In reality, wormholes are purely a scientific conjecture, a consequence of the same equations that describe black holes. There's no way that we can conceive of to get to one or use it for anything. In fiction, however, wormholes are a Swirly Energy Thingy that can be used as a convenient means of travel from one place to another.
The most common use is for FTL Travel. By extension, if they show up often enough and consistently enough, they can become nodes in an interstellar Portal Network. They can also enable Time Travel, provide a mechanism for FTL Radio, act as doorways to Alternate Universes, or any/all of the above. No matter what Technobabble is thrown around, rarely will any two authors treat them in precisely the same manner, which is why Our Wormholes Are Different.
Related to Negative Space Wedgie. Compare: Our Time Travel Is Different, which this may sometimes overlap. See also Swirly Energy Thingy. Compare Unrealistic Black Hole.
The Bifröst bridge in Thor is actually a traversable Einstein-Rosen Bridge (read: wormhole) appearing as a beam of light shooting to and from the sky. The myth of it being a rainbow bridge is due to the fact that it causes atmospheric disturbances as it opens up on Earth. It also comes with a neat light show.
Apparently, if you keep it open longer than a few seconds, it can act as a Wave Motion Gun and destroy an entire planet... Which makes a lot more sense when one considers the ludicrous energies required to make on of these things work in Real Life.
The portal created by the Tesseract/Cosmic Cube in The Avengers is a bit more conventional than the above, but no less spectacular: a circular doorway in the sky to wherever it is that the Chitauri come from, spewing out Aliens and Monsters to attack New York.
The Mi-Go portal from Yuggoth (Pluto) to Earth in the 2011 adaptation of The Whisperer In Darkness seems to be mystical in nature, rather than technological. An elaborate ritual is required to open it, along with, you guessed it, Human Sacrifice. It is critical that a shaman or priest from Earth passes through first, before it can be used, lest it collapses. Oh, and it was probably left behind by Shub-Niggurath.
In Contact, Dr. Arroway theorizes that the the alien machine transports its subject via an Einstein-Rosen bridge.
The only time a wormhole came up in the Star Wars Expanded Universe was in The Phantom Affair, an arc in the X-Wing Series comics. A superweapon known as the gravitic polarizing device made the enemy ships and a portion of the asteroid belt ringing a planet simply disappear, with one of the startled pilots saying that it looked like a wormhole had opened up.
In "The Glove of Darth Vader", a wormhole created by the exploding reactor is responsible for transporting Darth Vader's indestructible glove from the exploding wreckage of the Death Star II to the oceans of Mon Calamari.
The Night's Dawn Trilogy has humans using wormhole-generating ZTT drives to cross interstellar distances. The mechanical type requires the ship to be spherical◊ and is bound by orbital mechanics, while the ones used by the organic Voidhawks have no such limitations, but die after a few decades. The Kiint have refined the technology to the point where they use personal teleporters to jump between distant galaxies.
Lois Mc Master Bujold's Vorkosigan Saga has an interstellar community, "the Nexus," linked together by "wormholes." Rather than being stellar-scale objects of massive gravity, these are subtle flaws in spacetime that you need special equipment to detect and use. They are natural features of some star systems. Earth only has one, way out in the Oort Cloud. Lucky systems have a handful. Barrayar, the heroes' home planet, was cut off from the Nexus for centuries when their one wormhole unexpectedly closed.
In The Wheel of Time, the theory behind Traveling (aportation) for male channelers is to bend space until two points are next to each other, then to drill a tiny hole. A woman warns that a female channeler (whose method is the same in effect but is quite different on the backend) attempting the same feat would fall into the gap between the two sides, which, if it's anything like other methods of hyperspace travel, is just an infinite black nothingness from which there is no escape.
Sliders had wormholes that could only be opened at certain times, and transported people between parallel dimensions (alternate realities would be a better pair of words). A specific device was required to create said wormholes.
In fact, each timer was unique in that each had its own cycle. Should the traveler miss his/her window, he/she would have to wait for the next one with the current timer for over 29 years - a number defined by Applied Phlebotinum.
