What are the most important factors in determining how fast technology progresses? And roughly how fast might that be under optimal circumstances?

Innovations have to be dreamed up, but there must be other more basic restrictions on progress. In the scenario below I’m looking for the most important reasons, why they are so important and an approximate time frame to the nearest century perhaps. Here is the scenario:

A set of technical manuals describing in reasonable detail how to build every important technical innovation and describing every important scientific discovery from the last 2000 years has been written.

This would include such things as steam engines, electricity, batteries, electric motors, gas turbines, vaccines, computers as well as an outline of the works of Newton, Boltzmann, Pascal, Darwin, Einstein and more.

Technologies would be arranged in such a way that it was clear what the pre-requirements were, so electric motors require basic knowledge of electricity etc. Where necessary new words and concepts are defined in the text and diagrams are used.

Now imagine thousands of these sets of books being distributed across the ancient world in appropriate languages (by aliens or some other hand waved out of scope mechanism).

Copies go to all key figures in politics, religion, business and military affairs and further copies are hidden but in such a way that they are relatively easy to find over time.

Roughly how much faster would technology advance? And what are the main hindrances to the rate of that advance?

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    $\begingroup$ That's a large library, not a set of manuals. The ancients thought that the Library of Alexandria had a massive collection of books. Imagine their surprise when many copies of a truly massive collection of books plop down from the aether. (And for fun, translate into ancient Latin: a function f is continuous at some point c of its domain if the limit of f(x), as x approaches c through the domain of f, exists and is equal to f(c). Note that the words function, point, through, domain, limit and approaches have special technical meanings.) $\endgroup$ – AlexP Sep 28 '19 at 20:15
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    $\begingroup$ That’s a valid point, but perhaps they (the ancients) should just be amazed by the books and perhaps the books need to be very focused and concise encyclopaedia Britannica scale not library scale. Although fascinating the translation of the books are out of scope (there is a Latin Stack exchange if you fancy trying your luck…) $\endgroup$ – Slarty Sep 28 '19 at 22:15
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    $\begingroup$ (1) The famous 11th edition (1911) of the Encyclopedia Britannica is 29 volumes in-quarto. (2) It's not a technical reference in any way. You cannot build a steam engine, or an electric generator, or a ship, or make steel, or refine petroleum with what's in it. (3) It is intended for use by educated people who wanted to have a general idea about various subjects. It is available online, so you can check for yourself. (4) It would be useful to introduce the idea that technical and scientific progress is possible. $\endgroup$ – AlexP Sep 28 '19 at 22:26
  • $\begingroup$ Is this a reality check (on-topic) or a question (too broad and POB)? If a question, there are too many question marks, too much answer (which is prohibited in the help center) and too few specifics e.g. conditions, restrictions, and method of judging a best answer. If a reality check, there are too many questions (though an adequate amount of scenario). Please pick which side of the fence you're on so the answers will make sense. $\endgroup$ – JBH Sep 29 '19 at 0:19
  • $\begingroup$ @JBH I’m willing to consider changes if that would be appropriate. It is a question (I’m not sure what reality it could check), I have used four question marks but the last two are meant to be restatements of the first two so the last paragraph could be deleted. I’m not sure what you mean by suggesting that there is too much answer. The question is fairly broad, but I am looking for rough time scales to the nearest century so that element is quite granular. I’m also looking for broad reasons not fine detail. Is that enough to help. $\endgroup$ – Slarty Sep 29 '19 at 21:41

12 Answers 12


As many people have noted, you need "the tools to make the tools", and the "book" you really need is "The Way things Work" and a lot of additional technical manuals.

However, what might really be needed is not a technical library at all, but a book on economics. In the First century AD, Hero of Alexandria wrote a book on mechanisms which describe what we would term simple atmospheric engines, low pressure steam engines and so on. The Romans also knew about water wheels, crank mechanisms and devices that we would describe as clockwork. Even farther in the past, the Greeks had the ability to create a mechanical astronomical calculator (The Antikythera mechanism).

The Ancient Chinese were apparently aware of many of these things as well (I will leave any details to more well versed writers to answer).

Going farther forward, we have fairly advanced (for the time) societies like the Hanse, building ocean going ships and trading across Europe from their ports in the Baltic, and the Serenìsima Repùblica Vèneta, another advanced society which pioneered "assembly line" production in the Arsenal, and concepts like "double entry" book keeping for their trade and banking networks. The first modern steam engine was patented in Spain in 1606.

Despite all these advances, there was no "Roman Industrial Revolution", and we essentially had to wait for England in the early 1700's to "kick off" what we know as the Industrial revolution.

