
particles, the angle of their impact, the state of the neighborhood in
which they collided, and other factors.
Langton’s early interest in cellular automata has evolved into his cur-
rent involvement in the development of Swarm, a computer program
that allows researchers to simulate the interactions of actors in a com-
plex system. Langton and his colleagues at Santa Fe Institute and the
Swarm Corporation use the word “swarm” to mean any loosely struc-
tured collection of agents that interact with one another. In common us-
age, the term agent refers to an object in a computer program that has an
identity and performs some actions, usually with some ...