Farscape had a wormhole send the protagonist from our solar system into very unfamiliar space. Aliens (and thus hilarity) ensue.
Later he turned wormholes into offensive weapons, learned how they could be used for travelling to different points in time as well as "unrealised" realities", and eventually he learned how to make a "wormhole weapon" (essentially a black hole that doubles in size every few minutes). When he revealed that last one, every villain who'd been hounding him for the knowledge suddenly realized wormhole weapons were exactly as bad as he'd been telling them.
Stargate SG-1 has controlled wormholes created between the titular stargates, and as the means for spacecraft to enter hyperspace.
In the Stargate Verse, wormholes operate in subspace, rather than hyperspace. Atlantis (the city) used a wormhole drive (rather than a hyperspace drive) to get from the Pegasus Galaxy to Earth (in the Milky Way) in a split second, where Hyperspace was taking weeks. Our Wormholes Are Different indeed.
Atlantis used a hyperdrive to get from Pegasus to the Milky Way, and used its wormhole drive only after its hyperdrive broke down near the edge of the Milky Way. Also, in the first episode of SG-1's sixth season, a "hyperspace window" is referred to as a "wormhole," so wormholes are used to enter hyperspace.
This franchise also has the peculiar and arbitrary "time limit" rule. It's apparently a "law of wormhole physics" that it's impossible to maintain a wormhole for more than 38 minutes (unless it's plugged into a black hole or similar massive power source, which would suggest that it's more a limitation of the stargate's power systems than anything to do with physics). In effect, though, there seem to be more exceptions than cases of this rule being played straight.
The first time that the 38 minute rule was exceeded was because of time dilation, not energy expenditure: on the black hole planet, 38 minutes hadn't elapsed yet. This is why the wormhole remained open. Sadly, in later episodes it just became dumbed down to "black hole/energy = wormhole can stay open longer".
During solar flares, wormholes have a tendency to travel back in time, with the strength of the flare determining how far back/forward in time the wormhole can go. Strangely, the first time this happened, SG-1 were rematerialized without a stargate, something thought to be impossible. This forms the plotline of several episodes as well as the Continuum film.
Indeed, the rules for how wormholes behave under these conditions seem to be different in each and every appearance. Sometimes the wormhole "loops back" and travelers emerge from the gate they just entered, sometimes they come out of the gate they were trying to travel to, sometimes there is a visual effect associated with the disruption, sometimes not... There have been passing Handwaves about how different external conditions result in the different effects, but yeah... Those wormholes are different.
At first, it's not the 'solar flares', the flares are just bending the wormholes somewhere else. The implication is that someone who understood, and had full control of, a Stargate could basically connect a wormhole to any point in time or space, and the lack of time travel was a deliberate technological limitation of the gate you had to 'hack' by using solar flares to bend the wormhole. Although that raises other questions, like why did the Ancients have to build an entire separate time travel system? Later, they seemed to have forgotten this explanation, and time travel started requiring solar flares.
Additionally, trying to gate somewhere during a solar flare is normally not allowed using standard-issue DHDs (Ancient-build dialing devices), as their programming is designed to prevent this kind of thing. Since Earth doesn't use a DHD but has instead jury-rigged a regular computer and employs manual dialing (spinning the inner ring), the number of restrictions it follows is basically up to the programmers.
Star Trek has wormholes. For example, in Star Trek: The Motion Picture, an imbalance in the matter-antimatter ratio in the ship's engines can create a temporary wormhole that traps the ship and other nearby objects — like asteroids. An episode of Star Trek: The Next Generation had Ferengi trying to buy the rights to a wormhole. Deep Space Nine prominently featured a permanent wormhole as part of the premise of its show, created by Sufficiently Advanced Aliens; one episode featured a Federation scientist trying to duplicate this feat. And then there were the "micro-wormholes" used for communication between Earth and Voyager.
Terra Nova has a wormhole that exists in their universe 2149 and alternate timeline cretaceous period. It is still not explained if people can go back to 2149 or it is one way, but there are hints at it being the former.
