John Casti, of the University of Vienna (Austria) and the Santa Fe Institute (USA), presented a public lecture at the Main Lecture Hall focussing on the would-be behaviour of complex systems ranging from traffic patterns to stock markets to rainforests. Casti contends that high-powered computers now give us the ability to create surrogate versions of real complex systems--artificial worlds, if you will--that are analogous to the more familiar laboratories that have been used by physicists, biologists and chemists for centuries to understand the workings of matter and nature. The difference is that these new computerized laboratories allow us to explore the informational rather than the material structure of systems. The result, according to Casti, is that for the first time in history we may now be in the position to realistically think about the creation of a theory of complex systems.