Humans have seemingly always been fascinated by random phenomena. Randomness is a pervasive component of our everyday lives. It characterizes the patterns of raindrops, shape and location of clouds, traffic on the freeway. It describes the selection of winning numbers in the lottery and day-to-day changes in the weather. The science of chaos says that everything began in pure randomness and will end that way.
The computer provides a means for the systematic extended study of randomness and pseudo-randomness that is impractical using simpler methods such as flipping coins or rolling dice. A graphics-oriented computer and a simple algorithm such as a two-dimensional random walk is ideal for the visual display and exploration of random principles.
The random walk decision procedure, like the eight queens and knight's tour problems, predates computers. In one college finite math textbook (Kemeny et. al. , 1962) it is described in the context of an absorbing (i.e. terminating) Markov chain process wherein, at each decision point, only the most recent decision is considered when making the current one. Variations of the random walk method are currently used with computers to simulate systems in the fields of physics, biology, chemistry, statistics, marketing, population dynamics, and others. A bit of Internet prowling will unearth information on many current applications. An Alta Vista search on the key "random walk" generated 2988 hits, many of them redundant, but containing at least one hit for most of the current applications of the method. Sourcecode for various implementations is freely available on the net in languages ranging from Java to C to Lisp.
