What do we mean when we say that something grows exponentially?

Why does the number e appear in models of exponential growth?

Loquacious maths

Food evolution

Arguably, the exponential function crops up more than any other when using mathematics to describe the physical world. In the second of two articles on physical phenomena which obey exponential laws, Ian Garbett discusses radioactive decay.

Arguably, the exponential function crops up more than any other when using mathematics to describe the physical world. In the first of two articles on physical phenomena which obey exponential laws, Ian Garbett discusses light attenuation - the way in which light decreases in intensity as it passes through a medium.