Forgot your password?
typodupeerror
Hardware Hacking Build Technology

Hydraulic Analog Computer From 1949 184

Posted by Soulskill
from the upper-decker dept.
mbone writes "In the New York Times, there is an interesting story about a hydraulic analog computer from 1949 used to model the feedback loops in the economy. According to the article, 'copies of the 'Moniac,' as it became known in the United States, were built and sold to Harvard, Cambridge, Oxford, Ford Motor Company and the Central Bank of Guatemala, among others.' There is a cool video of the computer in operation at Cambridge University. I remember that the Instrumentation Lab at MIT still had an analog computer in its computer center in the mid-1970s. Even then, it seemed archaic, and now this form of computation is largely forgotten. With 14 machines built, it must have been one of the more successful analog computers — a supercomputer of its day. Of course, you have to wonder if it could have been used to predict our current economic difficulties."
This discussion has been archived. No new comments can be posted.

Hydraulic Analog Computer From 1949

Comments Filter:
  • Explosives factories (Score:5, Informative)

    by flyingfsck (986395) on Wednesday June 03, 2009 @01:19PM (#28198067)
    Some explosives factories still use hydraulics, steam or vacuum for process control. Although it tends to be digital now, with valves used as flip-flops.
    • by Thanshin (1188877) on Wednesday June 03, 2009 @01:27PM (#28198201)

      Some explosives factories still use hydraulics, steam or vacuum for process control. Although it tends to be digital now, with valves used as flip-flops.

      Furthermore, the factory itself can be considered as a digital information storage system.

      The problem is returning to the current state after it flips to the other one.

    • by diodeus (96408) on Wednesday June 03, 2009 @01:31PM (#28198263) Journal

      In college I built a divide-by-eight counter in pneumatics. One reciprocating cylinder was the "clock" signal, the rest was a bunch of pneumatic shuttle valves. Problems arose because I kept needing to increase the air pressure to move some of the switches because they were spring-loaded. The air hoses started to pop off their fasteners so it took a lot longer to get the assembly working that I had anticipated (talk about blowing a circuit). It did manage to get me an exemption from the rest of the labs though.

      • Re: (Score:2, Funny)

        by BrokenHalo (565198)
        In college I built a divide-by-eight counter in pneumatics.

        It would be more impressive if you could build a divide-by-zero counter. :-D

        (Almost) seriously though, this contraption rocks! A few more gear-wheels and this just might make a perfect steampunk computer... ;-)
    • by mcrbids (148650) on Wednesday June 03, 2009 @04:09PM (#28200339) Journal

      Often, digital computing is clumsy, awkward, and overly precise.

      A good example of this is in Aviation. Pilots are still trained to use the E6B Flight computer [wikipedia.org] which is really a glorified slide rule.

      When you are estimating fuel consumption, and figure you'll probably use about 11.5 GPH for 3 1/3 hours, it's not important to know any more accuracy than perhaps to a gallon or so, since reality will always be a bit different than your calculations, anyway. You don't need to be exactly precise on your degrees of heading, and when you are computing weight & balance, it's stupid to calculate your moment to the 4th decimal place.

      Knowing how to use an E6B, you can get calculations in a second or two with a single hand that are "good enough" - and that's important when you're flying an airplane in turbulence while trying to stay on top of busy ATC calls in a heavily trafficked area. You can't even enter the first of 3 or 4 digits into a digital calculator in that time, and you'd have to use two hands. (Frequently, when flying, your hands are both occupied and you're steering with just your feet)

      Digital isn't always better.

      • by ArsonSmith (13997)

        My car I can do it with one finger. Pres the display button a couple of times while it cycles through my MPG, Miles to empty, and several other options. And I didn't even need any training on how to use the device, and was able to use fairly common knowledge to interpret the results. Might have been more difficult if I was in a metric country and never messed with Miles though.

