Hydraulic Analog Computer From 1949

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."

Comments

Explosives factories

[flyingfsck]

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.

Re:Explosives factories

[Thanshin]

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.

Re:Explosives factories

[Jamamala]

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

Damn you entropy!

Re:Explosives factories

[Keruo]

Upgrade properly to what? Hydraulics is the most accurate way to control movement.
If your application needs force with direction and accuracy, then your only real choice is to use hydraulics.

Don't confuse modern hydraulic systems with something that just has few handvalves.
Almost every system we deliver these days comes equipped with computer controlled digital valves which you can use to control pressures at 0.01 scale from 0 to 500+ bar(depending on customer specs naturally), and can be integrated into factory networks seamlessly.

[disclaimer, I have bias on this subject since I work at one of the largest suppliers of hydraulic systems in the world]

Re:Explosives factories

[K. S. Kyosuke]

Don't be shy to say it, a factory is a 1-bit PROM. Perhaps one day, a socially challenged but otherwise very friendly hacker will try to become immortal by writing "HELLO WORLD" into such memory, but no one will understand him, as usual. :-(

Re:Explosives factories

[petermgreen]

Indeed, when it comes to anything safety crtical KISS is a good principle to follow as it will make it much easier to ensure safety.

Re:Explosives factories

[Prune]

BS. Piezo systems are immensely more accurate--they're used for atomic force microscopes, for example. Of course, the range of motion is very limited, but your claim was _unqualified_ -- you wrote "the most accurate way to control movement". Make outrageous claims--get shot down! You should have known better, considering you're not new around here.

Re:Explosives factories

[Anonymous Coward]

Not to be outdone, next week someone will invent a Java Hydraulic Framework and API.

Re:Explosives factories

[CyBlue]

The article is about using hydraulics as logic circuits to create a computer. I think you're talking about using computers to control hydraulics. From my understanding, his concept of upgrade is going from purely mechanical logic to the computer controlled valves you mention.

Re:Explosives factories

[Sen.NullProcPntr]

There is what could be described as a hydraulic computer that people use everyday;
The automatic transmission. Granted it has a fixed program but the early ones did use nothing but transmission fluid.

Re:Explosives factories

[Anonymous Coward]

1 12 IN UR 3xP1051v3 F4C70R135!

Re:Explosives factories

[Anonymous Coward]

I'm on a boat (I'm on a boat)
I'm on a boat (I'm on a boat) .... ....I got my swim trunks
And my flippie-floppies

Re:Explosives factories

[TapeCutter]

Good example. I was thinking of the Suez canal. It uses a "hydrolic computer" to prevent gates at distant locations from being opened in a dangerous combination. It's been working flawlessly for century now.

Re:Explosives factories

[mikiN]

n3wb> just got root at the tnt plant across the street
rlh8x0r> be careful
n3wb> wonder what this cmd does: pull plug 0
rlh8x0r> NO DON'T!!
 
...KABOOM!!...

Computers can't model macroeconomics

[MSTCrow5429]

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:Computers can't model macroeconomics

[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

Re:Computers can't model macroeconomics

[caffeinemessiah]

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:Computers can't model macroeconomics

[CorporateSuit]

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 years before anything like this happens again... in the NYSE.

Re:Computers can't model macroeconomics

[vertinox]

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 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?

Re:Computers can't model macroeconomics

[fiannaFailMan]

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!

Re:Computers can't model macroeconomics

[Trepidity]

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.

Re:Computers can't model macroeconomics

[fastest fascist]

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.

Re:Computers can't model macroeconomics

[OwnedByTwoCats]

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.

Re:Computers can't model macroeconomics

[TheRaven64]

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.

Re:Computers can't model macroeconomics

[Anonymous Coward]

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.

Also, 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:Computers can't model macroeconomics

[Fungii]

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:Computers can't model macroeconomics

[Anonymous Coward]

I don't know, I'd venture a guess that that machine could do a better job setting interest rates then the fed has.

Re:Computers can't model macroeconomics

[wjwlsn]

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:Computers can't model macroeconomics

[Tokolosh]

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

Re:Computers can't model macroeconomics

[Anonymous Coward]

You are right.
People will not understand that this hidraulic system does not models the Federal Reserve nor the fractionary reserve system, among other very important things.

Re:Computers can't model macroeconomics

[maxume]

"The U.S. government pays its debts" is a model. I wonder if it will stay accurate.

Re:Computers can't model macroeconomics

[zindorsky]

What they don't realise is that motorists are more intelligent than water particles.

Says you.

Re:Computers can't model macroeconomics

[petermgreen]

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 would have to deal with quantum effects which as far as we can tell so far seem to be random.

So instead of a perfect simulation we have to settle for models based on approximations of reality and imperfect initial conditions. Combine error buildup from the approximations in the model with a chaotic system and you will find that beyond a certain distance out it is not possible to make meaningfull predictions

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

Re:Computers can't model macroeconomics

[JesseMcDonald]

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.

