Black Box



""You don't really know how powerstones work. You've created a whole city that relies on an energy source you do not understand. 'Magic!' you say. 'It's magic!' Oh, how clever. And then when the magic fails, you simply say, 'It must have been more magic!'""

- Yawgmoth, The Thran

An elaboration on No Plans, No Prototype, No Backup.

In engineering terminology, a "black box" is a device with one or more inputs (cake ingredients, an excerpt of text in Mandarin, iron ore), one or more outputs (cake, the same text translated into Frisian, a battle golem), and internal processes that are either:
 * 1) irrelevant,
 * 2) unknown, and/or
 * 3) unknowable.

Such technology falls into the hands of some organization, usually the military or a commercial business. The original creator is dead (or is an alien or from a long-dead civilization or otherwise can't be reached), but said technology is really convenient. The organization's analysts went over the thing, and while most of it makes sense, there are these elements, either program or device, that they cannot comprehend at all. Removing them causes the entire thing to simply not function (or triggers a more active response). The organization may be able to reverse-engineer copies, or lesser versions, but they don't understand how it actually works.

So, since the financial bottom line or military advantage is so important, they go along with it anyways.

...yes, of course, the technology has a bizarre effect that nobody could have predicted - you really need to keep track of those inputs and outputs! Usually it's in the form of acquiring sentience or a bizarre weapon, or only being able to be used by people of the show's target demographic. (It's common in Humongous Mecha series.)

This is surprisingly common in Real Life, particularly in programming, where the programmer is the only one who really understands how what they've built works (and sometimes, not even them). Especially in high-level languages, where the programmer can for example tell the computer to replace all occurrences of "cake" with "apple" in a text, and doesn't have to worry about how the system does it - s/he gets a changed text back and that's that.

Compare Scavenger World, where everything is similar to a Black Box not by conspiracy but by The End of the World as We Know It.

See also In Working Order. Sister Trope to Disposable Superhero Maker.

Not to be confused with 'Black box' flight recorders

Anime and Manga

 * In .hack// CCCorp treats The World as the game it appears to be, but those who can find the so-called "Creator's Rooms" can discern some of the original designer's true intent.
 * And the game keeps sucking up player's, programmer's, and administrator's minds; even after they've rewritten it twice. Even so, that's much safer than the alpha version. The creator didn't dare playtest it.
 * Harald did. The result wasn't pretty when it came to debugging, though.
 * The core code of The World is explicitly referred to as a "Black Box" in several of the novels.
 * There are also occasions where the game circumvents or thwarts the administrators' attempts to fix issues, such as banning certain players, as well as spawn vagrant AIs.
 * The development of the Evangelions in Neon Genesis Evangelion is very much along the lines of this trope, although the source of the Black Box is not earthly.
 * The S2 engine is a particularly fitting example. American attempts to reverse engineer the device result in a massive disaster - the test engine vanishes, along with the entire research facility and all other objects in a 50-mile radius.
 * The plants in Trigun can do pretty much anything depending on how you power them, but nobody's really sure how they run anymore. (The manga actually calls them "humanity's ultimate black box".)
 * The flying machines in Simoun have two black boxes: the "Helical motor" (according to the sub) and the "Simoun Gem". Trying to find out how these things work apparently drives you mad for a little while.
 * The SDF-1 in Super Dimension Fortress Macross is riddled with black boxes.
 * Black Boxes are a dime a dozen in The Big O, ranging from nigh-indestructible giant robots to androids to underground tunnel networks. The last episode reveals that.
 * The Nanomachines powering the Otomes in Mai-Otome. Frankly, what kind of perverted scientist thought it would be a good idea to have them break down upon any contact with male DNA, thus requiring exclusively female virgins to operate it under the shaky hope they aren't depowered?
 * One that would be too threatened by the notion of wives who are stronger than them, most likely.
 * It's all but stated outright that the Otome were based on the Hime, the "natural" magical girls from My-HiME. So its a Black Box replicating magic. Its a damn miracle it works at all.
 * The Clow Cards in the first arc of Cardcaptor Sakura. The cards are sentient, though astonishingly specialized, and their creator is dead.
 * Zoids, anyone? The Ultimate X zoids are shown to have a "black box" that other zoids do not.
 * GaoGaiGar mentions this. In one flashback, they actually discuss a strange interface on Galeon, an alien mecha lion, and refer to it as a Black Box. Once they figure out how to activate it, it contains designs for half the Applied Phlebotinum in the show.
 * In the Nausicaa manga, the Crypts of Shuwa are full of Black Boxes—most notably the God Warrior. More mundanely, nobody has the technology to build new airship engines any more, so when an airship is downed, there's a scramble to salvage the irreplaceable engines.
 * Full Metal Panic!! has a bunch of them, collectively called 'Black Technology', created by the mysterious 'Whispered'. Many are simply extrapolations of existing technologies, which are mass-produced and change the world drastically - Whispered are explicitly NOT useless. Others, however, are perfect examples of the trope - Foremost among them is the 'Lambda Driver', a true Black Box which enables users to warp the laws of physics through sheer determination.
 * In The Second Raid it's mentioned that the Arbelest is optimised for the first person who used it (Sousuke) and as the designer died since then that means it can't be reset for another user. As Sousuke hates the unreliability of the weapon and is also undergoing a Heroic BSOD this causes major problems.
 * The FMP manga Arbalest won't work for anyone other than Sousuke because if anyone else tries to pilot it the AI just constantly asks for Sousuke, and no matter how many times the reset or reprogram the thing it still will only work for Sousuke.
 * Full Metal Panic? Fumoffu used this to humorous effect with the Bonta-kun class Powered Armor—it has a voice filter that renders all spoken speech as "Fumoffu!" to anyone listening. It causes the armor to shut down if disabled, and no one—not even Sousuke, who designed the thing—knows why.
 * Humans don't seem to figure out how to replicate Ganmen during the timeskip of Tengen Toppa Gurren Lagann. The Guraparls that form the backbone of the Earth military were reverse-engineered from Gurren Lagann, but they don't seem to have figured out much about Spiral energy or how to reverse-engineer the "generator" that lets a Ganmen use it. This means that forces initially superior to the Ganmen they replaced wind up looking like anemic kittens once the hot blood Goes To 11... Million... And drives the standard-issue Ganmen to absurd, physics destroying heights.
 * This is explicitly because Rossiu believes the Ganmen to be inferior and a reminder of Lord Genome's reign and so he had them destroyed rather than any lack of ability on the part of the humans.
 * The Reveal of Outlaw Star. The eponymous Cool Ship and were created based on the unknown data (the black box) that Gwen Khan could not translate from an advanced ancient civilization which is implied to have created all of the ancient ruins of the galaxy.
 * For a while the Caster Gun employed by main character Gene Starwind was a black box of lost knowledge. Caster guns are essentially antique pistols that fire unique shells with a wide variety of effects that can even counteract the magical attacks of Tao Masters. Nobody knows whether they are lost technology or, as later confirmed, magic that has been encapsulated within the shells.
 * The GN drives in Gundam00. GN Drive technology can be mass produced in months (reversed engineered by The Federation from the GN-X drive model), but true GN Drives, the ones which emit green "pure" particles used by Celestial Being's Gundams, are equipped with a "Topological Defect" Blanket, which can only be manufactured around Jupiter with a total production time of six years. Somehow harnessing the power of topological defects (a mathematical solution involving differential equations) allows the drive to funnel energy back into itself, allowing for unlimited operation time.
 * Additionally, Celestial Being's true GN Drives have a literal black box which no-one could figure out, which turns out to contain.
 * Darker Than Black has alien technology and powers coming from the "Gate"—among other things, tech that allows for Laser-Guided Amnesia, glowing flowers whose seeds halt the development of Contractor powers, and crystalline plants whose pollen make bees produce an intoxicating drug. Possibly inspired by Roadside Picnic (see below) -- at least, it can be interpreted as a Homage to and discussion of its setup.
 * This is a main plot point in Robotech: The Shadow Chronicles. The Haydonites provide humans with shadow technology which greatly aids them in fighting Invid. But, so even though the shadow devices were built by humans themselves, they still have flaws which   exploit when they attack humans.
 * In the American release of Voltron (which combined the separate series GoLion and Dairugger XV), it's established that the Vehicle Voltron was built as an imitation of the original Lion Voltron built by the late King Alfor of Arus. Since the original Voltron is semi-mystical in nature and the magic was not copyable, the duplicate can only stay unified in giant robot form for five minutes at a time.
 * Used in Mahoromatic. Mahoro was built using incompletely-understood Imported Alien Phlebotinum, including the power source. Which leads to the Death Clock - as the power source cannot be refueled or recharged by Earthly technology.
 * Puella Magi Madoka Magica: Despite going around creating Magical Girls, Kyuubey doesn't entirely understand how magic works.
 * A scientist in Yozakura Quartet equates the workings of youkai and supernatural powers to Black Box technology. He makes the comparison that just as we don't understand how magic works, most people don't understand how a computer turns on apart from pushing the "on" button.