The fugitives in Tracker came to Earth via a wormhole, and Cole used one in the final episode. The math apparently isn't easy to get, and he misjudged the timing, allowing him to come back to Earth in the very end. Zin apparently originated a lot of the wormhole stuff, then got laughed at by his fellow scientists for it.
Porte sorcerers in 7th Sea have access to a rather bizarre version of portals. They can mark an object with their own blood, and then pull the object to them across a hand-sized portal, regardless of where it is. Later, they gain the ability to pull themselves to the object, regardless of where it is (rather handy if, for example, the object is in the pocket of a friend who's been imprisoned), and still later they can bring others with them. There are even rules for creating permanent Porte holes, though they cost an extreme version of Cast from Hit Points (as 7th Sea doesn't have Hit Points per se, creating a permanent Porte hole will permanently cost a number of Sorcerers a point of the primary stat that determines when damage kills them). Porte has other restrictions, though; the dimension that the Sorcerer (and any passengers) must cross is implied to one of a few cans holding Sealed Evil in a Can, either hell itself or the abode of the now-vanished Abusive Precursors (or possibly both). It is explicitly stated that anyone, sorcerer or passenger, who opens his eyes during the trip will go mad—and that the denizens of this place will whisper sweet promises to any human making the trip, if only they'd open their eyes. All the sorceries but one in 7th Sea are also weakening the boundary between the real world and hell. Porte, as it tears holes in reality itself, is implied to be one of the worst about these. Lastly, Porte sorcerers are easy to spot—they have red hands as a consequence of frequently blooding objects for their art. As a result, gloves have become fashionable in Montaigne.
The consequences of Porte are dire enough that at least one canon NPC has been executed by L'Empereur (an Expy of Louis XIV) by having his eyelids torn off and being cast into a Porte hole.
The X-Universe has the Lost Technology Jump Gates, which are needed to get between solar systems. None of the races know how to make them except the Terrans (who developed the tech on their own) and the Paranid (because they were told how by one of the Precursors).
According to the X-Superbox Encyclopedia, the wormholes are different due to using exotic matter to power the wormhole, and by using magnetic forces to flatten the aperture. If those factors didn't occur, it would be the exact same as Real Life's theoretical wormholes.
Freelancer has Jump Gates that are implied to work as controlled wormholes, as well as normal, hidden wormholes that are implied to be dangerous, but perfectly safe in practice.
The portals in Prey, much like those in Portal, show a clear view of the destination, and have zero internal length. They also have only two dimensions and one side, and can be used to shrink things and create spatial anomalies.
The portals in Portal, though a bit more short ranged than most other examples.
As of Portal 2, they're not so short-ranged anymore; the portal gun is capable of generating wormholes at a distance of at least 356400 km (from Earth to the Moon).
The portals can only be placed on certain materials such as Moon rocks. They don't do good things for your health.. So long as they have a line to the target with no other solids in the way, the portal works.
EVE Online: the expansion pack - Apocrypha - caused numerous wormholes to open all over New Eden. They transport ships absurd distances instantly, either to elsewhere in New Eden (distances that would take an hour to travel via stargates) or to uncharted Sleeper space (which could conceivably be in an entire other galaxy). They are only open for a limited time, and will only allow a certain amount of mass through before collapsing.
This was also how the original EVE Gate worked in the backstory. It lasted several hundred years before collapsing and was considerably larger, but the principle was the same.
Conquest Frontier Wars has naturally occurring wormholes to travel between systems, but then they somebody starts making artificial wormholes and things get a bit complicated, then someone else steals that technology..
Wormholes in Nexus: The Jupiter Incident act as rapid transit between remote star systems. However, the latter stages of the game reveal that they were created by the Big Bad Mechanoids as a byproduct of them altering the universe.
In Haegemonia: Legions of Iron, wormholes are naturally-occurring space phenomena that allow rapid travel to other systems. The only other way to travel to other system is via an experimental technology that creates temporary one-way wormholes to "wormhole probes" which only becomes available in the latter stages. Wormholes can be blocked by Darzok-developed probes or natural events.