Re:Computers can't model macroeconomics

[Trepidity]

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 example, we have good data on, something like 4 or 5 of them--- and they happen in totally different eras, among radically different social and governmental backdrops, and are of different kinds. It'd be roughly like trying to build hurricane-prediction models with a sample of one Gulf hurricane, one east-coast Atlantic hurricane, one Hawaiian hurricane, and two southeast Asian hurricanes--- all from different decades and of very different magnitudes. With a data set like that, your hurricane model would not be good; and our recession-prediction models aren't, either.

Re:Computers can't model macroeconomics

[Anonymous Coward]

But it does take a computer to figure out where you are in the cycle, and where to invest given where you are in the cycle. That is, if your goal is to make money. Alternatively, a large government might be able to figure out how it can act to turn the wild roller coaster ride, into a Sunday drive.

Re:Computers can't model macroeconomics

[Prune]

From my point of view, grandparent was a troll. Browsing through his history, he's clearly one of the well-known types of people that disparage the utility of computers in scientific endeavours for anything more than basic calculation. I know a few examples in real life, such as a microbiologist who thinks that any computer-based "encroachment" into his field, from simulation to DNA microassays, is the sheerest garbage (to borrow the infamous phrase uttered by a skeptic in the early days of application of group theory to physics).

Re:Computers can't model macroeconomics

[CanadaIsCold]

Computers are never a solution to lack of knowledge although they can help us manage larger datasets in an efficient way. What it comes down to is the current state of economic theory is not sufficient to model macroeconomics. Some day these theoretical models may improve in which case computers are a great tool for managing what will be a large and complex dataset. To in any way suggest that the current macroeconomic models are anything other than predictive is a lie. So basically it's a choice of where to spend your research money and we should be spending on Economics if we want the model to improve not Comp Sci. Although I think there is plenty of Comp Sci work left to be done, which can be a benefit to multiple disciplines rather than an individual one.

Re:Computers can't model macroeconomics

[gilroy]

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.

Also, when you treat traffic as a compressible fluid, you get 20-car pile-ups, because cars aren't compressible... or at least, they're not uncompressible afterwards...

Re:Computers can't model macroeconomics

[DerekLyons]

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 accuracy than warranted.

Re:Computers can't model macroeconomics

[reverseengineer]

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 the interconnections among companies or economic sectors.

A hydraulic system however has the advantage that a tangible working fluid connects all the areas in your economic model. The idea of "Too Interconnected to Fail" really stands out in a physical model versus a computer program. Say you're AIG. It's one thing to create a model that calculates how much collateral you would have deposit with counterparties in credit default swaps should your credit rating fall. It's another to have the executives stand there and watch as a reservoir full of water that represents your company's cash on hand is sucked dry and the pumps continue to grind in demand for more water. However, in both cases, you still have to be able to admit the possibility that your credit rating even could fall.

"An engineer uses statistics like a drunk uses a lamppost- more for support than for illumination." I think that applies just as well to economists and financiers.

Re:Computers can't model macroeconomics

[vertinox]

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 predicted on the macro level when you are looking at crowd behavior.

And no one has a true random number generator involved in making decision processes in their daily lives. Well if you do, then you are pretty cool.

Re:Computers can't model macroeconomics

[JesseMcDonald]

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 behavior can be more predictable than individual behavior. I think you'll find, however, that even crowds are difficult to control deterministically over the long term, in part due to the ways in which individual contributors can influence the result entirely out of proportion to their apparent power and in part due to the effects of creative adaptation, which grow more pronounced over time. The system is far from random, but it is chaotic.

Re:Computers can't model macroeconomics

[Artifakt]

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 asphalt parking lot, and not just the metaphorical butterfly in Brazil. Essentially, if we based a weather prediction on sensors scattered a mile apart in a 3-D grid covering the whole planet, there are still macro-scale conditions less than a mile across that will significantly affect the outcome within a fey days. Even if we got down to where that hypothetical sensor grid was on the scale of 10 meters, there are smaller conditions which could have such consequences, and we would gain only a few days accuracy.

* If you would include minor QM effects in Shipbuilding or Dentistry, then by all means include them in Weather.

Economics is harder, for the reason you've given. To restate it, there are many more positive AND negative feedback loops in economics, and, for your fundamental particle, the same entities can act in a bewildering variety of modes.
        Though I don't know if I would characterize the 'fundamental particle' as people in all cases. For some economic math, the fundamental particle is better described as each individual value transaction. That model is attractive because it lets economists see a given sale as multiple transactions (for example, when a person buys a pack of gum, and the clerk also collects sales tax, that's at least two transactions. A given payment to an employee can include state and federal income taxes, health insurance premiums, a retirement contribution, and Social Security and Medicare withholding - that's six transactions, and I'm sure some cases involve more).

