The Jubilee leaves a timeline in which the South won the American Civil War and enters a timeline in which the North won. He moves left/pastward in T1 to a decisive battle but also up/futureward in T2 to the second timeline. Thus, he can say, from the point that he has reached in T2, that the first timeline no longer exists. However, it is still visible to an external observer of the sheet of paper. Further, it is of no concern to the inhabitants of the first timeline that they will no longer exist according to an observer in the second timeline.

Contradictions occur only when we try to cram all of these diverse events into a single temporal dimension.

Classics

The Classics are the works that are always in print. We can always buy a new copy of The Time Machine, and can even choose between editions. I do not have to name the author to identify the work.

Of the many works that do go out of print, some are remembered, referred to as "sf classics" and occasionally revived. I regard Bring The Jubilee by Ward Moore as a classic of time travel but it went out of print after two years, I bought an edition published nearly ten years later and the New English Library SF Masters Series republished it another decade after that.

When James Blish's After Such Knowledge Trilogy was published in a single volume, I did not buy it because I already owned the individual volumes and it simply did not occur to me that the single volume edition would go out of print or indeed that all the works of a writer like Blish would go out of print in my lifetime.

I am rereading Poul Anderson's Brain Wave, a good first novel, in a now out of print SF Masters Series edition with an appreciative Introduction by Brian Aldiss and am buying the Baen Books The Technic Civilization Saga, the first uniform edition of Anderson's major future history. It is to be hoped that Baen will publish Anderson's Complete Works?