Accidentally Correct Writing is a subversion of inaccuracy for Artistic License, and can come in a few flavors.
- The facts were available and could have been learned through research, but the writer assumed it was a fictional subject.
- The facts weren't available due to classified information or evolving discoveries, but the writer guessed on some parts that turned out to be surprisingly close.
- A premise, plot point or throwaway joke turned out to be prophetic in what was to come.
This can sometimes be hard to tell from Shown Their Work, and can often only be seen in context with the rest of the work and subject in question. A work that has Shown Their Work would be accurate overall, while one that has Accidentally Correct Writing would only get a few things correct. Alternately, the author could not have known the piece of information in question, and explicitly claimed to be "just guessing", but turned out to be right (as has happened more than once with real life classified information).
Accidentally Correct Zoology is a specific subtrope for an animal or other organism that was made to be fictional but turned out to be real.
If research not available at the time of the writing proves them right, that's a case of Science Marches On meeting this trope; if the work turns out prophetic, that's Dated History (and possibly Hilarious in Hindsight or Harsher in Hindsight) meeting this trope. If the thing is made true in real life, see Defictionalization. If the theory would never have been accepted by researchers working in whatever field (e.g. Professor Alexander Abian's theory that we should blow up the moon to stop Typhus), it's just the writers fertilizing some Epileptic Trees. If the writer was just showing off an obscure fact that they know, that's Shown Their Work. Compare Right for the Wrong Reasons and Genius Bonus. For the same principle applied to tactics, see Strategy, Schmategy. Compare: Accidental Truth, in which an in-story lie by a character turns out to be true after all, and The Cuckoolander Was Right, for In-Universe examples of something similar.
- This Snickers commercial ends with Eugene Levy (as a crewman) making a quip about Marilyn Monroe's iconic subway grate scene from The Seven Year Itch, saying it'll never make the final cut. Despite the obvious It Will Never Catch On joke, he's 100% correct; the actual scene is far tamer compared to the more well-known publicity stills, precisely because the censorship bureau wouldn't allow them to put something so risqué in the film.
- The cavemen depicted in GEICO's commercials are depicted as intelligent, sophisticated, worldly, and knowledgeable as a subversion of the stereotype of cavemen as brutes. Later studies of Neanderthals, and other species of humans who lived during that era, indicated they were likely just as smart as Homo sapiens, if not more so, and seem to have been about as peaceful and empathetic. That is, had species like Neanderthals avoided extinction to the present day, the GEICO cavemen would have probably been a stereotype played straight instead. To say nothing of the fact that cavemen of the species Homo sapiens (i.e. us) by all accounts had music, storytelling, visual art (some of it even incorporating motion effects with the aid of torches and movement through the cave) and a surprisingly versatile assortment of tools — all handcrafted from stone, bones and the like.
- AIR: The scene in episode 2 where Haruko mentions Misuzu thinking that dinosaurs came from chicken eggs. It has since become scientific consensus that birds aren't just the descendants of dinosaurs, but living dinosaurs themselves.
- The 2006 version of Doraemon: Nobita's Dinosaur featured feathered Ornithomimus with wings. 6 years prior to this study.
- Berserk: Miura originally designed Guts' prosthetic arm more out of Rule of Cool than anything, but it turns out it wasn't as far-fetched as he thought. Götz von Berlichingen earned fame and fortune in the 15th century with a prosthetic arm of his own. While it didn't have an Arm Cannon built into it like Guts' did, the fingers were very articulated, and an advanced series of springs and levers made the hand perfectly capable of holding a weapon in battle, among other things. Yet despite this shared trait between both people and their similar-sounding names, Miura has confirmed that he never even heard about Götz until well after he started publishing the manga.
- Final Fantasy: The Spirits Within: In the New York skyline set in 2065, the Twin Towers are completely absent.
- Golden Kamuy: Wilk raised his only child, Asirpa, to be a huntress, which is unusual because Ainu culture strictly enforced gender roles. However, as the series' Ainu language supervisor, Nakagawa Hiroshi, states in the seventh chapter of Ainu Bunka de Yomitoku Golden Kamuy ("Reading and Understanding Ainu Culture: Golden Kamuy"), Mokottunasi Kitahara discovered not only that there was an Ainu story about a girl raised as a skilled huntress in her murdered older brothers' place but also that Kinsei Ezo Jinbutsushi ("Personages of Early Modern Ezo") by Takeshiro Matsuhara documented a real-life Ainu huntress named Ciyuhirika.
- HuGtto! Pretty Cure: An interview with Keisuke Naito has him state that the only reason why they named one of the characters Ruru / RUR-9500 was because it sounded impressive, and that they never intended to reference the theater play R.U.R. at all. Despite this, Ruru's character arc revolved around her betraying her masters at the Dark Tomorrow Company and learning how to be her own person, much like the plot of the play.
- Muv-Luv Alternative: Total Eclipse: A Hot Springs Episode... set in Alaska. Yeah, it's probably just fanservice for its own sake, but Alaska is geologically active and really does have quite a few hot springs.
- One Piece: Shortly after the flashback about Corazon, Doflamingo's brother who wears a black version of his iconic pink coat, scientists discovered this.