The Protoss of Starcraft and StarCraft II employ some sort of wormhole-like "warp gate" to summon units to the battlefield instead of producing them. Also, plot-relevant Warp Gates, Warp Conduits and other variations on the technology are encountered throughout the campaigns and books; mention is made of a Warp Network connecting many Protoss worlds together, though their empire makes use of faster-than-light starships as well.
In the second Master of Orion, some planets are connected by a wormhole that allows a ship to travel between the systems in a single turn regardless of the race's propulsion tech. The wormholes can span distances anywhere from a few parsecs to going from one side of the galactic map to the other.
A one-time special event can also create a temporary wormhole for a ship/fleet in transit, letting them finish their trip at the start of the next turn, regardless of how long they would normally have had remaining.
Space Rangers has "black holes" (though their name is just pilots' slang) that randomly appear on the edges of star systems, and hurl you into a random system (be it one hyper-jump away or 50 parsecs into enemy territory). They also contain hyperspacepockets inhabited by unidentified ships.
In FreeSpace, Subspace travel utilizes "Subspace Nodes", which are essentially wormholes that link together certain regions of space.
Typing in "wormhole" in the Scribblenauts games will spawn a green portal that can't be directly interacted with. After a couple of seconds, the wormhole will automatically vanish and spawn a random monster, ranging from a simple mutant or alien to Cthulu.
In Command And Conquer 3: Tiberium Wars, the Scrin are all about this. Production structures are just anchors for wormholes reaching back to their fleet beyond Neptune (with the wormholes themselves being spherical, iridescent orbs of spatial disturbance and exotic matter) which get sucked back into the hole upon destruction. They employ the same technology to create two-way wormholes that allow them to teleport their units around the battlefield (but, being two-way, the enemy can send their own units back through them), and in their Rift Generator superweapon which opens one between your target and outer space, which will start to suck stuff (like infantry, vehicles, and structure armor) away. Finally, there's the 19 Threshold Assemblies, enormous towers that were meant to act as indestructible planet-scale Tiberium extractors and portals to ship the stuff back to their "Ichor Hub".
Integral to the existence of society in Orion's Arm due to the lack of any other sort of FTL travel. Actually traveling through them is time consuming and difficult, their main use is to transfer massive amount of information between star systems.
It takes so long because traversible wormholes need a "transition zone" clear of all massive objects that is at least 654 AU in diameter (over eight times that of the entire solar system). For some reason nanoscale wormholes used for data transmission don't need that much space.
Interstella 5555 features a wormhole located behind the moon that connects our solar system to another. It's particularly dangerous to use, and Shep's ship is badly damaged trying to navigate it.
The Invader Zim episode "A Room With a Moose" had Zim attempt to send the rest of his class (but especially Dib) through a wormhole to the eponymous room with a moose. It was not stated whether this was in their dimension or another.
In ReBoot, perfectly spherical "portals" connect different systems together. The "other side" is visible from all angles of viewing, distorted by the curvature of space around the opening—this is arguably the most realistic depiction of wormholes in any TV series, bar none. (Rather ironic, as ReBootdoesn't take place in the physical world and so could have easily justified a wholly unrealistic depiction.)
In "Roswell That Ends Well", radiation from a supernova combined with radiation from Fry putting aluminum in a microwave oven to create a wormhole that sends the Planet Express crew back in time. They have 24 hours before the wormhole closes, but need microwaves to make the return trip.
On Monsters vs. Aliens, Dr. Cockroach tries to invent a teleportation device in short notice to use to get around long distances during missions, but mostly to show up his rival, alien Child Prodigy Sqweep. He manages to create a working wormhole, but unfortunately, it can only go a distance of twenty feet. Also, it turns out to be lactose intolerant, somehow. He tries to pass it off anyway, and Hilarity Ensues.
Black Holes As Wormholes
The Black Hole treats its title menace, a collapsed star, as a wormhole. And not just in theory; when we finally travel into it, it is a wormhole.
