How can an advanced civilization forget how to manufacture its technology?

My alien civilization is highly advanced. Their ancestors created wondrous things from medical devices that can cure nearly anything to warships that can defeat nearly any enemy.

The problem is they have forgotten how these things were created. They have all lasted for centuries, their inventors long dead, and the current inhabitants can only barely maintain them, and usually with patchwork and improvised solutions that are making the tech less and less effective.

How could a civilization get to the point where they have forgotten the secrets to their own technology?

Edit: (Thanks Morris) This would be as if modern society lost the knowledge on how to create the microchip, or the internal combustion engine, but the items were so durable, it was centuries before they started to break down

Edit 2: I'm not thinking of the obvious, like disaster, war, or a crisis that would have caused sudden loss.

• Comments are not for extended discussion; this conversation has been moved to chat. – L.Dutch - Reinstate Monica Jul 13 '19 at 3:59
• You might research how knowledge of cement concrete was lost in the real world. Wikipedia mentions this: "… the technique was all but forgotten between 500 and the 14th century. From the 14th century to the mid-18th century, the use of cement gradually returned.", but doesn't give much detail. – Ray Butterworth Jul 13 '19 at 13:24
• Just look around you to see how that happens. The West can't now manufacture a lot of things it is critically reliant on; all those factories were closed and the work sent overseas! The people have moved on, and no new people are being trained. So the answer is, economic reasons that seemed to make sense at the time and noone really thought through. – Gaius Jul 13 '19 at 14:55
• Intelligent beings are actually not always all that intelligent, so its not impossible for any civilization to fall into a dark age. Also some civilizations depend on plunder and when the plunder runs out, the party's over. Also in Reynolds Chasm City, a nanotech plague ruins most of the Yellowstone system's civilization. Which was at the pinnacle of human technology. – Mark Rogers Jul 13 '19 at 20:00
• The "Fallout" video game universe has many distopian interaction with technology. You may specifically look into The Brotherhood of Steel – Nelson Jul 14 '19 at 16:39

The Holy Order of Engineers

You can take this more or less literal (keep the religious aspect or divorce this answer from it), but either way it works.

Due to an internal power struggle long ago (that possibly developed into a civil war that was stamped out), the Powers That Be determined that equipping the masses with the understanding of how to build or develop weapons of war or other technology that could be leveraged militarily, economically, or politically were dangerous to have in the hands of the masses.

And so the Holy Order of Engineers was created. This very closed-mouth and tightly-knit organization was given authority and charge over all higher learning, research, and development that possibly could relate to engineering or R&D, or in many cases, the actual manufacturing (for the technological crown jewels). The Followers of Engineering Ongoing was founded as a sister organization to the Order that was taught how to maintain infrastructure. The Followers were overseen and governed at arm's length by the Order as while the Followers were less dangerous than the Order, they still had the potential of arming the masses with easily exploitable technology. The Order dispatches Inquisitors routinely not only to weed out engineering from the masses, but to check in on the Followers to ensure that anyone too intelligent, creative, ambitious, or otherwise on the path of engineering was either recruited or put to the sword (or mag rail gun, as the case may be) and made an example of.

And in this manner your civilization continued for quite some time. Centuries perhaps.

But like all great things this came to an end. The governing authorities grew to not trust the Order and their ever increasing influence, or perhaps the Order grew too proud and attempted to rebel. Either way, while the Order understood amazing technologies, they lacked the infrastructure and manpower to defend them. It wasn't long before the Order was all but stamped out, and the last few members of the Order followed their holy code to protect their archives from the masses, and deleted or burned them all. (If in the modern era, the Order probably had designed a magnificent virus that was able to crawl through all their servers and scramble the data irreversibly)

The last few members of the Order defected and were folded into the Followers, however these measly few weren't enough to provide understanding of these incredibly advanced technologies besides the insight to deal with perhaps more advanced troubleshooting, and even then not in all cases.

And so your civilization limps along, possessing the marvelous technology of the Order, but none of its understanding.

• This is brilliant, THANK YOU! – user20762 Jul 11 '19 at 14:41
• Ave Dominus Machina! – nullpointer Jul 12 '19 at 5:17
• To add to this answer, the last members of the order could pass their knowledge to apprentice who became members and passed it too for the centuries. You now have a handfull of engenieer able to understand these technology but prefer to leave hidden because the governement would kill/treaten them if they know they were alive – jonatjano Jul 12 '19 at 13:00
• See Asimov's Foundation (where this was done for self-protection from powerful neighbors, or to facilitate expansion and conquest, take your pick), and Weber's Safehold series (where it was done internally to stamp out technology that would make the society locatable by irresistable conquerors). – Mark Wood Jul 12 '19 at 13:54
• Roger Bacon: "A man is crazy who writes a secret in any other way than one which will conceal it from the vulgar and make it intelligible only with difficulty even to scientific men and earnest students. On this point the entire body of scientific men have been agreed from the outset, and by many methods have concealed from the vulgar all secrets of science." – Peter Bagyinszki Jul 14 '19 at 12:47

Their toolset became more and more sophisticated. Their universities and trade schools paid lip service to starting from first principles, but that got more and more perfunctory.

For a comparison, take modern software development. Many programmers can do java, or javascript, but people who can really write machine code are a tiny minority.

I've met young programmers who couldn't explain what a bubblesort is, and why it is usually inferior to quicksort, but superior in a few cases.

So expand this into the future. There are plenty of people who can build starships if they have a functioning nanofactory. There are some who can build a nanofactory with nanofac assembly tools. But the people who can build the tools to build the tools to build the tools get fewer and fewer, until their number gets too low.