Comics

 * The first three THUNDER Agents were all recipients of black boxes. As their origin shows, their devices were found amid the rubble of the lab of a famous inventor, who had been killed by minions of the Warlord. The Warlord's mooks had looted the place, but missed a few items. Several early stories were about the agents discovering drawbacks to their new powers.
 * Captain America (comics)'s shield is essentially a Black Box in design; made of an unknown alloy of Vibranium, other metals and a mysterious bonding agent- which the creator doesn't know about, having fallen asleep during its production- which results in a shield that has properties unlike anything else in existence. Some say that agent was American Rightousness (as opposed to American self-righteousness), explaining why it seems to act as almost an Empathic Weapon to Cap.
 * Captain America is a Black Box. The only scientist who knew how to produce the Super Soldier Serum was assassinated, leaving No Plans, No Prototype, No Backup after exactly one test subject was treated with it: Steve Rogers. Trying to replicate the success of the project spawned Nuke, Deadpool, Wolverine, Fantomex and at least ten others.
 * In Ultimate Marvel and the Marvel Cinematic Universe, the serum itself was quickly replicated, but an army of Captain Americas is still impossible because the recipient is the key factor; In Ultimate, it only works on subjects with superhuman willpower, keeping the successes at a minimum. In the MCU, it grants Personality Powers, meaning unless the government is willing to stick needles in a card-carrying saint(who would thus never perform deniable operations), all they would get is more Red Skulls.

Film

 * The guidance system abroad the Russian communication satellite in Space Cowboys is so archaic that no one except the original creator understands it.
 * Something of a subversion, since the technology isn't too advanced or hidden, it is simply not known to the current generation of astronauts due to its extreme obsolescence. "It's pre-microprocessor! It's pre-EVERYTHING!"
 * The Machine in Contact is both this and Imported Alien Phlebotinum, as humans are given plans for a Machine, but not an explanation how it works.
 * When it is activated
 * They know how it works (well, how to work it at least), what they don't know is what it does.
 * In Sneakers the whole plot revolves around a black box device which is able to decrypt any western encryption (not the russian encryption-methods, however).
 * Does Triffid oil, which effectively saves the world from global warming, but then it turns out that Triffids are fairly dangerous beings if let loose, count?
 * Deconstructed in Galaxy Quest. The starship in a Star Trek type TV show has a superweapon called Omega-13; the aliens who became obsessed with the show built an exact duplicate of it in their reproduction of the Cool Ship. There's only one problem—nobody knows what it does, because the series was cancelled in the middle of a two-parter that would have shown it in action. Tim Allen's character (the William Shatner Expy) asks a fan if he knows what it does, and he says that the popular theory is that it destroys all matter in the universe in 13 seconds, but he thinks it lets you go 13 seconds back in time.
 * In Captain America: The First Avenger, when the Red Skull finds the glowing blue Tesseract (implied to be the all-powerful cosmic cube of marvel comics) he uses it as an energy source for his tanks and weapons. Until his supposed death when the cube sustained damage from Captain America's shield and began to warp reality itself, he only saw it as an unlimited power source. Ditto for the scientists on the American side, who attempted to harvest the miniscule yet overwhelming bits of energy powering the guns (blasting a hole in one of the research facilities when they tried to discover its properties). What will happen to the cube now that it is in U.S. hands after Red Skull's death, only time (and the Avengers movie) will tell.
 * Tony Stark's ability to miniaturize the arc reactor is what drives Stane mad in the latter half of Ironman, since Tony didn't exactly leave any blueprints of it in the Terrorist's base and none of Stane's Scientists can duplicate it (leading to his Memetic line about Tony building stuff in a cave with scraps). In Iron Man 2 the fact that the Ironman suit and miniature Arc reactor apparently not being Black Box tech is what kicks off most of the plot.

