The blurb for the story sets it in “the fourth dimension,” but alas, this refers to a parallel universe, not time travel for Charlie Wilson and his English friend, Captain Derek Mason.

In the first novella (“The Fifth-Dimension Catapult”), physicist Tommy Reames and mechanic Smithers must rebuild the broken machinery that’s catapulted Professor Denham and his beautiful daughter into a parallel dimension of vicious jungle people, strange life forms, and a beautiful golden city. And gadzooks! In the second novella (“The Fifth-Dimension Tube”), the vicious fifth-dimensioners invade Earth! But despite the suggestive titles and citations of both stories in Nahin’s Time Machine, the stories involve only handwaving about time and space dimensions, minor enough that we don’t even count it as a time phenomenon.

When Joan Carmody sends a plea to her ex-boyfriend Bert Redmond, he barrels from Indiana to upstate New York in a trice, only to see Joan and her borderline-mad brother Tom kidnapped by metal monsters from another dimension. Fortunately, a mourning, immortal wanderer through time and space also sees the abduction and fills in Bert with all the salient details and some unsalient ones, too.

When salesman Ralph Carson Drake tries to recover his missing memory of the past two weeks, he discovers he had interactions with three people: a woman named Selanie Johns who sold remarkable futuristic devices for one dollar, her father, and an old gray-eyed man who is feared by Selanie and her father.

Van Vogt combined this with two other stories and a little fix-up material for his 1970 publication of Quest for the Future.

Reporter Jeff Coates is working on a series of articles about the old Mississippi river mansions when he spots a riverboat near the old, dilapidated Waverly plantation.

Oh, dear! Albert Miller has dialed a wrong number on the Mugwump-4 exchange, and the mutants who answered have decided that the only solution is to catapult him into the future where he won’t be able to upset their plans for World Domination.

Hugh Farnam makes good preparations for his family to survive a nuclear holocaust, but are the preparations good enough to survive a trip to the future?

In his blog, Fred Pohl wrote about how Heinlein’s agent gave permission for Pohl publish the novel in If and to cut “five or ten thousand words in the beginning that were argumentative, extraneous and kind of boring” (and Pohl agreed to pay full rate for the cut words). But apparently, Heinlein “went ballistic” when he saw the first installment, so much so that when the book appeared as a separate publication, Heinlein made sure people knew who was responsible for the previous cuts by adding a note* that “A short version of this novel, as cut and revised by Frederik Pohl, appeared in Worlds of If Magazine.”

* The version of Heinlein’s note that Pohl recalled was much funnier than Heinlein’s actual note in our timeline, but sadly, we have lost track of where we saw Pohl’s version.

Although this one-page feature is title “Time Pocket,” it seems to be about travel to another dimension rather than through time.

After the Scarlet Centurion waylays the Avengers on their way back from the 1940s, they find themselves in an alternative 1968 where the five original Avengers stayed together under the thumb of the Scarlet Centurion.

The story includes flashbacks and previously unknown explanations of the team’s previous trip to the ’40s in Avengers #56, and at the end of the story, Goliath uses Dr. Doom’s Time Platform to banish the Scarlet Centurion back to his time—and we think this is the only time travel that actually appears in the story (apart from the flashbacks). We don’t know what happens to the alternative 1968 (now known as Earth-689, but the traveling Avengers return to the universe that we all knew and loved in the 1960s (a.k.a. Earth-616), with their memory of the whole affair wiped by the Watcher.

Using Doc Doom’s time platform, the tag-3743 } Wasp sends Cap and the other three 1968 Avengers back to observe Bycky Barnes’s death at the hands of Baron Zemo.

Detective-Lieutenant Gene Trimble suspects that the recent spate of suicides and violent crime is somehow connected to the discovery that the many worlds interpretation of quantum physics is real and each of those worlds can be traveled to.

With eleven years of marriage behind them, Ted and Alice’s fantasies frequently start with a time machine and end with killing one or another of their spouse’s ancestors before they can procreate. So naturally, they each end up at Temponautics, Ltd. Oh, and Ted’s grandpa has some racy fantasies of his own.
In Silverberg’s Something Wild Is Loose (Vol. 3 of his collected stories), he posits that this story is “probably the most complex short story of temporal confusion” since Heinlein’s “By His Bootstraps” (1941) or “—All You Zombues—” (1959), but I would respectfully disagree. In particular, I would describe Heinlein’s two stories as the most complex short stories of temporal consistency in that there is but a single, static timeline and (in hindsight) every scene locks neatly into place within this one timeline. By contrast, Silverberg story involves multiple time travel choices by the characters in what I would call parallel universes. The confusion, such as it is, stems more from what appears to be alternate scenes in disconnected universes rather than temporal confusion per se.

The 2020 posthumous publication of this 1977 manscript shows us Heinlein’s first forey into the multiperson solipsism of semi-mad scientist Jake Burroughs, his beautiful daughter Deety, her strong love interest Zeb Carter, Hilda Corners and their time/dimension-traveling ship Gay Deceiver. In all, the earlier manuscript has three adventures that were significantly changed in his eventual 1980 publication of the work, retitled as The Number of the Beast:

1. In Pankera, the Mars Ten actually is Barsoom where the gang meets the Princess of Mars and others, while in Beast, Mars Ten is a relatively boring futuristic British Mars.
2. Pankera has a long adventure in the Lensman universe, while Beast has only a few pages.
3. Pankera’s ending is a 30-page, rushed description of how they plan to launch a major war against the Panki, while Beast’s 130-page ending takes the gang to the universe of Dora and Lazurus Long where they rescue Maureen from the past and are joined by a passel of Heinlein’s characters.