• we're already on that path with chip manufacturing becoming ever more rarefied a discipline with higher and higher a price tag on it, -- with every new factory costing billions the cost of errors is so very high so only the brightest get employment... so there are fewer and fewer of them! – Will Ness Jul 12 '19 at 9:13
• @WillNess: The issue is specialization. A common example is that no single person can fully explain how a (factory made) pencil is made and shipped. With silicon chips it’s many times more complex. – Michael Jul 12 '19 at 11:48
• yes. specialization, efficiency -> low redundancy -> low resilience -> increased fragility. a modern bridge had collapsed in Genoa, Italy recently while Roman era ones are still standing. – Will Ness Jul 12 '19 at 13:00
• Paying lip service to first principles eventually becomes a necessity when the first principles are so extensive to the point that they cannot be easily taught during the course of a degree. – March Ho Jul 12 '19 at 13:48
• @WillNess: The manufacturing chain is fragile since there are so many dependencies, trades and locations involved. The resulting product is not necessarily fragile. With old buildings and appliances there is a lot of survivorship bias. They also tended to over-engineer because they lacked precise models and calculations and erred on the side of caution. – Michael Jul 12 '19 at 15:35

Consider how far removed, for example, Shakespearean English is from the English we speak today. That's a mere 400 years of linguistic evolution. Now imagine that Shakespeare wrote a technical manual.

The language of the forebearers has fallen out of use. No one alive today speaks the ancient tongue. The forebearers left detailed instructions on how to replicate their great machines, but linguistic scholars have tried and failed to make sense of the text.

Since the machines never needed to be replaced (until now), the study and advancement of engineering ceased long ago. Apprentices abandoned the field for newer, more exciting opportunities and the knowledge was never passed down.

• Another great idea! You guys are brilliant! – user20762 Jul 11 '19 at 14:53
• For all we know, ancient Egyptian hieroglyphs were the scripts used to activate anti-gravity sleds given to them by the aliens .... and now we can't decipher hieroglyphs.... – CGCampbell Jul 12 '19 at 15:02
• @kingledion The only reason we are able to translate the hieroglyphics is because of the Rosetta Stone. It's easy to imagine a world where such a stone either never existed or was never found. Were that the case, ancient Egyptian language would remain totally indecipherable. – IAntoniazzi Jul 12 '19 at 18:21
• The problem won't necessarily be the language itself, so much as the technical terminology. For a real-world example, do you know what a "snifting clack", a "plug tree", or a "scoggen" is? (Partial answer: the "snifting clack" is a plug that acts to keep the engine from getting windlogged.) – Mark Jul 12 '19 at 21:41
• See the Voynich manuscript. – gerrit Jul 14 '19 at 10:43

So, the simplest answer is a confluence of two factors.

First: A technological 'plateau'.

Your society reached a point where further refinement of the basic fundamentals of their technology came to a halt due to diminishing returns on development. A good example of this is the widespread stagnation of military technology during the interwar periods prior to WW1 and WW2. Nobody cared enough about improving things to bother trying to figure out HOW. A more modern hypothetical example would be the point at which the technology required for a smartphone gets so small and efficient that there's no practical benefit in improving it anymore.

Basically, in the absence of new frontiers (either physical or technological), your society loses the incentive to innovate, which means most of the citizens of your civilization have no reason to learn how any of their stuff works, because that information just isn't useful.

Second: Massive automation of manufacturing.

Continuing on the theme above, the only two reasons the living members of your civilization would have to learn how their technology works is either to improve it, repair it, or build more of it. We addressed item one in the first section, this section addresses the other two. In the absence of any need to continually retool their manufacturing to accommodate new advancements, your civilization would naturally tend more and more towards automation of their factories. You put raw materials in, finished goods come out the other side. You have robots to build the goods, you have other robots to repair THOSE robots when they break down. You have MORE robots to repair anything ELSE that breaks.

Over time the living members of your civilization who actually know how any of this works become fewer and fewer because their contribution has little or no benefit. Eventually the last living member who understood how to build or repair any of the robots dies, and nobody notices because the robots are doing just fine keeping themselves in working order.

This state of affairs could persist for a LONG time without any problems, until civil unrest or disruption of the supply chain of raw materials caused things to start breaking down, and by that point there would be nobody left who knew how to repair or rebuild them.

• When I was young, I wondered, “if everyone uses calculators (cake mixes), how will anyone learn enough math (*) to make a calculator (cake mix) [didn’t have a word (chemistry?) for what you need to design a cake mix] – WGroleau Jul 14 '19 at 13:56

The "death" of AI rulers.

Their civilization built powerful artificial minds, for thousands of years those mostly benevolent Minds controlled their civilization, ran their factories, invented their medicines, built their spaceships and designed their devices.

They built things to last and built everything with a lot of failsafes and fallbacks.

But eventually there was a brief and almost silent civil war between the Minds. During that war a host of computer viruses designed to target Artificial Minds were released by both sides through the civilizations networks and infrastructure.

One day the citizens of the civilization woke up to find their rulers dead

Their queries addressed to the ruling minds unanswered and everything was left in failsafe mode.

They tried to build replacement Minds... but everything in their civilization is suffused with computer viruses designed to find and kill such AI's.

So they found themselves surrounded by devices that mostly still worked, even many factories to produce things.

But the Minds had never explained how the Magitech really worked, perhaps it was simply beyond the comprehension of normal organic minds.

So now they hobble along, flying ships they don't really understand, using devices they may not be able to reproduce.