Re:Computers can't model macroeconomics

[Q-Cat5]

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 impossible to accurately model at the individual level. You hear "I never would have expected him to do that" when people speak about their next door neighbors who go on homicidal rampages. Husbands or wives are shocked when the spouse that they've lived with for years or decades has an affair, buys a sports car, or has a second cup of coffee after dinner. Even crowd dynamics can be altered by incredibly subtle, and unpredictable, circumstances. (Someone in a crowded line says "He's got hairy wrists", someone else hears "He's a terrorist", and soon 8 are trampled to death in the ensuing panic.)

Then, add people deliberately gaming the system into the equation. (i.e. someone else wants to steer the crowd in a different direction than your model would normally predict, perhaps even using your model to predict the best way to disrupt it.)

Raw computing power just can't compensate for all the variables. At some point of hyper-precision, they become recursive anyway, and Gödel gets to have posthumous a laugh at your expense.

Re:Computers can't model macroeconomics

[Q-Cat5]

Absolute accuracy would require this, you're right. To accurately map the whole universe, you'd need a 1:1 scale model, accurate to the Planck length, which somehow knows both the velocity AND position of everything despite Heisenberg. Good luck getting the "snapshot" to set the baseline. Better luck preventing your "measurement" of the universe in the initial snapshot from altering it by observation a la Schrödinger. And of course, best of luck finding somewhere to put it. =)

Re:Computers can't model macroeconomics

[Anonymous Coward]

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

Good luck with that.

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

I am an atheist, and I don't agree there has to be a supernatural explanation without rational rules. It's not a case of being one or the other.

Not being rational isn't "irrational", just random. To assume everything measurable interacts only in time-space is narrow minded. Without time everything happens at once, without space everything overlaps. Taking time or space out of the picture, gives and explanation for where randomness comes from. If there's any truth to that, then the universe is not rational because then there's always a part to everything that can't be perceived.

Re:Computers can't model macroeconomics

[JesseMcDonald]

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 understandable outside of technical discourse. I might even take it one step further, and assert that the fundamental unit is actually choices--but then we're talking about praxeology (the study of human action), which some would say is a superset of economics. I'm more inclined to see the two as equivalent, but my view of economics is more all-inclusive than most.

Re:Computers can't model macroeconomics

[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

Forget the customer's credit scores, what is the bank's credit score?

Re:Computers can't model macroeconomics

[ctmurray]

Although if you looked at the video - they had flow controlled by response to other flows in the system. For example the video goes over the roll of interest rates and how the water flow rate is affected by a non-linear response. It appears in the video that these responses are replaceable - you can choose a response with any shape. So you can try out model scenarios. In your example above you could create something like this computer - with flow on the road (congestion) that responds to stimuli - like more people using the road if you widen the road. Instead of modeling in a computer the flow of water they should have made a hydraulic computer. As an aside I heard some of the nuclear physicist that were lacking something to do when we stopped making nukes, got a grant and used their modeling skills on congestion. To test their models they would go out in cars and create traffic jams by following some of the model parameters. So who knows - many /.ers may have been test subjects for congestion model verification.

Re:Computers can't model macroeconomics

[MSTCrow5429]

This is inaccurate. I disagree with the chronic and consistent misuse of computer modeling, such as within economics or climate modeling, where the variables are assumed to exist without any rational basis, empirical history is disregarded as being a nuisance to the desired results, and past mistakes in the model are ignored or covered up. I have no problems with computer modeling in designing, say, a car, airplane, or bridge.

Re:Computers can't model macroeconomics

[smallfries]

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.

Why? The rest of your post explains why it was obvious the bubble would burst. But while common sense could tell us that it definitely would burst, it was not so good with the question of when. Many commentators confidently predicted the end of the bubble for years while the economy surged higher on a diet of credit and fairy gold.

So why do you think that we can't derive models more accurate at prediction than common sense?

Re:Computers can't model macroeconomics

[kinnell]

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.

Models are by their nature simplifications of a real system. The point is that some problems can't be simplified because there are no variables which are trivial enough that you can remove them and still get reasonably accurate results. While you may in theory be able to accurately predict a stock price, for example, by modelling every neuron in every brain of every stockbroker in the world, what would be the point? If the model ends up taking longer to run than the system it's modelling, there is no point in having a model.

Re:Computers can't model macroeconomics

[Anonymous Coward]

There is a difference between modeling to accurately predict something and in modeling to understand the underlying structure and thus the likely behavior of the system under certain conditions. Because the economy is subject to a large amount of "noise", it is next to impossible to make accurate numerical predictions of what a variable, such as GDP, is going to be at a certain point in time. This is why we can not predict when trends in the economy change. Most predictive models use statistically derived linear models that only offer some accuracy in predicting variations around the current trend. This is fine as long as the trend does not change. However, when the dominant structure of the system changes, those models become next to useless. This is why we could not predict when the current financial crisis was going to occur. What was possible though, is to predict that it would occur at some future point in time. There are models that are able to do this, also for macroeconomics. Phenomena such as the long wave, a sixty year cycle in the economy, was understood using computer simulation System Dynamics (SD) models. SD uses the feedback principle, just the same as the computer featured in the article, except of course that it is now digital. A Russian economist, Kondriatev, discovered discovered the long wave using historical data in the 1930s, however, understanding it took computer simulation. The simulation can predict cycles and that there will be changes, but not exactly when. Interested slashdoters may take a look at Business Dynamics, written by John Sterman and published by Irwin McGraw-Hill.