Literature

 * The Thran provides the page quote. The whole Thran Empire relies on powerstones, but even the engineers who work on them don't exactly know how they work.
 * The Strugatsky brothers' Roadside Picnic, as well as The Game of the Movie S.T.A.L.K.E.R (but oddly enough, not the movie) have a Danger Zone full of Black Box alien artifacts as the catalyst for the plot.
 * In Discworld the Devices discovered by dwarfs are ancient Black Boxes with assorted functions, including power sources and recording devices. The magical supercomputer Hex is also a Black Box; it's added so many peripheral devices to itself that even its original designer, Ponder Stibbons, is no longer sure exactly how it works.
 * A particularly good example is Hex's teddy bear- a simple cuddly toy, yet when taken away from Hex, Hex refuses to operate.
 * With the error message +++Mine! Wahhhhhhh!+++
 * In Philip Pullman's His Dark Materials, the subtle knife certainly fits the bill. It is an ancient weapon that can cut through anything, including the fabric between dimensions. However, it has the unfortunate effect of . The alethiometer also qualifies, though it has no negative effects.
 * The Posleen War Series by John Ringo features a number of examples of the Black Box. The alien Posleen (or "people of the ships" in their language) are similar to the Covenant in Halo in that they use technology they understand poorly if at all. A perfect example of this is one of their commanders staring in confusion at a computer helpfully informing him "Incoming ballistic projectiles. Impact in 10 seconds. Five.... etc" The views of their society in the initial books of the series are vague for the most part but imply that they only really use the systems that kill things or are almost entirely automated. A literal black box used by the humans in the same series appears in the form of the AID which is a black memory plastic box about the size of a pack of cigarettes with an extremely potent AI embedded in it. They act as a Universal Translator as well, but are provided by another species and the humans haven't a clue how they really work or how to make them.
 * There is also the small black box from his and Travis S. Taylor's Into the Looking Glass books, a device about the size of a pack of cards does "interesting" things with spacetime. It was given to them by the friendly aliens at the end of the first book, who had found it on some other planet and had no idea what it was for. Although they did warn that one should NOT apply a "significant voltage" to it.
 * Hooking up a double-A battery leaves a 10-mile crater. A car battery destroys the (deliberately uninhabited and unimportant) planet. Three-phase current erases the solar system.
 * In Robert Jordan's The Wheel of Time there are the ter'angreal (magical items), the secret of whose making has been lost for three thousand years. The Aes Sedai keep plenty of ter'angreal around for use as black boxes without understanding how they work, and many more items where they don't even know what they do.
 * Being subverted in the more recent books
 * In Fredrick Pohl's Heechee Saga, the entire plot of the first few books revolves around highly advanced alien space ships, though they do eventually manage to decipher the instruction manuals.
 * One big one is that after you set the targeting crystal, that no human understands, which glows various colours and auto-locks by AI, anyone who has changed those settings after launch has disappeared.
 * The hero eventually finds out why.
 * Parodied in The Galaxy Game (by Phil Janes) where a scientist trying to master FTL for a trip to the stars finds three small boxes each printed with the words "Inertialess Device" in his kitchen cupboard one day. We later find out they were put there by bored Energy Beings who pit civilisations against each other for sport.
 * In David Brin's Uplift War series all of galactic civilization is based on such technology (very much like Mass Effect) the exception being humanity's, humans STILL have to rely on Black Box technology in order to go FTL or fight in space, but they try to do it as little as possible, and sometimes having access to a technology you know intimately might be an advantage... Rock Beats Lasers after all.
 * This is a major feature in Alastair Reynolds' Revelation Space novels. Everyone uses a certain kind of stardrive, but only the makers know how they work, and fiddling leads to an enormous explosion. The most powerful weapons are barely-understood gifts from Sufficiently Advanced Aliens.
 * Judging by the eponymous character's vauge discription of the internal conditions in a stardrive in "Weather", the Conjoiners kept the stardrive technoloy Black Box so that the 'retarded' (everone else) wouldn't try and weaponise it.
 * The O/BEC processors in Blind Lake. Created by accident due to the use of self-rewriting code, not even the scientists who operate them are quite certain how they do what they do. There are only two in existence; all attempts to make a third by replicating the conditions that lead to the first two have failed.
 * This exact phrase is used to describe the Highway in William Gibson's short story Hinterlands. Astronauts go in and come out, sometimes bringing back pieces of alien civilisation with them. The "jump" only happens when the astronaut is alone and they all, invariably, come back either dead or catatonic. Sometimes the jump doesn't happen at all...
 * In The League of Peoples Verse, the Technocracy has pretty much no idea about how most of its own technology works, as the majority of it was just handed to humanity by Sufficiently Advanced Aliens.
 * In Atlas Shrugged the remains of John Galt's motor were found in an abandoned motor factory. Dagny Taggart's new purpose in life (for the next few chapters at least) is to find a scientist to reverse engineer the motor and put it to use on her railroad.
 * It's a particularly interesting case, as Galt realized that the unbelievable stupidity of Starnes heirs were the symptoms of a cultural decline. He could thus safely walk off and leave the prototype and the plans right there in the lab without fear that they would be stolen, as no mind capable of understanding how valuable they were, let alone making use of them, would ever work there again. A notable subversion of Low Culture, High Tech.
 * Colson Whitehead's The Intuitionist. The main MacGuffin in the story is known as the Black Box.
 * In Robert Heinlein's universe there is the Shipstone; a battery that comes in sizes from a lifetime miniature system for a flashlight, to a large battery that can power a house, to a possibly colossal one that powers space ships. The black box-ness of it comes because the inventor never patented it, since that would require that he publish the schematics. he just started a company and started manufacturing them under lots of secrecy. Attempts at dismantling and reverse engineering a shipstone usually resulted in a big kaboom.
 * In The Hitch Hiker's Guide to the Galaxy, the starship Heart of Gold features the infinite improbability drive that enables improbability manipulation up to a point where the ship exists everywhere at once and can drop out anywhere instantly - universe wide teleportation. The hitch is that nobody knows how the improbability drive really works, some smartass janitor just figured out one day that all he needed to know was how improbable it was for that drive to come into existance and voila, instant Black Box.
 * The starship Bistromath works on a similar principle. In restaurants math works differently than anywhere else in the universe. This is why you can never correctly guess what the bill will be, what a proper tip is, how much each person at the table should owe, etc. Nobody knows why this is, or how it works, but that doesn't stop them from building a spaceship modeled on a small Italian Bistro to take advantage of this fact and break several laws of physics.
 * The Belt of Deltora from Emily Rodda's Deltora Quest is technically a Black Box, with the belt part itself the box and the gems the internal mechanisms. It can be assumed that no one knows exactly how it works; indeed, how it works is irrelevant. All anyone knows is that the Belt is "greater than the sum of its parts" and removing one of the pieces (i.e., one of the gems) would stop it functioning.
 * In Animorphs, the kids are given the power to morph by touching the Blue Box by the alien Elfangor Later, David shows up with the same blue box and it is used to give him morphing power even though no one present has any idea how the technology works.
 * In Ian Irvine's Well of Echoes series, the clankers draw energy from nodes. No-one knows why it works, but their are some illegal books that speculate on these topics.
 * This becomes a major problem when
 * The Machine of Death is a device that takes a person's blood sample and predicts how that person will die. It's cheap to use and possible to duplicate, but no one knows how it works.

