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Could the ancient Romans have built a digital computer? (hscott.net)
179 points by blueintegral on March 1, 2013 | hide | past | favorite | 143 comments

I think the point of the article was "Could Romans build a computer, if plans were magically given to them?". Given this, the critique I am about to make is a little outside the scope of this thought experiment. However, I've wondered about questions like this a lot before, and I think it is also interesting to consider that the Romans (possibly) had many conceptual hurdles to cross as well. I am not a historian, but it seems that given their numeral system, they would not have had a firm understanding of mathematical bases, and thus would have not understood the importance of diodes/transistors/etc since they would have had to make the conceptual leap of representing numbers (and all information!) in binary (base 2). It's interesting to think about what obvious inventions we may not realize today due to the way we represent certain forms of information.

Interesting point. I wonder if you can flip that around and ask if there are any otherwise obvious inventions we don't have.


Apparently they could build bath amazing bath houses because of time traveling to modern Japan.

I agree that Roman numerals would make computers interesting. But if we extend the thought experiment to Greeks + Romans, could they have had some other kind of computing?

It might not have been binary. It might not have been digital, but analogue.

I don't know anything about philosophy but Zeno's Arrow Paradox shows the strength of analogue thinking.

> It's interesting to think about what obvious inventions we may not realize today due to the way we represent certain forms of information.

I've only recently learnt that in Russian there are different words for "blue", and that these are seen as different colours, not just lighter or darker shades of the same colour.

And while it's good that we have so much processing power it does tend to mean that we just throw more processors at something, rather than designing a radically new architecture for specific domains.

I think Greeks + Romans + Indians increases the odds significantly.

The Indians had an understanding of the required math...

1. Binary numbers: http://en.wikipedia.org/wiki/Binary_number#History 2. Zero: http://en.wikipedia.org/wiki/0_(number)#India 3. A brief history of Indian mathematics: http://www-history.mcs.st-and.ac.uk/Indexes/Indians.html

This combined with the engineering skills of the other civilizations could have in theory heralded the digital age a little sooner :)

I also believe there was extensive trade between Romans & Indian societies so it is entirely feasible that some exchange could have occurred.

> I've only recently learnt that in Russian there are different words for "blue", and that these are seen as different colours, not just lighter or darker shades of the same colour.

That's true in English as well. Pink is really just light red.

Have you seen: "The Two-Thousand-Year-Old Computer?


Amazing stuff!

I see the Roman numerals as actually more like binary than our decimal system. Then again their system has a lack of uniformity

I think that mechanical computers are dismissed too quickly. Babbage was a perfectionist, and his machines were crippled by the reliance on decimal numbers. Konrad Zuse constructed his Z1[1] singlehandedly over a period of several years, based on a binary design. While the Z1 was only Turing Complete by technicality (it had the same instruction set as the relay-based Z3[2]) and it was fairly unreliable, it could have been built with more primitive technology and paved the way for significant improvements.

  [1] http://en.wikipedia.org/wiki/Z1_(computer)
  [2] http://www.zib.de/zuse/Inhalt/Kommentare/Html/0684/universal2.html

Yeah, I think this is an interesting idea, but it sort of inverts causality in a way. Could we have gone to the moon without a computer? To what extent are our advances since the advent of computation a result of computation itself?

Put another way, if the Romans had invented a computer, would they have had our level of technology maybe just 100-200 years later?

It's likely that the greater forces responsible for the downfall of the Roman Empire would have happened regardless of what advanced technology they might have developed.

Actually, from what I understood from listing to a TTC lecture series about this, the "decline and fall" of the roman empire is somewhat of a fiction, in that it wasn't a brutal event, more of a long slow disintegration over the span of a thousand years. To give some sense of perspective, that's 3 times longer than the US has existed, and people have been clamouring that the US is in decline for the last 50 years.

What happened is that regions progressively became more independent and broke off from the central hegemony of Rome and then Byzantium. It took until the 1400s for that last official centre of Roman power to dwindle, and even through to today, Rome has maintained a huge influence on the rest of the world through the Roman Catholic Church.

So, rather than falling down, the Roman Empire slowly but surely transformed into something else. Arguably, we (western civilisation) are the direct descendants of the Greco-Roman Civilisation, and so one could make a (somewhat strained) argument that the Roman Empire is alive and well today, just in a different, more modern form, that has undergone 2000 years of evolution.

What to make of this myth of the downfall of the Roman Empire, the Dark Ages, etc? Well, according to that lecture series, this was largely a myth concocted during the Enlightenment to position it in history. The Renaissance needed to frame itself as a major cultural change, so it helped to frame history as "the Classical period, the Dark Ages, and now the Renaissance" - and draw on a fine period of history to support all the new ideas and revolutions brewing (i.e. "things were good back in Roman times, then things were really bad because of the Church, and now things are better again because we're standing up to the Church"). For the people living through the supposed transition between the Classical Period and the Dark Ages, though, apparently, there was no such stark difference.

Kind of but not entirely true - I will defer to real historians but roughly it breaks down like this 100 - 180 AD : golden age of emperors, what we think of when we think Rome

200-350 : serious decline and infighting, split into four regions, during this period attempts to enforce price controls to stem inflation. Rome itself stopped being political centre

350-400 Constantine recovery (unites to one region again - one empire of three parts, one god of three parts, one emperor - gettit?)

400 + : total collapse of western empire - communications fail, smaller regions contest with each other, and inflation wrecks the value of economies as trade collapses. Eastern empire carries on with vastly reduced army and trade links to Persia.

This really was a dark ages - impoverished, illiterate, backwards looking and lacking trade with most of the world. There was no single definition of dark AGRs - mostly because there are few ways to be right and many ways to be wrong In short, the glory of empire did not last as long as everyone thinks - mostly Rome was a trade agreement that everyone else was keeping up in lieu of anything better.

Well, that's the thing. Yes, the central control collapsed (though I still wouldn't underestimate the influence of the Church, which effectively controlled kings' actions through the threat of excommunication). However, on a local basis, there was no such great disaster, just a long slow change.