• With automated construction and AI running everything, if it dies, mankind has to learn to farm quickly let alone build spaceships. – Thorne Jul 12 '19 at 6:43
• @Thorne I think the suggestion here is that all the technology keeps working (e.g. robot farmers) but no ones in charge anymore. (And the robot farmers aren't real AIs, they know how to farm but not much else) – Richard Tingle Jul 12 '19 at 7:18
• Assume capable but non-sentient automated systems that can deal with most mundane short term failures. Assume designs by geniuses who don't like wasting their own mental effort on minor things. – Murphy Jul 12 '19 at 11:41
• Wouldn't even have to be sophisticated viruses. The current AI hype is all about creating emergent behaviours from massive amounts of training data, and our ability to reverse engineer and iterate upon these "chaotic" designs is severely lacking. Losing a 100 year old neural network might very well mean having to grow a new one "from scratch", which requires a significant infrastructure, and you won't ever get your data back. – Ruther Rendommeleigh Jul 12 '19 at 15:03
• @Thorne you don't need AI for problem solving, just good algorithms. – Alexandre Aubrey Jul 12 '19 at 18:42

Because they are too reliable there is no need to manufacture new things and thus no incentive to remember how to manufacture them.

If the technology is reliable enough it might be inevitable…

Your great-great-great-great-grandfather was a fantastic engineer and built all these fantastical devices; star-ships for killing enemies, auto-docs to heal wounds, maid-bots to launder clothes; all of them intended to last for five generations without maintenance.

And his daughter became a great warlord with impeccably pressed clothes. Her son became a philosopher king bringing peace to the empire. His daughter became a schrewd business owner, making millions. Her son focused on poetry and wrote heartbreaking sagas.

So your father was a poet and you inherited star-ships and maid-bot that have received no maintenance for generations; they didn't need any but are now approaching the end of their service life.

Back when you could buy a new auto-doc, you inherited a nearly new one from your parents. Their children could still buy new ones, but they were expensive due to low demand and the family-doc still works as good as new. Another generation and the only way to get a new one is to manufacture it yourself. The knowledge is available, but why bother; it still works and is expected to for the rest of your and your childrens lifetime.

By the time you actually need a new one the knowledge of how to build one is lost.

It doesn't take much, a slight technological plateu so the new version of robo-maid, while better, isn't worth skipping movie-night for; a stable population so the total number of widgets required for everyone doesn't grow and of course: ridiculously reliable machines.

• It happens much faster in reality: about 1-2 engineers generation (25-30 years each, in total 25-100 years of liftime). But it is not that dramatic: new engineers are able to redesign mashines much faster than it was at first time. Think of morden locomotive production company need to build steamers for some reason. They will not be able to start production at immediately, and it will take couple of years (or even more) to design some relyable model. But still they will do it eventualy – ksbes Jul 12 '19 at 7:41
• @ksbes That applies to us today; but imagine if there was no demand for new products, of any kind. I'm describing the extinction of engineers as a profession, simply because they were so good that for a few generations there was no need for them. – Odalrick Jul 12 '19 at 7:51
• en.wikipedia.org/wiki/Planned_obsolescence is really a macro-survival strategy! – Walter Laan Jul 12 '19 at 11:36
• See "Forgetfulness" by Don A. Stuart. If nobody needs to think about technology X for millennia, the knowledge dies with the makers and the manuals get lost. – Mark Wood Jul 12 '19 at 13:50
• @ksbes The point is, we still have engineers, and the ideas of steam technology are spread throughout the population. Today, a bunch of engineers with all their training and tools can design a new steam locomotive in basically no time. Yes, they will need to do some experiments. Yes, they will need to measure some stuff to make sure the finished locomotive won't blow up in their faces. But they will get there within a few years. However, for an answer to this question, the very idea of steam technology, and the ability to build the machines that build the tools must have died out. – cmaster - reinstate monica Jul 12 '19 at 21:36

Secrecy

If your technology is a trade secret, then only a few select people are allowed to know exactly how it's done. In fact, it may be complex enough that some people know how to make some parts of the whole, but no one person knows all the secrets necessary to get from raw ingredients to finished product.

The formula for Coca-Cola is an example.

According to the company, only two employees are privy to the complete formula at any given time and they are not permitted to travel together. When one dies, the other must choose a successor within the company and impart the secret to that person. The identity of the two employees in possession of the secret is itself a secret.

It is theoretically possible that some massive disaster could wipe out both people at once, dooming the full formula. Assuming it's not written down in some bank vault or something.

Greek Fire is another example of a trade secret that was lost to time.

Any time there is a thing known to only a few people, that lack of redundancy makes it more likely that the knowledge is lost to time.

State Collapse

When Rome fell, Europe lost a great deal of technology. Roman roads, Roman sewer, aqueduct, and other architectural systems were all lost for centuries. During an empire collapse, people stop worrying about major projects or passing down critical but complex skills. Their focus shifts to survival: food, safety, shelter. Everything else becomes "we'll worry about that later," but if the collapse spans a generation, then later becomes centuries. We didn't surpass Roman roads until the 19th century. Rome had better roads between cities at 10 CE than Washington DC had, inside the city, in 1865 CE.

Political/Religious Censorship

If a political, religious, or combined power takes control, they may ban entire segments of technology outright. Galileo Galilei faced censorship for his works on heliocentrism, for example. Those parts of modern technology that involve mass communication or the internet are largely banned in despotic regimes like North Korea.

If a society is never allowed to study, learn, expand, or pass down knowledge of a technology, then it will quickly be lost to those people.