Live Action TV

 * Western Example: Stargate SG-1 often adapts lesser versions of the technology the crew encounters from other planets. "It doesn't quite work like the original" is commonly stated. However, they're far more aware than most Black Box users of the potential for unexpected side effects.
 * In fact, nearly every piece of technology they pick up is mentioned to be sent off to Area 51, either in the episode where it's introduced, or when they decide to use it again. This leads to situations that look like Forgotten Phlebotinum, until two or three years down the line where the device pops up again. Except for anything that comes with a trigger (Zat guns, anyone?) which is usually put into active service immediately. Which should come as a surprise to nobody, since military usage (including stuff that makes an Earthshattering Kaboom) is usually the first application mankind can think off for any given tech. Naquadria bombs, anyone?
 * There are few ideas that are missing however. So they can take apart staff weapons but can't build them or speed up rate of fire but could find them by the buttload after a firefight right? Well, seeing as how that whole unlimited ammo for machine guns thing would be very useful in their fighters, why didn't they strap six or seven of the firing portion onto a rotating contraption and make an impromptu gatling weapon and mount one of those?
 * It was mentioned in show, that kinetic weapons make better infantry weapons because staff weapons are self-cauterizing and less accurate. As for space weapons, they probably never actually captured a ship class staff weapon. The infantry ones they have are much less powerful the the F-302 railguns.
 * While never utilized in the show, that idea is one of the first uses Humanity finds for all the extra Staff Weapons in the Fan-Fic series 'XSGCOM', among other things...
 * This also extends to the spinoff/sequels Stargate Atlantis and Stargate Universe, where the protagonists uncover a dearth of Ancient and alien technology. Though they know how to operate the Ancient technology they find (most of the time), they don't know their exact inner workings.
 * The Goa'uld, on the other hand, make very little effort to study the Ancient technology they use. They've based their empire on things like the Stargates and ring transporters, but they really have no idea how any of it works.
 * The Jump Gates in Babylon 5 - nobody knows who built the first gates or what principle they operate on, and every spacefaring race in the universe simply produces replicas thereof without understanding how they work.
 * Other leftover First One technology likewise. For example, Shadow devices that allow for remote control of ships. Like Sheridan says, the younger races don't understand them and can't build them, but are sure willing to use them.
 * In the re-imagined Battlestar Galactica, it's eventually revealed that the "Significant Seven" Cylons don't understand how the resurrection process they use actually works, and so
 * The positronic brain that makes Data a Ridiculously Human Robot serves as his black box in Star Trek: The Next Generation. While Starfleet has a pretty good idea of how the rest of his body works, the technology that actually makes him sentient is a complete mystery to them, especially since the genius inventor who built him is dead. They're understandably reluctant to take Data apart to figure it out, since they don't know if they'd be able to put him back together afterwards, and after a particularly overzealous researcher took the issue to court, Data gained the legal right to refuse such a dismantling anyway. His own attempt to replicate the technology seemed to succeed when he built a "daughter", Lal, but her positronic brain became unstable and she only lived for a few weeks. Nobody's tried to build another one since.
 * Also, the risk of creating another Lore (Data's dangerously flawed older brother) highlights the risks of building anything less than a flawless brain on the first attempt.
 * Finch and his partner invoke this trope in Person of Interest when questioned by the CIA on how the Machine provides intel. Finch feels the Machine is too powerful for any person to have access, and so encrypts it so heavily even he will never be able to access it again.

Newspaper Comics
"Dilbert: Frack."
 * The legacy server in Dilbert, which Dilbert was put in charge of. It's worth noting that Dilbert's immediate response upon seeing it was

Tabletop RPG

 * Justified in Cthulhu Tech-Since the Dimensional Engine runs on non-Euclidean mathematics, attempting to find out what goes on inside one will cause weak minds to break.
 * The term non-Euclidean here is meant to be a hint of how complex and hard or impossible to understand this geometry is, rather than a strict description. According to one article, 4D geometry isn't Euclidean because there's an easy way for corners to mathematically become curves. We're familiar with geometry that works with respect to spheres, because trying to travel in a large enough square path will not result in getting to the original place. That's a standard example of non-Euclidean geometry. Imagine going to a realm where backtracking would *also* take you to a different place. Or travelling in distances that cannot be expressed only in real numbers, so imaginary numbers must also be used. See Alien Geometries.
 * Mathematicians most likely have theory that works with these geometries as well. They seem to like inventing things that can cause madness in more grounded in reality people. Fortunately, most of these are kept out of public view.
 * Anisotropic space? What's wrong with it?
 * 4D geometry can be Euclidean. Can be not. It's not a case of dimensions - Minkowski space(time) can be easily represented for 2D instead of 4D as in special relativity. Actually we are sure since special relativity has been proved not disproved that our space is not Euclidean. Set Theory did drive people insane.
 * "In the center of every ANIMa creche lies a scavenged piece of an alien's brain. It's possible that this is the only thing that an ANIMa requires to function, and that the rest of the machine is there to inspire more confidence on the part of the pilots." - Bliss Stage: Ignition Stage rulebook
 * In the Eberron campaign setting of the Dungeons & Dragons roleplaying game, black box magic was used to develop the warforged through schemas, which are essentially magical blueprints conveniently left behind by an ancient giant civilization. It turns out (in the Secrets of Xen'drik supplement) that it was, though this doesn't explain why modern warforged are fully sentient and appear to have souls.
 * Syrneth artifacts in the 7th Sea RPG setting are an intentional use of this trope. Syrneth technology doesn't just do whatever is convenient; the results of humans tinkering with it can have effects ranging from miraculous to horrendous, and sometimes no effect at all.
 * Syrneth artifacts also run the gamut in regards to the complexity of their function. The Pirate Nations sourcebook includes several that players can purchase. They include a completely functional cybernetic hand and a marble that, once tapped, will always roll back to the position it was last tapped, showcasing how bizarre some of the effects can be.
 * As a borderline Scavenger World, Warhammer 40,000's Imperium of Man has some examples of this. A great deal of technological knowledge has been lost over the millennia, and as a result many of the devices lovingly-maintained by the rituals of the Adeptus Mechanicus are irreplaceable ancient relics. One example would be the Standard Template Construct systems, self-contained manufacturing programs that can produce anything from medicine to battle tanks to knives - they're some of the most valuable treasures in the galaxy, and the Imperium eagerly uses them whenever one is discovered, but nobody has any clue how they function and certainly isn't going to risk cracking one open to find out.
 * What the ST Cs actually are depends on the author, although they may just use the same name for different systems. The most common is that it was a massive database on how to build anything given basic tools and resources without any real mechanical or scientific skill, but the last working system was lost millenia before the founding of the Imperium. The print-outs of a few plans that remain are the most valuable things in the galaxy as a result.
 * A nonhuman example would be the Blackstone Fortresses of the Gothic Sector, a sextet of ancient space stations left behind by an extinct alien race. The AdMech were able to patch into the stations' power systems and hook up their own weapons and life-support, but nobody was sure of the things' function... until Abaddon the Despoiler showed up with some artifacts of his own and fully activated the Blackstone Fortresses, deploying guns that tore holes in space-time and could make suns go nova.
 * Mad Science in Deadlands is a prominent example. A Mad Scientist may create fantastic devices that surpass anything "regular" science is able to produce, but it's impossible to mass-produce Mad Science gizmoes - they just don't work. Throughout the centuries, Mad Science gains or loses popularity, depending on the shifting popular opinion.
 * Wonders in Genius: The Transgression work in a similar way to Deadlands: Geniuses can build devices that delicately bend the laws of physics, usually with a crackpot theory given legitimacy by the light of Inspiration. For many years, various Geniuses have tried to find out the secrets behind Inspiration, with little success.
 * And don't even think about having a regular scientist examine it. That does not end well.
 * It also adds some serious Fridge Horror for anyone who is scientifically inclined. Imagine being a scientist or engineer (the most common people who become Geniuses), someone who dedicated their career to discovering the truth and pushing technology forward and creating something that can bend the laws of reality... but you can never show anyone, can never prove anything and you will never know how it works.
 * Subverted in Exalted. Many of the great and wondrous artifacts can be understood... it's just that most of the great designers would have been among the Solar Exalted, who were murdered and had their Exaltations sealed away so they couldn't reincarnate. It doesn't help that the Solars specifically designed many artifacts to only function for Solars... because they never imagined there would be a time when they weren't around.
 * In theory, any Celestial Exalt (or Terrestrial of sufficient age and experience) could bring themselves to understand the complex workings of Solar artifice. The problem is that reaching that level of excellence is much harder for non-Solars, they can't achieve nearly the same level of speed, and besides they've been a bit distracted since then.
 * Well, now that the Solar Exalted are back, they can begin reverse engineering all of the old First Age tech... as can their corrupted cousins, the Abyssal Exalted and Infernal Exalted, whose bosses have other ideas about what to do with all of that technology.
 * To a degree, Exaltations themselves are black boxes, to the point where the guy who made the Celestial-tier shards probably can't make any more. The main alterations made have been the result of insane supergods launching curses fuelled by the power of their own deaths (the Great Curse), the random action of a zone of infinite probability (the breaking of the Lunar castes), flipping a switch that may have been there all along (Abyssals), and using an intact Solar shard as the battery pack for a web of Yozi Essence (Infernals). Alchemicals can only be made by demiurges channelling the Design of Autochthon and have no idea how to make more when not channelling. About the only Exalts it's easy to make are Dragon-Bloods, and that's because all you need is two other Dragon-Bloods, one male and one female.

