If you are misremembering a few details, you may be partially remembering the first book of Zelazny's Chronicles of Amber series. The first book is 'Nine Princes in Amber' (1970).
The 'Childhood Friend' would be his brother, Random
They set off in a car to get to Amber, the one, true world (well, as of what we know at that time in the series) that casts ...
There are at least five. (and an unnamed one)
First appeared in Animal Man #23 (1990), as an illusion of sorts (generated by Psycho-Pirate's mask), along with other twisted versions of known characters. Then, his nationality is uncertain.
Kal-El of Earth D
Featured in Legends of the DC Universe: Crisis on Infinite Earths (1999).
Almost certainly Asimov's The Gods Themselves.
The plot description on wikipedia gives most of the detail.
The book is in 3 parts.
Part 1, "Against Stupidity...", deals with the discovery:
Radiochemist Frederick Hallam discovers that a container's contents have been altered. He initially accuses a colleague of tampering with his sample, but eventually ...
Maybe not exactly what the OP is looking for, but we'd be remiss if we went without mentioning
Flatland: A Romance of Many Dimensions
Published in 1884, Flatland depicts a 2-D world inhabited by polygons and lines, which then interacts with a 1-D world inhabited by points, a 3-D world inhabited by a sphere, and a 0-D world which is a point.
While none of ...
The International Space Station...in the opening credits of Enterprise.
Construction started 1998 and completed 2011.
Certainly latest 2009 as, per Wikipedia
The truss and solar panels are also a large part of the station. (launched in multiple flights between 2000-2009)
From Space.com (See Date Link above)
This photo of the International Space ...
1928: "The Blue Dimension", a short story by Francis Flagg, published in Amazing Stories, June 1928, available at the Internet Archive.
The first-person narrator's friend, a retired optometrist, has discovered that there are coexistent worlds separated from ours by different rates of vibration:
"[. . .] Consider that we are living at a certain rate of ...
To your question "Does the original version of the universe still exist where Marty simply disappears", I would say the answer is "no". I think I'm not really disagreeing with Axelrod's answer since that answer is focused on whether Marty could recreate his original timeline, not on whether it continues to exist in parallel with the original, and Axelrod ...
Eye in the Sky, a 1957 novel by Philip K. Dick; also the (unaccepted) answer to this old question. Does any of these covers ring a bell?
The inside-out cat is in section XIII. The cat-hater is a woman:
Miss Reiss had never liked cats. She had been afraid of cats. Cats were her enemies.
The thing on the floor was Ninny Numbcat. He had been turned inside ...
According to the Wikipedia article on Parallel Universes, In one of the stories-within-a-story of Thousand And One Nights, "The Adventures of Bulukiya",
the protagonist Bulukiya [learns] of alternative worlds/universes that are similar to but still distinct from his own.
I don't know if you consider 1001 Nights as a human belief system, but I think it ...
"Tiger by the Tail" by Alan E. Nourse.
It's a steel bar instead of a wire but otherwise you remembered it perfectly.
This story is often remembered from the popular anthology "50 Short Science Fiction Tales."
I'm pretty certain that this is an Australian TV show from the 1990s called Spellbinder.
It has power suits which can throw balls of lightening, and are recharged by rubbing the cuffs together.
In the first episode, the main characters attempt to create gunpowder, and in a later episode a main character is forced to create gun powder by their captors.
Episodes were aired out of order, so it's not entirely obvious what happened.
Episode 1x06, Summer of Love, was intended to be episode 1x02. At the beginning of this episode, we see Quinn reopen the vortex so that he and Arturo could go through - he had control at that time, as you suggest.
However, due to that slide, the timer was damaged. There's a ...
Sounds like the Neanderthal Parallax by Robert J. Sawyer to me, which is a trilogy composed of Hominids, Human, and Hybrids.
Neanderthals have developed a radically different civilization on a parallel Earth. A Neanderthal physicist, Ponter Boddit, accidentally passes from his universe into a Canadian underground research facility. ...
A Crack in the Line by Michael Lawrence, 2003?
It's been two years since his mother died in a terrible train crash, and Alaric's life continues to unravel. He and his father are barely on speaking terms, and Withern Rise, their Victorian mansion, is in shambles. Trapped at home during a blizzard, Alaric stumbles into a parallel world; a reality in ...
The latest people referenced that match our reality were George W. Bush and Tony Blair, shown in the ENT episode Future Tense:
This was part of a historical database that included Bush's 2003 State of the Union Address.