And it was not really a dark age. As I said in my previous post, the dark age narrative is largely an invention of the 17th-18th century. What actually happened in that period was the development of a whole lot of great stuff like city states, art, commerce, banking, kingdoms, navigation tools (compass), military inventions (crossbows, guns), hourglasses, farming technology (ploughing), metallurgy, optics (eyeglasses!), mechanical clocks, textile technology (spinning wheel), the printing press, windmills, glassmaking...

For the people living in those times, it probably didn't feel anything like a "dark age". Just a fairly smooth progression upwards, with the usual ups and downs of wars, plagues and other disasters that are hardly confined to the middle ages.

I know the narrative of "here's the awesome roman empire, and now the church takes over and you have the dark ages, and now reason comes back in the form of the renaissance" is very compelling, particularly if you don't like the church very much, but it is just a narrative, and is not very well supported with facts.

Quite a lot depends on when we say the dark ages began / ended. By say 1066 I would say Darkness was lifted, trading and Europe stabilised and by 1200 and Marco Polo Western Europe became fully involved / aware of with the rest of the Eurasia continent.

Taking 1066 as a uk centric cutoff much of the above had either not been invented / rediscovered

Kingdoms and city states - The Roman Duc and knightly organisation of armies appeared before 350, banking was I thought super charged by the crusades. Compasses - Marco Polo, the Mongols, guns - not till what 1300?

I am aware there is always some in Europe knew but it did not benefit most.

So it does depend in definitions (as always). If its the simplistic Romans/bad church/good renaissance then yes I agree with you, but if it is Good Romans/messed up Romans/dark ages/Europe starts to join the world/renaissance Then I am much happier to argue for a period of 400+ years where development in Europe was largely static and the agrarian based economies just slowly adjusted to lower levels of trade etc, and certainly 450-550 was just a morass of backwards sliding.

I am just re-reading this and something has struck me - my posts sent by iPhone are always less coherent and more difficult to read than those I type at a desk.

It may be because I am more rushed on the phone, but I suspect it is a function of how I think - I seem to think by typing and my typing speed on Iphone is much slower than my brain can handle

You think as you type? Try it the other way around.

I am no historian, but what I was taught in high school is that "dark ages" are called so because of the little knowledge we have about them compared to the comparatively well documented Roman Empire and Renaissance periods, not because they were themselves "dark" in any sense.

I agree with you, but I think it's safe to say that contemporaries didn't think that Rome had fallen at all. As you say the western emperor felt about 400, but the Eastern lasted to 1453. Even not taking the east into consideration, the Papacy was seen as a continuation of the empire, and it was the Pope who crowned Charlemagne emperor about 800AD. Circa one hundred years later, the Holy Roman Empire was formed claiming "traslatio imperii" (that is, that there was a legitimate line of succession since the last west emperor), and it lasted until the XIX century.

being seen as a continuation of the Roman Empire is not the same as providing the material benefits of the Roman Empire.

In my view the Dark Ages were a rolling back of the benefits of a continent-wide peaceful trading bloc and a scramble to find a non-anarchic equilibrium from which everyone could rebuild. The multiple sackings of Rome however really made contemporaries realise Rome had fallen (and probably drove everyone to look for a solution closer to home - just the wrong move in Economics 101)

European history is full of petty dictators claiming heir to a new and resurgent Roman throne.

The crazy thought is, would it still be possible for the world to fall back into some sort of "dark ages", and we all end up living in some crazy mad max/aquaworld nightmare? It's happened before when societies fall apart, just because we have more technology now doesn't seem to me to mean it can't happen again.

Mad max worlds are deeply crazy and whilst there were I am sure equivalents (without the fast cars and the hacksaws) Mostly they would be short lived - no-one benefits from madness and humans don't like it. So pretty quickly a more stable equilibrium asserts itself, usually around one strongman. Democracy definitely optional.

Will it happen again - pretty likely. We are on a growth treadmill - the Romans growth fed by an seemingly inexhaustible supply of slaves from conquered regions, that dipped after Tiberius around 110.

And us. Well we have machines to do all the work for us - on average a UK citizen burns up 120kw per day - or 40 slaves burning 3000 calories a day. We need to keep inventing more efficient machines or inexhaustible energy supplies

So make room temperature fusion work and I will say its unlikely we will collapse. Without it, probably inevitable - but we keep going, because the poor are starving and the Syrians are getting shelled.

Yeah, I didn't mean mad max worlds literally, as much as I meant "a darker period of 'civilization'", or a loss of knowledge/ability/technology.

That's interesting thought you have though, of building society on "energy consumption" (labor, work, joules, whatever) whether it be slaves or oil. I suppose you could say it boils down to physics.

To be fair I doubt it's mine - but I fully agree - one could use energy or rather work efficency as a proxy for economic wealth.

The first wood burner must have halved the energy needed to keep warm - probably the best investment society made ever.

Of course energy efficiency as a metric Must make bankers even less useful to society than we think :-)

I'm there with you, as in I also think that there wasn't one particular event that triggered the fall of the Roman Empire (the year Rome was sacked etc.), but the changes between the "civilized" Romans and the "barbarous" migrants/germanic/slavic populations were nevertheless huge.

For example I live in the Lower Danube area, from where the Romans retreated around 275 AD. Reading about the near-by Roman city of Ulpia Traiana Sarmizegetusa (http://en.wikipedia.org/wiki/Ulpia_Traiana_Sarmizegetusa) it's surprising to see that only 2 generations after the retreat of the Romans the local people would revert to living in sunken huts, oftentimes a stone's throw away from the ruined Roman villas. The same people probably also lost the art of writing, because in the case I'm reading about there are no written documents or stone-graves or anything that could attest to the fact that they knew how to write for more than 700 years.

The thought that this kind of things could happen again should be on the back of our minds. For example I'm a little bit worried that more and more information about our civilization is only stored in electronic format. It suffices for us not being able to produce electricity for like 2-3 weeks and all of this will get lost.

The whole "Dark Ages" thing is a little contoversial, because it depends on your point of view. If you were living around the Mediterranean basin, things weren't so bad. If you were living in the periphery of the empire, civilization basically disappeared and reverted to tribal living or feudalism.

One of the big changes with Rome was that at some point, they became too big. Earlier in Roman history, the Romans would either kill everyone (Ceasar's conquest of Gaul killed a substantial proportion of the population) or begin a process of Roman-ifying the populace. The Roman armies kept the peace and spread the civilization.