Modeling to predict a specific numerical value of a variable at a specific point in time, is pointless. What must be done is to understand the structure of the system that causes major changes in trends, for example business cycles, to occurr. When we understand the structure that causes the problem, we can change the structure. Eliminating the need to point predict specific variables.

Now, why are we not able to fix the problems in the economy given that we have modeling methodologies that are capable? In my mind there are two answers: 1) Most decisionmakers, if they use models at all, rely upon inadequate linear statistical models. They are easier to understand as they are usually equilibrium based, and can therefore be simplified to a point where an analytical solution is possible. It is common practice to "fudge factor" these models to make them fit the data. Fudge factoring is the addition of extra variables or scalars not present in the real system, simply to make the model conform to expectations. 2) The decisionmakers do not understand the models they are using and thus does not believe in them. Even if they were using a truly useful model, their lack of trust in it means that they would disregard its advice.

Re:Computers can't model macroeconomics

[DragonWriter]

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.

Well, duh.

Because computers simply implement basic logic, rigorously; they can't do anything basic logic can't do.

OTOH, "common sense" is mostly just what people use to describe their own unexamined prejudices.

Re:Computers can't model macroeconomics

[caffeinemessiah]

where the variables are assumed to exist without any rational basis, empirical history is disregarded as being a nuisance to the desired results, and past mistakes in the model are ignored or covered up.

I was with you till here. Plenty of people build bad models, such as the recent admissions by all-knowing Physicists at Northwestern and Indiana that their swine flu models were bogus. For heaven's sake, they based their models on movement data from WheresGeorge.com -- real scientific.

On the other hand, you lose a bit of credibility with a trollish sounding statement like the following, which seems to imply that we can't in principle build complex computational models of reality.

I have no problems with computer modeling in designing, say, a car, airplane, or bridge.

Re:Computers can't model macroeconomics

[MSTCrow5429]

In principle, i.e. in theory, sure, but in reality? There are too many constantly changing variables to calculate. Unless you're both omnipotent and omniscient, it won't work.

Re:Computers can't model macroeconomics

[caffeinemessiah]

In principle, i.e. in theory, sure, but in reality? There are too many constantly changing variables to calculate. Unless you're both omnipotent and omniscient, it won't work.

The purpose of a mathematical model is to simplify reality so that it becomes tractable to analyze while still being a good approximation, i.e. so that you don't need to be omnipotent and omniscient. Almost all of modern science is based on this principle, so I'd say we're doing pretty good. If you're saying that reality can't be modeled in general, then that's a different debate and the evidence isn't too favorable in that direction.

Re:Computers can't model macroeconomics

[MSTCrow5429]

I have no problems with models, or saying "if we assume this and this and this, and if we're right about this, and maybe if this is true, then doing X may result in Y." What drives me crazy is when people willfully misrepresent the practical usefulness of models for political ends, or the scientifically illiterate media jumps upon a study, and starts blathering that we know something to be true, so we'd better do what they, or the media's favored politicians, want us to do. The more complex the model, the more problems in relying upon it, and most of the models thrown at us are the sketchiest models, with the least understood principles of operation, with the most assumed variables, with the most hysteria regarding what the models predict.

ya gotta be kidding!

[macbeth66]

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

You didn't need a computer to tell you the current economic mess was coming. It was obvious something big was coming by the end of the year. Of 2007, that is. They were giving mortgages to people that wouldn't have allowed to rent.

Re:ya gotta be kidding!

[Anonymous Coward]

LOL wake up sheeple.

END THE FED!

Re:ya gotta be kidding!

[Brett Buck]

1998, you mean. There was a reason they had all those banking rules developed over centuries, You can't just wipe them out with a stroke of a pen, and expect no consequences.

        Brett

Re:ya gotta be kidding!

[fastest fascist]

Yea, because without them there wouldn't be any economic problems at all. The way I'm leaning is, you can try to mitigate the worst effects of market fluctuations, but you're not going to get rid of the boom-crash-boom cycle without doing something pretty fundamental about human psychology.

Re:ya gotta be kidding!

[MartinSchou]

You can't just wipe them out with a stroke of a pen, and expect no consequences.

True - but isn't it possible that the consequences were exactly what "they" were after?

Think about it - remove the regulations and you can make oodles of money in short time. Make your money and get out while the going is still good (but slowing slightly). Wait for the entire system to crash through the floor. Buy up the traditionally safe investments (now going at much cheaper prices than normal) and repeat.