Fauna of Mirrors - 2697BC
This probably doesn't count, but I believe mythology has this one in the bag. Specifically: the Chinese Myth of the "Fauna of Mirrors". It involves mirrors being used almost exactly as a portal in modern literature.
According to the myth, behind every mirror is a different universe (...
The main theme of that episode (DS9: The Visitor) is that Jake's father was trapped in time. By freeing him, Jake caused that particular timeline to cease to exist.
JAKE SR: You see, Melanie, after the last attempt to rescue my father failed, I spent months trying to figure out what went wrong.
Eventually, I came to understand the nature of what was ...
I'm not sure you could strictly describe the creation of a music track as an historical event, but nuKirk playing the 1994 song Sabotage (by the Beastie Boys) on his Nokia phone would have to be a strong contender.
You can see the London Eye and 30 St Mary Axe (otherwise known as "the Gherkin") in the distant London ...
Although some of the details are a bit off, this sounds like Conquistador by S.M. Stirling.
From the Wikipedia description:
John Rolfe VI is an infantry captain who comes back from World War II with a war wound and few prospects, but in 1946 a radio he is rewiring malfunctions and creates a gateway to a parallel universe. This universe is one in which ...
Some early examples, surely not the first:
Arabian Nights, e.g. "The Adventures of Bulukiya". Arabian Nights subsequently became a big influence on European literature upon the 1704 translation. Would be from ~750 AD at the earliest.
So Gabriel descended and, saluting Bulukiya, opened the gate to him, saying, 'Enter this door, for Allah commandeth me to ...
What "time travel" story required the traveller to mentally reconstruct his world in order to return to it?
"Flux" by Michael Moorcock and Barrington J. Bayley, first published in New Worlds Science Fiction #132, July 1963, available at the Internet Archive.
1. The protagonist is sent a relatively short distance into the future (maybe a year? I've ...
The question snippet matches with practically the only thing I remember about the 1993 made for TV movie Doorways.
Cat, a fugitive from a parallel Earth ruled by aliens, lands on "our" Earth in the middle of a freeway, causing an accident. She is slightly injured, and wakes up in the emergency room of a hospital, where Thomas, a doctor, takes care of her....
You're thinking of Manifold: Time (1999) by Stephen Baxter. It is the first book in the Manofold trilogy followed by Manifold: Space and Manifold: Origin.
Time is set on Earth, the inner part of the Solar System and various other universes onwards from the 21st century. The novel covers a wide range of topics, including the Doomsday argument, Fermi ...
Not much to go on here, but this might be West of Eden by Harry Harrison. The protagonist is a human(ish) who was raised by the dinosaurs who had recently discovered and begun to colonize what we'd think of as the new world. As a young adult, he is "rescued" by another group of humans, and has to adjust to living among his own kind, then to act as an ...
Wikipedia has this to say:
One of the first science fiction examples is Murray Leinster's
Sidewise in Time, in which portions of alternative universes replace
corresponding geographical regions in this universe. Sidewise in Time
describes it in the manner that similar to requiring both longitude
and latitude coordinates in order to mark your ...
This sounds like The Boy Who Reversed Himself by William Sleator. The characters were able to move around in higher-level dimensions (four-dimensional space, five-dimensional, etc.) They didn't visit a mirror universe, exactly — what happened was that, if they weren't careful, they could get themselves turned around and come back to our world as their own ...
I have been reminded that a related question, What was the earliest SF work that used the idea of the "Multiverse"?, was asked a couple of years ago, at which time I gave the following answer, which was accepted:
1915: A Drop in Infinity, a novel by Gerald Grogan, available at the Internet Archive. Reviewed by Everett F. Bleiler in Science-Fiction: The ...
I suspect this is The Lathe of Heaven (1971) by Ursula K. Le Guin.
The main character, George Orr, suffers from "effective dreaming", which means that his dreams can alter reality. With training, he can use it to achieve desired changes.
He initially receives treatment from a psychiatrist in order to suppress the dreaming, but the psychiatrist realizes ...
A few answers come to mind:
There's the Mirror Universe from TOS, which reappears in later series. It seems to be connected to the primary universe in some way.
There's the antimatter universe, from TOS.
There's a near-unlimited number of quantum realities seen in TNG 7x11, "Parallels".
Then there's the alternate timeline created for the 2009 movie.