# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Chaos: Useful at Last?" by Jaroslav Stark and Kate Hardy. *Science*, 29 August 2003.

Stark discovered that his new microwave oven had a "chaos defrost" setting---based on chaos theory (nonlinear dynamics). "A simple chaotic system is used to generate an irregular heating sequence, which can reduce the time required to defrost food by up to 60%." The authors note that although nonlinear dynamics may not be necessary for this particular use it shows that the branch of mathematics does have practical applications. The authors then note that modern nonlinear dynamics has been around for more than a century, although few scientists in other fields took notice until recent years, when the field has been applied to solve problems in engineering and medicine---designing spacecraft trajectories, predicting weather, operating production lines, modeling blood flow, and understanding epidemics, for instance. Concerning why nonlinear dynamics is now contributing to the solution of such a wide range of practical problems, the authors write: "The likely reasons include the ever-increasing availability of high-performance computing and visualization tools and the rising interest in interdisciplinary research. But perhaps the most important factor, which is particularly apparent in the best applications today, is the interplay between the model-driven ideas developed in the 1960s and the data-driven ones of the 1980s."

*--- Annette Emerson*