Chaos And Forecasting - Proceedings Of The Royal Society Discussion MeetingIt is now generally recognised that very simple dynamical systems can produce apparently random behaviour. In the last couple of years, attention has turned to focus on the flip side of this coin: random looking time series (or random looking patterns in space) may indeed be the result of very complicated processes or real noise, but they may equally well be produced by some very simple mechanism (a low dimensional attractor). In either case, a long