    • Re: (Score:3, Informative)

      There is what could be described as a hydraulic computer that people use everyday;
      The automatic transmission [wikipedia.org]. Granted it has a fixed program but the early ones [wikipedia.org] did use nothing but transmission fluid.
  • by MSTCrow5429 (642744) on Wednesday June 03, 2009 @01:22PM (#28198117)
    There is a serious flaw in thinking that computers can accurately model macroeconomics, or predict systematic collapses, any better than commonsense and basic logic can. It is a given that if you massively inflate the monetary supply, you will create a false sense of wealth and a false understanding of risk, and people will malinvest in sectors that they otherwise would have spent far less resources on, or none at all. This is an unsustainable artificially created bubble, and all bubbles burst. Many people saw this coming years, even decades ago, and didn't have supercomputers. People understood this scenario centuries ago, before computers even existed. Using computers as a crutch to make up for a lack of understanding of basic economics is an aggravating factor in the current scenario, not the solution.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      "What the hell can go wrong with lending $500,000 for a house to someone who's salary is only $20,000 per year?" - Brainless Banks

    • by caffeinemessiah (918089) on Wednesday June 03, 2009 @01:47PM (#28198511) Journal

      There is a serious flaw in thinking that computers can accurately model macroeconomics, or predict systematic collapses, any better than commonsense and basic logic can

      It might not be an accurate descriptive model (one that describes reality), but discriminative models are very useful -- not to predict systematic collapses, but to discriminate irrational behavior. Computers step in when your response time has to beat efficient markets. You could be a common sense and logic genius, but you can only apply those rules and react in so much time, and computers will always beat you for speed at applying your own rules. So it's a different kind of crutch, and just like a crutch, it can help you walk better, not walk for you.

      I might have digressed from TFA, but this is /.

    • Re: (Score:3, Funny)

      There is a serious flaw in thinking that computers can accurately model macroeconomics, or predict systematic collapses, any better than commonsense and basic logic can. It is a given that if you massively inflate the monetary supply, you will create a false sense of wealth and a false understanding of risk, and people will malinvest in sectors that they otherwise would have spent far less resources on, or none at all. This is an unsustainable artificially created bubble, and all bubbles burst. Many people saw this coming years, even decades ago, and didn't have supercomputers. People understood this scenario centuries ago, before computers even existed. Using computers as a crutch to make up for a lack of understanding of basic economics is an aggravating factor in the current scenario, not the solution.

      Yeah, but if I can program a fly on the wall to recognize speech on the NYSE trading floor, and whenever it hears the words "The payoff is greater than the risk. Even the big guys are doing it like crazy. What's the worst that could happen?" then it sets off an alarm and shoots every Fortune 1000 controller in the face with a lethal stream of sulphuric acid... not only could I predict these things over a year before they happen, but after the two or three are predicted, I'm sure it would be at least 20 ye

    • by vertinox (846076) on Wednesday June 03, 2009 @01:50PM (#28198563)

      There is a serious flaw in thinking that computers can accurately model macroeconomics, or predict systematic collapses, any better than commonsense and basic logic can.

      Are you saying that human irrationality is defined by something other than the laws of physics, genetics, and chemistry?

      If we are to believe that the universe does have a set of laws applied to it, then by understanding those rules can lead to models that will predict otherwise seemly irrational universe.

      You just have to have the right model and a computer powerful enough to compute all the date required to get something use.

      And you have to sometimes build something as big as the LHC [wikipedia.org] to figure what model you should use.

      To assume that this cannot assumes that universe does not have rational rules and is ruled by something else like a supernatural force.

      Like you know... Like a Flying Spaghetti Monster?

      • by Trepidity (597) <.delirium-slashdot. .at. .hackish.org.> on Wednesday June 03, 2009 @01:57PM (#28198655)

        I think it's not so much that it can't in theory be modeled, as that in practice it's extremely hard---much harder than modeling the weather, which we can barely do accurately out to 5 days. There's somewhat of a gap in expectations when you go from high-level qualitative descriptions of phenomena, like hurricane experts discussing trends in intensity and formation basins, to an implemented, detailed computational model that purports to simulate what "really" happens. The 2nd one usually diverges extremely quickly from what actually does happen, because these sorts of nonlinear systems are very sensitive to slight errors in the model or its initial conditions.

        That's fine, as long as people understand its use and limitations; but there's a tendency, especially among the only-sort-of-technical folks who are involved in a lot of areas of business and economic policy, to trust these computer models as more than they are, as if the fact that a "computer simulation" told you it makes it some sort of neutral third-party truth that represents the state-of-the-art in guessing what will happen.