Videogames

 * Xenosaga: KOS-MOS is an android built by Kevin Winnicot, but when she goes berserk and murders hims she has to be rebuilt. Unfortunately, the only way Kevin's successors are capable of creating another KOS-MOS is to reverse-engineer the same prototype unit that killed him because he took the plans for her to his grave. As a result, KOS-MOS is laden with black boxes with unknown functions (like her X-Buster ability), which come online at seemingly intervals, often to shocking effect. Series protagonist (and KOS-MOS co-creator) Shion is only able to figure most of them out enough to rebuild KOS-MOS a second time after gaining access to Kevin's original plans via a time paradox.
 * Also, a great deal of the series's technology is the product of one man, Joachim Mizrahi. After he died on Militia during the Federation's invasion, a great amount of effort has been poured into piecing his prototypes back together, as well as reassembling his codex of knowledge: the Y-Data. Efforts to recreate his work from scratch by his rival Dr. Sellers amount to impressive, but fatally flawed knock-offs.
 * Xenogears has Gears, the giant mecha of the game. Gears are obtained both through construction and excavation, but it's never elaborated to exactly what ratio most Gears are are comprised of irreproducible black boxes, copyable black boxes, and commonly understood technology. The primary Gear of the game, Weltall, is comprised almost entirely of black boxes, which, much like KOS-MOS, are stunningly powerful and come online at seemingly random intervals. According to the Perfect Works Book, . Eventually,.
 * In the Mega Man X game series, the sentient robot X is copied imperfectly, resulting in the Maverick uprisings.
 * The documentation for the original SNES game outright stated that there were some systems that Dr. Cain just didn't understand and therefore didn't reproduce. He even called them "Black Boxes". It's unknown if these parts were part of X's ethical training, or his various weapon systems (his ability is repeatedly described as "limitless", and no one understands why). Later games revealed that Zero has similar black boxes, mostly likely stolen by Wily.
 * But in the Mega Man Zero series, Ciel, as a young kid, manages to reproduce X perfectly. Unfortunately said perfect reproduction showed why Dr. Light had X put into ethic training sleep for at least 30 years.
 * Ciel's no slouch though; didn't she spend much of the series developing a revolutionary new energy source, one that would end shortages and bring about world peace? Yeah, you never saw Dr. Cain pulling something like THAT off.
 * And then you can't call it a perfect reproduction. Yes, it looked like X, it had an arm cannon, a variable weapons system (though he only used three moves), and a set of armor... but it's much weaker than X in many ways and in fact is quite comparable with
 * In Armored Core: Nexus, this comes back to bite the Corporations in the ass. One Corporation activates the robotic equivalent of a weapon of mass destruction to protect their territory. So, it promptly goes berserk and ends up killing the executives of that Corporation and most of the people who work for them. This happens again when Kisaragi, in the same game,  which, again, promptly go apeshit and   It also
 * A rare example where the black box is in the alien's hands is in the Halo universe, where all of the super powerful technology used by the Covenant are just leftovers of another alien race called the Forerunners. Instead of even trying to discover the means of its operation, they take them to have divine powers and remember the Forerunners as gods. For this reason it has been established that they do not even use the technology very efficiently. By contrast, human attempts to analyse captured Covenant technology, as demonstrated in the Expanded Universe novels, result in drastic improvements. Cortana, for example, analyzes the tech and uses it against the Covenant by
 * The inability of the Covenant to use their technology is made very obvious in the manual with the Halo 2 collector's edition, where the Covenant hierarchy themselves state they have no way of recharging plasma weapons in the field, and all Covenant troops are trained to throw away a depleted weapon and take a charged one off their dead comrades.
 * In the Mass Effect series, the Citadel and mass relays are thought to be built by the Protheans. Humans and other races use them, though their inner workings and construction are poorly understood.
 * Worse than that,
 * Much of the Tiberian story arc of Command & Conquer revolves around recovery, possession and use of the Tacitus - a black-box type artifact misplaced by the Sufficiently Advanced Aliens.
 * Not only that, but the in game resource "Tiberium" which acts as the catalyst for the entire series is an alien terraforming plant that will shape earth to become like their planet. In their attempts to study the plant both sides find ways to turn it into a weapon.
 * In Sins of a Solar Empire, the Advent field Phase Inhibitors stolen from the TEC, who use Phase Inhibitors captured from the Vasari. . . who also don't know how Phase Inhibitors work, and simply field copies of ones that they found.
 * The Metroid Prime subseries involves the use of Phazon, a blue gooey substance that turns its users Nigh Invulnerable and greatly amplifies their weapon strength. It also corrupts its users into willing slaves of the host planet Phaaze, but thems the breaks!
 * The PED suit from Metroid Prime 3 contains a "black box" that allows the user to boost their power with Phazon, though how the corruption is contained is not explicitly stated. Samus's black box breaks early in the game.
 * Samus's suit has tons of hidden properties the Chozo didn't have time to tell her. Fortunately the suit is smart enough to do that for them. Not only that, but the suit is actually capable of using non-Chozo technology to upgrade itself when Samus acquires it, which gets really strange when she picks up Luminoth, Space Pirate and human technology (though human power suits are most likely based off Chozo power suits anyway).
 * Played with in Homeworld, whose Historical and Technical Briefing describes the discovery of a large amount of Lost Technology in the wreck of an ancient spacecraft, including something eventually identified as "a solid-state hyperspace induction module". It's implied that much of their limited understanding of how it actually works was gained from building a couple of scaled-down copies and fitting them to small spacecraft, pressing the 'on' button and watching to see what happened.
 * Then it turned out that said module is actually a 10,000-year old Progenitor Far Jumper; only three of them exist in the whole galaxy. One of these are in the posession of the Bentusi and it's the basis of all hyperdrives in the galaxy, save the Kushan ones. It is also said that no matter how much they study them, they can't figure out why the reverse-engineered versions are much slower than the originals even though they know how to make other ships tag along by "riding the quantum wavefront". In fact, combining the three Far Jumpers will break the laws of physics (black holes disable hyperdrives yet the Trinity still works flawlessly).
 * In Final Fantasy VII: Dirge of Cerberus, no one knows how the power source of the airships works.
 * Epitaphs in Infinite Space. They're more-or-less useless one-foot-square rust-red and slime-green cubes, but if you can figure out what they do, you get rewarded with the power to alter the universe.
 * In the Touhou Expanded Universe, there's a character named Rinnosuke. Rinnosuke has the power to immediately identify the function of any device he sees. This does not mean that he knows how to use it. (He sometimes gets strange results too, like identifying a Nintendo Gameboy as a "World Controlling Device," but that's a different trope.)
 * The Metal Max series has this in spades. Aside from the world having been wrecked so badly no one even remembers what several machines DO, let alone how to build them (tanks among them - although The Disassembler seems to know his way around them, but he's insane and only disassembles them, hence the name), there's in Metal Saga, whom nobody knows how to fix (hence why ). The genetically engineered dogs in Metal Saga may also count, as they are very clearly far more intelligent than they appear, bordering on being smarter than quite a few humans.
 * Dwarf Fortress, reportedly, is one. Not only is Toady One very protective of the source code behind his masterwork, but his software development skills are almost entirely self-taught. The handful of people who have been entrusted with backup copies of it have attested that the code is almost impenetrable to mere mortals.
 * The superweapons of the Naval Ops series, especially in Warship Gunner 2, are considered to be Black Boxes by the people fighting against them. In WG 2, they run off a Black Box "Engine" strapped into oversized conventional ships (for a given value of conventional).
 * Played with through the gates of the X Universe. While operation is terribly easy—push a spaceship in one gate, and it'll pop out the other gate in the pair a few seconds later, no matter how far away—no one in the central interstellar trade system understands anything but the lies-to-children version of how they work. While there are a few scientists capable of repairing damaged gates, no one even thinks about trying replication or reconfiguration, and the irregular outages or changes in the system caused by meddling precursors is treated like mystery or even legend where it's not just a natural risk of the gates. The species that actually made the system in the first place not only consider it outside of the range of understanding of the normal races, they think it's impossible for a species to understand without getting a few points higher on the Kardashev scale. Then the Terran humans get involved, and not only get the theory down and create a new gate on their own, but also create a Jumpdrive that's a separate Black Box to everyone else in the setting.

Webcomics
"Dr. Westman: Gotta love that military mentality: "Ah don' know why ut works, but they sure do kill!" Idiots."
 * In a flashback arc of Gnoph, a scientist criticizes the military for creating a breed of Super Soldier pretty much by accident and then using them despite not really understanding how or why they work. Sure enough, things soon Go Horribly Wrong.


 * According to Word of God, the Beam swords in Exterminatus Now are Lost Technology from a long-gone empire, and are not comparable to any other technology (modern or otherwise) in the setting (so the dark Machine God cannot possess them). This goes a way towards explaining why the Forgemaster who builds them is ignorant and suspicious of modern plumbing.
 * Some government agents in Real Life Comics once confiscated an interplanetary ship Tony made. They opened up the reactor and found . . . jam.
 * Nobody Scores had an arc where the main characters ended up getting their hands on a literal black box—things went in, and other things came out. It was when it started producing multiple copies of the severed head of Shia LaBoeuf (who was still alive) that they started trying to get rid of it...
 * In Gunnerkrigg Court, Anja and Donald Donlan created a computer that runs on magic, which even they don't fully understand the workings of. They're the only ones who use it—the rest of the Court distrusts it precisely because it's a Black Box.
 * Diego's Super Prototype robots (which also appear to run on a combination of magic and technology) are also black boxes. They have no visible power source, nor means of moving their limbs. Modern robots are black boxes even while self-documenting. When asked to print their operating code, one produced a 3D image of some complex structure made of runes, with density requiring a microscope to read, without any sort of map legend, and neither derived from nor designed to be compatible with, any human languages, natural or programming (they are robot-built).
 * The Star core in Mushroom Go, nobody on the ship has any idea how it works.
 * An early Goats storyline involves such a machine - you put kittens in, and pop tarts come out; nobody knows what happens to the kittens. Later it's revealed that the machine is
 * In Westward, Escherspace—a form of Faster-Than-Light Travel—appears to be a Black Box. Publicly, the government claims that "only a few scientists" know how it works; in reality, it's strongly hinted that only the mysterious alien Phobos may be capable of understanding it, and he must personally work the controls when the webcomic's eponymous Cool Starship makes an interstellar jump.
 * In Spacetrawler, it's implied that the eponymous spacetrawlers (which the entire galaxy relies on to enable faster-than-light travel and matter synthesis from space debris) are so complicated that only the technopath Eebs can understand and construct them.
 * During the "Star Trek" parody arc of Quentyn Quinn, Space Ranger Omnibus described the devices running the essential functions on the "Glorious Undertaking" as "black box" devices.

