# Crucial and unlikely discoveries in history [closed]

I'm trying to come up with an alternate reality where some specific invention or discovery was never made.

Many inventions or discoveries in (mainly European) history were not a 'miraculous event,' but much more often just waiting to be made, given the technology at the time. Many discoveries and inventions were even made independently around the same time (such as the telegraph, discovered independently by Wheatstone and Morse; or calculus, formulated around the same time by Newton, Leibniz and others.)

I'm looking for some examples of those 'miraculous event' discoveries that were way ahead of their time and, if they hadn't happened then, would not have happened for a long time (if ever).
I'd also appreciate some hints as to the consequences of not making this discovery or inventions. Or maybe more accurately: the consequences of this invention/discovery in our own history, that we would be lacking otherwise.

Edit: I'm looking for inventions or discoveries which, if they hadn't happened, would have drastically changed centuries of history.

To stick with my previous examples, if Wheatstone or Morse hadn't invented the telegraph, it likely would have taken another year before someone else figured it out, and in the grand scheme of things, we would still be where we are today.

From the answers to this question there are already some wonderful ideas for alternate history. Such as the game-changer that modern sail rigging would have been had it been invented much earlier;
Or a Roman steam engine, had Romans actually had pistons to properly utilize it;
Or penicillin, the availability of which arguably played a role in many countries' willingness to go to war.

## closed as too broad by Mołot, L.Dutch♦, Snow, James♦, cobaltduckFeb 21 '17 at 20:58

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• Given even our current understanding of special and general relativity, that might be something to consider. The discoveries were probably just waiting to be made -- after all, lots of smart people were at the time trying to work out why the experimental data disagreed with the theories of the time -- but we might not have got the general framework that we ended up with which would stand the test of time as well as Einstein's theories of relativity have. – a CVn Feb 19 '17 at 14:05
• How about penicillin? Or radiation? – WRX Feb 19 '17 at 14:44
• In Roger Zelazny's anthology, The Last Defender of Camelot, there is a one page short story called The Game of Blood and Dust. One of the ramifications of this masterpiece is that we are currently living in an alternative history where the Romans did not create the steam engine. – Henry Taylor Feb 19 '17 at 14:45
• @MichaelKjörling Not really. GR is extension of SR. SR is application of Lorentz transformation to timespace. Lorentz transformation is derived from Maxwell equations. Maxwell equations are works of Gauss, Ampere and Faraday put together... and so on. Nothing exists on vacuum, it only appears to do, if you don't know the background. – M i ech Feb 19 '17 at 14:52
• Things that appear before their time disappear unnoticed. First steam power dates to antiquity, but there was not enough demand for autonomous power sources for steam power to be practical, development of mechanical looms and lathes is what made steam power useful or indeed necessary. Antikythera mechanism is remarkable for it's time, but lacking precision of tools, and lack of computer science meant it was of little use and wasn't generalised into computer. Babage's differential engines even if made, probably wouldn't catch on for similar reasons. Nothing exists in vacuum. – M i ech Feb 19 '17 at 15:01

You don't really need some speculative alternate reality, our own history is full of such events.

Two "missing inventions" are for example the wheel in pre-Columbic America, or the computer in the early 20th century, when Babbage’s pre-work was already close to 100 years old and vacuum tubes (triodes) and relays were otherwise widely used and available.

The fore-and-aft sailing rig came only in the middle age, when the idea should have been obvious to any observant Greek, Roman, Viking, etc. sailor and shipbuilder.

The chimmney is equally obvious, but was only invented by the Romans, then forgotten, and reinventend after 1000AD.

Don't even mention optics. Clear glass was available since 200BC (depending on how transparent you want it), Aristoteles reputedly made himself a pair of glasses and had even solved the laws of diffraction(!?!), but the magnifying glass took till 1100, the telescope till 1500, and microscope even longer. The Romans had a jump of 1500 years in medicine in their hands, and just overlooked it. Seneca (50AD) knew about the magnifying effect of a drop of water. How hard can it be to transfer that to a similarly shaped piece of glass? Very, evidently.