England had a different social, cultural and economic system than any of the other societies which had developed parts of the Industrial Revolution as far back as 100 BC (the date assigned to the Antikythera mechanism). Ancient and early modern societies did not have the sorts of social or economic incentives that market capitalism does, and until the "Glorious Revolution" in England in 1688, social and political institutions did not explicitly place power in the hands of merchants, artisans and the middle class. This widely distributed and diffused social and economic system seems to be the major difference between England and all the societies that came before, allowing ideas to rapidly spread and providing the incentives to adopt and experiment with ideas.

So ultimately it does not seem that a lack of knowledge or technology was the deciding factor, but rather the social and economic conditions that allow incentives for ideas to spread

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    $\begingroup$ I upvoted this answer. Economics is really the key. No innovation will be implemented in practice unless the capital cost of implementing it is outweighed by the cost savings or increased production it creates. And non-market systems put severe limits on the ability of producers to reliably recapture capital costs. Investing in building a steam engine from scratch in ancient Rome would make no economic sense relative to other potential uses of the capital involved. $\endgroup$ – tbrookside Sep 29 '19 at 13:07
  • $\begingroup$ Also upvoted. The keys to the explosion of the industrial revolution were intellectual diversity, specialization, and capital accumulation in the hands of private individuals who then had the incentive to improve their own productivity through invention and the means to invest in other promising inventions, expanding their scope. $\endgroup$ – Dan Hanson Sep 29 '19 at 20:09
  • $\begingroup$ What about the military? An arms race is a solid way to invite increased productivity top-down instead of bottom-up. If I find out my neighbor King Bob is building this machine that moves faster than horses and is immune to arrows, I'm probably going to look for something that hurts more than arrows. (And of course steal his mechanical horses) $\endgroup$ – Mars Sep 30 '19 at 4:15
  • $\begingroup$ The Arsenal of Venice was built for military purposes, and cast cannon and built warships for the Republic. Even that combined with the advanced economic structures of Venetian society was still not enough (and the Ottomans did work hard to steal Venetian technologies in cannon foundries). $\endgroup$ – Thucydides Sep 30 '19 at 14:57

For a technological advance one must have

1: Population density. This is a proxy for having (by luck) a person smart and clever enough to quarterback the innovations. I suspect that this was the limiting factor for many millennia.

2: Food availability. If your entire populace spends all of its waking hours trying hard to get fed, it is hard to expect any of these folks to advance technology in their spare time. They have none. Your innovator must be confident enough that he or she will be fed regularly to spend time on a long term project with an uncertain payoff.

3: Incentive. What is the payoff? The innovator who invests time and resources needs to see clearly how this is a better use of time and resources than hunting or farming. Will the mill run faster? Will the crops grow greener? Will she save sick workers from dying? Will the enemies of his king be handily slaughtered?

  • $\begingroup$ Good answer - may be worth expanding on the "Incentive" point you make. Many inventors / innovators through history are famed for their persistence in the face of obstacles to prove that their idea was great. The books will actually remove this incentive, as the idea is no longer the inventor's idea they have less incentive to persist with it. $\endgroup$ – KerrAvon2055 Sep 29 '19 at 2:39

There's several factors that will come into play, but they all fall under one standard heading. I of course, am a fan of the less-standard heading put forth in the wonderful webcomic, Schlock Mercenary:

If I have pissed further than others, it is because I have stood on the shoulders of giants.

Obviously the books are what you intend to use to stand on other's shoulders, but there's a few other things needed:

  • Trust -- People have to actually trust the book enough to go out and follow it. Frankly, if it were two hundred years ago, and someone described QM to me, I'd probably try to lock them in an insane asylum. Nevermind that we know now that it's a pretty good model. Its the insane asylum you go! On the other hand, if any of your cultures develop a religious following surrounding these scriptures of wisdom, they'll happily look for what's next in the book of truth.

  • Tools -- Just having a book isn't enough. You have to actually have the tools. You mention having a prerequisite tree, which helps. However, you still have to make the things. Consider the difference between having someone describe the branch prediction model in an Intel Core i7 CPU, and having the VHDL model of it. The latter would be gargantuan (speaking to AlexP's concerns in the comments about just how much material is needed). The latter really barely gets you started in making it happen. People still have to put in the elbow grease.

  • Technical skill -- You actually have to have the skill to do things. Some stuff you can learn in books. Others you can't. I can tell you about the optimum chip load for milling stainless steel with a given 3 flute bit, but it still takes a remarkable amount of training and practice to be able to achieve that optimum as a machinist. Many skills are this way. They're more than just reading books. They require teachers passing on an art from one generation to another.