        • by JesseMcDonald (536341) on Wednesday June 03, 2009 @02:52PM (#28199307) Homepage

          It's worse than that, actually. Weather prediction is at least based on physical processes, which, allowing for some minor concessions to quantum mechanics, are based on fundamental particles which follow deterministic rules. Given all the initial conditions and sufficient computing power you could accurately simulate what the weather will be at any point in the future. Moreover, you can use simulations to predict how that future weather will change in response to deliberate artificial influences; weather doesn't have goals of its own, and won't actively resist attempts to control it.

          Economics isn't like that. The "fundamental particle" of economics is people, and people are adaptive. Under many conditions is it possible to predict how they will behave--assuming rational self-interest (i.e. sanity) and decent psychological models of their personal value scales--but all that breaks down when someone attempts to use the models to control the outcome. At that point you have a competition between the people being studied, who seek to achieve their original goals and thwart any attempt at outside control, and those seeking to do the controlling. As with any long-running competition between creative individuals, the outcome is impossible to predict with any degree of accuracy.

          • by Trepidity (597)

            Yeah, that's true; and an addition complication for anything long-term is the lack of any significant amount of data. With the weather, you can try to build, say, hurricane models by feeding data about hundreds of hurricanes, and thousands of other "negative" examples of weather patterns from which hurricanes didn't form. Then prediction models can try to find regularities among those data sets.

            With economies we just don't have that much data. If you want to predict a major recession and recovery, for examp

          • by vertinox (846076)

            Economics isn't like that. The "fundamental particle" of economics is people, and people are adaptive. Under many conditions is it possible to predict how they will behave--assuming rational self-interest (i.e. sanity) and decent psychological models of their personal value scales--but all that breaks down when someone attempts to use the models to control the outcome.

            I see what you are saying, but you haves to realize humans are irrational, not random.

            And that irrationality can sometimes be easily predicte

            • Re: (Score:3, Insightful)

              by JesseMcDonald (536341)

              I never said humans were random. I also wasn't assuming that humans always pick their goals rationally. "Rational self-interest" doesn't mean that humans are completely rational, but rather that given subjective (and possibly irrational) goals, and a possibly inaccurate and certainly incomplete subset of the relevant knowledge, humans will tend to act in ways which appear likely to them to bring them closer to their goals. Anything else would be, as I said, the essence of insanity.

              I acknowledge that crowd b

          • by Artifakt (700173)

            Weather prediction is hard because of extreme variability in initial conditions, and the math which covers such states is called Chaos Theory. Those conditions are not down on the quantum level, and there is no particular reason to make a concession to Quantum Mechanics for weather besides the fact that QM underlies all sorts of macroworld processes.* The scale of a single initial condition for weather could be, for example, a rising moisture laden hot air zone filling a many cubic meter volume over a large

            • I am fully aware that QM is not the main reason that weather prediction is so difficult. I mentioned it only because it introduces a qualitative barrier--without QM it would be possible to predict future weather with 100% certainty, given all the initial conditions; with QM the best you can do is calculate the probability of each possible future.

              Going back to economics, I can see the benefits of using value transactions as fundamental, although I think "people" might be less jargon-laden and thus more under

        • there's a tendency, especially among the only-sort-of-technical folks who are involved in a lot of areas of business and economic policy, to trust these computer models as more than they are, as if the fact that a "computer simulation" told you it makes it some sort of neutral third-party truth

          And to be fair, a great deal of that tendency comes from technical folks who almost never provide the appropriate disclaimers with their predictions and who often represent their simulations as being of a higher accur

      • by OwnedByTwoCats (124103) on Wednesday June 03, 2009 @02:02PM (#28198717)

        There are some fundamental limits to what models can predict. If a model demonstrates extreme sensitivity to initial conditions, then any deviation between actual and measured initial conditions will cause the output of the model to deviate from actual at an exponential rate.

