But some do not.

There are certainly many aspects of real materials that this model does not even come close to capturing.

But it turns out that some of the most important unresolved issues in physics concern phenomena that are in a sense more general—and do not depend much on such features.

In each case all the paths shown start parallel, but do not remain so when there is curvature.

And all of this supports my strong belief that in the end it will turn out that every detail of our universe does indeed follow rules that can be represented by a very simple program—and that everything we see will ultimately emerge just from running this program.

At first glance, these images do in some respects look more random.

so long as the structure of the network is kept the same, it is fairly easy even in this case to deduce from a given set of data what probabilities in the network provide the best model for the data—for essentially all one need do is to follow the path corresponding to the data, and see with what frequency each connection from each node ends up being used.

So what can one do when the behavior is more complex?

But one can also get cellular automata to do more complicated computations.

For rule 188 the cellular automaton that does this involves 12 colors; for rule 60 it involves 6.