Technically, they use a "quantum singularity" (as in semi-controlled artificial black hole) to power the ENGINE which creates a wormhole. Somehow. Still goes to hell though.
The Giant Spider Invasion has a miniature black hole(that can be contained in a meteor and impact the Earth without compressing the whole thing) that apparently leads to the spider dimension. Also it can be closed off by filling it with SCIENCE!
The 2009 Star Trek features an Unrealistic Black Hole that functions exactly like a wormhole leading to the past...when it isn't instead acting like a black hole by destroying things with no explanation of what makes it act one way or another. Or maybe two different phenomena that look exactly the same? Confusing as it is, note that the Star Trek franchise has used both wormholes and black holes on many occasions, but never mixed them up before. On a couple of occasions, black holes were used for time travel not by flying through them but by a by-product of the black hole's gravity, or warping near a black hole, or some other technobabble. This is not a case of getting the terms mixed up; the black hole is explicitly created by a collapsing star, which is (roughly) how real black holes form.
Except the black hole in that movie wasn't created by a collapsing star, the first one was created when Spock used the "red matter" to stop the "supernova" that was going to destroy the galaxy. Because that's what red matter is used for, creating black holes.
Also, the only times the black holes are used as weapons, they're created inside their targets, and since Spock and Nero's ships were displaced so far in time entering the initial black hole from opposite sides, presumably the same would happen to anything that gets swallowed by such a black hole, resulting in parts and pieces of the targets being sent to random time periods separate of each other, unless the whole thing comes through in one (inside-out) piece.
The wormhole-like phenomenon connecting the Klaatu Nebula to the Solar System in Galaxy Quest is explicitly identified as a black hole. This one has an added bonus of super-accelerating spaceships that travel through it.
The Flinx and Pip novel The End of the Matter features a white hole used not for transportation but to destroy (slowly) a black hole of equal but opposite mass. This is of course nearly as unrealistic as the trope being discussed.
In Sphere, the future ship used a black hole that creates a wormhole, using a Kerr metric; the black hole spins so rapidly that it warps nearby spacetime so that two distant locations and times touch.
While the word "wormhole" is never used in Angel Station by Walter Jon Williams, all ships use captured black holes in order to perform FTL jumps. This requires precise calculations, which are done perfectly by one of the protagonists, because she's a "witch", a genetically-engineered girl with the ability to see and alter electron motion. Opening a "tunnel" creates in a massive radiation wave that can damage anything for thousands of miles, meaning jumps have to be made far away from planets or other ships. It is also revealed that aliens use the same method. Apparently, any ship can be equipped with devices for capturing black holes. Why they don't get torn to shreds by gravity is never brought up.
Joe Haldeman's The Forever War uses "collapsars" to cover vast interstellar distances in the blink of an eye. These collapsars (short for collapsed stars) are probably meant to be black holes. Although transit through collapsars is instantaneous, getting to a collapsar, and then getting from the destination collapsar to where you want to finally end up, can take decades due to the fact that they're so spread out in space.
Black Hole High originally called it a black hole, though they later speculated that it was actually a wormhole and preferred that term, despite occasionally reverting to the less accurate term for its mnemonic transfer ("Black Hole" also sounds a lot like "Blake Holsey", the name of the school). Wormholes can do just about anything in this show.
In First Wave, Joshua claims the Gua use "white holes" to transport objects from their planet.
Space: 1999. Moonbase falls into a 'black sun' and, as per the black hole/white hole theory, comes out a white hole. Intact. Without everyone and everything being compressed into tiny tiny tiny pieces.
A white hole appears in the Red Dwarf episode "White Hole". It spat out the matter and time that a black hole swallowed up, leading to short time loops and similar disturbances.
In the album: The Universal Migrator Part 2 - Flight of the Migrator by Ayreon, the protagonist plunges into the black hole located in the center of the quasar 3C 273 to end up in a wormhole that will carry him to the Andromeda Galaxy (M31).
Spore treats its black holes as wormholes, and in fact often names one as the other and vice versa.