      • by TheRaven64 (641858) on Wednesday June 03, 2009 @02:05PM (#28198751) Journal
        Modelling the economy is more difficult than most other modelling tasks because everyone is trying to do it. Every single actor in the system has their own model, of varying quality, which governs how they interact with it. When you build a better model of the economy, you have an advantage over the other players and so can make more money, which alters the economy. An accurate model which no one acts on is possible, but an accurate and useful model needs to be sufficiently complex to model itself and all of the other players. Or, to put it another way, needs to be more complex than itself. That's not to say that you can't build a partially-accurate and still useful model, of course.
        • by wjwlsn (94460) on Wednesday June 03, 2009 @02:21PM (#28198923) Journal

          Your post reminds me of a quote from Gordon Box that I often relate to new trainees: "All models are wrong, but some are useful."

          I don't think this modeling difficulty is unique to economics. (You didn't state or imply that it was... I just wanted an excuse to quote Gordon Box.)

          I like your characterization of the problem though. It applies to pretty much any complex system.

      • Re: (Score:3, Interesting)

        by petermgreen (876956)

        If we are to believe that the universe does have a set of laws applied to it, then by understanding those rules can lead to models that will predict otherwise seemly irrational universe.
        It is not feasible to make a perfect simulation of the universe since that it would require a computer more complex than the universe (and therefore unable to exist in our universe) to run and require information that the heisenberg uncertainty principle makes impossible to obtain as an initial state. Even if we could we wou

      • Re: (Score:2, Insightful)

        by Q-Cat5 (664698)
        There's a difference between mapping rules in a general fashion, and applying them to actual situations. Invariably, reality always has elements that differ from the model, and thereby make it inaccurate. This is why reductionism doesn't generally map back accurately to the big picture. Understanding a component is different from understanding how the component integrates into the whole, and how other components within the whole interact with, and alter, the component.

        Human behavior is very nearly impo
    • by fiannaFailMan (702447) on Wednesday June 03, 2009 @01:55PM (#28198619) Journal

      Spot on. I saw this mechanical computer on TV years ago, they were talking about how it was a noble attempt to model the economy but it's just too complicated an organism to be modelled by any means, to say nothing of a mechanical device. Sometimes the economy reacts differently when you poke it the same way depending on a myriad of other factors.

      Another example is traffic. Some people assume that traffic can be modelled like water in pipes. "Road is congested? Make it wider and the congestion will ease." What they don't realise is that motorists are more intelligent than water particles. They can be aware of a widening of the pipes/roads and choose to go into a system at a certain point at a certain time to take advantage of the widened road, with the net result of a road that's just as congested at 4 lanes wide as it was at 3 lanes wide. There's also the matter of being able to move one's home to a different location along the road to avoid congestion. Others follow suit, and the congestion is back to where it was. Want to model that using water in pipes? Good luck!

    • by fastest fascist (1086001) on Wednesday June 03, 2009 @01:59PM (#28198679)
      It doesn't take a computer to predict what happens. You get a boom, people spend money, they overspend, you get a crash. Repeat. The details vary, but the basic pattern seems pretty clear.
    • by Fungii (153063)

      I don't see how anything you've said implies that computers can't model macroeconomics. The kind unstable behaviour you're describing certainly limits the accuracy, but instabilities can definitely be predicted too. It's not as futile as you seem to be making out.

      And another thing - people's sense of wealth and understanding of risk isn't something that should need to be modeled, those two things would be something that you would infer from the results/state.

    • Re: (Score:3, Insightful)

      by Tokolosh (1256448)

      All you need is the Micawber Principle:

      "Annual income twenty pounds, annual expenditure nineteen pounds nineteen and six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery."

      From David Copperfield, by Charles Dickens

    • What I think is interesting about the hydraulic Phillips computer though is that its workings are straightforward enough to act as an aid to common sense and basic logic. An issue with using modern digital computers in economic models is that it becomes very difficult to just follow the money around. You don't get the notion that you're looking at an unsustainable bubble, because the inputs and outputs in your model are obscured by mathematical abstraction. In particular, it becomes easy to lose sight of
  • by OolimPhon (1120895) on Wednesday June 03, 2009 @01:24PM (#28198151)

    It might have been more successful if they had used beer instead of water...

