Mapping Alternate History and Time Travel Tales

Differences & Overlaps, Essay. 1400 words, 7-minute read.

Oct 09, 2025

Mapping Alternate History and Time Travel Tales

By Ray Tabler

One of the reasons I attend science fiction conventions is that they almost always spark ideas for essays, rabbit holes to fall down and write about. This past weekend, Archon 48, near St. Louis provided numerous examples. I was on a panel which explored the differences, similarities, and overlap between Time travel stories, and alternate history.

First of all, gratitude and kudos to my co-panelists: Kathy Bailey (moderator), Steven H Silver, R J Carter, & Codi Coleman. We were tasked with riffing on time travel and alternate history. The number of ideas and insights you get from corralling a few writer/fans behind a folding table at the front of a room full of interested and opinionated individuals greatly exceeds the number you get from the same crew sitting and thinking individually.

A lingering curse of a technical education is the compulsion to convey a complex concept in the form of a graph. See the above. It occurred to me that the vast sweep of alternate history and time travel tales could be captured in an x-y graph. The x axis represents how hard it is for a time traveler to monkey around with causality. The y axis shows the number of parallel universes allowed by the rules of the tale in question. The graph naturally divides itself into quadrants by a vertical line separating no forward/back time travel from some time travel, and a horizontal line above 1 universe and below >1. Zero universes are not on the graph, because we wouldn’t be here to graph that.

At the lower, left corner is real life, in which we find ourselves. At least I do. If you’re not, let us know. We’d love to hear all about it.

Adjacent to real life is “secret history.” That is, fantastical historical events of which most people are not aware. The Dark Skies TV show is an example, relating a covered-up alien invasion at Area 51. Forrest Gump would technically fit into this part of the graph, as Forrest nudges history this way and that without credit (or blame, depending on your point of view).

No time travel per se takes place in secret history, forward/back or sideways. However, an example of a fence-sitter would be Steve White’s Jason Thoreau series. In this set of novels, a future time-traveling organization battles an evil conspiracy which seeks to set the stage for a final conflict. Recorded history is unchangeable, but events which the human race doesn’t know about, in history’s shadows, are fair game for monkeying with. Think of it as ”Schrodinger’s history.” Not set in stone until we look at it. So, I’d place the Thoreau books as just across the line from secret history. Maybe straddling it.

To the right of real life and secret history, hugging the x-axis, are all the tales we think of as traditional time travel. That is, back and forth time travel in just the one universe. Adjacent to real life would be time travel in stories where changing history is difficult, if not impossible. The main character in HG Wells’ The Time Machine doesn’t change history. Writing such stories are like assembling a Swiss watch. All the parts have to fit together and mesh, or it just doesn’t work.

As causality gets squishier and squishier, you get tales like the movie Looper, Harry Turtledove’s Guns of the South, Poul Anderson’s Time Patrol series, Back to the Future, and finally Ray Bradbury’s A Sound of Thunder. In A Sound of Thunder, a time traveler accidentally steps on a butterfly, altering the future he returns to beyond recognition.

Rising up the y axis are alternate history stories, where timelines split history into parallel universes without the benefit of forward/back time travel. It is convenient to distribute these tales by the number of universes in each multiverse. This scale generally measures the difficulty in generating daughter universes from a given point of departure (POD). That might take a lot of effort, or be unavoidable. In It’s a Wonderful Life, opening a temporary window into an alternate timeline requires semi-divine intervention. At the other end of the y axis, Man in the High Castle tells of universes dividing at the drop of a hat, perhaps even on a subatomic level. In between, a finite number of parallel worlds reflect the increasing ease of calving off a whole other universe.

H. Beam Piper’s Paratime series is about an advanced human society which polices a relative handful of parallel universes, split off from their timeline by fateful PODs. In Phillip Jose Farmer’s World of Tiers books, a now-decadent civilization created a group of parallel pocket universes (of which ours is one) then mostly died out to leave their handiwork unattended. One could argue that World of Tiers is not truly alternate history, the universes being artificial. Perhaps. I plotted this tale as alternate history, because I didn’t know what else to do with it.

The stories plotted all allow sideways time travel. But that doesn’t have to be the case. Numerous (myriad?) alternate history stories simply explore the possibilities of what if things had gone another way. Alternate endings to the Civil War or World War II? What if a comet hit Europe in the late 1800s? What if the Nina, Pinta, and Santa Maria sank in a storm before reaching the new world? Once you start ticking off the PODs, it’s hard to stop. Fortunately, there’s a database to consult. Uchronia.net is an online, searchable collection of alternate history galore. Many thanks to Steven H Silver for making me aware of this resource. Fair warning, this rabbit hole is deep and dark.

Complicating the number of universes in a given fictional multiverse is the decision the author might make to allow split universes to recombine. If the change is small enough, and not very noticeable, the separate parallel worlds might merge again, like a river flowing around a midstream island. This could provide drama, as some characters might want them to remain divided. Perhaps this is an explanation for the Mandela Effect.

Surprisingly, I could not come up with all that many stories which include both alternate universes and forward/back time travel. But then, I don’t know everything. I don’t even know as much as I like to think I do.

This is how You Lose the Time War tells of a pair of lovers, on opposite sides of a time war, who collude to stop the madness. Backwards/forward and sideways travel is included. The 1632 (Assiti Shards) series is about an arrogant, callous alien race (the Assiti) who relocate entire human communities across time as a sort of performance art, splitting off alternate universes in the process. The novels relate how these communities deal with their unexpected trips. In Sea of Tranquility, various characters roam across time and alternate timelines. Weber’s and Holo’s Gordian Division series is about a future society which uses time travel freely, recklessly, assuming that the past can’t be changed, no matter how badly they behave there. Until it is discovered that their actions are not only spinning off unsuspected alternate universes, but building up chronological stresses which threaten the entire multiverse.

And then there are the confusing plates of forward/back and sideways spaghetti which comprise the Marvel and DC multiverses. I wouldn’t even know where to begin.

There you have it, an attempt to categorize and map alternate history and time travel. You may angrily reject the entire concept, or quibble with where some tales have been plotted. Please do so. In fact, I encourage you to question and/or improve the graph, as well as adding what I have overlooked. Because, the only thing which precipitates more discussion than corralling a few writer/fans behind a folding table at the front of a room full of interested and opinionated individuals, is posting an opinion online… Let the games begin.

END.