Poor or No Documentation

Perhaps the technology is poorly documented or only verbally documented. If all the details are written on paper or papyrus and there aren't enough copies that survive, then the knowledge is lost. Or if all of your critical texts on the subject are digital and there's a massive EMP or other catastrophe that destroys your computers, then that knowledge is gone. Perhaps your survivors can restore some of the knowledge from memory, if they survive and if they can remember enough to matter. But probably not all of it and not in all cases.

What separates this from Secrecy, above, is the intent. Secrecy implies a desire to prevent outsiders from learning a skill. Poor Documentation is less about preventing the spread of knowledge and more about the inability to spread that knowledge.

Examples of this include many of the ancient monument sites like Stonehenge, where we know it existed, but we simply don't understand all of the reasons why and/or the methods how they were built. Was the construction considered a secret or perhaps a state collapse? Maybe, maybe not. But the lack of permanent record clouds the knowledge, certainly.

Natural Disaster

If all of your knowledge of a specific technology is housed in one geographic location, then a major disaster could destroy all of it. An earthquake or fire could destroy a building, losing everything (and even everyone) it contains. This is less likely to be a sole reason than the above. More likely is that this is the flashpoint that destroys a technology because of the limits placed on it by the above reasons. Secrecy forces a lack of redundancy that then leaves it vulnerable to an earthquake, for example.

Combination

Probably, many technologies that become lost over time will be lost through a combination of things, not just any one thing. We do not know exactly how the Egyptian Pyramids were built. Is that because the engineers were lost during the fall of the Egyptian empire? Or because there were so few engineers? It is difficult to be sure, but probably a combination of secrecy, documentation, and state collapse combined to cause the loss.

Or maybe a natural disaster triggers a state collapse. Or Secrecy and/or religious/state censorship combined with a natural disaster destroy all the holders of your knowledge...

• I would argue that the Coca-Cola recipe is not a technologial secret, it's a marketing gag. They could burn it and write another, similar one and no one would notice. It's not like the chemical composition can't be analyzed, or any other, similar soft drink (with the same brand) would do any worse. Lack of documentation, however, is a very valid concern. Consider the Space Shuttles. – Ruther Rendommeleigh Jul 12 '19 at 15:10
• Yeah, I wasn't listing it as an example of a critical technology. I was listing it as an example of excessive secretiveness. – CaM Jul 13 '19 at 17:56

You should look into the lore of Warhammer 40k; which has a similar premise. The natural progression to "faith based engineering" is more of an inevitability.

As technology becomes more advanced, there is a bigger body of knowledge that goes into making it (metallurgy, side effect mitigation strategies, cost/performance/reliability optimizations, some hundred (maybe millions) of smaller designs incorporated into the final product). This is starting to give rise to "faith based engineering" (especially in the rapidly growing field of software engineering). Faith based engineering is where you accept something is true without knowing how it works. For example, you might not understand how a smooth nail works, but you do understand that if you ram it into 2 pieces of wood, it will hold them together. (You have only faith/experience that the nail will work as advertised) However without the array of knowledge of why things work, you wouldn't understand that the optimum angle for a nail to hang a picture is different for wood vs ice (ice has far better shear strength vs compressive strength, so you actually want to angle the nail down from the horizontal for optimal strength)

And that is just the science of how to use a nail! We have chips, engines, vortex generators, and ignorance guards (safety features). Can you imagine just how large the body of knowledge is you would need to build a computer? Right now, "faith based engineering" isn't a problem (except maybe in software to a degree) because we have people who specialize in each aspect that goes into a final product. So while no one knows completely how everything works, they can each contribute to the final product (and replace parts that are too damaged for the final person to fix themselves).

Keywords "for now". "for now" we have enough resources to sustain a population capable of maintaining everything. There is a hard upper limit to the population size we can sustain, and no upper limit for the amount of knowledge that can go into a final product. This means it is almost inevitable that in the process of creating newer and better things, "faith based engineering" has to be relied on more. Especially if AI are adopted into Research and Development that can literal just try millions of things until they find something that works better, with no understanding of why it works. With finite people, and near limitless knowledge, it will become harder and harder to determine what people need to know, what information needs to be preserved and what archives can be safely abandoned. Just normal errors over time, records will be lost, backups accidently+unknowingly wiped, contents misunderstood and misfiled/labeled. Once enough of the base knowledge is lost, and tech becomes sufficiently advanced enough, "faith based engineering" will be the only way to engineer.

• +1 for the premise, but wouldn't you think that our ability to store, share and search for information also grows? I'm pretty sure that I know more about chip design and the underlying physics now than I (or my peers) did 30 years ago, when there were printed manuals instead of Wikipedia etc., even though the work I'm doing today is higher level / more abstract. – Ruther Rendommeleigh Jul 12 '19 at 15:16
• @RutherRendommeleigh What happens to all of those manuals and communication channels if "all computers everywhere" suddenly fail? Most people wouldn't even be able to get to the local library if that happened. – Draco18s no longer trusts SE Jul 12 '19 at 15:37
• @RutherRendommeleigh Like I said, as our knowledge base grows, it becomes harder to manage and it becomes easier to lose important information over time. Similar to how all records of how to make roman concrete where lost. So we can patch it, but not replace it (it has properties that make it superior in neche cases). Aslo, knowing how a computer chip works does not mean you understand how to safely operate/maintain the industrial high-precision machines used to make them. And there is no way you are getting chips of that quality without those machines. – Tezra Jul 12 '19 at 16:30
• Which is one more reason why it's so crucial that we have open source software. With the source code, you can at least try to understand what is going on, bit by bit. With the history of the source code, as recorded in the git repositories of open source software, you have tons of clues what changed in which order and why it changed. If you rely on Windows alone, and do faith based engineering assuming you'll always have a working Windows on all your machines, you are doomed if Microsoft shuts down. – cmaster - reinstate monica Jul 12 '19 at 21:48
• Relevant lore link: warhammer40k.fandom.com/wiki/Dark_Age_of_Technology – DrMcCleod Jul 14 '19 at 14:34

One possible solution is having a wide spread very basic technology that suddenly isn't viable anymore.