X-COM Interceptor features black holes all over the sector that can wreck havoc on your ships and probes. Playing through the game and researching the alien intentions reveals that there is exactly one black hole that is actually a worm hole to a pocket solar system, where the aliens are constructing their doomsday weapon, and the game becomes a race against time to discover the method to use the wormhole to reach the pocket dimension and destroy the weapon before it's completed.
In Gateway II: Homeworld, the player uses a Heechee ship to go through a black hole that leads to a pocket universe, which is the sanctuary of the entire Heechee race, who hid there after discovering the Assassins. Apparently, only certain ships are able to safely pass through the black hole, and it requires certain devices, which the Heechee promptly remove from the ship, preventing the player from leaving.
At the end of the Futurama episode "A Flight To Remember", the spaceship Titanic gets sucked into a black hole along with Countess Dela Rocha, the rich robot Bender fell in love with. Fry reassures Bender that no one really knows what happens in a black hole and that the Countess could still be alive somewhere. Prof. Farnsworth agrees with him, but then turns to Hermes to say "not a chance."
One Real Lifeoutdated theory proposed that black holes are the counterparts of "white holes" located elsewhere. All of the matter and energy falling into a particular black hole is supposed to be ejected from its corresponding white hole. But even white holes are subject to their own "Ours are different" among the scientific community: Dr. Stephen Hawking suggests that the "time reversal" of a black hole is also a black hole; another common perception is that white holes recede faster-than-light from attracted matter.
Other Wormhole-like Phenomena
The DC Universe has Mother Boxes that can apparently open portals between any two points. These portals are called Boom Tubes.
The electromagnetic storm in the 2001 Planet of the Apes, which not only goes through space, but also time.
A Wrinkle in Time has Tesseracts, which basically function as wormholes. Real Tesseracts have nothing to do with this, being a geometric concept related to cubes (basically, a Tesseract is to a cube what a cube is to a square). Wormholes were not topical at the time.
Quantum Gravity: There are portals between realms used to get from one to the other. Or into I-space.
The Honorverse has several wormholes but rather than a tunnel in space they are described as points where extremely powerful standing grav-waves that normally exist in hyperspace overlap with real space and allow effectively instantaneous travel between their two ends. They all come in clusters of at least two and a large portion of Manticore's wealth comes from shipping fees of their own six, later seven, terminus wormhole junction, the largest in the known galaxy.
In Necroscope a "white hole" crash landed on a Vampire World creating a small one-way wormhole that links it with ours (specifically Romania). A few millennia later a Phlebotinum Overload in Russia's ambitious continent-wide Deflector Shield creates a much bigger wormhole in the heart of the then U.S.S.R. The twist is that each wormhole is a one way trip, but by using both you can turn them into a superhighway.
In the Carrera's Legions series, Earth and Terra Nova are connected by what's referred to as a rift that allows nearly instantaneous transition between the two star systems, the only FTL Travel option for humanity.
In The Pentagon War, "hyper holes" are created by detonating very expensive hyper bombs. If two hyper bombs are set off simultaneously, and pointed directly at one another, the two hyper holes will be permanenly linked and thus create a tunnel between them through parallel space. The five inhabited star systems are linked together via these hyper hole tunnels, which also form natural choke points for invasion when they go to war with each other.
Lexx's fractal cores, glowing swirly points in space where the Two Universes intersect.
Jumpgates and jump points in Babylon 5 are very much wormhole-like on their ends, though the big expanse of hyperspace in between bears little resemblance to the theory.
Wormholes haven't actually appeared on Supernatural (unless you count a few magic portals), but they have been mentioned. When the Trickster is interrogated on where a missing skeptic is, he says smugly "He didn't believe in wormholes. So I dropped him in one."
In Starfire, every accessible star system is home to one or more naturally-occurring "warp points." A warp point provides an FTL link to another specific warp point in another star system (or, occasionally, to a warp point floating deep in interstellar space). Sometimes, one of the two warp points that forms a warp-link may be "closed" (totally undetectable unless you happen to see something coming out of it), which means there may be undiscovered warp points lurking about in any star system. (This created a dire threat to the Terran Federation during Interstellar War IV.)