Or their cartography: An empire without proper maps! All the necessary astronomy was known from the Greek already, and the Romans had the organisational means and strategic need to do it. Would also have given the ideal opportunity to do trigonometry some 1000 years ahead of time.

I'm aware it is very easy for a modern ignorant to insult the elders of having been ignoramuses. ;-)

Somehow the time wasn't ripe for those inventions, although it's hard for us to imagine why exactly.

• +1 for mentioning the magnifiying glass (and glasses for reading are a consequence of this, without them all people older than 40 are functionally illiterate) – jknappen Feb 19 '17 at 20:20
• @Karl As they say in mathematics, every proof is obvious once you've found it. – Federico Poloni Feb 19 '17 at 21:32
• The difference between being able to make flat panes of glass and being able to precisely grind (e.g.) parabolic lenses is extreme. Not to mention that the mathematics and science of optics is nontrivial. I wouldn't be so hard on the Romans. – Charles Feb 20 '17 at 3:59
• For one that happened and probably shouldn't have: electromagnetism. There's no sensible reason why you'd have a compass on your workbench while testing an electric circuit. – Mark Feb 20 '17 at 8:13
• @Charles I wouldn't be so hard on the Romans - Really? What have they ever done for us..!? – Grimm The Opiner Feb 20 '17 at 13:49

## If there are any miraculous events, I am not aware of them.

Technology, science and society don't exist in vacuum, as you noted, most discoveries are a logical next step. While it's important to distinguish incremental improvements of existing theories or technologies (like steadily raising speed of CPU clocks, or increasing precision of measurement of physical constants) from basic research discovering new phenomena and leading to new technologies (by feeding applied research with those phenomena and ideas), they both work by building on existing foundations. Main difference is, in latter you can't really predict what you will find (that's kind of a point of basic research, to find out), while in former you can make general projections and predictions on rate of improvement and limits.

## Most of the science and technology (if not all) would be discovered later by someone else if for some reason historical discoverer wasn't available.

Same works in reverse, many technologies and ideas appeared before their time, and slid into obscurity, because there was no need of them, or there was no axillary tech to make them useful.

Good examples are steam power, mechanical computers and smartphones. While they are examples of ideas or devices failing to catch on prematurely, they show exactly why that happens, and what happens later, when, figuratively speaking, world is ready and time has come for them to catch on.

First steam power dates back to antiquity. It's simple, but shows that work can be extracted. However, without auxiliary knowledge, like knowledge of thermodynamics, it wasn't improved to the point of being useful, furthermore, there wasn't so much need for mechanical power back then. Through most of history, windmills and watermills were sufficient, until advancements in tools led to construction of mechanical looms and lathes, which rapidly increased demand for mechanical energy. At the same time, mechanical tools, allowed for construction of more precise parts, in greater quantity, leading to positive feedback loop of industrialisation.

Antikythera mechanism was a remarkable mechanical astronomical/astrological computer from antiquity. However, it was designed to be more precise than tools and craft of the time could build it. At the same time, there was no computer science, calculus, or even concept of "0". Because of lack of axillary knowledge and technology, whoever designed and built it wasn't able to generalise the device and thus, it remained a very specialised novelty.

Babbage's differential engines were mechanical general computers, designed nearly 100 years before electronic computers. That's the closest to major alternate history that I know. There was no computer science back then and there was little interest in computational power, furthermore, mechanical computers would be large, error prone and less efficient than electronic ones, but that was probably the first time in history where all the elements for computer to become reality were in place. There was steam power to drive them, there was design, tools and alloys might have been up to the task, and there was Ada Lovelace who might have been able to play the role which Alan Turing played nearly century later. However, there was little need for computers. Practical applications of early XX century computers were encryption/decryption and calculating firing solutions or firing solution tables for submarines and artillery, at the time of Babbage, neither of those were advanced enough (or even present) to warrant existence of computer. Thus, Analytical engines were never built, perhaps if there was someone else to the duo of Charles Babbage and Ada Lovelace, someone who could see practical applications the history might have played differently, but as it is, Analytical engine served as the theoretical foundation for further developments.