  • Raw materials -- Materials matter. When America dropped a nuclear bomb on Hiroshima, it was the full extent of our available nuclear material. It was all we had mustered. Can't have a device without the materials that make the device. Some things are easy to find, but others, like oil or uranium, are a bit pesky. And they're also completely without value until the technology is in place to use them.

  • Desire -- You need a populace that actually wants science. My expectation is that if you gave these books to a group of Amish, they'd be very polite, thank you, and offer to give you a night's stay before you were on your way tomorrow. Then they'd toss the books away and go about living the life they want to live. Potentially the best case for this scenario is a continuous string of wars. Wars have a history of bringing out technological advancement at a rapid pace.


Existing viable workforce, existing technology, available infrastructure, average education. Less easily defined are things like current relationships between countries and the towns&villages within.

Examples: during WWI these countries will not pool their resources to advance, but war does show a greater willingness to accept and use technology.

You can have the requisites to build a steam engine, but if your populace doesnt have the education to know how it works they dont know when they do something wrong and will most likely fail building them properly or even know how to operate them.

You can have the knowledge and facilities, but if you have but a tiny workforce of 10.000 people across the entire world (the rest is still busy with mostly subsistance farming) you arent going to progress very quickly.

If the infrastructure isnt there you first have to build it. Our infrastructure is build on the infrastructure that went before. Just paint is made in factories that themselves are painted with paint from factories that went before... and now imagine trying to get uranium and other components for nuclear reactors without first having the infrastructure.

As for the time it takes, it depends on all those factors. What is the willingness to embrace those technologies? (Or will you be burned alive for posessing such literature and using the technology?) The amount of people you can spare at that moment to learn the technologies and insights and teach these to the next generation? What is the current pool of resources and infrastructure to work with it, transport it, store it...? It is almost impossible to determine.


If I gave you instructions on how to build an engine what would you do? I can tell you what I would do, I would go to the store and buy the metal get my welding kit fired up and build it. this would not work in medieval times, you do not have any way to get the materials by either getting them and refining or outsourcing it. Getting them your selves. Medieval England does have factories in place to refine galvanized steel. outsourcing it, countries now trade for lots of there stuff lets take rubber as an example. To harvest rubber, a requirement in engines you need the rubber tree not native to 7th century England. lets say you build this car you need fuel. A peasant with a pickaxe cannot get you enough diesel to run your smithed together chevy. I,d say your time would be a quarter. as for the theories you have a new problem if I went to the Vatican and handed the pope the works of Charles Darwin I would be burned at the stake. Because of the need to first get the materials then build the machines to make the stuff if a society dedicated all of its time into id say a quarter if they dint then half the time. keep in mind guns would be the first thing anyone would build it would kick of medieval cold war.



In your scenario, there's no need for intelligence, just rote learning. Once the people decide to follow these manuals (which isn't as likely as it sounds - but that's another question entirely) they'll run into a problem - the need for rare resources and metal. Black gunpowder is charcoal, sulfur, and saltpeter. Saltpeter isn't rare, exactly, but it's not common either. And the ways of gathering differentiate - if you live in Italy, for instance, there are caves of the stuff. If you live in Russia - well, that's a lot trickier.

Thus, a civilization with access to natural deposits of rarer minerals and compounds will be able to progress faster up the tech tree than civilizations that live in the middle of barren and devoid lands. That's not to say that you can't eventually manage to make modern tech in those areas (though that may be the case for certain places), just a civilization with access to natural resources will fare better.

Food isn't as large of a problem, especially since a lot early advancements can help the crops, and seeing as the incentive for mastering these crafts are the material comforts of the 21st century, the ruling body will have no problem demanding the scholars work as fast as possible, on the penalty of death.


Technology is really just finding ways to use oil production.

Semiconductors are about the size of the plant to build larger devices, which build smaller chips. More oil means faster progress.

If resources are unlimited you could probably advance from nothing to everything in a few months or years. China built a modern economy in about twenty years.

  • $\begingroup$ How does this answer the question? $\endgroup$ – elemtilas Sep 29 '19 at 2:32


Empires don't invent much new stuff because they're not in competition with other regional powers. (The British Empire was an empire in name only, just because of India.)


Look what happened to Confucian China when the straightest path to success was to become an Imperial Bureaucrat and the Caliphate when his rule was threatened.

Your culture has to value discovering how the world works instead of just accepting that's how God made it, and that His Will continuously powers the Universe.


Too cold, too hot or too dry, and you spend all your time trying to survive.

Too wet and disease constantly ravages you, and stuff always rots.