The problem is that you had this built-in tension between keeping Rome (the City) under control, which was extremely challenging, and keeping the provinces in line and secure. Emperors had to spend fortunes subsidizing the City with grain, festivals/circuses and other support. Getting those fortunes meant levying onerous taxes, and collecting in the provinces meant enpowering the local Roman officials and military -- which in turn created rivals to the emperor.

Another issue is that as time went on, gaps in agricultural technology fundamentally changed the society. The core of the Roman republic was citizen solders and civil servants -- many of which were yeoman farmers. As crop yields declined and demand grew, these farmers went out of business and consolidated into much larger estates that were dependent on slavery.

All of these things resulted in changes to the character of the Roman system. Roman armies were not made up of Romans. Roman generals were not necessarily loyal to Rome. It just turned into a big mess.

For the people living through the supposed transition between the Classical Period and the Dark Ages, though, apparently, there was no such stark difference.

Yes and no. Roman decline really happened, but the significance attached to 476 AD is an artifact developed later, when the decline actually happened over hundreds of years. As you noted, the Eastern Roman Empire carried on for another thousand years, and the Catholic Church remains the largest religion in the world.

There was a decline in trade complexity, literacy, and probably standard of living at the top of society. Medieval historians did believe they were in a time of decline and ruin (this was heavily influenced by Christianity and its apocalyptic prophecies) but the average Germanic peasant didn't know enough to care either way, and probably had no substantial change in his material well-being from 100 AD to 600 AD (or 1700 AD).

One of the things to keep in mind is oblique comparison. Most people who perceive decline compare their status to that of elite people in the past, creating a sense that things were better then. You'd certainly be better off as a Roman patrician than as a peasant in 7th-century Bavaria, but that's not a proper comparison.

From the perspective of a literate elite, there was civil and industrial decline, explaining the impressive infrastructure that had fallen into disrepair. For the average European, there probably wasn't a directional change, but the average European left no writing.

There where significant advances in mathematics and technology in the dark ages along with a massive population boom. Most notably algebra, armor, bows (long, compound), clocks, and fortifications. But, also agriculture, animal husbandry, musical instruments, tools, manufacturing, and many others. What was missing was a unified empire and the trappings of such, but there where a lot more practical advancements than most people understand.

PS: The roman army was great for it's time, but they would have been decimated by far smaller 'dark' age equivalents. The closest real world comparison was Hernán Cortés and the fall of the Aztec Empire using 6 guns ~2,000 people, 100 horses they could easily take on the euqivelent of an 100,000 man incan army. (Incan army was larger than that but they had native help.) http://en.wikipedia.org/wiki/Hern%C3%A1n_Cort%C3%A9s

You're right, and the "Dark Ages" concept comes with a Western European bias. For China and the Muslim world, it was a time of prosperity and advancement.

War, as you've noted, is one thing that medieval Europe was (compared to the Romans) quite good at. There's a misconception that European swords were heavy, awkward, and dull. While they were never as aesthetically attractive as Japanese swords, they were formidable and more than good enough to do the job.

>For the average European, there probably wasn't a directional change, but the average European left no writing.

The average European went from a free citizen of Rome to a serf, laboring under conditions that bordered on slavery. I'd say that's a pretty radical negative change.

"The average European went from a free citizen of Rome to a serf, laboring under conditions that bordered on slavery."

~30-40% of the population of Roman Italy was made up of (real) slaves and most Europeans did not have Roman citizenship until so late in the Empire that it didn't really gain them much (it was actually disadvantageous to most -- Caracalla only instituted universal Roman citizenship so he could raise the taxes on the new "citizens").

I agree that serfdom wasn't much better. IIRC, one of the few advantages of serfdom was that you couldn't (in general) be sold away from your family. Serfs were considered part of the land.

Thank you - that has made a difference I could not express much clearer.

Would it be fair to say that the average rural worker since the invention of farming had a sh*t standard of living till sometime in 20th century. It is just the upper levels of society that saw and benefited from swings in civilisation.


Inflation mostly. Kind of ominous isn't it?

I think the cross-feeding between technologies cannot be underestimated

You need metallurgy to get better at metallurgy (so you can build tools to build better tools, etc)

At the same time, you need metallurgy to build delicate electronic circuits: tools, terminals, etc, be that a transistor or a relay or a tube

Slight tangent, but there is a marvelous series about this crossfeeding of technologies called 'Connections' by James Burke. Its old but still great to watch.


I can't recommend it highly enough, its worth taking the time to start at series one.

Also by Burke, "The Day the Universe Changed", Netflix had/has it through their DVD service a few years back. In that series he goes into the history of the ideas that make our modern world possible. The idea being that the day the universe changes is the day you start looking at it differently.

Oh, of course I remember it. It was also a column on SciAm

But yeah, I've watched a couple of episodes, and it's very good.

They absolutely could have built a digital computer and much more. He's slightly underestimating Roman enginuity for delicate manufacturing. Consider for example the Cage cup[1]. It's an exquisite piece of art and creativity and, all things cosidered, engineering as well due to the very tight tolerences and detail.

There's a lot more to progress than just the capacity for great leaps in engineering and sciences. Often times, there's a bit of luck and timing (Newton's apple and, of course, Newton himself) and also a societal willingness to promote new kinds of thinking.

The Antikythera mechanism is thought to be more a Greek invention than Roman[2]. And I've felt the Greeks were more appreciative of experimentation than the Romans who were driven more by the necesities of war and maintenance of the empire and they may be better candidates (with perhaps some Roman help) to go about making a proper computer.

We also need to understand that certain concepts in mathematics didn't exist in Roman mathematics at the time, like Zero (before Ptolemy)[3], which in addition to meaning "nothing" as quantity it also means "something" as a value.

We also know the Romans traded extensively in the Middle East which means they could have potentially been exposed to very early experiments with electricity[4]. While the age of "Bagdad Battery" like devices are debatable, it's not too much of a stretch to see ancient alchemists experimenting... more than likely the Greeks.