Perhaps it used the wrong working fluid

[OolimPhon]

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

Re:Perhaps it used the wrong working fluid

[ufoolme]

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

freaking genius

Re:Perhaps it used the wrong working fluid

[Duhavid]

There would have been too many rounds of "profit taking".

Hot and cold running money!

[thewiz]

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

Re:Hot and cold running money!

[langelgjm]

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:Hot and cold running money!

[adolf]

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?

Gack... troll in summary... must resist...

[Red Flayer]

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.

Re:Gack... troll in summary... must resist...

[Anonymous Coward]

there is also the problem with qualifications to invest. basically you just have to have money, if it is someone else money then they may require you to have good sense or at least the appearance of good sense but they are asking you to invest so likely they are not very good with investing and have little idea of what it takes to be a good investor. take for example day traders they don't look for overall long reaching good performing companies but rather short term fluctuations in the perceived value of a company. When SCO started its lawsuit their share price jumped some people saw validity in the lawsuit others saw the rise in stock price and held the stock long enough to profit and got out before everyone realized they were blowing hot air. So back to the current problem in the end everyone saw that it was working the day before and saw no real reason why it should not work the next day and this is how they got their credibility by following the crowd like lemmings right off the cliff.

Re:Gack... troll in summary... must resist...

[rgviza]

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.

The whole problem was caused when congress passed a bill removing the regulations which kept FDIC insured banks from buying loans from non-FDIC insured banks, effectively removing the rules under which FDIC insured banks could loan money.

If you "did the right thing" you went out of business all together, thanks to class action lawsuits. This one is entirely Washington DC's fault, not the mortgage brokers. The guy is a good friend of mine and incredibly smart. He explained exactly how it happened and my own research confirmed what he was telling me. Congress dropped the ball on this one. They wanted everyone to be able to buy a house, whether or not they could pay for it.

-Viz

Re:Gack... troll in summary... must resist...

[Red Flayer]

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 lenders offered both conforming and non-conforming loans, with different fees, rates, etc. I spoke with several lenders who only offered conforming loans (ended up going with one of them), and they weren't sued out of business. Requiring substantiated income is a prerequisite for conforming loans.

Congress dropped the ball on this one. They wanted everyone to be able to buy a house, whether or not they could pay for it.

I think if you do a little deeper research you'll find that that myth has been debunked. I'm not sure how well read-up you are on the issue, from your post it seems like you have some understanding, but are missing important pieces... I don't mean to be mean or condescending, please don't take it the wrong way... but there were a lot of deregulatory actions that affected the mess. Effective repeal of Glass-Steagal, etc.

I don;t think Congress wanted everyone to be able to buy a home... they wanted (1) a place where the bubble money from the dot-com boom could be put to delay the burst and (2) to make their buddies in the financial industry happy.

What economic assumptions is it using?

[MSTCrow5429]

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.

Re:What economic assumptions is it using?

[MrMr]

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.

Re:What economic assumptions is it using?

[Anonymous Coward]

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.

It's a series of tubes.

Wierd! Just read Terry Pratchett's

[bareman]

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

Blowing a circuit - with air

[diodeus]

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:Blowing a circuit - with air

[BrokenHalo]

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... ;-)

Re:Blowing a circuit - with air

[Anonymous Coward]

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

Only with a vacuum system.

Hanz and Franz...

[kj_kabaje]

are here to *Pump* you up!!

A hydraulic computer did model the economy

[Anonymous Coward]

... in Terry Pratchett's book Making Money. There was such a computer in the basement of the bank in Ankh-Morpork.

I wonder if Terry knew about the one in TFA.

Making Money wiki article.

Re:A hydraulic computer did model the economy

[Pembers]

Since there's a note from Pratchett at the start of the book saying, "There's a machine very much like bank's computer in the Science Museum in London," I'd say yes, he did know about it.

A funnel can model "current economic difficulties"

[shadowofwind]

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.

Used in fighter planes

[Maximum Prophet]

Hydraulic computers are used in some military aircraft because they are very reliable and can withstand EMP.

Re:Used in fighter planes

[Lord Ender]

... but not an ice storm.

Re:Used in fighter planes

[neomagus00]

[Citation needed]

This sounds cool, any examples?

Re:Used in fighter planes

[Anonymous Coward]

[Citation needed]

Try Here.

Re:Used in fighter planes

[YenTheFirst]

#1 result is the parent comment. Fail.

Re:Used in fighter planes

[Duhavid]

I don't know about helicopters, but older car automatic transmissions used circulating transmission fluid to determine what gear the car should be in, when the shifts should happen. I think that qualifies as a hydraulic computer.

language

[jsnipy]

That's pretty slick considering the times ... Hydro-functional programming :)

Discworld anyone!

[DadLeopard]

Seems Terry Pratchett is ahead of /. on this issue as one of his characters in "Making Money" uses just this type of Analog Computer to model the money flow in the novel! Though since magic doesn't work in this universe, ours' don't have the same effect!!

Re:Discworld anyone!