- In his famous Pachelbel Rant, Rob Paravonian makes some very inaccurate claims about the piece, such as getting the date wrong by more than a century. However, the one thing that he admits that he doesn't know is the composer's first name, but guesses that it's Johann, since "they're all named Johann". Turns out he's dead right about that one.
- In "Weapons of Self Destruction", Robin Williams joked that the next Pope after Benedict would be from Latin America "or Brazil" (which is part of Latin America). Come 2013, Pope Francis is elected and hails from Argentina.
- French stand-up comedian Coluche did a skit on TV in 1979 in which he joked, "Just wait 'til the left [wins the presidential elections] in 2012!" At the time, a French president's term was 7 years, until Jacques Chirac changed it to 5 in 2000 after a referendum, 14 years after Coluche's death. Not only did the presidential election happen in 2012 (and not 2014, like it would have had Chirac not changed it), but the left did win. At the time of his skit Francois Miterrand (French President 1981-1995) was seen as a somewhat ridiculous perennial candidate who'd never win, so the left winning the presidency at all seemed far-fetched.
- The Agents of Atlas are all composed of '50s superheroes, but one conspicuous absence is 3-D Man, part of the '50s Avengers team that inspired the group's creation in real life. When discussing the roster in the introduction to the book's hardcover release, Jeff Parker said all the other characters were pulp archetypes, and 3-D Man wasn't, so they decided to to bench him for now (his chance would come in the miniseries titled simply 'Atlas'). But Parker's instincts turned out to be more accurate than he might have thought: 3-D Man really wasn't a character created during the fifties. That was only his gimmick, and he was created in the seventies. So he really shouldn't be part of a tribute to Atlas Comics, which is what Agents of Atlas was. So either Jeff Parker could just feel the non-50sness of 3-D Man in his bones just by looking at him, or Marvel is really, really keen on preserving Kayfabe.
- In a mid-'80s issue of Uncanny X-Men, Rachel Summers describes the future of Days of Future Past to the X-Men. Among the things she recalls is the destruction of the World Trade Center towers in 2001.
- In the Wildstorm miniseries Freddy vs. Jason vs. Ash, the latter title character makes a comment about 'Romans and their pyramids'. While obviously he was meant to be confusing them with the Ancient Egyptians, in real life the Romans actually did construct several pyramids, the most famous being the Pyramid of Cestius. Really, just about every ancient culture you can think of tried their hands at some kind of pyramid structure, given that the shape is pretty much perfect for ensuring that the resulting building can be big without collapsing under its own weight.
- A 2008 issue of Iron Man had Tony Stark invent titanium-gold alloy. The idea was to make it sound impressive and something so expensive, only Tony himself could afford to produce and use it. In 2016, titanium-gold alloy was produced for real. Titanium-gold alloy is also four times tougher than regular titanium, so it would be very useful material for his purposes.
- Ultimatum: Magneto flipped the poles of the Earth to cause a worldwide cataclysm, and perhaps even an extinction-level event to destroy humanity. At the time the comic was written, there was little evidence that flipping magnetic poles would do much of anything. However, in 2021, real-world researchers suggested that a magnetic flip that happened 42,000 years ago coincided with many cataclysmic events, possibly leading to the extinction of some species of megafauna and the Neanderthals.
- In one issue of Y: The Last Man, Yorick tries to use his illusion skills to pretend to be God, and yells out a Bible verse for dramatic effect—but because he's clearly never read the Bible, he just quotes the Ezekiel 25:17 speech from Pulp Fiction. Its supposed to make Yorick look like an idiot, and someone immediately calls him out on it ("Thats not even real scripture! Its a quote from fucking Pulp Fiction!"). But the passage that he quotes actually is real scripture: by coincidence, he quotes the only part of Samuel L. Jackson's famous speech that wasn't made up by Quentin Tarantino.note
- Garfield hates raisins. While this was just because Jim Davis hates them, in real life he would have a very good reason not to like them — they are poisonous to cats.
- Jon once bought a "battery operated battery charger". The joke was supposed to be that he falls for scams and blows money on "useless" stuff, but it turns out such a concept is far from useless and is totally real. Such devices exist as a means to give portable electronics such as cell phones, laptops, and even car batteries juice in the event of an emergency or if they are being used much more than their battery can handle. In fact nowadays, owing to the much higher reliance on electronics and 5V USB power becoming standardized, power banks are a common household item.
- One Pearls Before Swine strip has Guard Duck at a fancy restaurant ordering "chateaubriand, cooked medium well". In the commentary for that strip, Stephan Pastis admitted that he only used chateaubriand because it sounded fancy without knowing what it was, but he hoped it really was a type of food. It is — it's a type of steak (more specifically, a thick slice from the center of the beef tenderloin). Guard Duck also orders "a glass of your finest pinot noir", which is in no way a bad wine pairing.
- There is a Calvin and Hobbes strip where Calvin sneezes and then looks at the tissue and says "Uh-oh. I'm leaking brain lubricant." This is most likely just Calvin being an ignorant six-year-old, but cerebrospinal fluid — the stuff that insulates your brain — actually does sometimes leak out of your sinuses and come out when you sneeze. And there actually have been reported medical cases of people with chronic runny noses being discovered to be leaking cerebrospinal fluid through damage to the protective layers around the brain, which can happen on rare occasions from trauma such as a car accident.