  • by thewiz (24994) on Wednesday June 03, 2009 @01:25PM (#28198165)

    Wow! Great article about it in Wikipedia. Loved the picture that showed the two faucets on the side.

    • Re: (Score:3, Insightful)

      by langelgjm (860756)
      Yeah, the WP article is much more informative than the video. The guy in the video spends the first minute kind of standing there saying "now what I'm going to do..." without actually doing anything. The next two and half minutes aren't much better.
      • Re: (Score:3, Insightful)

        by adolf (21054)

        And then the video just sort of ends, without the computer having, um, computed anything. The whole thing is about as entertaining and instructive as watching the skimmer on my swimming pool (except the skimmer might actually be more interesting).

        Does anyone have a better (or simply more-complete) moving-pictures demonstration of this remarkable machine?

  • by Red Flayer (890720) on Wednesday June 03, 2009 @01:26PM (#28198181) Journal
    Dammit. Couldn't resist.

    Of course, you have to wonder if it could have been used to predict our current economic difficulties.

    No, you don't have to wonder that. The current economic difficulties were easily predicted by many.

    The problem was that the people with any kind of ability to stop the conditions that led to the current situation were those who profited most from those conditions. Not a good recipe for prevention.

    • by rgviza (1303161)

      The problem was that the people with any kind of ability to stop the conditions that led to the current situation were those who profited most from those conditions. Not a good recipe for prevention.

      Even those people, in reality, had no ability to stop it.

      In fact, I know a mortgage broker that had his own company. He wouldn't lend to people that didn't have a job, source of income, or the independent wealth to cover the loan. He refused to get caught up in the "loan money to anyone that has a pulse" frenzy and required proof beyond stated income (like paystubs and W2's) to show that you could make the payments. They started a class action suit alleging discrimination and the legal costs bankrupted him.

      • Sorry, I wasn't referring to the mortgage brokers. The stood to gain some, but the people who stood to gain the most were the people dealing in securitized mortgage derivatives. These are the people with the $50 mil bonuses. As long as they weren't left holding the bag when it came tumbling down (and they weren't -- their employers were), then their best choice was to keep the cash flowing.

        As for your friend, there's more there than meets the eye, and definitely more than what you stated.. Almost all l
  • What are the underlying economic premises of this machine? I cannot discern this from its diagram or descriptions, but it just looks wrong to me.
    • by MrMr (219533)
      The machine is based on the principle that you cannot create an infinite amount of water from nowhere.
      Any modern banker will be able to explain you that that assumption is incorrect in the case of money.
  • by bareman (60518) on Wednesday June 03, 2009 @01:30PM (#28198247) Homepage Journal

    I just finished with Terry Pratchett's "Making Money". I think I'm having a flashback now.

  • by shadowofwind (1209890) on Wednesday June 03, 2009 @01:35PM (#28198321)

    If lots of people are extracting money from the system and not contributing real wealth, then there will be problems. Money has complicated dynamics, but its not magic. People who make a living shuffling numbers around in spreadsheets are providing a useful service that makes the system more efficient. But only up to a point. Few people believe greed is a vice anymore, hence certain results follow.

  • by Maximum Prophet (716608) on Wednesday June 03, 2009 @01:35PM (#28198323)
    Hydraulic computers are used in some military aircraft because they are very reliable and can withstand EMP.
  • That's pretty slick considering the times ... Hydro-functional programming :)
  • Memory Leak (Score:5, Funny)

    by SubjectiveObjection (1541619) on Wednesday June 03, 2009 @01:42PM (#28198415)
    "Johnny, there's another damn memory leak! Bring the bucket!"
  • by modmans2ndcoming (929661) on Wednesday June 03, 2009 @01:44PM (#28198459)

    Probably not, but Byron Dorgon Predicted this trouble in 1995 when teh derivatives markets starte to get noticed and again in 1998 when the "securities modernization act" was passed, deregulating the banks, insurance companies and investments firms.

  • by sootman (158191) on Wednesday June 03, 2009 @01:45PM (#28198463) Homepage Journal

    ... the Internet truly would be a series of tubes.

    Also, little known fact: Gordon Moore's father was a mechanical engineer who predicted that the size of hydraulic valves would shrink 50% every 18 months.