In both books, Gay Deceiver can clearly travel through any one of three time axes at will, although that ability is largely ignored apart from Maureen’s rescue in Beast. Because of this, we had a fierce debate up in the ITTDB Citadel about whether to even include Pankera in the database. In the end, we decided yes, marking it as the parent work of Beast, but on account of no easily recognizable time travel, we also marked it as having only debatable time travel.

Semi-mad scientist Jake Burroughs, his beautiful daughter Deety, her strong love interest Zeb Carter, Hilda Corners (“Aunt Hilda” if you prefer) and their time/dimension-traveling ship Gay Deceiver yak and smooch their way though many time periods in many universes (including that of Lazurus Long), soon realizing the true nature of the world as pantheistic multiperson solipsism.

In Heinlein’s first version of this novel, written in 1977, the middle third of the story takes place on Barsoom, but in the 1980 published version, Barsoom was replaced by a futuristic British Mars

A boy’s bedroom is invaded by six dwarves who have stolen The Supreme Being’s map, which naturally leads both boy and dwarves on adventures through time.

Living an isolated life on the spaceship Maid of Astolat, Lady Dela and her crew of cloned servants designed in the image of Arthurian legends are pulled into a parallel dimension, but despite the title of this first book in Cherryh’s Alternate Realities series, there is no actual time travel.

Every year, Jason Babbidge competes in the skate-sailing race on the two-and-a-half-mile-wide glass surfaces left behind by slowly flying birds when they occassionally explode before disappearing. This year’a race is not a win for Jason, but even worse is what happens when his brother Daniel climbs aboard one of the birds afterwards.

Banzaiers keep writing to the ITTDB Citadel, telling us to add this cult movie to our database (or else we should prepare ourselves for the unexpected, as He would). We finally gave in to keep them from banzaiing us, but alas, oscillation overthruster ≠ flux capacitor, and the rock-musician-neurosurgeon-particle-physicist Banzai merely travels through all the dimensions except time.

With the help of ominous music and a Cosmic Key that opens portals to other places, the evil Skeletor has finally conquered Castle Greyskull, giving Skeletor the power needed to become the Master of the Universe himself. Fortunately, He-Man and his warriors have a copy of the Key and can save the universe! Unless they misplace it and two current-day Earth teens stumble upon it.

I watched the movie through to the end(!), but spotted only one explicit small item to indicate that the Key might transport through time as well as space: When Skeletor’s minionette locates the copy of the Key, she says that they can find it within a “parsec-eon,” which kind of sounds like a space-time measurement. In addition, those who know the He-Man franchise tell me that he is a far-future descendant of Earth humans on the planet of Eternia, which means that the trip back to current-day Earth was through time. So it is a time-travel movie(!) but that fact has no bearing on the movie’s plot.

Literature professor John Baird and conman Sylvester Castlemaine hatch a plan to get rich forging Hemingway’s lost stories, but before long, Baird is confronted by an apparent guardian of the many timelines in the form of Hemingway himself.

The first story in the Diving Universe series finds the captain (a.k.a. “Boss”) of Nobody’s Business and her motley crew of five wreck divers grappling with a five-thousand-year-old derelict spaceship that’s farther from Earth than it has any right to be. Their own spaceship has an FTL Drive, which always implies time travel, and there are suggestions that the old ship has areas of differing time rates based on interdimensional, parallel universe hand-waving, but the confirmation of actual time travel doesn’t occur until later in the Diving Universe series.

This time around, “Boss” puts together a crew to dive into the central part of an age-old abandoned space station where many have entered but, apparently, only Boss (long ago, as a young girl) has ever returned. The universe is largely unchanged from the first Diving Universe story, replete with mysterious interdimensional ambiguities and timey-wimey goings-on, but still no actual time travel.

Imagine you’re a young boy in 1921 Cambridge when your equally young first love dies in a deep well. What would you do? Naturally, you’d vow to become a great scientist in an artsy movie so you could go back in time to alter the tragic event.

Apparently, people in early 20th-century Cambridge espouse many wise thoughts about time, parallel universes that encompass every possible combination of events again and again, and something about every decision every made creating a branch point. In the end, it's difficult to make a cohesive model of time from the plotline of Dimensions, but we tried our best to do so in our plot notes.

Time travel is implied right from the first episode of the CW’s rendition of The Flash where a newspaper from the future is seen in the closing scene. The rest of the first season builds a fine time-travel arc that includes a nefarious time traveler from the far future, a classic grandfather paradox with a twist (sadly not examined), a do-over day for the Flash (which Harrison Wells calls “temporal reversion”), and a final episode that sees the Flash travel back to his childhood (as well as a hint that Rip Hunter himself will soon appear on the CW scene).

After Barry aborts his mission to the past in Season 1 in order to prevent his own present from being erased, he finds that his travel has caused even bigger problems! Yep, a rift has been a-opened to a parallel world with an alternate Flash and an evil speedster and—it would seem—more time travelin’ and another attempt to save his mom and dad!

Although the story has no explicit mention of time phenomena, please see our tagging of the story for one interpretation of Imoghen’s multiverse travels.

Two men—a garage shop owner and a mad scientist—loop through 13 days, meeting and shooting each other and themselves, but not so that we could understand much (beyond that there was a time portal made of hubcaps and blue electricity).

Forty years after NASA explorer Tessa Raij attempted to step through a dimensional portal and was instead relegated to an inexplicable state of isolation in a radioactivce crater, a dead girl—resembling her grandmother as a teen—shows up at her feet.

A bad egg creates chaos by leaving time portals open between various times in various parts of the multiverse.

Audra Cobb is pulled through time rifts from one parallel universe to another with a bit of time travel thrown in. I think the parallel universes are a literary mechanism to explore daydreaming about what might have been while under the spell of limerence.