- There is a joke in Coco about a skeleton being allergic to a hairless dog. In reality, you can still have a reaction to a hairless dog if you're allergic to their saliva and not their dander.
- In Fantasia, a double-error caused accuracy in the "Rite of Spring Suite": The famous Tyrannosaurus rex vs. Stegosaurus battle was impossible. Tyrannosaurus lived in the Cretaceous period, while Stegosaurus lived in the Jurassic. Furthermore, the T. rex was drawn with three fingers instead of two. These are both resolved if it's not a T. rex at all, but an Allosaurus or a Torvosaurus, both of which did live in the Jurassic alongside Stegosaurus and had three fingers.
- Ice Age:
- The creators made Scrat, the sabre-toothed squirrel, as a joke. But later scientists unearthed a prehistoric sabre-toothed squirrel-like mammal, albeit from the Mesozoic rather than any time close to the last ice age.
- The Gastornis from the sequels don't appear to invoke the same Carnivore Confusion among herbivores as other carnivores in the series do. Skip ahead several years and it's discovered that Gastornis was actually an herbivore.
- The Kentrosaurus in the third film are depicted with longer necks. Years later, it's discovered that stegosaurs indeed had fairly long necks.
- The Lorax: In the film, the main villain is charging people for clean air mainly because of their overly polluted air and smog. Later on, an "oxygen bar" in Delhi gave Indians a gulp of fresh air, and even later than that, China began selling bottled air as well. Low air quality has given a business opportunity to entrepreneurs offering pollution-free oxygen at a price.
- In Osmosis Jones, Pikachu has a split-second cameo in one of the bar scenes. Six years later, a protein was discovered christened Pikachurin by Japanese researchers for its lightning-fast moves and electrical effects.
- Megamind: Titan, who is Tighten, rants on Roxanne's naivete, claiming that "There is no Easter bunny, there is no tooth fairy, and there is no queen of England!" The intended joke is clear, but there actually hasn't been a monarch of England since the Acts of Union 1707 united England, Wales, and Scotland to form Great Britain. Currently, the title is "Queen of the United Kingdom of Great Britain and Northern Ireland".
- Monsters, Inc.:
- There's a joke where Randall calls Mike a "cretin" and Mike responds that he's pronouncing it wrong. However, Randall's specific pronunciation ("creh-tin", rather than "cree-tin" as Mike insists) actually is the common pronunciation in the United Kingdom (not that Randall has any kind of British accent).
- According to Michael Reeves's video on scream-powered microwaves, it is possible for screams to be a source of power in some way, and with some modification so can laughter.
- In Mulan, Shan-Yu is understandably furious with Mulan for destroying his army, but he doesn't seem to care that she's a woman, and is also one of the few male characters in the whole film who never says anything sexist towards her. Given it's never commented on, it's likely the writers didn't realize that many nomadic tribes (including the actual Huns and the Xiongnu) did have a widespread culture of warrior women. Because of this, it's not too surprising that Shan-Yu wouldn't care about Mulan's gender, instead viewing her as just another soldier on the battlefield.
- In the animated version of The King and I, Tuptim's lover Lun Tha is Adapted Out, she becomes Prince Chulalongkorn's love interest instead, and the two of them get a Happily Ever After ending in place of the original Tuptim and Lun Tha's tragic fate. This was obviously done to make the movie more family-friendly. However, according to one of King Mongkut's descendants, Anna Leonowens' story of Tuptim's forbidden romance and death was total fiction; there really was a Tuptim, but she outlived Mongkut and became one of Chulalongkorn's wives. (Here's her modern day descendant◊ Her Serene Highness Princess Vudhichalerm Vudhijaya (green dress, far left).) So in this detail, the animated version is more accurate than the original!
- In Disney's Sleeping Beauty, Prince Philip is trying to get his moody horse Samson to follow his orders, so he bribes him with "an extra bucket of oats" as well as carrots. Oats and other grains are supplemental feed used for an energy-boost, and most horses only need a few pounds per day if at all. Since Philip promised an EXTRA bucket of oats (assuming it holds 1-2 gallons for your average hand-carried "bucket"), this means Samson gets ten or twenty pounds of grain along with his regular oats, which horses do eat...after insane exertion of Epic Race levels. This would mean: 1) racehorses who sprint for several miles, 2) war-horses after a battle, or 3) endurance horses who can truck along for a whole DAY of eight to ten hours. Given that they DO end up fighting Maleficent at the climax, twenty pounds of oats would certainly be a good idea, but as it was used for a Running Gag, it's not clear if the writers actually knew horses need that much grain after hard work.
- Wreck-It Ralph is set Inside a Computer System and has characters travel between video games in an arcade through the machines' power supply cords. One may think it unrealistic to transfer data through electrical wiring, but it is in fact possible, and often very practical, especially in homes that don't carry a Wi-Fi signal well and aren't wired for Ethernet. Of course it's still not the most practical way to link arcade machines that are literally right next to each other; any meaningful data link between arcade machines would far more likely take place over network cabling.
