one-sided surface

In the first of a new series 'Imaging Maths', Plus takes an illustrated tour of an extraordinary geometric construction: the Klein bottle.

Maths in a minute

Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.

How to work out doubling time

The doubling time for the Omicron variant seems to be scarily fast. But how do you calculate it?
Maths in a minute: QALYs

What's a quality adjusted life year, or QALY?
Why the generation time of COVID-19 is important

To work out the famous R number you need to know the time between infections.
What are probability distributions?

Here's an introduction and some examples.
Understanding waning immunity

What can we expect from a disease for which natural or vaccine induced immunity wanes?