  [1] http://en.wikipedia.org/wiki/Cage_cup
  [2] http://en.wikipedia.org/wiki/Antikythera_wreck
  [3] http://en.wikipedia.org/wiki/0_(number)
  [4] http://en.wikipedia.org/wiki/Baghdad_Battery

> They absolutely could have built a digital computer and much more.

No, absolutely not. I think you are deluding yourself. There is a long way to go from building a fancy vase or discovering the existence of the zero quantity to developing the necessary mathematical, physical and chemical framework needed to produce even the most rudimentary piece of digital technology.

An abacus is essentially digital.

Considering the abacus is finger operated, it is digital.

I actually meant that it is used to store discrete values.

For that matter, a pile of stones is essentially digital.

In the same way that counting stones or counting on your fingers is "digital."

Sure, it's a bit of a pedantic point. I don't think it is particularly tiresome in this case, I think the interesting thing about computers is that they are programmable.

A smarty pants answer would be, yes, but it took 2000 years....

The problem with this is that you end up with lots of additions to the premise. So, you ask the question: "Could Romans build a computer, if plans were magically given to them?. Then, you have to say, if they had plans they understood, then if they had plans using a certain technology, then if they had zero, and if they had an understanding of x, then y, then z, and on it goes. In then end, it becomes pretty clear the answer is no because of the sheer number of caveats we have to add to make the original premise work.

The whole thing seems to be a bit of an idolisation of an ancient civilisation. Its like we want them to have had mystical powers. Like how some people want to connect ancient Egyptians and Mayans to aliens. This is the fantasy of forgotten super knowledge.

Or, consider this: do we seriously that we could build something that we designed and built 2000 years from now? Something that could reasonably include or be based on alien technology and knowledge.

A connected tangent type thought, and I have no idea where it goes; but how come Romans were so clever, but current tribes around the world, sort of, aren't? How does that work? Is it a resource thing? Environment thing? Seems a bit odd to me that even now we have societies who are actually behind a society 2000 years old.

A connected tangent type thought, and I have no idea where it goes; but how come Romans were so clever, but current tribes around the world, sort of, aren't? How does that work? Is it a resource thing? Environment thing? Seems a bit odd to me that even now we have societies who are actually behind a society 2000 years old.

It depends on what you mean by clever. If you mean proficiency at building tools and mechanical technology, then I suspect the reason is because the Romans had a culture conducive to developing certain types of technology. How much technology is derived from the need for military conquest? How much is military conquest dependent on the type of religion you have? How much of the capacity to develop technology is dependent on having a privileged class that has enough free time to think about things unrelated to food and reproduction? These are political and social conditions and they depend on the political and social conditions of surrounding tribes.

The people that still live in a tribal society today have found a cultural and resource equilibrium with their environment. They are fortunate enough to have avoided or overcome all external and internal pressure to change. They don't need to develop technology because their environment and way of life don't require it.

Arguably they were just an insight away from the hot-air baloon, so yes, I think there ought to be something 2000 years ahead that we can build today if we magically get the plans.

There's probably some really impressive nanotechnology we could theoretically build today, bootstrapping off our today's tech fairly quickly, if we just knew what we were doing. I don't mean necessarily a full-on self-replicating machine, necessarily, but who knows, maybe even that, with the right bootstrapping sequence. We just don't really know what we're doing today.

In A Fire Upon the Deep by Vernor Vinge, one of the minor points is the bootstrapping hobby that some in the galactic civilization undertake, trying to determine the minimal steps that could be transmitted to primitive civilization to most rapidly bootstrap them to "real" civilization. I find myself curious about that too, and would probably enjoy that hobby, but alas, we lack the knowledge and perspective to properly play today.

Why would they need to build a digital computer? How about an analog one. A good example is Moniac http://en.wikipedia.org/wiki/MONIAC_Computer

It uses water to model an economy. Taps can be used to change variables (eg interest rates). If the Romans wanted to do engineering calculations then there is no requirement for digital - an analog computer could do the calculations just fine. You can imagine taps to set lengths, widths, heights etc.

The problem really is in defining a computer. The first mechanical computer was not designed by Charles Babbage. Some thing like a clock/wrist watch is a mechanical computer. A marine chronometer like this(http://en.wikipedia.org/wiki/Marine_chronometer) is an advanced mechanical computer. The marine chronometer of the 17th century in our terms was basically a GPS device of that era.

Think of it that way. How do you think future generations hundreds of years now will look at our server farms. I bet our server farms won't even fall in their definition of a computer(or whatever term used to define a computer at their time).

Turing equivalence means that computers hundreds of years from now may be quantitatively vastly more powerful, but they still won't be capable of computing anything that today's computers can't given sufficient time. The same is not true of today's computers vs. special-purpose computation devices, like chronometers.

"computer" usually includes some concept of "programability".

There are many mechanical calculators (some of them are really nice!) but they are just calculators.

Curta - (http://www.vcalc.net/cu.htm) (http://www.darkroastedblend.com/2008/09/stunningly-intricate...)

Arithmometer (http://www.mhs.ox.ac.uk/staff/saj/arithmometer/)

Stepped Reckoner (http://history-computer.com/MechanicalCalculators/Pioneers/L...)

And there are a bunch of gadgets (http://history-computer.com/CalculatingTools/gadgets.html)

as DanBC said, the "canonical" definition of a computer is based on programmability. In that sense, the precursors to Babbage where some mechanical looms like the Jaquard Loom ( http://en.wikipedia.org/wiki/Jacquard_loom ).

http://news.ycombinator.com/item?id=2670203 has good links on mechanical computers and small CPU designs. http://lists.canonical.org/pipermail/kragen-tol/2010-June/00... concludes "There’s a strong appeal in the idea that universal computation has been within the grasp of human materials and manufacturing technology since the invention of sewing in the Paleolithic; it is only the mathematical sophistication that was absent. I don’t yet know if it’s true."

I don't understand the focus on tolerance for gears.

Tolerance is about miniturisation and commoditisation. These are not critical-path concerns here.

You could build a 'mill' analytical engine from very large wooden spars and wheels and it'd still be a mechanical digital computer.

The bigger question is WHY would they build one? What purpose would it solve?

Babbage wanted to reduce error in the lookup tables used by mariners. There wasn't a lot of other things it needed using for, and it would have been cheaper to instead have the charts compiled three independent times and comparing them.