  • by OrangeTide (124937) on Wednesday June 03, 2009 @01:47PM (#28198519) Homepage Journal

    In class I built a half-adder and a full-adder and could do 2 bit addition with it. subtraction too if I interpret input and output as 2s complement numbers. I ran out of parts in my kit to make it bigger. but with enough parts you could do pretty much anything, as long as you don't mind the slowness and noise and possibly a tremendous amount of power.

    hydraulics have the advantage that you can apply a great deal of force through them precisely. which is useful when you have many layers of "logic gates" that you have to drive by pushing a fluid through some tubes. with pneumatics I could have quickly ran into an issue if I made a ripple counter for example where the amount of pressure necessary to switch the furthest most element might exceed the abilities of my pump.

    • In pneumatics you can use "pilot valves" to amplify your digital signals back up to full strength. I needed some fairly strong pneumatic (signals) to switch fairly quickly, the only valves on the market that would do it used pilots.
    • This should be a solved problem. I don't know the terminology or component in pneumatics or hydraulics. In electronics, you add an inverter or a buffer, to use a weaker signal to control larger currents. You don't power following transistors using the output of a previous transistor, each one is connected to the power rails and are controlled by input.

  • I recall reading , many years ago in a magazine like popular science, that the air force was exploring analog computers for use in fighter jets; the rationale was that analog computers would be resistant to the electromagnetic pulse (emp) emitted by a nuclear blast; jets with analog computers could keep flying...

  • by thethibs (882667) on Wednesday June 03, 2009 @01:53PM (#28198597) Homepage
    Which gave rise to one of the oldest computer jokes: "If it doesn't work, piss on it."
  • by DrugCheese (266151) on Wednesday June 03, 2009 @01:56PM (#28198635)

    This was water cooled before water cooling was cool

  • Not quite (Score:5, Informative)

    by DerekLyons (302214) <`fairwater' `at' `gmail.com'> on Wednesday June 03, 2009 @02:03PM (#28198739) Homepage

    With 14 machines built, it must have been one of the more successful analog computers

     
    In the early 80's the USN had over 30 analog computers driving various submarine simulators. Heck, each of the original '41 SSBN's had an analog computer driving the hovering system. Then there was the 100+ analog installations of the CONALOG system.
     
    Etc... Etc...

    • Every B29 built during WWII had four analog fire control computers. US WWII subs used analog computers to generate torpedo firing solutions. Surface ships used them to direct their guns.

      • US WWII subs used analog computers to generate torpedo firing solutions

        Yep - and the analog descendants of those didn't start to be replaced with all digital systems until the 1970's. The last of those descendants didn't leave service until Kamehameha and her MK113 were decommissioned in 2002.

      • Re: (Score:3, Informative)

        by Nimey (114278)

        Also the famous Norden Bombsight, the most accurate in the world at the time, was an analog computer.

  • That's pretty cool, and a little steampunk. Is it just me, or was that thing wheezin' like an iron lung in the video?
  • EAI sold more than 500 of their 1952 16-231R model alone.

    • by S-100 (1295224)
      Heathkit sold two different analog computers: the EC-1 and H-1. They were sold for educational purposes rather than any practical application, but I'd suspect that they out-sold any other analog computers (with the possible exception of military applications of analog computers in artillery or bomb sights).
  • Yep (Score:4, Funny)

    by madnis (1300099) on Wednesday June 03, 2009 @02:11PM (#28198807)
    Shows that our economy is down the drain.
  • was all that was necessary to predict our current economic crisis.

  • Water flows through a series of clear pipes

    If only this article came out a few years earlier, maybe we wouldn't have given him so much crap!

  • But given its speed, the result would have been available by 2012.

  • Adding a little bit of dye to the water would make that thing a lot easier to read! (probably just a shortcoming of the demo video)
  • by Nom du Keyboard (633989) on Wednesday June 03, 2009 @03:12PM (#28199559)
    What about The Great Brass Brain? An analogue computer for computing tide tables that when replaced by a CDC 6600 super (for its time) computer, the 6600 couldn't perform all of the tricks (i.e. pause at each low/high tide moment or produce a continuous) graph of the machine it replaced? There's some great, mostly lost, history out there.
  • by nedlohs (1335013) on Wednesday June 03, 2009 @03:14PM (#28199581)

    Could predict todays our current economic difficulties and spend 18 minutes playing with the abacus.