- Raggedy Ann & Andy: A Musical Adventure: The vertically-challenged King Koo Koo claims at one point that Napoleon would look tall compared to him. This line was based on the common myth that Napoleon was abnormally short. However, Napoleon was actually 5'5", so technically, he would be tall compared to Koo Koo, it's just that so would almost any other human.
- Jimmy Neutron: Boy Genius includes a humorous scene where Carl stupidly tries to eat a tube of toothpaste in zero-gravity after the kids blast off into space, mistaking it for "astronaut food". In fact, astronauts do eat toothpaste in Real Life: in most space programs, astronauts use edible toothpaste that's designed to be swallowed after use, ensuring that they don't contaminate their airtight space capsules by spitting out their toothpaste after brushing their teeth.
- A blonde joke (replacing "blonde" with whatever Acceptable Targets you like) tells of one who chose the password "MickeyMinniePlutoHueyLouieDeweyDonaldGoofySacramento", because it needed to have at least 8 characters and include at least 1 capital. The humor comes from the person being overly Literal-Minded, but a password like this would actually be really good because of how difficult it would be to crack — assuming an attacker only knows how long it is and that it's composed of the letters A-Z (not taking into account upper/lowercase), the password is 52 characters long, giving 26^52 = 3.79x10^73 possible combinations; even assuming the attacker knows it's a literal "8 characters and 1 capital", the sheer number of different characters and decent number of capitals would still place the number of possiblities in the tredecillions (that's a 1 with 42 zeroes after it). And because it's eight closely-related names (plus Sacramento), it would also be fairly easy to remember.
- Any joke about France using a white flag. The punchline is that a white flag is a symbol for surrender, but France really did use a pure white flag for a while (1814-1815), both as a Naval ensign and as a national flag during the Bourbon Restoration.
- An old Australian hoax pulled on tourists is that of the drop bear, a supposed deadly Koala that jumps unsuspecting people from trees. Cue the discovery of Thylacoleo carnifex, the "marsupial lion". Some scientists believe it jumped down at prey from trees, and it coexisted with humans. It remains unclear if the drop bear hoax has origins in native oral history of the creature, or the similarities are a mere coincidence.
- There's a joke that deliberately invokes this trope: A guy is on Who Wants to Be a Millionaire? and is at the million dollar question, which is "Which of these birds doesn't make its own nest?" A) Sparrow, B) Eagle, C) Dove, or D) Cuckoo. He only has "call a friend" left so he calls his friend and repeats the question. The friend immediately says "the cuckoo". He says "are you sure" and the friend says "yes, positive". He answers the cuckoo and wins the million dollars. When he goes to thank his friend later, he asks "how did you know a cuckoo doesn't build its own nest" and the friend says "Because it lives in a clock, duh!"
- One theory about Fermat's Last Theorem is that Fermat's proof was actually wrong, but the results were correct anyway. In fact, this is almost universally believed within the mathematical community. Fermat always did turn out to have a proof when he said he did, so it's likely that he at least thought he could prove this. Fermat essentially created several areas of math despite not publishing much of his work, including a general form of integration along with finding a general way to get rates of change, making it possible that far from being mistaken, he did discover a proof for a special case and generalized it incorrectly (the book that he wrote it in was actually the first attempt ever to use a symbolic system to write algebra). Given the insane complexity of Andrew Wiles's proof, very few mathematicians believe that 17th-century mathematics could have produced any solution at all, much less a simple one. Both of the theorems Wiles used to make his proof were twentieth-century in origin. Also, the theorem holds the record for the most wrong proofs.
- It's unlikely that any of the writers of "One and One" — as performed by Edyta Górniak and later by Robert Miles and Maria Nayler — were talking about Boolean logic when they created the line "one and one still is one", but they hit the nail on the head. There is also Medicine Head's legendary"One and One is One", and yet I don't expect that John Fidler, Medicine Head's main man knows much about Boolean logic either...
- "Ironic" by Alanis Morissette has been widely lampooned for not being ironic, and Morissette has admitted this. Michael Stevens of Vsauce points out that one could interpret the song as being dramatically ironic, when the significance of something is unknown to a character but known to others. The individual events aren't examples of situational irony, but life is ironic because life knows what we need while what we think we need differs. It's also been suggested that the song "Ironic" not having any examples of irony is itself ironic and appropriate. This is also a meta-example of irony, as there is one instance in the song that is often overlooked — a man overcoming his fear of flying to end up involved in a plane crash — which ironically makes the accusations of being entirely unironic inaccurate.
- Originally written in 1980, "Weird Al" Yankovic has a song called "Yoda" that correctly predicted that Mark Hamill would play the role of Luke Skywalker until he's "old and gray". He also wasn't too far off when claiming "they'll be making these movies 'til the end of time".
- The folk song Oh Susanna begins with the contradictory line, "It rained all night the day I left; the weather, it was dry." Considering the following lines also contain contradictions, songwriter Stephen Foster probably didn't know that in arid and semi-arid climates, the humidity sometimes gets so low that raindrops evaporate long before they reach the ground, allowing for hours of rain while the air at ground level remains dry.
- "The Freshmen" by The Verve Pipe includes the line "His girl took a week's worth of valium and slept" - the intended meaning is that she took a deliberate overdose and died, with "slept" being a euphemism. However, "a week's worth of valium" alone isn't likely to kill you, so in real life she probably would have just fallen asleep.
