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

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

[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

[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

[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.

Hot and cold running money!

[thewiz]

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

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.

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.

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: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

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.

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.

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.

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.

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...