If we're talking about predicting technological development, instead of designating something as the "cause", here are some fun spurious correlations:

-Meat Consumption. More specifically haggis consumption, Scotland leads the world in per-capita research output. Meat consumption will be associated with both agricultural surplus and high average wealth (making a Malthusian catastrophe more difficult). Historically the only major brakes on meat consumption were religion, generally a factor restricting scientific development.

-Navy Size. Takes wealth, certainly a factor. May indicate active conflicts, creating a demand for innovation (Get those old books out, maybe there's something in there we can use as a gun). Many play a role in overseas trade protection. Requires a highly centralised government. Would correlate more closely than money, war, trade or centralisation, despite not necessarily being causal.

-Immigration. People don't tend to immigrate to poorer countries. Many historical developments happened in places receiving large quantities of (voluntary or displaced) immigrants. Mobile and educated populations will travel to wealthier places for economic reasons. Take northern Italy with the fall of Byzantium (craftsman fled the ottomans, bringing byzantine secrets) or the modern United States (over 1/3rd of the research in the US is conducted by the approximately 13% immigrant population)

So raise malthus's limit, provoke trade conflicts and push tradesmen and artisans to regions where they are able to promote technological progress.


A middle class and social mobility

You need a lot of people with: enough wealth to be literate, the free time to tinker and experiment, but also a reason to share what they discover/create and not just make one off curiosities. To get that you need social mobility (being an engineer in a caste system is not rewarding)

But you say they have instructions why do they need to to experiment, because instructions are not good enough, it is impossible to create a perfect set of instructions, more so with people not used to thinking ins a rational logical manner. Impurities, errors, misunderstandings will happen. Without a fundamental understanding of science they have to build scientific knowledge alongside the technology, they need to be able to problem solve. this will be especially true of getting raw materials, geology requires interpretation.

Ok but why not just the wealthy, the wealthy are great at creating one off curiosities but not great at seeing widespread utility, they tend to be either a, too far removed from labor to understand the process, or B disinterested in widespread implementation, the point of showing off wealth is about having things others don't so you don't want to share your secrets. A flexible middle class however can see useful individual gains from production and selling, they are incentivised to build and improve. You need people educated enough to see the implication of a technology but not so privileged they have nothing to gain from it.

A final note you need these "manuals" to be so widespread they can't be easily hoarded, this will happen anyway in some places no matter what you do but as long as most places can't manage it technology will progress.


Connectivity , reliable communication and trade networks.

Trade helps ideas spread from their point of origin to new places where they can fall into new hands and minds that tinker with them and add their own knowledge to the new concepts and inventions.

Think about how the renaissance started in Venice which acted as a middle man between the Islamic nations, the Far East and Europe which led to many ideas and inventions passing from the former two to the latter which combined them to what would become the industrial revolution and the age of science we live in today.

For a more recent example think about how increasingly specialised scientists are becoming coupled with the increasing complexity of our technology (creating a new pharmaceutical drug requires chemists, biologists, pharmacists and so much more ). Without the internet providing fast communications between far flung research teams around the world m technological development would be slowed just by the communication lag alone.

Finally increased prosperity for the lower and middle classes who would have a stake in all the new technologies being developed, thus giving more incentive for innovation


The number one factor gating the progress of technology is whether progress is gated on information.

Moore's Law is the doubling of transistors in the same area every 24 months. An even faster trend is the Law of Accelerating Returns - the amount of computation than can be purchased for 1,000 USD is doubling every 3 months. This trend has been holding across five paradigms of computation across 120 years. To put that in perspective - that means if that 120 year trend continues until 2030 then 1,000 USD buys you the computational equivalent of 1,000 human minds. That means that the iPhone X came out in 2017 and when the iPhone XX comes out in 2027, it will be as fast or faster in computations per second as the person's brain who is buying it.

The reason that is important is that because once a technology becomes an information science - then its progress can ride the same curve that is doubling every 3 months.

You can see these exponential trends wherever information is at the core of progress. For example, computers are now being used design computers in an ever escalating cycle.

As for other examples - we are starting to see protein folding and receptors interactions be completely simulated in computers - and as a result are testing exponentially more potential medications than at any time in human history.

We see this is simulated design as well - where computers are creating thousands of designs in seconds that used to take hours to days each.

As a counter example, batteries and their complete physics and atomic interactions cannot be completely simulated in computers yet. The progress in batteries has been linear rather than exponential. Once they can be simulated, however, then the progress will be gated based on the progress of the Law of Accelerating Returns.

Thus the single most important factor gating progress of technologies is whether and when it becomes an information science.


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