- In The Simpsons Pinball Party, Abe is sometimes heard saying, "Back in my day, we didn't have flippers!" While flippers are such a core part of pinball now that it's hard to imagine it without them—and the word for pinball in some languages is literally "flipper"—they were introduced in Humpty Dumpty in 1949. Any elderly person in 2003, the year of The Simpsons Pinball Party's release, would have been alive at a time before pinball machines had flippers; Abe would've been old enough to play some of them when they were new.
- Mike Duncan Of Revolutions derives a lot of self-deprecating humor from his tendency to mangle foreign words despite his best attempts. However, he does pronounce the surname "Windisch-Grätz" correctly despite the correct pronunciation being anything but intuitive to a native German speakers, simply by virtue of pronouncing "ä" like "a" which is wrong in 99.9% of cases but happens to be right here.
- MAD Magazine and its parodies of the Rocky movies:
- In "Rockhead III", because Rockhead twice stands nose-to-chest with his ring opponents, he remarks, "If this kind of posing keeps up, I want my next match to be with Dolly Parton!" Stallone's next film after First Blood? Rhinestone, where he acts opposite guess who.
- In "Rockhead IV," during "Appalling Greed's" funeral, "Brawly" muses to "Atrium," "I wonder which one of us gets our ticket punched in 'Rockhead V'?" While it doesn't happen during the events of Rocky V, one of them (Adrian) is indeed dead before the events of Rocky Balboa.
- MAD spoofed Cathy with one called Amy!, which depicted Amy Winehouse pulling a vial of cocaine out of her beehive hairdo. Later on, the real Ms. Winehouse was filmed doing exactly that.
- A very old Al Jaffee strip, "Some Mad Devices for Safer Smoking", contained a bunch of utterly ludicrous devices to help quit or reduce the dangers of smoking, such as a fan that sucks the smoke out through your nostrils (reasoning nasal cancer is easier to reach and treat), an explosive-rigged cigarette that encourages you to only smoke some of it via "psychological warfare", and a metal holder that burns your lips while you smoke. However one of them, the "Smoke Simulator", was a vial of liquid that was heated up and released water vapour that feels like smoke but is far less dangerous — practically identical in function to E-Cigarettes and Vapes which, indeed, are touted as healthier alternatives to smoking which can also help you quit. Not bad for a strip that was drawn in 1964.
- Averted: a newspaper crossword-puzzle editor was once briefly arrested for using the words "Overlord", "Utah", "Omaha", "Mulberry", and "Neptune" in a number of puzzles in the weeks leading up to D-Day.note The same editor, Leonard Dawe, had previously been investigated for having put "Dieppe" as an answer — on August 18, 1942, the day before the disastrous Allied raid on Dieppe was to launch. An investigation at the time could only conclude that it was a bizarre and astonishing coincidence. Only in the 1980s did the answer come out — the crossword-puzzle editor was a teacher, and he used his students to collect odd words. One of those students had hung around military camps and bases enough to overhear the unusual words being spoken, and promptly turned them over.
- When Místico signed with the WWE and was rebranded Sin Cara, Jim Ross made mention that as Sin Cara, he'd have the potential to be a global cultural icon. Well, Mistico's style was wildly incompatible with "WWE"-style wrestling, and thanks to his propensity for screwing up, became almost synonymous with botching.
- Journey into Space: Journey to the Moon / Operation Luna accurately predicted that the first spacewalk would take place in 1965. On March 18, 1965, the Soviet cosmonaut Alexei Leonov became the first person to conduct a spacewalk when he exited the capsule during the Voskhod 2 mission. This first spacewalk lasted for twelve minutes.
- The Greek philosopher Leucippus created the atomic theory, as an argument against another philosopher, Parmenides. While Parmenidies argued against the idea that a state of nothingness could exist, Leucippus argued that there were in fact voids and that everything that was not a void was made of small units of matter that assembled to create larger ones. Aristotle scoffed at the argument, stating that in a complete absence of matter, motion would no longer encounter friction and allow for infinite speeds, which he saw as ridiculous. Well, turns out that what Aristotle used to try to discredit the theory is pretty close to what actually occurs to objects in motion in space. Of course, his view of atoms was also confirmed, though there are more particles than he thought.
- Finnish naturalist Immanuel Ilmoni hypothesized in the early 18th century that diseases were actually living beings, not unlike animals. While he was ridiculed, the germ theory of diseases was confirmed less than a hundred years later.
- The rules for heat movement were created based on the idea that heat was a fluid/gas called caloric. One of the reasons that this theory stuck around so long is that the rules concerning the movement of heat are the exact same as the movement of diffuse material in a fluid. Thus, while caloric was abandoned as a theory, the rules of heat movement were unchanged.
- This apparently happened twice due to correspondence between Galileo and Kepler. Scientists at the time would sometimes write down discoveries with scrambled letters when they weren't ready to publish their findings, but wanted to establish priority of discovery. Galileo wrote two such letters to Kepler, one concerning his discovery of Saturn's rings, the other concerning the phases of Venus. Kepler tried to unscramble them both and ended up with different sentences, one claiming that Mars had two moons and the other that there was a moving red spot on Jupiter. By complete coincidence, both of those claims were correct, but neither would be proven for centuries.