What would the Romans have used a computer to compute?

Physical simulations. Computer-aided design. Finance. Bookkeeping. <half-joke> If they also had cameras, exchanging pictures of cats <half-joke>

The design of the difference engine and the analytical engine were dependent on tight tolerances in the parts, but that was a design choice not a fundamental constraint on mechanical computing devices. Indeed, look at "experiments" such as the tinkertoy computer (http://www.rci.rutgers.edu/~cfs/472_html/Intro/TinkertoyComp...) for examples of other designs based on other principles. The idea that the ancient Romans would have been incapable of building tinkertoy parts is simply not believable.

Also, people have managed to build difference engines using legos, meccano/erector sets. Here's a video: http://www.youtube.com/watch?v=KL_wy-CxBP8

This description does not discuss reliability. IIRC, these cat's whisker diodes need frequent readjustment. (http://en.wikipedia.org/wiki/Crystal_radio#Crystal_detector agrees with that)

Using a single one to build a primitive radio receiver is easily doable, but combining a couple of thousands of them to get a 4004? I doubt one could ever get that to run for a second.

So, they would have to step up to better diodes. Of course, one can speculate that they could have done that, and they could. In the end, it is all down to the observation that flattery (aka imitation) is way easier than invention.

They could do what modern computers do and apply error correction codes. I mean if we're already teleporting knowledge into the past we might as well go all the way.

The somewhat recent 'Why didn't the Romans invent the internet?'


> I don’t think the Romans could have built the analytical engine or other purely mechanical computer because of the tolerances required. I don’t know much about their manufacturing abilities, but I know they didn’t do a lot of it and imported most things.

But yet the greeks produced machines of incredible precision and function circa 150 to 100 BC.


And whether they imported them or not, clearly the ability to manufacture to such precision did exist.

If only one would read the actual article...

> It’s hard to know how precise manufacturing techniques were back then, but one of the best clues we have is the Antikythera mechanism. It uses hand cut gears that are surprisingly precise, but still probably not good enough for a mechanical computer. Small inaccuracies in the gear trains would add up, and this is evident in the Antikythera mechanism. It would be even more pronounced in a room sized contraption and would almost certainly prevent any useful calculations from being performed.

Not sure about that, but it always amazes me how the advanced the Greek and Roman societies were at the time, by the documents that reached our times.

If the fall of the empire were not to happen, who knows how advanced the mankind could be in our times.

Don't ignore the extremes. Before coming to conclusions with statements like "Romans didn't know X", "Romans couldn't do Y", reflect on what you mean: you are referring to the general and ignoring the rare extremes. I bet you could find a few people in the whole empire who knew about more advanced math and even the number zero. You could also find the best craftsmen to make intricate gears, and forge strong magnets. Indeed, that's how things would go in the old times. Masters would protect their secrets, and only if you had the money to hire them, you'd get the exquisite work. That's why, sometimes the know-how would be lost; like the examples for masterful crafts in the other posts.

In short, they didn't have the scientific and industrial revolution that we had. In their times, the masters were able to make money out of their knowledge and eliminate competition through secrecy. So, with enough money in hand, you could do a lot better than what was available to an ordinary person in the Roman times

>They even began dabbling in technology vastly ahead of their time. Hero of Alexandria drew up plans for a rudimentary steam engine in his Spiritalia seu Pneumatica.

Sorry, but Hero of Alexandria was a Greek. Not a Roman.

The Antikythera mechanism, mentioned casually in the article was Greek too.

I think the more interesting question is, would they?

Let's assume they can build the computer, including all the supporting technologies, like electricity and precise mechanics.

What use case would they have where it would make economic sense to spend countless man hours developing it?

Fortunately, all the component technologies are useful in themselves, so you could start by developing them independently, just like it happened naturally. Let's say you start with electricity. It's really useful right?

Well, without a power grid, electric engines, industry to use the engines, and large electric power plants to supply a steady supply of electricity, it is really much less attractive.

I'm doubting you could actually get a computer built until the civilization was ready for it, and there was a need.

I completely agree. I'm kind of surprised more readers don't seem to have this sort of reaction to the article.

interesting analysis, but I would prefer if it were pitched as - could a time traveler to ancient rome build a computer or could you build a computer while lost in the woods?

The article talks about the knowledge of the romans, regarding making wires and such, but building core memory or a transistor successfully and stably requires a very high level of knowledge of electricity, magnetism and some important higher level abstractions for thinking about storing information.

So, I think no, to a very high degree of certainty the romans could not have built a computer. If a society has not developed light bulb, I don't think they understand electricity well enough for a computer.

Romans didn't have a number zero.

Good point, but the question the article addresses is if they could have physically built one, not designed one.

I think that's why I don't find it a very interesting article. The capability to build isn't very useful unless you have a theory that informs it.

First thing that came into my head as well.


philosophical (or philological question): is having a word for 'nothing' the same as having a number 'zero'? my answer would be no. when zero entered western civilization from the east, my understanding is that it triggered profound changes. yet indo-european languages have probably pretty much always had a word for 'nothing'.

Yes I think you are correct.

Nil/null/nothing is different to zero. The former is the lack of anything and the latter is an integer with no magnitude. This is something I'm always having to hammer into our developers' heads over and over again.

'nihil' translates to nothing, but 'nullus' translates to 'lack of' and was recognized and used as a number, even if the symbols didn't reflect this. Just because zero wasn't typically used when teaching mathematics (i.e. teaching quantity instead of number line) doesn't mean that there was no concept of 'zero' in the numerical sense. Both the romans and the greeks had concepts and proofs based around negativity and zero.

However, modern notation, including negative sign, zero, and algebra, are all rooted in eastern and middle eastern cultures.

The number zero wasn't itself the big thing, it was the introduction of a positional numeral system, which needs zero to represent quantity in a given position, so you can note numbers such as 101 to mean "one hundreds, zero tens, one ones")

Many cultures had at least a word for zero/nothing in the context of numbers, but didn't have a positional numeral system, and in many cases didn't have a numeral notation for it either.

In the Doctor Who episode The Fires of Pompeii, the romans in pompeii constructed a digital computer using blue prints given to be them by some aliens and doctor who destroyed it.

