Welcome to Plus magazine!

The Delta variant: What do we know?

As the Delta variant is worrying the UK, researchers from the JUNIPER consortium have published all they know about it.

A breath of fresh air

Could COVID-19 change our expectations for clear air indoors?

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.

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.

Maths in a Minute: Computational fluid dynamics

The mathematical equations governing fluid flow may have no known solutions, but maths still has the answers!

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.

Maths in a minute: Asymptotes

Curves can be crazy, but asymptotes are nice and straight.

The hardest logic puzzle ever

Stretch your neurons with this tricky, but lovely, variation on the Two Door riddle.