- In 1900, the Russian archaeologist Friedrich Zibold discovered the remains of a mysterious domed structure in the Byzantine Crimean site of Theodosia. After studying the ruins and some terracotta pipes found nearby, he proposed that the structure was an air well designed to condense moisture from the air into water, and built a replica to test it. This replica was successful and became the precursor of modern air wells. However, it was discovered later that the ancient structure was actually a tomb, the pipes were not related to it, Zibold had used the wrong materials for his replica, and weather conditions at the time (which had included thick fog) had exaggerated the results of the experiment. But by sheer coincidence, these materials were the right type to make a working air well — had Zibold used the real ones in the tomb, his experiment would have been a failure — and had weather conditions been more characteristic of the area (not as much fog), it wouldn't have worked as well as Zibold reported it did. Neither of these problems were discovered until 90 years after Zibold's experiment. In other words, Zibold inadvertently invented a new technology as a result of an attempt to replicate a Lost Technology that didn't actually exist in the first place.
- The play Abigail's Party makes a humorous reference to putting red wine (Beaujolais) in the fridge, as a comment of misguided middle class aspirations in the '70s. However, playwright Mike Leigh later learned that Beaujolais is one of a few red wines that is best when chilled.
- In The Mikado, W.S. Gilbert used the name Ko Ko because he thought it was funny-sounding, and didn't know at the time that it is a legitimate Japanese name. Just ask Kouko Kaga.
- One of the biggest points of academic contention about Hamlet is whether or not the eponymous Prince of Denmark is actually mad, or just faking it. The Vikings did allegedly have some sort of taboo against killing a person afflicted with madness, which makes pretending to be one a viable survival trait for the son of a usurped Danish king. Apparently, it's doubtful that Shakespeare would have been aware of this. Even so, it's not entirely a coincidence. While Shakespeare wouldn't have known about this taboo, the authors of his source material would have. He probably kept the Obfuscating Insanity plot without understanding the societal context of it.
- The play Brand by Henrik Ibsen made an eerie prophecy concerning the consequences of British pollution reaching Norway, leading to dying forests and lakes. The play was written in 1866, while this problem became apparent in the 1980s. The accuracy of this passage is quite chilling:
Britain's smoke-cloud sinks corroding
On the land in noisome fume;
Smirches all its tender bloom,
All its gracious verdure dashes,
Sweeping low with breath of bane,
Stealing sunlight from the plain,
Showering down like rain of ashes
On the city of God's doom.
- Shakespearean geography and history is often all over the place. For example the only way his "seacoast of Bohemia" is anything other than Artistic License is by the Epileptic Trees logic that the ruler of Bohemia at the time also ruled territory in the Balkans and Italy which had a coast — never mind that the difference between a personal union and two realms being joined as the same legal entity was very important in Shakespeare's day and even laymen knew (and cared about) the difference. He did, however, despite what many might tell you get a few surprising things about Italy right, such as seafaring and sailmaking traditions in inland cities (those cities had access to the sea via rivers and the ships went out sails and all) or the fact that Richard III was a hunchback (long dismissed as Tudor propaganda, the 2012 discovery of his remains proved that he was a hunchback after all). Especially in the case of Richard III who died over a century before Shakespeare wrote the play, Shakespeare cannot possibly have known for sure, but he guessed accurately, nonetheless.
- WarioWare: Touched: When Wario got a cold, he decided to eat garlic, his favorite food. Garlic is antiseptic and antiviral and therefore used in treating colds, which would explain why Wario never got a cold until that time.
- Deus Ex:
- The game came out in 2000, but takes place in 2052. It has, in certain areas, the New York City skyline as background scenery, but missing the Twin Towers. This was due to technical limitations where one half of the skybox texture — the half that just so happens to lack the Twin Towers — is mirrored over the other half rather than applying the full texture, but the explanation the developers gave is that they were destroyed in a terrorist attack some time in the game's past. This may have been an educated guess on their part, as the World Trade Center had been the target of a terrorist bombing back in 1993, but not nearly on a large enough scale to actually topple any of the buildings. As well, terrorism is a large part of the game's plot, so that explanation fits within the mythology, too.
- Another one that sort of adds a little uneasiness, in the mission where you save someone from a gas station, you can see the prices. At the time it may have represented something far off, as gas prices were on average about $1.20 and the game depicted gas prices at $3.58, for regular. Cue 10-12 years later after the game's release and that's exactly where those gas prices are, although the early 2015 drop in gas prices let us breathe easily.
- A most thought-provoking, or perhaps scary, example can be read on government-sponsored electronic bulletin boards across the game. One article found at the very beginning of the game tells readers to keep an eye out for terrorists and report any suspicious activities. The messages are clearly intended to be alarming signs of the dystopian state of the current government, both in the fear mongering "everyone can be a terrorist" message used to scare everyone into accepting the Big Brother level of control the government has, and in the invasion of privacy advocated by suggesting a thorough background search on anyone who is a foreigner or has spent too much time on the net. Thus, it's rather shocking how close this came to actual suggestions put out shortly after 9/11 for 'how to spot a terrorist'. What are you supposed to think when your own government is now repeating word-for-word the dystopian messages we're told to watch out for?