The broader question is why the technology of classical civilizations was not far better than it actually was, given that they clearly knew many of the basic principles - eg steam power. The traditional answer is "slavery": in societies where copious manpower, in the form of slaves, is so cheap (not free - you still have to feed 'em !), the incentive to productionise technology is vastly reduced.

I've always wondered about this. What are the chances electronic devices have been built in the past and for some reason there are no remains, we just can't tell them apart because we have no idea what to look for, or the materials they were made of have completely disintegrated by now?

The Baghdad Battery may have been invented back then, but there is no evidence that it is used for anything more than electroplating in small scales.

I think this article is actually quite interesting and given a bit more, could make for very compelling alternate history

I think the article is missing the process of technological development. What kind of culture, funding, ideas needed to be in place to drive the innovation needed?

> I think if you traveled back in time to the Roman Empire and told them how to manufacture this stuff, you could plausibly create a very modest computer.

Then finally there'd be a use for the Pope's tweets in Latin.

So what would they do with this computer? (This pre-George Boole computer, so no Boolean algebra at the time).

Pre-Newton: rules out ballistics calculations, the favourite of early computers.

No Enigma machine or other calculating devices, pretty much rules out codebreaking.

No long term high capacity storage, or much in the way of large scale precise information available to work with.

Large, expensive, only one in existance, no lights for output. Nothing it could do that a dozen trained slaves couldn't do much quicker.

Maybe they could. Why would they?

Water power, someone else may have mentioned it, but water power was already used to power sawmills as possibly early as the 3rd century BC[1], I think a better question then isn’t why didn't they build a computer, as much as why didn't they use their water power to industrialise?

[1] http://en.wikipedia.org/wiki/List_of_Roman_watermills

One reason is slavery. You don't have as much incentive to industrialize when labor is dirt-cheap.

I think what was missing was theory - numeric systems, chemistry, electromagnetism and other sciences.

In the Roman era science wasn't invented yet - they were excellent craftsmen and sometimes Greeks produced excellent ideas, but there was also a lot of really bad ones and the facilities to weed out the bad ideas (peer review and scientific method) and propagate them (the printing press) weren't available yet.

Nice article, but I must take exception to one claim. The Antikythera mechanism is in fact a computer, it's just not a programmable one.

Romans building a digital computer? Seriously?? almost all of their so called achievements were actually stolen frm the East (India). 2500years ago India had two biggest universities in Nalanda and Thakshashila which encouraged scientific thinking. and you are talking about a barbaric civilization that was good at war and killing? pathetic...

For extra credit, figure out the surprising thing we can build now that won't otherwise be built until the year 3000.

Another way to read this article would be as follows: There has to be something big out there ready for us to build.

Now consider (just consider) that one does not necessarily need a "plan" or a "theory" to build things, one should definitely do so, preferably something (seemingly) useless.

I build little things without a plan or theory (or at least, without a coherent one) fairly regularly, to see what I can learn from them (and because it's fun.)

But building something big? Without a plan or theory, it's hard to justify the time and cost of doing that.

(Kind of reminds me of the film Contact: the engineers just kind of built a machine from the plans that the aliens sent, without seeming to do any research at all into what the purpose or theory of operation of it was. My reaction to that was complete incredulity.)

The article is mainly a good reminder of how many things you can do yourself. The a posteriori reasoning without concrete proofs is faulty in the sense that the same reasoning can be applied to a lot of things beyond the romans: could the ancient greeks have discovered penicillin?

I like this because it's interesting to think about what we can build today with existing technologies that future civilizations will look back at in the same way we have done here! It's inspiring, all the potential around us that we cannot see.

I like to consider if I could build a computer if I was transported back to Ancient times. Having a fair amount of knowledge, it would still be an immense challenge to start from scratch and build up the tools and chemicals one needed.

If they could, they would program in Lingua::Romana::Perligata.


The Romans did something more masterful than building a computer. They built an empire with a system of roads, etc. without which, the Europe and the U.S. probably wouldn't exist today. But the incompetence of their emperors and the selfishness of their people eventually led to their demise. (They should have been friends with the huns, or have been able to adequates protect themselves.

Sure they could have built a computer if they had learned the technology. We are still amazed now as we learn of methods and technologies that human cultures had before us. Humans are much more able than we give them credit, and much more innovative than history endures and relates the resulting inventions.

This would be fun inserted into Rome, Sweet Rome:


> While [the difference engine is] a beautiful piece of engineering, it’s actually not a computer.

What exactly is the distinction the author is making here?

Uh, in hindsight is so simple! Duh! Those lazy Romans.

According to my Civ 5 game they could.

I'm going to do my usual OT hijacking and mention the upcoming novel of a friend. Her premise was: how would an industrialised, polytheistic society cope with monotheistic terrorism?

It's an alternate history; the point of departure being that Archimedes of Syracuse was captured, taken to Rome and then funded (because the Romans were nothing if not practical). In her setting, the Romans are well into an industrial revolution.

The blurb she wrote for an agent:

    Pontius Pilate is a successful corporate lawyer 
    headhunted by the Roman Senate to run a difficult 
    province in need of a gentler, civilian touch. He’s 
    been in the job five years — and is starting to get 
    the hang of it — when the Yeshua Ben Yusuf file 
    lands on his desk. This is not ideal right now. 
    Judaea is in the midst of a major terrorism crisis, 
    his wife keeps threatening to go back to Caesarea (
    she can’t stand Jerusalem), his son is becoming far 
    too friendly with the High Priest’s son, and his 
    boss keeps forgetting that he isn’t actually in the 
    army. Even worse, his closest friend and greatest 
    rival from law school is Ben Yusuf’s lawyer. A 
    Jerusalem courtroom is the setting for the first 
    clash of civilisations, where people from a 
    fundamentally different tradition are forced to 
    engage with religious ideas that in many respects 
    they do not want to understand.

