- Reconstructing the Past:
I used to be rather a hardnose on this: “Viewing the past without being able to affect it is not time
travel, not even if you are a holiday ghost,” I said. In my older and wiser self, I am now more lenient.
Unless the past is being reconstructed from items that never time traveled, then I’ll assume that viewing
the past generally involves some information or noncorporeal being undergoing time travel. See
“A Christmas Carol”.
This same philosophy applies to:
- Sending a Vision to the Future
- Ancestral Memory
- Viewing Alternate Pasts
- Continually Viewing the Past
- Calculating the Future:
In the same way as viewing the past, viewing a possible future (or observing it in some
other way such as a computer generated image) will generally be considered time travel unless
we are simply viewing a possible future that is computed based on items readily available in the present.
In addition, I'll assume that stories involving the following psychic abilities are on the same plane as indigestion
unless the story explicitly states that
information is being passed from the future to the present; although as keeper of the Big List,
I reserve the right to include such stories on a whim, especially if there are interesting
questions about predestination afoot.
- Indigestion Results in Premonition:
Not time travel.
- Differing Time Rates:
Clocks may run at different forward time rates under different
circumstances, but such differences are not time travel. Includes:
- Time Dilation (relativistic or gravitational)
- Personal Time Rate Differences
- Stopping Time
- Civilization Regresses:
Which may seem like time travel, but in fact, it’s just
something that will happen sooner or later.
- Just a Dream:
Yes, they still write stories like this.
No, they are still not time travel.
However, if the characters of the story believe that the
events in the story actually happened in their own world, then I shall
trust the story is not a dream or travel to a separate world—so,
yay for Connecticut Yankee in King Arthur’s Court!
- Just a Wish:
- Supernatural Story:
Supernatural stories, in and of themselves, are not time
travel. Not even Ben Franklin’s ghost appears. Includes:
- Ghost Story
- Flying Dutchman
- 4D Spacial Topology;
The fourth dimension does not always refer to time. Many
stories consider the consequences of a fourth spacial
dimension that we are not usually aware of, in much the same
way that Flatlanders are not aware of the third spacial
dimension. For example, these stories allow shortcuts by
folding our 3-D world in four dimensions or flipping a left
hand into a right hand. Klein bottles may also apply to this category.
- Bizarre Aging:
Bodies or objects aging quickly or decaying or growing young
again or renewing—none of that is time travel when time
is otherwise experienced ina normal fashion. Includes:
- Backward Aging
- Memory Tricks
- Rapid Aging
- Fountain of Youth
- Odd Entropy:
I am reluctant to use the phrase “time travel” for
a world in which the entropy of a closed system always
decreases (or other odd entropy behavior). Of course it is
bizarre to us to read about a world of unscrambling eggs,
increting poop, exgesting food, and perhaps (as
in Knight’s “The Way to the Regress”) the
history shelves are
full of predictions—but that’s just the way they live.
- Sped Up Evolution:
This may allow us to imagine what humankind’s future will
be, but it’s not time travel.
- Long Sleep:
As did Rip Van Winkle, someone falls into a long sleep and awakens in
the future. The sleep could be described in many ways, such as cryogenic sleep
or suspended animation, but it amounts to the same thing: no time
- Other Universes:
Traveling between different universes is
not usually time travel (although it could be if you both move into that universe and move through time). Many possibilities:
- Parallel Universes (worlds similar to but not
derived from ours)
- Alternate Timelines (timelines diverge from ours)
- Alternate History (a single alternate timeline with
historically significant change from ours)
- Many-Worlds Quantum Mechanics (universe branches at
quantum wave collapse)
- Secondary Worlds (e.g., fantasy world)
- Monster-Filled Universes
- People-Trapping Dimensions
Oddly enough, faster-than-light travel or communication is always equivalent to
backwards time travel from an appropriate relativistic frame of
reference, but unless the story makes the time travel explicit,
I won’t include it in the list.
- Long Life and Immortality:
Neither living for centuries nor living forever is not time travel.
...is not time travel. Although I suppose it could be if you
were not living your lives in chronological order.
- Legendary Figures:
Greek gods, Paul Bunyan, and their kin may pop up anywhere in
history without invoking time travel (unless time travel is explicitly used as an explanation).
- Calendar Tomfoolery:
Crossing time zones and date lines and otherwise messing with
the calendar is not time travel, not even if the characters
in the story believe that it is.
- Despite Appearances, No Time Travel:
A hoax or ruse or misunderstanding or other circumstances
(including misdirection by the author) may
make it seem that time travel has occurred, but that
doesn’t mean that it has. Includes:
- Despite Title, No Time Travel
- Just Teleportation
- Time Phenomena without Time Travel
- Virtual Reality
- Post-1969 Comic Books:
After 1969, everything in comic
books became time travel, which is logically equivalent to nothing
being time travel.
- Romance Travel:
If at any point there is a whole bodice, and at some subsequent
point there is a bodice that is less than whole, then the story
is not time travel.
- No Definite Time Travel:
Sometimes it’s just plain hard to tell whether time travel occurred
or not. In this case, I will generally say not time travel. Includes:
- No Time Travel . . . Yet!: Characters traveled in later story.
- Sequel: Characters traveled in earlier storys.