Smartphones are quite ubiquitous nowadays, but they are not the first attempt at such device. First PDAs appeared in 80s, but without axillary network infrastructure, cheap computational power and plentiful storage, they didn't catch on. Later, with advancements in infrastructure, processing power, batteries, screens, wireless communication and lot more, phones started acquiring new features, effectively merging with PDAs, until finally in mid 00s all was in place to begin the era of smartphone.

Louis Pasteur said that "Fortune favors the prepared mind". Have Alexander Fleming not been bad at keeping sterile conditions, or haven't been knowledgeable enough, someone else would have discovered the penicillin. It already was known that some moulds had antibacterial properties, and research was done in that field. Alexander Fleming certainly wasn't the only capable of that discovery, but chance decided he had greatest opportunity, and he used it to the fullest.

Now, this doesn't mean there aren't discoveries fitting your criteria, but I am not aware of them.

• In fact, the concept of zero was known to the Ancient Greek mathematicians: They used the Babylonian sexagesimal system for large computations, and that system has a zero. – jknappen Feb 19 '17 at 20:16
• Just to add that it's entirely possible various inventions and discoveries were made by lower classes and never 'surfaced' to the general populous because of politics and lack of a suitably 'connected' sponsor. For generations fledgeling medical science was restricted to a few elites and anyone outside that circle were not allowed (publicly) to even make observations, much less draw conclusions or take obvious actions. – Ralph Bolton Feb 20 '17 at 11:35
• @RalphBolton That's still true, really. In many countries, you can't legally practice medicine without a diploma from an accredited university. I'm not trying to argue whether this is a good idea or not, but it's certainly a mechanism that presents a barrier to entry, the same way as in earlier times. And that's just scratching the surface :) – Luaan Feb 21 '17 at 10:03

As a meta answer look at different cultures before we had world level communication. Why were some things invented at such drastically different times, and others not at all.

Inca, Maya, Aztec civilizations never invented the wheel. Why not?

The Plains indian culture took a radical shift with the introduction of the horse. (Imagine hunting buffalo on foot.) Imagine North America if horses and wheels were here by AD 1000. The Americas didn't have a usable saddle animal nor a draft animal. Could moose have been domesticated? Why did the populations of camels and horses die out? (Llamas are members of the camel genus, but are too small for riding, and apparently won't pull.)

The horse collar was much later than it had to be. Prior to it, a band around the horse's neck was used. The horse couldn't pull hard on it because it cut off his air. There was a reason that chariots had 2-4 horses on them. Once you had the horse collar, you could use a horse as a draft animal.

The moldboard plough. When it did come in, it allowed the tillage of northern soils which were too difficult to manage with the mediterranean scratch plough. The non-suitability of northern soils for agriculture put a limit on the Roman empire.

Centerboards/leeboards on sailing ships. Not practical on big ships, but small boats with one of these can sail much closer to the wind. This would have changed the whole history of naval warfare and smuggling.

I suspect that many of the innovations in sailing ships could have occurred earlier. E.g. A schooner like the Bluenose can be handled with fewer men, and has better upwind handing. (Fore/aft Bermuda rig) Schooners with gaff rigged sails were introduced by the the Dutch in the the 16th century. I don't see why they couldn't have been done 2 centuries earlier.

Math: There was no reason for zero to take so long to get from India to Europe. Romans used what amounts to an abacus for doing arithmetic. It would have been such a simple step to go from there to a decimal notation.

Imagine Rome with double entry bookkeeping.