Web Original

 * Most of the super-advanced technology in the Orion's Arm universe is at least partly powered by transapientech. This is by definition designed by beings orders of magnitude smarter than ordinary folks. This is something of a subversion in that the inner workings are completely known, and probably published somewhere on the net, but the people using them can't understand them, since their brains aren't complex enough. It's sort of like trying to teach a small child nuclear physics in depth.
 * Some artifacts in custody of the SCP Foundation - for example, SCP-914.

Western Animation

 * Ben 10's Omnitrix. Not from earth. Seemingly simple to use on the surface... But it has secrets, hidden abilities, glitches, and occasionally, a mind of its own.
 * Eventually they meet its creator, who doesn't seem to understand what he's built either.
 * In Thundercats 2011 Young Catfolk Prince Lion-O is a Collector of the Strange, namely "technology." He purchases a piece of what he suspects is Lost Technology from a Friend in the Black Market, and spends quite a bit of time puzzling over it and diagramming it, but only realizes its function when he sees a Lizard use one to blow up a wall during The Siege on his kingdom of Thundera. Finally understanding the device's interface as a Sticky Bomb, he grabs some others, also In Working Order, to join the fight against the Lizards, saving his father Claudus and brother Tygra by using the bombs to blow up some of the Lizards' Walking Tanks.