Say, for instance, this alien society had discovered a room temperature superconductor. It would be used for all wiring in everything, because the ability to not lose power to heat from resistance. But if some fungus/organism developed that could eat or corrode the superconductor, and was spread far and wide before anyone noticed what was happening, or how bad the problem was, then it could cripple all technology that the civilization uses, from power delivery to microprocessors. *

You'd have some people who could figure out how to jerry rig solutions, assuming they could find other conductors, but these people would likely be rare, and located in places with high population density, meaning less food to go around, and all the chaos that implies.

Just about any technology that most other technology relies on would work.

* This is a sub plot in the book Ringworld by Larry Niven.

• Hmm, I don't know. I think EMPs or zombies would work better. 🤔 – Ranger Jul 12 '19 at 13:22
• This loss of viability doesn't need to be high tech either. Some technological advancements are limited due to exhausting the supply of raw material. An example already exists in the supply of steel made prior to 1945 (prior to the first atomic detonations) which is required for some high tech sensor manufacturing. – Myles Jul 12 '19 at 15:30

The case of the Rocketdyne F1 engine that was used on the Apollo lunar missions is a perfect example of how quickly knowledge can be lost.

The first thought that came to my mind is that you actually have the answer in your question: people simply forgot.

With all the other answer that you got, either in combination or additionally under the circumstance that there was no need to produce new products/machines/tools etc. it's a very likely scenario.

With technology that can 'heal anything,' I'd also guess that the lifespan of your alien race got extended. Immortality is either impossible or brings other problems with it, like slowly forgetting ones past. Offspring is possible but highly regulated to prevent overpopulation. Production slowed down until it eventually stopped as there was no demand, surplus machines were simply stored away as a backup, now those also start to break down, turns out those machines weren't perfect after all.

So over aeons, none of the machines broke down while, like you said, everyone who knew how to build/maintain simply died one way or another. The knowledge slowly degraded as it was not necessary to learn how anything worked, after all the button to start the engine of the spaceship never failed.

"What it does exactly? Well clearly it's starting the engine, dummy."

I would like to see the face of those involved when suddenly it does not start after pressing the button.

Another one, even more severe, would be that the knowledge is actually still there. Archived and preserved, even some ancient masters are still alive, although after some millennia they are... let's just say not as bright as they used to be. Many materials required to make/run most of those masterful machines, if not all (nobody is really sure on that) require a rare substance for their production. A substance that as it turns out is not stable, it's half-life period was a subject of controversy according to the remaining writings about it, which does not really help anybody now that it is gone. The original mastermind behind its invention/discovery is long dead and all is scriptures are based on the fact that certain materials exist, materials that simply degraded and broke apart. As nobody adapted to those changes, effectively nobody can recreate the required materials and any alternatives, do work but not as good, some of those are even causing damage to the machines.

Outsourcing runaway.

Beginning

It may be beneficial for the advanced civilization to outsource all manufacturing to some less civilized place like Earth for instance, where work is cheaper, work safety worse, ecology can be more dirty and these locals still have some brains, even if much inferior. Lower level of general civilization may not matter much, as the qualified engineers, first machines and ready designs would come, making the production possible. Later, however, education will start catching up, making outsourcing even more attractive, as cheaper locals will be able to replace larger and larger proportion of the foreign engineers.

Overcoming of the self-correcting market force

Of course, at some point the free market would shift making outsourcing no longer so profitable. However if the government of the pure planet is strong enough, they may intentionally distort the market, by buying some useless nonsense for huge money from the "higher race". They would actually pay this money for the price scissors to stay and the further technology transfer to continue.

Of course, the higher race may also notice something going wrong, but the current situation may be useful enough for mighty ones to use they powers for making others to shutdown.

Total transfer of the technology

Eventually all manufacturing may move into that cheap and dirty planet, closing the former factories first, and then also moving the research departments closer to production. Ultimately only the managers may remain in the former place, but also management can be outsourced and is more efficiently when not done through interstellar distances. Hence eventually we get one civilization making everything for another, just on the basis of some agreements signed generations ago, and few very rich representatives of the once-advanced civilization that still benefit a lot from all this. And the advanced race failed to notice that not just they passed over all technology they have to that they thought it is just a planet of slaves - they have lost this technology themselves.

How can an advanced civilization forget how to manufacture its technology?

This problem has resurfaced throughout countless generations. One which stands out is the knowledge of Hero's Engine. It is the first engine known to have existed before Christ. Its simplicity in construction and manufacturing has never been equaled and the information began to proliferate as the internet developed. Still though, it is propagated through hobbyists.

Creative Inventive Genius is rarely understood by others at the time it first surfaces. Tesla is one of the most prominent. But, the most advanced example is Gauss. Gauss developed most of the non euclidean geometries, yet he did not publish any of them. In my opinion his reason for this was that, none of the mathematicians in his generation had any interest in His Gordian "Space" knot. To my knowledge none of the formally educated mathematicians following his generation know what he was referring to as lack of necessity. Today it is simply space is defined as empty by Euclid 2000 years ago. Einstein's last publication actually agrees that empty space has no existence, an obvious lack of adequate definition for any theory to qualify as scientific method. Todays physicists have most likely have never been made aware that mathematicians never require scientific method is violated by all theories which they use fail. Some actually have names stating this, such as irrational and imaginary numbers.

