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.

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.

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

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.

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...