[SteveAstro]

You'll actually see TP give due acknowledgement to the Phillips Economic computer, Moniac, at the front of the book.

As a result of reading Making Money, I tracked down the prototype, which is in the foyer of the school of management at Leeds University in the UK, and now have the job of rebuilding Phillips very first machine.

Steve

The Real Question

[Razalhague]

Can I duplicate this in Dwarf Fortress?

Re:The Real Question

[The Archon V2.0]

Can I duplicate this in Dwarf Fortress?

You can, but then carp get in the water and all the operators get butchered.

Memory Leak

[SubjectiveObjection]

"Johnny, there's another damn memory leak! Bring the bucket!"

Yes!

[drewsup]

But will it run hydraulic Linix

Predict the economic trouble today?

[modmans2ndcoming]

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.

Re:Predict the economic trouble today?

[inviolet]

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.

As we say in Economics circles: "Yes, the man is a genius: he predicted 9 of the last 3 recessions!"

Re:Predict the economic trouble today?

[modmans2ndcoming]

Har har, except he is not predicting individual events, but a single event that is caused by the predicate legislation... guess what... he was right on the money.

If we would have stayed with this technology...

[sootman]

... 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.

pneumatic computers exist too

[OrangeTide]

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.

Re:pneumatic computers exist too

[JoeMerchant]

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.

Re:pneumatic computers exist too

[Anonymous Coward]

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.

They used to call this tab-out. That's where fan-out comes from.

Re:pneumatic computers exist too

[Jeff DeMaagd]

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.

Re:pneumatic computers exist too

[OrangeTide]

not really. eventually, even with pilot valves, your structure exceeds the ability of your power source to drive. if you change too many states at once, some will fail to switch over because there is not enough pressure in your tank (if you're using pneumatics) to switch all of them at the same time. In electronics this would be equivalent to a brown-out because your circuit required too much current to switch from one state to the next. Using gray code and other techniques, in some cases, can let you control the number of gates that switch each clock.

I never did anything truly interesting with pneumatics, for example I never built a pneumatic flip-flop (JK, D or any other type).

Re:pneumatic computers exist too

[petermgreen]

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.
Sounds like you just need to have some buffers in the design.

Obligatory

[mandark1967]

Imagine a beowulf cluster of these!

Yeah...but can it run Linux?

(with the obligatory troll post about the level 5 dwarf maintaining my OS in at least one of the replies)

How many LOCs can this thing hold?

Didn't I see that thing in Charlie and the Chocolate Factory?

That sbout cover them all?

Re:Obligatory

[DriedClexler]

No, you forgot:

"There's a world market for maybe 14 hydraulic computers."

Re:Obligatory

[Anonymous Coward]

I, for one, welcome our ___________ overlords...

modeling current economic woes = attach a balloon

[Anonymous Coward]

Modeling the current economic woes? Just attach a balloon in the appropriate place.

When it bursts, there'll be a big mess to clean up and it'll take a while.

also explored by air force for emp resistance

[cinnamon colbert]

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...

Hydraulic Computers

[thethibs]

Which gave rise to one of the oldest computer jokes: "If it doesn't work, piss on it."

Not that I would start a new slashdot meme...

[tjstork]

But do you think this analog technology might explain or predict why Bing is pointless?

Trend setting

[DrugCheese]

This was water cooled before water cooling was cool

Re:Wierd! Just read Terry Pratchett's

[emudoug42]

I love it when I read about some bizarre contraption in the discworld books only to discover later that it's based on some bizarre contraption in reality.

Not quite

[DerekLyons]

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...

Re:Not quite

[John Hasler]

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.

Re:Not quite

[DerekLyons]

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:Not quite

[Nimey]

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

Re:Wierd! Just read Terry Pratchett's

[TheRaven64]

And this is why you should always read the author's note at the end, where he mentions all of the things that he based inventions in the book on. You also get fun things like, in the end of Nation, an explanation of thinking, followed by 'do try this at home'

Cool differential equation engine in action

[Muad'Dave]

That's pretty cool, and a little steampunk. Is it just me, or was that thing wheezin' like an iron lung in the video?

Re:Cool differential equation engine in action

[Garridan]

No, you cad, this is not steampunk. Correlation is not causation: this is history. Steampunk is a fictional genre that romanticizes the period in history that this real machine came from. Moreover, the thing appears to be made of plastic -- I'm betting that if some steampunk fanboi built one of these today, they'd use a metric fuck-ton of brass, and it'd have pointless dials and knobs out the wazoo.

Article has inventor name wrong.

[Gouru]

Article has it wrong though, claims some unknown named 'Philips' invented the glooper. We all know it was Hubert.

14 machines? One of the more successful? ROFL

[John Hasler]

EAI sold more than 500 of their 1952 16-231R model alone.

Yep

[madnis]

Shows that our economy is down the drain.

I think simple addition and subtraction

[Xonstantine]

was all that was necessary to predict our current economic crisis.