When Harrison was building chronometers, mariners were calculating their longitude using lunar distances. Initially a difficult problem taking several hours of calculation, with later tables, the process got down to about 10 minutes. To do this earlier would have required several prior breakthroughs in math -- tables of sines; spherical geometry, but give the Romans the zero, and this may have occurred much earlier.

Germ theory of disease, and the attendant revolution in public health.

Another source of inspiration is to look at some of the appropriate technology aids in the third world.

In the 50's and 60's India was subject to famine. Now India is a food exporter. While the Green revolution had a significant impact, far bigger was the simple expedient of lining grain silos with plaster or cement. Rats were eating half the crop. One of those "Duh!" ideas.

• There's an argument that the South American cultures didn't invent the wheel because they lacked the flat hard open ground that it could be used on. If you're climbing mountain passes and crossing gorges on rope bridges, the wheel is a bit useless. – Separatrix Feb 20 '17 at 10:05
• @Separatrix South America is BIG and lots of places have flat hard open ground, yet they didn't use it. And in Europe or Asia most places didn't have flat hard open ground, so people build roads, leveled mountains and build bridges. I think a better explanation is that they didn't commerce enough for the wheel to be interesting, as the wheel comes with roads, and all this infrastructure has a cost and with no commerce it is not worth it. – Shautieh Feb 20 '17 at 11:54
• They had the wheel - they just didn't use it, for some reason. Don't forget that the wheel in Europe was originally rather important for something else than transportation - pottery. While the south americans had toys with wheels (even for movement, so they obviously understood that concept), they didn't have pottery wheels. Wheels are a great way of turning back-and-forth movement into rotation and vice versa. – Luaan Feb 21 '17 at 10:08
• they did not have an animal to pull the thing you put wheels on, without that there really is no benefit to early wheeled devices. That's why wheels stayed on toys. – John Feb 21 '17 at 17:04
• Really bad the vikings didn't introduce horses to America. Columbus might have found quite a different continent 500 years later. – Karl Feb 22 '17 at 21:06

## The Discovery of Penicilin

According to Mighty Wiki on PCN:

The traditional version of this story describes the discovery as a serendipitous accident: in his laboratory in the basement of St Mary's Hospital in London (now part of Imperial College), Fleming noticed a Petri dish containing Staphylococcus that had been mistakenly left open was contaminated by blue-green mould from an open window, which formed a visible growth.[29] There was a halo of inhibited bacterial growth around the mould. Fleming concluded that the mould released a substance that repressed the growth and caused lysing of the bacteria.

So if Fleming had cleaned his lab properly, PCN would not have been discovered (at this time).

Crucial: Oh yes. Without PCN many people would have died due to (seen from today) most simple illnesses.

Unlikely: Yes. If he had followed the rules of the lab, the petri dish would have been cleaned and PCN never discovered.

• I read somewhere that it was well known that moulds killed bacterial cultures but that nobody made the (obvious? Clearly not!) mental leap to a possible new drug before Fleming. – nigel222 Feb 20 '17 at 8:29
• @nigel222 It's not exactly obvious. Think about it - you need to leap from "some moulds kill bacteria" to "while not killing humans" and "working even when put inside the digestive tract of a living organism". It's not hard killing bacteria in a petri dish - just set it on fire or whatever. The hard part is killing the bacteria without killing the host - and that's the leap Fleming didn't make. He just planned to use it as an anti-septic - seeing how good it was at killing bacteria, and testing to see it was not toxic. It took another 11 years for it to be used in vivo, and not by Fleming. – Luaan Feb 21 '17 at 10:15
• Obligatory xkcd – user1975 Feb 21 '17 at 18:16

# Maxwell's equations

Hertz did not realize the practical importance of his [experiments]. He stated that,

"It's of no use whatsoever[...] this is just an experiment that proves Maestro Maxwell was right: we just have these mysterious electromagnetic waves that we cannot see with the naked eye. But they are there."