    What is most distinctive about the book is my 
    imagining of what a technologically advanced pagan 
    civilisation would look like. That is, what if the 
    Romans won much of their empire under conditions 
    that we associate with the Industrial Revolution? 
    What if — with their distinctive, non-Christian 
    moral values — they were gifted with all that 
    immense fire-power and confronted with monotheistic 
    I do not think the Romans were secular in the 
    modern sense, and I haven’t portrayed them as such. 
    They were, however, very different from the 
    monotheistic peoples they confronted in Judaea. My 
    Roman characters are still religious, but 
    differently religious. Unlike many authors of a 
    skeptical bent, I do not seek to score cheap shots 
    by denigrating religion per se. Rather, Bring Laws 
    & Gods recognises the persistent vitality of 
    religious traditions, especially when their 
    practitioners are confronted with overwhelming 
    military power and physical occupation by non-
It should be published this year and I am very much looking forward to reading it, based on the introduction and samples she's dropped:


http://skepticlawyer.com.au/2010/09/24/the-angel-bring-laws-... (NSFW)


http://skepticlawyer.com.au/2010/11/25/patria-patria/ (NSFW)

"how would an industrialised, polytheistic society cope with monotheistic terrorism?"

Add to this a side plot about creating sentient machines and you basically summed up the storyline of Caprica, Battlestar Galactica's prequel.

That may be the case (I never watched BSG), but I'm not sure if that precludes her from writing a story in what is ultimately a very different setting.

I'd also note that sometimes plots occur more than once in literature and entertainment by mere chance. Shocking, I know!

Edit: having looked up the Caprica plot on Wikipedia, really, they have nothing in common.

> Shocking, I know!

I didn't want to sound dismissive or snarky in any way. If I did, then I apologize. I was just providing an example of other story based on "industrialised, polytheistic society with monotheistic terrorism" :).

I hope strongly that your friend will publish her novel successfully; I'm eager to read it.

BTW. If you never watched BSG, I recommend it strongly (the new one). It's a masterpiece.

I was snarky too.

I mean to get around to lots of things, but there's so much other stuff to do, read, watch or play.

At the end of the Western Roman Empire in 300AD they became monotheistic. The interesting piece is, what if they had been able to eliminate all the civil wars? In that case their would have been a unified force to resist the rise and spread of Islam. Islam filled a void left by the collapse of the Roman Empire even though the Western Empire still existed.

Not exactly. When the Western Empire fell, the Eastern Empire retained Constantinople as its capital, from which it engaged in a protracted series of increasingly expensive wars with the Sassanid Empire (modern-day Iran). These conflicts peaked in the early 7th century, at which point the Sassanids suffered an astonishing implosion.


That was the vacuum that Islam (then nascent) filled. Only after seizing the remnants of Persia (and, critically, control of the silk routes running through it) could the first Caliphate move into territory once controlled by Constantinople. By the time the second Caliphate had extended Islam's control into Spain, more than four centuries had passed since the abandonment of Rome as a capital city (330 CE), after which the city persevered for another century before being sacked entirely. However the Western Empire was long gone by the time Islam appeared in the territory it once controlled.


The thing is that a lot of what we associate today with Islamism is really a property of monotheistic zealotry in general.

In fact, the very word "Zealot" originally referred to a particular religio-political movement that sometimes dabbled in what we might in today's terms call "terrorism".

I'm not sure that would have helped that much really. The Eastern Empire had been propping up the West for years with trade and money. By splitting off, the East was able to keep all that funding for itself. However, internal/external struggles, the Forth Crusade[1] and political intrigue ended up being the downfalls. I do think there is some "what if?" factor in all that. Such as what if the unified empire had not wasted all those resources on the civil wars.

In some ways, the Western Empire was sort of doomed from the time of Augustus onward when their embedded fear of the German tribes was established[0]. The defeat at Teutoburg Forest and the loss of around 20,000 Roman legionaries stopped all expansion into Germany and most likely lead the the eventual confrontation with the Goths. There's also a "what if" due to the Huns and pushing the Goths across the Danube, but if it were not the Huns, it could have been other factors as well (famines or another barbarian tribe).

The Eastern Empire almost reconquered the Western half in the 6th century under Justinian[2] and Belisarius[3]. However, internal bickering and mistrust led to squandering much of the gains that were won.

The Islamic forces were also able to capitalize on the chaos brought on by the perpetual wars between the Eastern Empire and the Sassanids[4] as well as the various barbarian tribes (such as the Bulgars and the various Gothic tribes that filled the vacuum of the former Western Empire) that still preyed on the Constantinople and other areas. There was just too many fires to contain them all at once and when one was put out, another was started in another region.

Honestly, I think it was for the best the Roman Empire ended for the sake of renewal (as much as I love Roman History). It had started to stagnate by the forth century and the more Greek side in the Eastern Empire was far from being the intellectual and cultural epicenter that it was during Classical Greek times. Sure, they built great things such as the Hippodrome and the Hagia Sofia, but those were just reincarnations of similar things done under the unified empire.

[0] http://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest

[1] http://en.wikipedia.org/wiki/Fourth_Crusade

[2] http://en.wikipedia.org/wiki/Belisarius

[3] http://en.wikipedia.org/wiki/Justinian

[4] http://en.wikipedia.org/wiki/Sassanid_Empire

One thing that's a bit confusing about "The Roman Empire" is that it bifurcates into the Western and Eastern empires, which were two wildly different polities with a shared name.

If you thought the gcc/egcs fork was a big deal ...

Yeah, very true. The Germanic Tribes were probably as much, if not more Roman by the 6th Century than the Eastern Empire (Byzantines) were. From my understanding, the Germanic tribes did not exactly want to destroy the empire, they just wanted to be a part of the Roman Empire and share in its protection--to be Roman and share in their luxuries and technology. However, the Romans were too distrusting of them and treated them as second or third class citizens and isolating them on worthless lands far away from the core empire[1]. It was also business as usual for the Romans and how they treated many of the civilizations they saw as inferior--sucker them out of whatever you can and assume they're too dumb to know. They even traded the Goths dog meat in return for their children[1]. However, the Germans were smarter than the Romans gave them credit for and realized what was going on. When the Germanic tribes saw how weak the Romans were and after years of mistreatment, they decided they had enough.

Byzantines with a more Greek Culture (and spoken language) and different religious practices in some ways, despite being part of the same Catholic Church. I'd imagine that many in the West by the time of Justinian viewed them as invaders as much as any of the other groups.

