If the number of types of chocolate known at each stage is plotted on a graph, it will roughly correspond to a mathematical curve called a hyperbola.

ECONOMIST: Statistics

Whether based on data or a mathematical ideal, such a curve always has two parameters.

ECONOMIST: Climate change

To do so, astronomers resort to Fourier analysis, a mathematical technique that allows them to break a complex curve into a set of simple ones called sine waves.

ECONOMIST: Extrasolar planets