Asked about the ramifications of his discoveries, Hertz replied,

"Nothing, I guess."

Said by Heinrich Hertz just as he had for the first time proven the existence of radio waves.

Maxwell's equations are the theoretical foundation for everything concerning electromagnetism, which in turn is the foundation for 1) generating electricity and 2) radio. If Maxwell had not formulated these equations, electricity and radio would have been seriously delayed.

• Again, someone would have put the pieces together at around the same time. Mxwell’s true invention was solving the “capaciter problem” to make a clean unified solution. Without that, the approximation and refinements would spread over the course of a few years. – JDługosz Feb 21 '17 at 17:10

The single most "miraculous discovery" in my opinion is the theory of Special Relativity. Even having reviewed all the data available at the time Einstein came up with it, I cannot see how he came to the conclusions that he did. Together with General Relativity the concept is not only a work of genius, together they are one of the most creative works that I believe humans have created.

I really think that relativity would have been easy to miss, and I do not believe that any of Einstein's contemporaries would have come up with the ideas.

Without relativity, we would continue to doubt Newton's laws of motion and understanding of gravity, as we know of counter examples. In a practical sense, we would not be able to account for our artificial satellite's orbits.

• Einstein was no doubt a genius but the failure of the Michealsen-Morley experiment to detect the luminous aether was a huge unresolved problem in physics. It would soon have been joined by the experimental impossibility of making electrons travel faster than light. Finally the Lorentz transforms were known, and the Maxwell equations of electromagnetism were already relativistically correct. There is no way these dots would not have been joined within a few decades. – nigel222 Feb 20 '17 at 8:47
• Assuming that the course of history and people's lives was not drastically altered, I'm certain in my mind that Feynman would have found relativity had neither Einstein nor any of the other great physicists between them done so. Relativity becomes so much more obvious and necessary once you have failed to persuade electrons to go faster than light! – nigel222 Feb 20 '17 at 11:03
• @dotancohen: I think the creativity of these sorts of advances is often overstated -- the main hurdle when the math is telling you that your preconceptions are wrong, is not about coming up with a brilliant new theory, but to actually let go of your preconceptions and be willing listen to what the math is telling you. – Hurkyl Feb 21 '17 at 9:12
• @Hurkyl: You're not wrong about letting go of preconceptions but that is a lot harder than it sounds. Which preconceptions to let go of? The math doesn't tell you anything, the only information that Einstein had was that the measured speed of light was constant within experimental error. Which preconceived notion should he let go of, let alone the idea that time is not absolute? How would he even know that he had a notion of that? Absolute time is such a given (albeit wrong) that I really don't see how he let go of it. That is creativity, not genius. – dotancohen Feb 21 '17 at 9:45
• @dotancohen: As the other posters pointed out, the Lorentz transformations were already known. Even the idea of the 'local time' of clocks in a moving reference frame predates Einstein's paper on special relativity! Relativity of time was right there in the math, and was merely waiting for someone to take it seriously. – Hurkyl Feb 21 '17 at 10:01

Science works in a way that nobody is really irreplaceable. However, delays could have happened. I can talk for computers. If IBM (it wasn't called IBM back then) was failed to deliver a computer that helped with US census data in 1890, people might have kept their mindset about computers being useless toys, and this could have delayed computers and related technology for a long while. But probably not as long as you would like. I would guess it might have taken another 40-50 years and it would have delayed a lot of the advancement we have today.