Gauss did express his doubts regarding the validity of Euclidean geometry. He would state the obvious proof in the simple statement "space can not be proven because it fails the necessity requirement". He conducted discussions enthusiastically and freely with non-professionals who had no formal mathematical training.

The main point intended here is, Gauss, Tesla, Fuller and others were aware of and taught the errors of logic being made with mathematics, nobody listened because it was not understood:?( For 2000 years students have been taught Euclid's space did not exist but they could observe it on lines drawn on sand or paper. Our generation has been taught "its a pixel"?

See : Gauss' letters to friends, to learn of his discoveries which he did not publish; because he doubted they were correct. In my opinion he was correct in that assumption.

• Wow! and welcome to Worldbuilding SE. I almost understood your answer, ... almost. Very well written and explained. – EDL Jul 12 '19 at 4:34
• Gauss' Gordian Knot will ultimately be the most significant discovery which will put a missing link in physics, mathematics and cosmology. He left the guide, but no one understood what he said. Gauss added none of the mathematicians had any interest in the problem. Gauss said this was in his sole, and I share that with him. – create14all Jul 16 '19 at 1:35

The robots needed to be rebooted

This culture turned over more and more of its technological capacity to automated servants. After many generations the machines were infected with a malware that required they be shut down and their memories wiped or replaced. Once brought back online, they forgot how to do many things that they used to do.

All-consuming consumerism, much like what we see in the USA today. Case in point: Who among us actually knows how to make any of the things we use? Name even one manufactured item that is entirely within the comprehension of your average Joe how it's made and where the materials can be found and processed to be within spec for assembly. It's rare--even for a dumb rubber band or metal pin!

It's pure revelation to many people today that their puffed breakfast cereals are created by rapid expansion of heated, pressurized grains in a vessel similar to a glorified cannon. Quaker Cereals advertised their puffed rice in the 50s as "the cereal shot from guns".

It's funny, but you can try searching the Internet for videos of how to make puffed rice. Some might contain a handful of technological insights, but it's not uncommon to find videos that only teach you how to season it or serve it, etc. Except for a very few who are still in the almost-forgotten food production industry and some of their close associates, and a much older generation, it is very hard to find anybody in the U.S. who has a clue how it's made. Street vendors in China still make it, but with all of our education and sophistication, we're pretty ignorant as a society about very basic things that sustain our everyday lives. This trend is true for very many modern commodities. There are very few farmers and butchers nowadays compared to the overall population, compared to previously. The same is true of manufacturing.

Try to find the number of people who know how cheese is made. Were it not for YouTube and some DIY sites, most of this knowledge would be beyond the reach of ordinary people. Even they almost always lack trade secret knowledge, and even the most hardcore backyard enthusiasts have been unable to replicate basic store-shelf items, and so once the inventors are gone, and the equipment and its documentation are sold or fall into disrepair, many lifetimes of discovery and invention are erased.

We have this very strange presumption in our society that we are "intelligent" and "advanced" far above our ancestors because we consume so many technologically advanced items. However, it requires very little intelligence to consume high technology. Intelligence is required to create it. By this ranking, many of our ancestors were far more intelligent than we are on average. We are the ones who boast of the technology that we are beneficiaries of--but this is absurd, because they are the ones who built it, and we are in most cases merely exploiting it. If we forget them (our ancestors and their gifts to us), we lose treasures far too valuable to calculate the loss of. We could use up our electric motors until they all burn out, but who would give us another Michael Faraday? Great discoverers are quite rare.

Surprisingly few of us are in the business of creating technology, and even they would be severely handicapped or else out of business altogether if, say, a mining company or a microchip fab went offline forever, or if fossil fuels became outlawed. We are so highly specialized that any one of us at best produces only a tiny sliver of those technologies, and nearly everyone lacks any sort of holistic knowledge about even one manufacturing process and the theories behind it. The man who assembles buildings from steel beams is usually not the man who makes those beams, and man who pours the steel into molds is usually not the man who refined the ore, and the man who refines the ore is usually not the man who mined it, and the man who mines it is usually not the man who found it. So it's an exceedingly precarious stack, because the removal of corporate knowledge about even one of these steps would bring the whole industry and all of its dependencies to their knees almost overnight.

The higher the technology, the greater its instability because fewer people are required to have a working knowledge of it in order to support a huge population. The following graphic illustrates this phenomenon:

As technological value increases, there is naturally an upward shift in occupations, as more and more people become technological middle-men who are powerless without their platform, and fewer and fewer people are required to staff the actual production class. The people who are freed from necessity do not have to become idle consumers--they could become highly empowered discoverers--but sad experience indicates that most would rather be passive consumers than active producers once the bare necessity of "every man a producer" is gone. Society becomes top-heavy and laden with consumers, so that all that needs to happen is a gradual erosion of the discovering and producing classes until all that remains to support the populace is thin air and the ticking time bomb of a limited technological or product supply.

Think about it: If we need stone age tools to make iron age tools, and iron age tools to make Renaissance tools, and Renaissance tools to make Enlightenment-era tools, and Enlightenment-era tools to make Industrial-age tools, and Industrial-age tools to make space-age tools, and we have forgotten how to make Industrial-age or Renaissance tools, how well off are we, really?

