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.

Going with the flow: are lateral flow tests useful?

Lateral flow tests have become a common feature in our lives. What impact can they have on managing COVID-19?
Complex square roots

How to take the square root of a complex number — and discover a beautiful new surface in the process.
Maths in a minute: The positive predictive value

When you receive a positive test result for a disease, the chance you actually have it depends on how common the disease is.
The shower equation: Dealing with delay

Many processes, including climate change and the spread of COVID-19, involve a delay. Here's a beautiful equation designed to model such processes.
Happy birthday Quicksort!

Next month sees the 60th birthday of a famous algorithm called Quicksort. We explore its origin, its workings, and some other work of its inventor Tony Hoare.