Real Life

 * In WW II, at a time when electronics were evolving rapidly (e.g. microwave/RADAR technology), the British assembled electronic parts into random yet convincing circuits, then shot and otherwise mangled them, then let their bombers carry them. If one of them was downed, the Germans would go through the wreckage, find the remains and then spend valuable time and manpower to try to figure out what this secret device was supposed to do.
 * On Doctor Who, one of the companions, Kamelion, was, behind the scenes, an actual, animatronic robot. Unfortunately, the person who had designed it and who knew the control codes died after the episode where it first appeared, so the character mostly had to stay in the background.
 * The Jargon File and its dead-tree twin, The New Hacker's Dictionary are rife with terms describing programming Black Boxes, most notably Black Magic.
 * The most memorable of which is the "Magic/More Magic" switch. The only wire soldered to the switch goes directly to the case of a server. There is electrically no way it can affect anything on the server (except for extremely bizarre capacitance effects) and yet switching to "Magic" causes the server to die.
 * It could also be due to a difference in electric potential between the ground and the case.
 * Genetic algorithms (computer programs that emulate neo-Darwinian synthesis) can produce hardware that no human could design. For example an array of logic gates that sets its output high when it hears go and low when it hears stop. Inside the circuit 5 of the 37 gates are not even connected to the rest; and the device stops working when their power is disconnected! An order of magnitude weirder than the magic switch. Other examples include a research team accidentally reinventing the radio receiver while trying to evolve an oscillator and very unusually shaped antennas that can be held in the palm of the hand and transmit signals from satellites to the surface of the earth. More about the magical stop go circuit here.
 * Large amounts of real world software source code is an absolute abomination of incomprehensible abbreviations, architectures which haven't evolved and grown so much as become cancerous, baffling hacks and plain old carelessness and stupidity or even just plain old lack of programming know-how. Such software will gain Black Box status pretty soon after the original developers move on.
 * Fun fact: Masi Oka (yes, Hiro from Heroes) still has to do occasional effects work for his former employer, ILM, because nobody else knows how to use his software.
 * This isn't unusual. Truly understanding non-trivial code written by someone else without documentation is considered the mark of a master programmer. It's said engineers don't retire, they just become consultants and come back to fix their old things when they break.
 * Particularly this is true of cryptographic algorithms. You put plain text and an encryption key in, and you get back line noise. Put line noise and a decryption key in, and you get back plain text. Unfortunately so few people actually understand the algorithms and code that, even in open source software, bugs can lurk for a long time.
 * A more humorous example: in an attempt to cut government costs, California decided to fire a large chunk of government workers, then redo the pay rates for everyone left. Well phase one went off fine, but come phase two they realized that every single person who knew enough about the payroll software to implement the changes had been fired in phase one.
 * Older electronic (and most especially military) technologies may well have been designed by people who are dead, coded in languages which no-one ever hears of nowadays, use electronic standards long since obsoleted and built by companies that dissolved or got eaten by other companies some time ago. Black-Boxhood arrives quite naturally for such devices, which could conceivably include missile guidance systems or nuclear warhead triggers which are still quite usable today.
 * FOGBANK
 * COBOL used to be a very common language for developing business software in. Though superseded by modern languages like Java or Visual Basic, old working software was not replaced. The pool of skilled COBOL engineers is rapidly dwindling simply because they are retiring and in due course upgrade and maintenance engineers will simply not exist anymore.
 * This is largely the philosophy behind object orientated programming; once that class in Java, C++, Python, etc is done then all that matters is the numbers you can throw in and get out. If someone else wants the class to do something else, the chances are they'll write a class that extends the old one or even (if they're sloppy) just calls it rather than risk fiddling with the source code.
 * Favoring composition over inheritance is considered good programming practice, it's certainly not "sloppy".
 * The whole point of any standard device interface or Application Programming Interface: abstraction means compatibility. A trivial task turns into nightmare the moment coders have to know how each variant of the external stuff really works instead of one set of common operations. Remember those sound setup programs of DOS games?..
 * It seems that the original programming of Microsoft Excel might be a black box, since after the principal programmer quit, the project virtually stopped. Luckily he came back.
 * Many psychiatric drugs work via mechanisms that are either unknown or only loosely understood. The laborious (sometimes decades long) process of searching for side effects and other quirks irons out many of the Black Box problems that plague fiction.
 * On that subject, some (if not most) chemical reactions in general have mechanisms which are only vaguely understood at best.
 * Real Life is rife with stories of a programmer being fired for whatever reason; only for his ex-boss to realize nobody knows how to maintain the server.
 * Due to the "digital rights" controversy, certain laws have been put into effect that require black boxes to remain black boxes, making it illegal even to try to crack into them. For example, it's now illegal to write programs to get past certain types of encoding on music, DVDs, and electronic books. If you have even a slight understanding of the way technology progresses, you'll probably see this move as either "stupid" or "scary", possibly both.
 * If you've followed the results, "laughable", "doomed" and "legally unenforceable" are more likely.
 * Older Than Radio: During the early 18th century, Antonio Stradivari hand-crafted several wooden violins that, compared to other violins before or since, produce the highest-quality sound. Many violin manufacturers have, for centuries, attempted to not only replicate the sound of the Stradivarius, but have even labeled violins as "Stradivarius" as a marketing ploy. Unfortunately, when Stradivari died, the technology and skill required to produce a violin of such caliber died with him. Scientists continually do research on the Stradivarius sound and technologies to replicate that sound, and original Stradivarius violins remain to be the most valuable musical instruments in the world.
 * The "Stradivarius" label on violin is not there for marketing reasons. It's actually a model of violin - Antonio Stradivari's instruments had very specific proportions (also being slightly larger than ones made by competing crafters). If you see a violin labeled "Stradivari", it means that its proportions and size match those of an original Stradivari instrument.