- Its prequel, Deus Ex: Human Revolution, mentions an oil crash in 2015. While we didn't have an oil crash, prices did fall significantly.
- Naruto Shippuden: Ultimate Ninja Storm 2 has an Easter egg in which Naruto and Hinata are declared "secret lovers", despite not being too much canon support for it in the original manga at the time. Turned out that Naruto and Hinata ended up married and with two children in the canon story.
- Ever17: It was assumed that the scene with Tsugumi and the jellyfish-themed gondola was significant symbolism due to her immortality and there is a species of jellyfish that are considered biologically immortal. The writer responsible for that scenario admitted that he did not know that at the time.
- In the concept art book for Doki Doki Literature Club!, Dan Salvato noted that "'Sayori' was some kind of unholy fusion between 'Sayuri' and 'Saori', and to this day Im not even sure if it could pass off as a real Japanese name." However, "Sayori" (さより) is an actual Japanese girls' name (as well as the name of the Japanese halfbeak fish), albeit an uncommon one, as seen with voice actress Sayori Ishizuka.
- The plot of Hong Kong '97, which was released in 1995 but takes place during the transfer of Hong Kong's sovereignty in 1997, involves the mainland Chinese resurrecting the deceased "Tong Shau Ping" (i.e., Deng Xiaoping) as a weapon against the player character. Deng Xiaoping was alive in 1995, but he did end up dying in 1997.
- A plot point late in Splinter Cell involves a missing cache of Americium-239, which the game makes a big enough deal about that it's implied that the bad guys are planning to use it for nuclear weapons. Americium-239 would actually be very bad for this purpose, between it not being a fissile isotope in the first place, its ridiculously-short half-life of less than 12 hours, and the fact that it decays via electron-capture, which produces no harmful radiation for use in a dirty bomb. Thing is, though, when it does decay, it turns into other isotopes that would be much more suitable for weaponization — 99.99% of it decays into Plutonium-239, and the remaining .01% eventually decays into Uranium-239, either of which would definitely warrant the Oh, Crap! sort of reaction the game assigns to it.
- Sonic Mania introduced a new abilty for Sonic, the Drop Dash. In 2019, two years after Mania's release, an early beta of Sonic 3 & Knuckles surfaced, featuring an ability that was dropped from the final game that works very similarly to the Drop Dash. The game's director Christian Whitehead stated on Twitter that this was an uncanny coincidence.
- Team Fortress 2: The Medic's hometown was originally Stuttgart, Germany, but was later retconned as hailing from the fictional town of Rottenburg. Except there's three real towns named Rottenburg in Germany, one of them (Rottenburg am Neckar) being only 60 kilometers away from Stuttgart.
- Déjà Vu (1985): The game takes place in Chicago on December 7, 1941 (newspapers point out that the Japanese bombed Pearl Harbor). Yet, there's no indication that it's winter, as everyone is dressed for warm weather. However, Chicago on December 7, 1941 really was unusually warm, or at least above freezing.
- Metal Gear Solid 2: Sons of Liberty has a part where Snake can contact Otacon and complain of seasickness, and Otacon will suggest he take pentazemin (a fictional form of benzodiazepine he normally uses to reduce hand tremors while sniping). When he does and it actually somehow works, Otacon admits he suggested the drug as a placebo effect and that it shouldn't have actually worked. In real life however, drugs from the Benzodiazepine class actually do treat motion sickness and Mal de Debarquement presumably by suppressing central vestibular responses.
- In Super Mario Bros. 2, the use of "BOMB!" as an Unsound Effect for Stuff Blowing Up is purely humorous. However, the word "bomb" does derive from the Ancient Greek onomatopoeic word "βόμβος" ("bombos") meaning a booming noise.
- Portal 2 has you discover from Cave Johnson's leftover recordings that ground up moon rocks are "pure poison" and that he's dying from exposure to them. While not chemically poisonous, moon dust actually is deadly to inhale as it is so fine that it causes Silicosis, a form of Pulmonary Fibrosis where the inhaled dust scars your lungs which causes (among others) all of the symptoms Cave Johnson is suffering: coughing, shortness of breath, weakness, and fatigue. It even inadvertently justifies why Chell has no such reaction to the white gel made from it, as it's no longer in dust form unlike when Cave was exposed to it and she's not around it nearly long enough to develop symptoms.
- Puffin Forest: Ben once played as Sauron in a The Lord of the Rings villain campaign. But after he chose Sauron, he realized that he had no idea what Sauron's personality and abilities were and had to make them up based on what on what little he did know. What he came up with (a blacksmith with the personality of a micromanaging Corrupt Corporate Executive) was actually surprisingly close to canon Sauron in The Silmarillion, if a bit goofier.
- hololive: Momosuzu Nene's Animal Motifs was supposed to be a bear, but her fans would often joke that she is more of a seal. However, as it turns out, bears and seals are related to each other.
- In the webcomic DM of the Rings, the players tend to mangle their characters' names. At one point, "Gimli" introduces himself as "Gimli, son of Groin", obviously mispronouncing "Glóin". However, in The Lord of the Rings canon, Gimli actually is descended from a Gróin, who is his grandfather.
