differential equation
Saying that someone is a chaotic thinker might seem like an insult  but, according to Lewis Dartnell, it could be that the mathematical phenomenon of chaos is a crucial part of what makes our brains work.


André Léger studies the fluid mechanics of food travelling through the intestines for consumer goods giant Unilever.

How does the uniform ball of cells that make up an embryo differentiate to create the dramatic patterns of a zebra or leopard? How come there are spotty animals with stripy tails, but no stripy animals with spotty tails? Lewis Dartnell solves these, and other, puzzles of animal patterning.

In issue 29 of Plus, we heard how a simple mathematical equation became the subject of a debate in the UK parliament. Chris Budd and Chris Sangwin continue the story of the mighty quadratic equation.

To study a system, mathematicians begin by identifying its most crucial elements, and try to describe them in simple mathematical terms. As Phil Wilson tells us, this simplification is the essence of mathematical modelling.

Fluid mechanics is the study of flows in both liquids and gases, and is therefore enormously important in understanding many natural phenomena, as well as in industrial applications. Geophysicist Herbert Huppert tells us what happens when two fluids of different densities meet, for example when volcanos erupt and hot ashladen air is poured out into the atmosphere.

Over the past one hundred years, mathematics has been used to understand and predict the spread of diseases, relating important publichealth questions to basic infection parameters. Matthew Keeling describes some of the mathematical developments that have improved our understanding and predictive ability.

During World Mathematical Year 2000 a sequence of posters were displayed month by month in the trains of the London Underground aiming to stimulate, fascinate  even infuriate passengers! Keith Moffatt tells us about three of the posters from the series.

Those who understand compound interest are destined to collect it. Those who don't are doomed to pay it  or so says a wellknown source of financial advice. But what is compound interest, and why is it so important? John H. Webb explains.