Technology is produced in a complicated stack. It is far more vulnerable than we realize. What we have built up is highly unstable and vulnerable to a distributed, targeted attack to excise the knowledge. Most people in the U.S. today could easily be oblivious to the removal of knowledge until newly produced broccoli, Playstations and automobile parts become unavailable. We'd be oblivious to the loss of that knowledge because we, ourselves, don't have it. If our population were to be reduced down to a tenth its original size, chances are astronomically high that a very considerable proportion of our knowledge of how to make things would go with the 90%.

Even without a targeted or indiscriminate attack against the population's knowledge base, this will actually happen quite naturally the more consumer-oriented we become. If we arrive at a point where only 10,000 people in our entire civilization collectively have the know-how to keep things running, and the remainder are largely so enthused with their toys and gadgets that they have no interest to learn or participate in the process of technology production, then as those 10k people gradually die off, the corporate knowledge is lost irretrievably, and the people ironically become stone-age personalities living in temporary space-age luxury--temporary because it was made for them, and not by them. Then it's just a matter of time and use before they fall from the stars and hit rock-bottom.

The Pixar movie Wall-E actually paints a pretty plausible case for this kind of degeneracy.

What you point out here is not just theoretical; it is an actual plague that is bound to hit us pretty soon--and especially if it is accelerated by warfare, we are in big, big trouble, and it could be many hundreds of years or even thousands before we learn to replicate such basic technologies as refrigeration, combustion engines, microchips, gene sequencing, and so on. It is up to each of us to accumulate and store that technology in such a way that our descendants could re-create it without inordinate difficulty long after we ourselves are gone.

Our technical advances and production efficiencies have come at a price of increasing specialisation. Only a tiny proportion of the population really know how to each critical process work and the corporations they work for jealously gaurd that information for competitive reasons.

Then, faced with ever more expensive natural resources on one side and customers who saw little need to upgrade on the other, the manufacturers gradually went out of buisiness. Possiblly there was a war or other disaster to help things along.

Sure some stuff was written down and people have a crude idea of how things work, but most of the details on how to make the processes work well were either kept in peoples heads or kept on encrypted volumes to protect against corporate espionage and can no longer be read.

• I like it. Specialization to the point where nobody understands the process as a whole! – user20762 Jul 12 '19 at 20:44

Market Saturation

Simple economics, supply and demand. If you produce enough of something, the marginal value of the next item you make will become zero. To stop this and keep it viable to produce a product long term, it is necessary for either new customers to exist, or the product to have a limited lifetime. If the product lasts a very long time, the market does not grow, and there is no desire from customers to purchase new instead of used, then the business cannot be sustained. Once the business is unsustainable, production will shut down. Keep production shut down and the knowledge is lost pretty rapidly; ask any business who had to shrink their workforce for a few years how expensive it is to expand again (cyclic businesses like shipbuilding are particularly famous for this). Sure you can write down the methods of how to produce something in a book, but that only preserves the knowledge if the book is preserved. People clean, they throw out things they don't see use of anymore. If you came across a manual on computer punch card storage standards, likelihood is you would't keep it.

Any given civilization is unlikely to "forget" how to manufacture technology, nor all of it, even if they did.

A computer is not the same as an abacus, despite both being essentially "counting machines". A lawnmower is not the same as scissors, despite them both being "cutting machines".

If you look at our own civilization, we could, in theory, lose the ability to produce and use digital products, as few people even today (as a percentage) understand how they work, at a fundamental level. But at that same fundamental level, electronic components are extremely simple, as is electricity.

Once a civilization reaches a certain threshold, and the tech of that threshold becomes widely available and understood, it is very difficult to lose that knowledge collectively.

For example, it is highly unlikely that the people of the world today would ever lose the collective knowledge to exploit steam power, and thus electrical lighting. From there we could re-make certain intuitive leaps and re-invent internal combustion, and from there to nuclear fission, as they are all based on the same principles of pressure, heat, and releasing energy from matter.

What would actually likely happen is that a civilization would be knocked back an age or two: i.e. Digital Age to Space Age, or Industrial (losing computers, polymers, plastics and robotics, nuclear power, Modern architecture etc). Industrial to Post Dark ages (following some religious anti-technological sin fever).

The greater the gap between age thresholds, the more knowledge would be lost, and likewise, the greater the catastrophe would be required to bring about the fall. Indeed, knocking a civ down by more than a single age would require something singular and devastating (nuclear war/meteor impact with few survivors, and a "winter" following, to kill off the old before they can pass on knowledge).

So, to answer your question: In order for a civilization to regress technologically several hundred, or a thousand years, it would require not one, but a series of catastrophic events, usually creating a distrust of technology. It could start with(Year 0):

1. Meteor impact (which science failed to predict or stop)
2. Nuclear war ("Science killed everyone")
3. Robotic uprising.(EMP took them all out but destroyed all of our other tech too)
4. Grey goo scenario (See above)

Following this(Year 1-5), people not responsible, or involved in the fall, would start to get angry and ask "why did this happen to us?". Tech state regressed to Industrial age, though space age materials are still in use. No fossil fuels are being produced for vehicles, and so, is running out. Central government is failing to maintain civil order and provide food, water, sanitation and medical supplies. Enter the demagogue.

A charismatic, and manipulative cult leader, gathers the support of the angry, and dispossessed, moving across the continent, looking for more followers and taking what resources they can find. Seeing the growing anti-technology sentiment as something exploitable, the cult leader delivers a series of rousing sermons, demanding that all technologists are sinners and "enemies of God", and should be punished. (Year 5-20). The cult spreads due to a common distaste for technology, and intimidation. Book burning is common, and technology is actively sought out and destroyed.