Mistrust of foreign cultures still plagues us today in most countries throughout the world. It's too bad we do not learn from the mistakes of the past, such as those of the Romans and Gothic tribes. Isolating your fellow man because he speaks a different language or has a different culture/religion ends up making a country less safe instead of more safe.

[1] http://en.wikipedia.org/wiki/Gothic_War_(376-382)#Outbreak

Sort of reminds me of India (the polytheistic "industrialized" society).

She mentioned somewhere that she sees India and Japan as good case studies in how modernist polytheistic societies works.

Not exact models of what a modernist Rome would look like, though. For one thing the Roman legal system, in its various forms, was a different creature. They had slavery ... but also very liberal marriage and divorce laws compared to most societies in history.

They're also one of only two legal systems which developed torts -- in Roman law, delicts. As an innovation torts/delicts take a lot of pressure off the state to provide regulation of commercial and personal behaviour, because a lot of it is then handled at the lower level by individuals and companies.

Many Christian societies are also polytheistic. The trinity is nothing if not an expression of polytheism.

A lot of the Roman impatience with early Christians was due to their energetic ... disagreements ... about your statement that "the trinity is nothing if not an expression of polytheism".


Right, however the Pauline creed places Jesus as divine alongside God. This is polytheistic as it has assigned divinity to something/someone other than God alone. And predates the period you describe. Of course, Christianity has become more and more polytheistic over time and now resembles, particularly in the third world where saint worship and veneration of bones is common practice, a belief system that is only marginally more monotheistic than Hinduism.

Nowadays, the only two major religions that one can say are even remotely monotheistic are Judaism and Islam. The Islamic notion of "tawheed" (unity of God) being a good example of a belief system that is genuinely monotheistic.

The actual question of whether Jesus is "alongside" God or whether he is God (and whether God is one being with three aspects or three independent aspects that combine like a divine Voltron) is literally the root of most of the nasty bustups of the first few centuries of Christianity. Those early bongpipe debate clubs really got out of hand.

In terms of veneration of saints etc; that's mostly because the early church deliberately went out of its way to absorb existing customs and beliefs. Many of the dates in the Christian calendar are pretty much stuff scribbled over the top of an existing pagan festival. Christmas pretty much replaces the Saturnalia, for instance.

>* This is polytheistic as it has assigned divinity to something/someone other than God alone.* //

It sounds like you're outside your comfort zone. Jesus is not other than God [the Father or God the Spirit] in orthodox [little-o] Christian belief. It's confusing for sure.

Catholicism includes the veneration of saints but they are categorically not gods, nor are relics gods, so how can the inclusion of such elements indicate polytheism.

Interesting that you mention Islam as one of the criticisms of Islam is that many supposed adherents appear to worship Mohammed as a god, certainly as much as Catholics "worship" the beatified. There is also the notion, warned against in the Quran IIRC, of worship of the djinn which could be considered analogous in some ways with veneration of the saints.

The orthodox belief you state that Jesus is the same as God is basically equivalent to the Hindu belief that their various gods are just different facets or aspects of God (with a capital G). If Christianity is monotheistic then, by this definition, so is Hinduism.

As for veneration of saints and relics, then anything that worshipped is a god and asking for blessings, intervention in worldly affairs, etc are all acts of worship. So when someone prays to a particular saint seeking something they are engaging a polytheistic act just as one who prays to an idol is engaging in polytheism.

I am not sure about Muslims worshipping Muhammad. Maybe in some polytheistic branches of Islam such as sufism and so forth which were themselves influenced by hindu/christian/etc ideas.

Some Hindu thought tends towards monotheism in considering the Brahman to be personal but that's certainly not true across the board. Personally I don't know enough hinduism, or hindus, to comment properly.

For those that don't consider the Brahman to be personal, and some that do, then within their philosophy [or practise] there are certainly distinct gods with distinct beings.

Not everything that is worshipped is a god. You can certainly worship something which is not divine - one of Jehovah's big beefs (!) with the early Hebrew tribes was their tendency to make things to worship.

When Catholics appeal to dead "Saints" (quite contradictory to NT use of saints to mean those who believe in Christ Jesus and so are saved) they ask for them to intercede before God for them. The thought is that the Saints are in heaven and so have the ear of God in a way that mortals do not - that is not deifying the Saints. It is not polytheism in practise or reality.

Poly + mono-terror: look to India

Isn't that what Battestar Galactica and especially Caprica detail? Not that they're a research or high-brow look at that question, but all the same.

I honestly don't know, I never watched BSG.

Was it set in early imperial Rome with particular reference to a fairly famous Jewish rabbi?

It takes a lot of cues from Mormon dogma, actually. http://en.wikipedia.org/wiki/Religious_and_mythological_refe...

The show's premise is an space-faring, industrialized, polytheistic society are surprised-attacked (and devastated, only a small band of humans survive) by Cylons, a sentient, monotheistic 'terrorist' group.

Ah, I see.

I think it's a different premise though. The novel is about an uncontested superpower dealing with asymmetric conflict.

BSG seems to be more of a classic symmetric war to me.

Caprica is more on the terrorist end of things where the BSG reboot is more of a normal war/in fighting/search and destroy premise.

Now that you mention it, it matches up exactly with Caprica's plotline!

I decided to look it up on Wikipedia. As best as I can make out they have basically nothing in common except the polytheist/monotheist division between characters.

wrt. the Adamas and the Greystones

What about electricity to use these things :) ? A schottky diode works on electricity...

"My main concern is powering the device, I still don’t know if that would work well enough." ;)

tldr: maybe, with a big if around powering it

You do not need powerful magnets to make a generator. You use whatever permanent magnet you have and put an electromagnet in parallel with it. When it starts turning, the output power from the permanent magnet can be fed to the electromagnet and the generator pulls itself up by its own bootstraps.

I think the bigger question is: could they want to?

Yes, but it wouldn't have been able to run Ruby ; )

(smile, it's funny)

This seems like a classic example of Betteridge's law of headlines...

Every time someone references Betteridge's 'law' of headlines, god kills a kitten.

Seriously, read the article. It's a tremendously interesting look at a hypothetical world in which the Romans decided to build a digital computer, and how they could've gone about it using the technology available to them. It doesn't need an answer.

Thank you.

The other projects on his page are also fascinating.

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