Zeeman, (Erik) Christopher (1925– )

British mathematician concerned with catastrophe theory and its applications to the physical, biological, and behavioural sciences, and with dynamical systems. For example, he has constructed catastrophe models of heartbeat and the propagation of nerve impulses.

Zeeman studied at Cambridge. In 1964 he became professor at Warwick, where he founded and became director of the Mathematics Research Centre.

Zeeman's interest in catastrophe theory arose from his study of topology and brain modelling. If two elementary catastrophes (two conflicting behavioural drives, for example) are plotted as axes on the horizontal plane – called the control surface – and the complementary result (the resulting behaviour) is plotted on a third axis perpendicular to the first two, resultant points can be plotted for the entire control surface, and when connected they form a surface of their own. Catastrophe theory reveals that in the middle of the surface is a pleat, which becomes narrower towards the back. For Zeeman, all the points on the surface represent the most probable behaviour, with the exception of those on the pleated middle part, which represent the least likely behaviour. At the edge of the pleat, the sheet on which the behaviour points have been travelling folds under and is wiped out. The behaviour state falls to the bottom sheet of the graph and there is a sudden change in behaviour.