 * It has been speculated that the sound quality is due to the wood available at the time. He built them around the little ice age, and wood at that time was particularly thin and brittle due to the odd weather patterns, making them irreproduceable. On the other hand, other violin makers of the time were unable to reproduce it either.
 * There's also evidence that Stradivari violins aren't that great in the first place.
 * The philosophy of instrumentalism boils down to "the only important thing about any theory is whether it's usable, i.e. predicts a result of given experiment". Hunting for explanations is but a pointless infinite regression. This means that "light is truly made of particles" and "light is truly made of waves" are fancy statements that delusionally bind real events to imaginary constructs while "wave model correctly and in convenient form predicts diffraction/interference effects" or "particle model correctly and in convenient form predicts absorption/emission effects" states everything that really matters in this issue. From this point of view anything is a Black Box, the only difference is that we already know how to dismantle some blackboxes to several smaller blackboxes and what buttons to push.
 * Arguably the universe itself is a black box since we don't (yet) have a complete physical theory of the universe. Also, while we do have two theories that work fine in their respective arenas (General Relativity: big and heavy stuff, Quantum Mechanics: small and light stuff), they are contradictory and become completely incomprehensible when used together.
 * The plans for the Saturn V rocket from the Apollo Project are stored in a format that isn't readable by any computer currently in use. Since there are a few leftover rockets, that could potentially be fueled up and fired, they have become black boxes. When the new designs for the Orion spacecraft (not the nuclear-bomb one, the newer one) were in the works, the ability to look at the old Saturn design and learn from them was denied the engineers, who had to waste potentially years starting from scratch. Since then, to avoid this trope, a project was initiated to attempt to retrieve the data and transfer it onto a more modern storage medium, but it's so underfunded that it's not currently active.
 * Although some of that is true, there are other significant factors involved - for instance, not being allowed to use asbestos anymore even though we know how. It's not purely a case of "no longer able to read the plans."
 * This is an urban myth. The Saturn V plans are stored on microfilm. While readers are not nearly as commonplace as they were at the time of the rocket's conception, they're still readily available.
 * Though microfilms do exist, several key parts were destroyed due to Cold War policies on classified materials. The Orion engineers also had access to the engines from one of the original (IXX, I think) F1 engines taken from the rocket currently displayed at the Marshall Space Center in Huntsville, Alabama.
 * The engineers also have had to look in junkyards for intact components from the old program in order to try to figure out how they work.
 * Nikola Tesla, thanks to a heady mixture of personal eccentricities, outlandish claims, and industrial FUD both during and after his time, has a reputation for this sort of thing rivaled only by fiction. All his well-documented inventions work from explicable, if clever, principles of engineering—but poorly documented claims abound of death rays, earthquake generators, and yet stranger things unreproducible by modern science.
 * The fact his documented ideas tended to get stolen (usually by Edison) might have something to do with it.
 * SR-71 Blackbird recon plane: Due to ongoing modifications to their respective airframes each Blackbird had its own set of blueprints. Thus, each Blackbird was unique, although they looked identical. The original molds or dies used in the manufacturing of the planes were ordered destroyed by then Secretary of Defense McNamara (cold war policies again) so it would be nearly impossible to make new Blackbirds or even spare parts (in fact other airframes had to be cannibalized to keep the fleet airworthy), although a lot of planes survive to this day so reverse engineering could be feasible.
 * The human body itself is quite the black box. With the exception of your occasional doctor or biologist, everyone uses theirs without the slightest hint of how the lot of it works. The brain in particular is quite the mystery, for if it was simple enough we could easily understand it, we would be unable to do exactly that.
 * Don't even get started on the human mind!!!
 * Frankly every discovery about that has just been depressing. For instance, seemingly minor damage can re-write parts of a person's personality or even taste in food, seemingly at random.
 * Or is that just the filter through which a person's true self emanates? Probably impossible to know...
 * It doesn't help with the understanding of the human body or mind that there's so much misinformation that's continually being repeated, especially by proponents of "alternative" medicine and psychics.
 * The claim that we will never be able to understand the brain because we use it to think is absolutely without proof. Furthermore, other systems such as computers can know the rules that govern their functions so there isn't even any precedent for it.
 * While there is still debate on the subject, nobody knows for sure why a bicycle stays upright when you ride it. It just does. Numerous theories have been put forth with some of them holding water. See this Cracked article.
 * The same article also lists several other questions that even modern science can't answer: why we sleep, how many planets are in the Solar System, why ice is slippery, how to beat Solitaire, how many animal species exist, what is the length of the US (or any) coastline, how does gravity work. A lot of these questions that we just either never ask or accept a universally-known explanation, which is actually false.
 * Some of these are somewhat trivial, while others are more interesting. How many planets are in the Solar System depends on one's definition of planet -- it isn't the result of lack of knowledge but rather of definition, and if we mean a real planet, not a minor one, the answer is pretty clear at 8 -- while it is possible we will find a far-flung planet in the solar system, it would be pretty remote (there certainly isn't a planet anywhere nearby, and the vulcanoids are not hiding a planet), and this is simply mistaking science for something else (nothing is ever proven in science, after all). The length of any coastline depends on your level of precision. And while we don't know exactly why ice is slippery in the sense of not knowing what causes it, we are pretty sure we know the cause of the low friction - a thin layer of water on the surface. On the other hand, we really don't know why we sleep, how gravity works, how many species there are (though like the planets one, this is more of a lack of total knowledge than a lack of theory, which is a very different thing), why bicycles stay upright (sort of... we do know some of this, at least the obvious bits, but there are clearly more factors at work)... it's a bit awkward that the article mixes two things (knowledge questions vs theory questions), as there are lots of knowledge questions unknown to science.
 * There was a fad for "miracle cure" machines at the beginning of the twentieth century that were actually called Black Box machines. You just set a few controls, turned it on, and whatever quack therapy that model was based on would cure the illness. The reason they were intentionally kept as black boxes was the controls did nothing to their function, and most in fact had no working parts.