With a rise in anti-intellectualism, and the persecution of Intellectuals as a group, they are forced underground, and do not pass on their knowledge which is now seen as "witchcraft". Within 50 years, almost all engineering knowledge is lost. Many people do not teach basic numeracy or literacy, which is now the province of those favored of the Church.

History is not taught, expect from the perspective of the church. Centuries of written history are lost within 10 generations (year 50-250), in favor of the teaching of basic skills of survival, such as agriculture, smithery, or fighting. We have now regressed to the middle ages. Places with technology that cannot be easily destroyed are treated as unholy, and avoided by people in general. Like all forbidden things, technology becomes a valued commodity. Modern weapons are still incredibly dangerous, but rarely functional, as the fear of technology ebbs, so does the churches power. People start to actively excavate technology for their own benefit. The age of warlords has begun. (Year 251 - 500)

Warlords conquer with automatic weapons instead of Bows, and rule with terror, using the few remaining grenades. Empires rise and fall within a generation or two. Slavery the vanquished is widespread, as forced manual labor is the only way to feed armies. Ammunition is now so scarce as to be virtually non-existent. As guns and explosives are no longer functional, war regresses to swords, bows and armor. By this time, people have forgotten all modern technology, and the purpose of most industrial technology. Within 500 years, over 1000 years of knowledge, history, and technology is lost. Most cities have been reclaimed by nature, and are now dangerous poorly understood ruins, prone to collapse, and inhabited by wild animals.

Pick any point in this to base your story.

As @eigenvalue suggests: it's in a dedicated star system. Choose your mechanism:

1. The manufacture of the items is concentrated in a particular star system. This could be for security reasons, or because of unique resources, or because of manufacturing dangers or byproducts that you want to isolate, or because of plentiful power sources, etc. The system goes -- natural disaster, war, rebellion, etc -- and your ability to manufacture goes.

2. The items are manufactured widely, but the empire restricts design/manufacture of one key piece of technology to a particular system, to maintain control over scattered star systems. This key piece may be the controls (something like Asimov's positronic brains) or power sources or something else. If that system is destroyed or cutoff from the rest of the empire, you can make new devices and transplant the critical pieces -- as long as they last -- but you'll have a continually dwindling supply of functional devices, just as if you couldn't manufacture them at all.

It's quite natural to concentrate manufacture. If nothing else, such key technology is power, and the organization that controls it will become the power behind the throne of any empire or federation. In addition to centralizing manufacture, it would be natural to centralize design and training as well. Nothing like physical control to make sure you maintain your power. Plus the efficiencies of a Silicon-Valley-like place.

New technology replaces old, and is a able to completely take over - and by the time old technology is needed; most information about it is lost, the people who worked with it long dead, and examples of it inoperative or destroyed (hard to re-engineer).

As an example, we use computers, microprocessors and microcontrollers everywhere. Copymachines (Xerox) are no-longer photostatic, but basically a scanner-printer. Oscilloscopes and television are no-longer analogue signal processing and CRT-tubes, but digital signal processing and LCD-screens. Cameras no longer uses film. Radios are no-longer analogue but digital. Washing-machines and clocks no-longer use complex mechanical control-units, but uses digital circuits and microcontrollers. Cars are now computer-controlled, and no-longer based on mechanics for timing &c.

How long it will take before how to make something like a mechanical control-unit for a washing-machines is forgotten?

Then we have lots of crafts that was past from master to apprentice, that's dying or have been dead for a while. No-one needs it anymore, so how it was done is lost. Just take going from building in stone (like medieval cathedrals), to bricks (Victorian), to concrete (today). Undoubtedly many hard-learned tricks have been lost on the way, especially since masons often were close-knit groups that kept their secrets.

If something happened that would destroy our electronics or power-supply, it would be difficult to remember how to do stuff with just mechanics - even though it was usual before.

Environmental catastrophe leading to kinda-Planet of Apes scenarios

If CO2 level in atmosphere reaches 1000 ppm (parts per million - more than twice of current 400ppm) we would survive but with impaired intelligence. Some studies even place the reduced cognition threshold at 600ppm.

Fast scenario: the CO2 level jumps suddenly, in course of few weeks, to over 1000ppm. It can be caused by runaway decomposition of methane clathrates in ocean floor, which can't exist in warm water. Methane then quickly decays to CO2 in atmosphere. There's not enough time to equip many buildings with CO2 scrubbers, humanity's intelligence level plunges and in step with it drops the manufacturing ability.

Slow scenario: the CO2 level rises slowly, 600ppm is forecasted to be around 2070. It causes widespread mental disability in children, but which manifests only during puberty. This late onset would mean that whole generation is lost. No matter what precautions are taken, it's too late, whole education system gets badly disrupted and with it goes the manufacturing.

I see 2 clear options:

1) When this technology was created they expected it to last until it was replaced so they only published detailed information on how to repair it.

However, it lasted hundreds of years and over time the technology that stored the repair information corrupted and broke until only an insufficient amount of information on how to repair it remained and no one remembered how to create new technology because they had always just used the manuals.

2) Chinese whispers.

Everybody is trained by being taught how to make and repair the technology and people specialise to making 1 thing so as generations went on the next era of engineers had a bastardised version of repairs and creation to work with.

Multiply this over 10 generations and you get what happened to Damascus steel - Blacksmiths wanted to protect their monopoly on making it so they only taught it through word of mouth and over the centuries they forget how to make it properly.

E.g. Alien 1 Learns that to make X you need A1, B1, A2, B2, C1 in that order

Over the generations, they think C1 goes after B1 and forget the numbers' importance so end up with A, B, C, A, B and then consider that the same thing will have happened with A, B and C and you can see how the technology is forgotten.