Scaled-Simulation versus Computer

[Tablizer]

The boundary between "analog computer" and "scaled simulation" seems rather fuzzy. I suppose the more it physically resembles the original (but smaller), the more it's a simulation rather than computer. But many of these old devices seem a mix, and thus the classification is multi-pronged.

Poor Ted...

[Java Pimp]

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!

Sure we could have used it to predict it

[Opportunist]

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

Comment removed

[account_deleted]

Comment removed based on user account deletion

An idea 60 years too late...

[Onyma]

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)

Re:14 machines? One of the more successful? ROFL

[S-100]

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).

Other Great Analogue Computers

[Nom du Keyboard]

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.

A five year old with an abacus and 20 minutes

[nedlohs]

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

Another resource too...

[DrYak]

The Annotated Pratchett File has also interesting resources to help grasp to more obscure jokes.

Zero, it's Jonathan E

[RoverDaddy]

Answer the question Zero, tell Jonathan about the Corporate Wars.
*blub blub blub 13th Century blub blub*

Re:Zero, it's Jonathan E

[MickyTheIdiot]

Damn you. I wanted to watch Rebecca Romijn with a scar across her eye...

Modern Replacement

[Nom du Keyboard]

Seems to me that this could be replaced today with an Excel spreadsheet - and no I'm not being facetious.

before there was MAKE

[duckHole]

one of CL Strong's "Amateur Scientist" articles in SciAm gave construction details for logic units based on water jets... gates, flip-flops, etc. 1966 or thereabouts...

I Once Had a Toy...

[Nom du Keyboard]

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.

Re:I Once Had a Toy...

[offrdbandit]

No, we weren't a Leggo family.

Clearly.

Re:I Once Had a Toy...

[Anonymous Coward]

You're probably thinking of a hydrodynamic builder's set...I had one too: http://scientificsonline.com/product.asp_Q_pn_E_3081216

Re:I Once Had a Toy...

[Limburgher]

Capsela? http://en.wikipedia.org/wiki/Capsela

Re:I Once Had a Toy...

[Nom du Keyboard]

Capsela?

No, this one had clear rectangular plastic tanks and clear 1/4" tubing.

Analog Into the 70s

[fm6]

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.

Hydraulic Analog Computer ....

[davidsyes]

If it were organic, i'd dare say it could be called a.... hip-shooter...

It's so old

[Ukab the Great]

That you program it using the Waterfall Model.

So... Where does the boom come from?

[Colin Smith]

In order to have a boom, someone must be spending money. Where does it come from?
 

Re:So... Where does the boom come from?

[Anonymous Coward]

From all the money the guy in the last crash made.

Chicken meet Egg.

Most price and market models ive seen work look lke mountain ranges. Up to say 10, down to 8, up to 20, down to 17, up to 30, down to 26, till it hits 100 or so then drops. Inflation keeps the price growing steadily over time. Compare multiple companies in the same industry over a course of 50 years, and you see they follow the same path. Look at all companies across all industries and you see the same trend, regardless of the company or industry. You can also pin-point historic events. (9/11, Gold deregulation, JFK's death, Water gate) based purely on market data in macro terms. Its quite amazing. (In my Highschool econ class I did this, pin pointed some strange date, apparently it was the day one shuttle launch failed during the 60s when people cared, market dropped pretty hard, and rallied when it finally launched)

My great-uncle once told me (playing the market with a 6 grade edumacation and making millions in his life time) "The trick is, to find the right spot" Im pretty sure he was talking about women at the time, but for markets, it works the same. The market is just an extension of human behavior. The problems are the same.

obvious...

[FalloP]

now i truly understand a buffer overflow, and the implications of a memory leak are clear.

Re:obvious...

[Anonymous Coward]

Oh no! Water in the datacenter. lol

biennale

[spud603]

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.

If these ran the internetz. . .

[kimvette]

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

Analog computing has its place

[mcrbids]

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 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.

Re:Analog computing has its place

[ArsonSmith]

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:Analog computing has its place

[ctmurray]

Wow does this bring back memories. I learned to fly in grad school in 1984 and learned to use the E6B. I may still have it, even though I no longer fly. Each time I move I consider tossing the item, but can't for sentimental reasons. Amazing they are still in use, not replaced by electronics, but I understand now having read your post and the Wikipedia article.

Biased? hardly

[Runaway1956]

I work with and service a lot of hydraulic machines. Generations of them, in fact. The pilot valves and such really haven't changed much in 50 years, as they are a simple device - but the CONTROLLERS are simply awesome. We use mostly David Bradley stuff, but there are plenty of Japanese, Chinese, and Korean valves and controllers in the plant. Amazing how accurate they can be when remotely controlled by a computer. Hydraulically powered computer can be sent 30 feet away from you, and come back, kiss your forehead, or a baby's cheek, and sent out again. It will repeat ad nauseum, and NEVER strike you hard.