• But the first electronic computers were used for breaking codes in WW2. Hollerith cards were for sorting and counting data, and did not come into computing until well after WW2. Paper tape, as first used for teleprinters, came earlier. – nigel222 Feb 20 '17 at 8:38
• Probably that would be the first time a computer would have ever used, pushing everything by nearly 50 years. When we talk about early computers, we are talking about mechanical stuff. Without the interest in computers as early as 1890, electronic computers wouldn't be around at WW2. – Cem Kalyoncu Feb 20 '17 at 8:48
• You get a rather different version of the history of computers at Bletchley Park. The background of the engineers there was in telephone systems and Turing's mathematical genius was given electromechanical realization in that context. BTW the most advanced pre-war computers were German. Fortunately Zuse was not a nazi and did not push his inventions at the German military. – nigel222 Feb 20 '17 at 9:01
• @nigel222 AFAIK Zuse was not a nazi, but he still tried to get funding from the military. That was rejected, though, with comments along the lines of "one year to make it work? The war will long be won by that time". I forgot where i found that, though. But it did seem highly plausible. – Burki Feb 20 '17 at 13:59

Telescopes were invented in the Netherlands about 1608. Several lens makers claimed to have done so. Hans Lippershey is usually credited.

Suppose that Hans Lippershey was the actual inventor and the others were early adopters of his discovery instead of independent inventors at the same time. Suppose further that one story is correct. This story says that Lippershey's children were messing around with lenses and discovered that a certain arrangement made distant objects look closer.

According to this version, the discovery as a result of the children happening to play a particular way and Lippershey recognizing the practical usefulness and marketability of telescopes. Either part of the event might not have happened.

Thus it is possible that telescopes were a largely accidental discovery instead of one that would have been made in a few years anyway. Thus telescopes, with maritime and military uses, might not have been invented for decades or centuries. And thus they might not have contributed to scientific discovery for decades or centuries.

Thus, if that story about the invention of the telescope is correct, comparatively minor events in the Lippershey household could have changed history significantly through delaying an important invention.

• I would argue that telescopes are actually a prime example of discoveries 'just waiting to happen', as around 1600 lenses of high enough quality were widely available. And it seems many people were at least experimenting with them even before Lippershey: en.wikipedia.org/wiki/… – Swier Feb 20 '17 at 8:57
• (Magnifying) Glasses were in wide use for centuries already. – Karl Feb 22 '17 at 21:12

It is not so much an unlikely invention as a possibly unlikely social development, but The Industrial Revolution deserves mention. Why did it not take place earlier, in Rome or Bagdhad or China?

We don't have access to alternative histories to know whether it was inexplicably delayed here, or whether it was a one in a thousand chance which everywhere else was prevented by conservative attitudes and vested interests. Certainly in the early Islamic world and in China (twice), many of the component pieces were in play, and were then suppressed.

• Rome or Bagdhad or China: they didn't produce enough power to feed an industrial revolution and the masses didn't have enough money to consume it. – ecc Feb 20 '17 at 13:39
• You need to invent Capitalism first: Let private entities pool their resources to build large organizational entities that do not belong to the king, are controlled by the king or are taxed to death or zero-growth by the king. Also, you need low-to-zero-warfare conditions / political stability for a long time. – David Tonhofer Feb 21 '17 at 18:27
• The industrial revolution came about with * decline of forests for fuel * the rise of coal for fuel * flooding in mines * need for transport because the coal and the ore weren't at the same place. It could have risen in the Ruhr Valley. Rome didn't have all the pieces at the right time and place. – Sherwood Botsford Feb 23 '17 at 23:24

The discovery of Czochralski process (a method for manufacturing single crystals) by a Polish scientist Jan Czochralski was an accident. Quote from Wikipedia:

He discovered the Czochralski method in 1916, when he accidentally dipped his pen into a crucible of molten tin rather than his inkwell. He immediately pulled his pen out to discover that a thin thread of solidified metal was hanging from the nib. The nib was replaced by a capillary, and Czochralski verified that the crystallized metal was a single crystal.

This method is used to this day for manufacturing of semiconductors. If he didn't have a crucible of molten tin on his desk or had insufficient scientific background to recognize the importance of what has just happened, the development of modern computers would be delayed.