- Somewhat early on in Homestuck, John uses a Modus Control Deck to convert his Sylladex's Fetch Modus to a queuestack array by combining a queue, a stack, and an array. While Andrew Hussie was more than likely just making a pun based on John Cusack, a queuestack is actually a real data structure, although it's more often referred to as a double-ended queue, or deque (pronounced "deck") for short. And yes, you can in fact make an array of them, although there's not usually much reason to do so.
- This chapter of the Project Moon webtoon Leviathan (which is related to Lobotomy Corporation and Library of Ruina) has a character look into a trance-inducing kaleidoscope of sorts, after which her eye starts tearing up. The guy that showed her it has constantly watering eyes as well. Watering eyes are a common side-effect of induced trance like hypnosis and the Estes method.
- In Nebula, the creators admitted that Ceres' emergence from Black Hole's head wasn't intended to be anything close to realistic or plausible, but some months after the comic's publication NASA actually observed an object coming out of a black hole.
- In Sonichu, beer is usually referred to as "reeb". Reeb is actually a brand of beer in China, and was also a 19th-century slang term for beer.
- Learning with Manga! FGO has at several points inadvertently predicted story or gameplay developments in Fate/Grand Order that Riyo had no knowledge of actually being true. Nasu confirms that the series predicted a major reveal for the second story line Cosmos in the Lostbelt that Riyo was never told about, and while he did not divulge what that was it's heavily implied it has to do with Olga Marie, the Sacrificial Lamb who dies at the end of the prologue, returning to life, albeit in much different circumstances between the two forms of media considering canon Olga Marie is now the Big Bad.
- One plot point in The Order of the Stick involves Durkon trying to research a mass counterpart to the core D&D spell Death Ward; while such counterparts are common, Death Ward doesn't get one. However, a Mass Death Ward spell was described in an official D&D book, Libris Mortis. Rich Burlew claimed he hadn't heard of it, and noted that the spell was a bit higher-level than he'd pegged it as, and shouldn't be taken as indicative of Durkon's real level—the real version is 8th-level, the comic version is 7th-level. More than that, though, it turned out to be unintentional foreshadowing: Durkon initially can't cast the spell until he makes changes created by another, that turn out to have been modifying it to add backdoors and weaknesses. Presumably, those changes were enough to drop its level.
- A filler strip in The Whiteboard posted on January 3rd had Doc flipping a calender and receiving a Pie in the Face. In one of the most prophetic webcomic strips ever, he thinks "Ah. So it's going to be one of those kinds of years, is it?" To be more precise, the strip was posted January 3rd, 2020, a very eventful year indeed.
- In Cracked article 10 Brilliant "Comedy Gems Hiding on Youtube", the author quips that he hopes the authors of "Jean-Luc Picard Doesn't Give a Fuck" only stopped making them "because they became super famous and died from all the sex and money that was thrown at them." As a number of the comments pointed out, the reason they stopped making them was so one of them could work on Homestuck, this article having been written after the celebrated 2.5 million dollar Kickstarter.
- This article from Sonic The Hedgehog fansite The Sonic Stadium about this terrible review from the British tabloid newspaper The Sun decribing that it sounded something like what Fox News would write. In fact, both The Sun and Fox News are owned by the same guy.
- At the end of this review for The Tigger Movie, Duckyworth wonders if the director, Toby Bluth, is related to Don Bluth. He is.
- For TV Tropes itself, the description of the page Invincible Hero used the Perfectly Cromulent Word "vincible" to mean the opposite of "invincible". Not only is it perfectly cromulent, it's perfectly real as well. And it means exactly what it's suggested to mean: beatable.
- Not Always Right:
- One couple on Not Always Romantic started mutating "Hey, baby!" until it became "Habibi". Upon realizing that "Habibi" was an actual Arabic word, they looked it up in case they were saying something inappropriate. It means "my beloved".
- This brother and sister duo on Not Always Related jokingly settled the matter of "who would give their mother grandchildren first?" through a best-of-three game of Rock, Paper, Scissors, after they had both brought their respective partners to a family dinner, with the brother "winning" the honor of having children first. As the story notes, it has been a few years since that dinner, and that brother has since gone on to become a father, and with the same woman he brought to that dinner, no less!
- Many furry artists, unsure of how to draw the arms of spectacles for characters who wear glasses, omit the arms altogether. Rest assured, ye artistic masses, such glasses exist: They are called pince-nez, and use a spring or clip to pinch the nose, or are made to fit an individual's nose.
- The infamous "Tampocalypse" tumblr post where a tampon commercial involving survivors of a zombie apocalypse using them to plug bullet wounds is described. It makes you wonder if anyone taking part in that discussion knew that feminine hygiene products actually were originally invented to treat battlefield wounds, and the Xstat Rapid Hemostasis System is very similar in concept to a tampon.
- Happened right here on This Very Wiki on the page Creepy Hairless Animal. A troper discussing bears that had suffered from hair loss joked about them looking like something that belongs in Dungeons & Dragons and suggested naming such a creature a "grizzly bare." Except as another troper points out, there actually is a hairless bear monster in D&D, called the tooth beast.