Air? I would never trust air powered mechanisms to touch a baby, and simple electric motors can scare me too. Don't even dream of doing it with some kind of gasoline powered machine. Hydraulics are more reliable than anything I can think of.

Re:Biased? hardly

[mataap]

Indeed, my father used to build hydraulic gang nail presses for a reseller, and the original (successful) design also used hydraulics to move the gantry and the hanging presses, which the operators loved, as it gave them good control and gentle takeoffs and stops. Then a young buck decided to change to electric motors for positioning the gantry and the press, to save money ( against the advice of older and wiser heads). The customers didn't like them, the stops and starts were too sudden, and it was very hard to position the press where they wanted it. It was like those old gags with elevator operators constantly overshooting and undershooting the floor level. The company went back to hydraulics.

Re:Biased? hardly

[Anonymous Coward]

David Bradley controllers? Dont you mean Allen Bradley?

Re:Biased? hardly

[TapeCutter]

"I would never trust air powered mechanisms to touch a baby"

I agree, we should ban politicians from kissing babies.

Cool video

[YourExperiment]

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.

It's...

[l0b0]

The Glooper!

wear and tear

[Anonymous Coward]

As all mechanical machines are a subject to wear I bet it could 'simulate' a catastrophic loss of pressure.

Parhaps wear is something not counted with in economics and should be.

(Now lets get back to learning for tomorrows macroeconomics exam)

Re:Your Signature

[Artifakt]

Technically, Rush is 100% correct, for once. It still feels like he's lying by omission though, because he didn't mention the other eight in the Bill of Rights. For that matter, what if the government fails to follow the 14th amendment, or some part of the original constitution? can we rebel then as well? Rush is a speaker, of course he wants his free speech rights protected. When he supports protecting somebody else's right against a warrantless search, or argues that some other right might be one of those not specifically enumerated but still real, I'll start believing Rush can count above two.

Fluidic Systems

[TheSync]

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

See this powerpoint for a great history of fluidics.

Analog is slick

[g01d4]

I took an (electrical) analog computing course in the mid-70s. Best (only?) way to solve differential equations in real time till clock speeds caught up. LIke music on vinyl vs. 1KHz sampling. Optical ain't dead - how about a 2D FFT at the speed of light?

Obligatory Ada Lovelace comic

[lennier]

Featuring an Economic Model inspired by MONIAC:

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

Crunchly's hydraulic computer

[dido]

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

Re:A funnel can model "current economic difficulti

[Anonymous Coward]

So can a toilet....

Re:Wierd! Just read Terry Pratchett's

[Captain Nitpick]

I love it when I read about some bizarre contraption in the discworld books only to discover later that it's based on some bizarre contraption in reality.

I got in an argument once with someone who thought the clacks system was completely implausible. While the mechanical devices inside are pure Pratchett, optical telegraphs really existed.

Re:Your Signature

[Anonymous Coward]

I put that quote in there precisely to tweak people, because it is both correct and said by Limbaugh, ordinarily a contradiction.

horrible video

[Teque5]

'cool video' is really a misnomer - the guy doesn't explain anything and nothing happens. 3:28 of my life i will never get back.

The linked movie seemed to be applicable, still...

[ibsteve2u]

A seemingly intelligent fellow, explaining how it should work - while it never actually did work. Just like listening to Paulson, or Geitner, or...

if it could have been used to predict our ...

[ezzthetic]

you have to wonder if it could have been used to predict our current economic difficulties

Only if it sprung a leak.

I want one

[jandersen]

That's a cool gadget to have in your living room; described by Terry Pratchett in "Making money" as the Glooper.

"Igor?" said Moist, "You have an Igor?"
"Oh, yes", said Hubert. "That's how I get this wonderful light. They know the secret of storing lightning in jars! But don't let that worry you, Mr Lipspick. Just because I'm employing an Igor and working in a cellar doesn't mean I'm some sort of madman, ha ha ha!"
"Ha ha," agreed Moist.
"Ha hah hah!," said Hubert, "Hahahahahaha!! Ahahahahahahhhhh!!!!!-"
Bent slapped him on the back. Hubert coughed. "Sorry about that, it's the air down here", he mumbled.

Re:Wierd! Just read Terry Pratchett's

[vegiVamp]

The compact paperback versions I have don't have that note. Makes it all the more fun to discover stuff like this, tho :-)

The original is in the London Science Museum

[entirely_fluffy]

The computer in the article installed at the LSE is now on display in the London Science Museum:

http://www.sciencemuseum.org.uk/images/I033/10303308.aspx

Phillip's Economic Computer, 1949. The machine was conceived by Bill Phillips (1914-1975), a New Zealand-born engineer turned economist. Phillips designed the machine to demonstrate in a visual way the circular flow of money within the economy. Approximately fourteen machines were built, and this particular machine was used as a teaching aid at the London School of Economics. It ran until May 1992.

It's been done in Phun

[bomek]

It's been done in Phun, a physic 2D sandbox

http://www.phunland.com/phunbox/details/22598