  • Answer the question Zero, tell Jonathan about the Corporate Wars.
    *blub blub blub 13th Century blub blub*
  • Modern Replacement (Score:3, Insightful)

    by Nom du Keyboard (633989) on Wednesday June 03, 2009 @03:38PM (#28199875)
    Seems to me that this could be replaced today with an Excel spreadsheet - and no I'm not being facetious.
  • I Once Had a Toy... (Score:5, Interesting)

    by Nom du Keyboard (633989) on Wednesday June 03, 2009 @03:46PM (#28199985)
    I once had a wonderful, yet frustrating, toy whose name I can't remember any longer that was kind of a hydraulic Erector Set. It came with battery-powered pumps, clear plastic tubing, splitting/combining Y and T connectors, valves, tanks, items that filled and then tipped out, a board and supports to arrange everything, and even coloring tablets (messy) to allow blending different streams -- just add water. The frustration came from the poor level of construction that resulted in it not being all that durable and the pumps not seeming to work as long or as well as I felt they should. And when you used it you pretty much ended up with water, and staining colors when you added them, in a mess all around. Even so it was one of the great fun toys (along with Lincoln Logs, Tinker Toys, Erector Sets, and Flexigons) that I would happily play with now if I could find them again. No, we weren't a Leggo family.
  • When I first got into computing during the 70s, there were still a lot of analog computers around. Solid-state circuitry was just getting cheap enough to eliminate their advantage for specialized computing. Never worked with them, but UCSC, where I transferred in 1974, had just recently removed one that the Social Sciences division had been using for statistical work. Somebody told me it had a gigantic lense. No idea why.

  • That you program it using the Waterfall Model.

  • obvious... (Score:4, Funny)

    by FalloP (1375137) on Wednesday June 03, 2009 @04:04PM (#28200273)
    now i truly understand a buffer overflow, and the implications of a memory leak are clear.
  • biennale (Score:4, Funny)

    by spud603 (832173) on Wednesday June 03, 2009 @04:06PM (#28200309)
    I saw one of these in operation at the Venice Biennale in 2003. It was really remarkable to watch, but then I was thinking of it as more of an art project pointing out the absurd nature of economic forecasting than a serious research tool.
  • by kimvette (919543) on Wednesday June 03, 2009 @04:08PM (#28200321) Homepage Journal

    If these did run teh internetz, then the Internet really WOULD be a series of tubes! :D

  • Cool video (Score:3, Interesting)

    by YourExperiment (1081089) on Wednesday June 03, 2009 @05:01PM (#28201171)

    There is a cool video of the computer in operation at Cambridge University.

    No, there really isn't. The video consists of 3 minutes and 38 seconds of a guy explaining how he's not an economist and doesn't really understand this stuff, and clearing his throat an awful lot. Meanwhile, he proceeds to explain how he's shut off or removed most of the parts of the machine, and intends to only demonstrate a little bit of it. Just as he's about to begin the demonstration, the video ends.

  • by l0b0 (803611)
    The Glooper [lspace.org]!
  • Fluidic Systems (Score:3, Insightful)

    by TheSync (5291) on Wednesday June 03, 2009 @05:23PM (#28201545) Journal

    I'm a fan of Fluidics [wikipedia.org], which can create analog or digital devices based on fluid flow.

    See this powerpoint [mit.edu] for a great history of fluidics.

  • by lennier (44736) on Wednesday June 03, 2009 @06:48PM (#28202947) Homepage

    Featuring an Economic Model inspired by MONIAC:

    http://sydneypadua.com/2dgoggles/lovelace-and-babbage-vs-the-economy/ [sydneypadua.com]

  • by dido (9125) <dido@@@imperium...ph> on Wednesday June 03, 2009 @07:42PM (#28203691)

    There's a whole series in the Crunchly cartoons by Guy L. Steele, such as this one [catb.org] where he buys a hydraulic computer of sorts...

Swap read error. You lose your mind.

Working...