• And the serendipity of just happening to have a crucible of molten tin near to his ink well. Having never had a crucible of molten tin lying around my office, I'm not sure just how that happened... – Jon Custer Feb 21 '17 at 17:39

Not quite what you're looking for since it's a modern one, and I'm not sure how many people outside the field are even aware of the revolution that green fluorescent protein has brought to biology. It was discovered by Osamu Shimomura in the course of marine biology research, as the basis for the the bioluminescence of a certain species of jellyfish.

Decades later, in molecular biology, many people were working on reporter assays--ways to determine whether a protein is being produced in a cell, and where. Many were available, but all had their flaws.

The reporter assay people (in particular Martin Chalfie's group) found that green fluorescent protein (GFP) perfect solution to their problems. (By this time history was determined--Chalfie's was one of three groups simultaneously trying the same thing.) You could make cells express hybrid proteins with a green fluorescent protein attached, by splicing the GFP gene into the gene that codes for that protein. Then the GFP would fluoresce green when illuminated with blue to ultraviolet light. In this way, you could see the location of the protein, under a microscope, even in living cells! (Chalfie used it to study nematode development--he could see the GFP shining in living worms.)

GFP is now used routinely in molecular biology, to study patterns of protein expression and protein function. (Or one of it's variants such as mCherry, many of them created by Roger Tsien's group by modifying the GFP sequence.)

But what if GFP, this decades-old discovery in marine biology, had not been out there for them to use? If Shimomura and his mentors, Hirata and Johnson, had not been studying this species of jellyfish, there's no guarantee that anybody else would have. It just didn't seem of any practical importance. I'm pretty sure the reporter assay people wouldn't have thought, hey, let's study jellyfish.

Other technologies would have been developed for reporter assays, and MAYBE they would have been just as good? I'm not sure.

It's very plausible that there could have been a little less funding for marine biology research, or Shimomura, Hirata and Johnson could have chosen different projects. To make it even more of a near miss, Shimomura lived in a city only 25km from Nagasaki during the atomic bombing. How would biological history have gone if he had been visiting that day?

It's not exactly the sort of history-altering discovery that you're looking for, but it may provide a schema for the kinds of things to watch out for. Important discoveries that in some way depended upon some other, seemingly irrelevant discovery.

• Nice first answer. Maybe not really a "miraculous event" type of discovery, but as you say, the implications of even seemingly unimportant discoveries can be far-reaching, and you do give a valid example which in my opinion turns this from a bit of a discussion point to an actual answer. Welcome to the site; we hope to see more from you! – a CVn Feb 21 '17 at 7:19

It's obvious, but...

The Internet.

Seriously. It started as an information-sharing protocol between servers, and branched out because some OTHER people with servers wanted in. It would have been so, so easy for some CEO to say "Okay, good, now we're gonna keep this technique a secret so our competitors can't use it." If the Internet never got started, computers would never have become the massive driving force that they have - instead of even Grandma needing to go buy her "Internet box," computers would be the toys of scientists and researchers using them for robots and the like. They wouldn't be half as advanced, either, considering that researchers don't devote as much effort to things without a demand. We'd still be stuck in the 90s without the Internet.

• I don't think it's really all that critical. We had phone networks long before the internet, and they were used for the same purpose (and indeed, still often are a carrier for "the internet"). It didn't take long to spring up after the necessary infrastructure was in place either - it all followed very quickly from the development done in the telephone companies (e.g. automated switching boards). The technique is worthless if you keep it a secret - and in the US, it was heavily monopolised regardless (again, by the same telephone companies). – Luaan Feb 21 '17 at 10:23
• That did happen. Other private networks faded away in favor of an open system. I agree it might have not happened. – JDługosz Feb 21 '17 at 17:13

Galois Theory

https://en.wikipedia.org/wiki/Galois_theory

in the [Aftermath] section: "Galois' theory was notoriously difficult for his contemporaries to understand"

also check