The Connection Machine

For a few million dollars you can buy a rather special supercomputer.  Called the Connection Machine, it is by no means the biggest in terms of raw power; that honour belongs to the famous Cray machines, though they are being increasingly challenged by other manufacturers' models, notably the Japanese. What the Connection Machine has is processors, lots of them. Sixty-five thousand, five hundred and thirty-six to be precise.

A processor is, as its name suggests, where a computer does all the work, processing the information that is fed in, and producing the output.  Micros have one of them, and a few of the bigger systems have several. None of them has anything like the number of the Connection Machine.

As you might expect, each of these processors is quite weak in itself, and certainly cannot compare with the single processors found even in ordinary office and home computers.  But these processors have been specially designed so that they can work alongside thousands of copies of themselves, joined up to them by hundreds of thousands of connections, something that would be near-impossible with conventional processors. 

This approach has been adopted on the Connection Machine because certain computational problems prove to be far more tractable when dealt with by many processors rather than just one.  Where there are lots of separate but linked events occurring it is far easier to model what is going on in this way. Typical examples are predicting things like the weather where everything affects everything else in a highly complex manner.  Using a single processor machine, however powerful, requires some awkward calculational contortions.

In fact there is a good precedent for taking this multi-processor approach.  The human brain consists of just such a connection machine, with billions of neurons joined together by trillions of axons to produce a computer which makes the device described above look like an abacus.  Indeed, these similarities between the two have been fruitfully exploited to investigate models of the brain.

But there is another intriguing use for the Connection Machine.  It is possible to set the computer up as a cube of 496 processors along each of three dimensions.  By entering the laws of physics as equations at each of these 65,536 points, it is possible to model an entire three-dimensional universe, albeit a very small one.  In principle you could introduce the computer equivalent of atoms into this universe and watch their interactions.  It would even be possible to simulate a Big Bang in this artificial cosmology, and to sit back and watch the universe form.

Imagine now a similar computer, but with trillions, quadrillions or even more processors.  The model it could run would now be even more accurate, the universe it predicted even bigger.  As the number of processors grew so would the accuracy of the model, until finally there would be no perceptible difference between the observed universe and the output we saw from an unimaginably huge computer which modelled it.  The brain, the universe: it is not called a Connection Machine for nothing. 

(1.3.92)

See also Moody Sonnets - Thus Spake AI

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