Why These Discoveries Were Not Made Before

The main result of this chapter—that programs based on simple rules can produce behavior of great complexity—seems so fundamental that one might assume it must have been discovered long ago. But it was not, and it is useful to understand some of the reasons why it was not.

In the history of science it is fairly common that new technologies are ultimately what make new areas of basic science develop. And thus, for example, telescope technology was what led to modern astronomy, and microscope technology to modern biology. And now, in much the same way, it is computer technology that has led to the new kind of science that I describe in this book.

Indeed, this chapter and several of those that follow can in a sense be viewed as an account of some of the very simplest experiments that can be done using computers. But why is it that such simple experiments were never done before?

One reason is just that they were not in the mainstream of any existing field of science or mathematics. But a more important reason is that standard intuition in traditional science gave no reason to think that their results would be interesting.

And indeed, if it had been known that they were worthwhile, many of the experiments could actually have been done even long before computers existed. For while it may be somewhat tedious, it is certainly possible to work out the behavior of something like a cellular automaton by hand. And in fact, to do so requires absolutely no sophisticated ideas from mathematics or elsewhere: all it takes is an understanding of how to apply simple rules repeatedly.

And looking at the historical examples of ornamental art on the facing page there seems little reason to think that the behavior of many cellular automata could not have been worked out many centuries or even millennia ago. And perhaps one day some Babylonian artifact created using the rule 30 cellular automaton from page 27 will be unearthed. But I very much doubt it. For I tend to think that if pictures like the one on page 27 had ever in fact been seen in ancient times then science would have been led down a very different path from the one it actually took.