## Articles

**Phil Wilson**looks at

*constructivist mathematics*, which holds that some things are neither true, nor false, nor anything in between.

**John Billingham**investigates and saves the national grid in the process.

**Lewis Dartnell**looks at some stunning examples.

**Peter Markowich**is a mathematician who likes to take pictures. At first his two interests seemed completely separate to him, but then he realised that behind every picture there is a mathematical story to tell.

*Plus*went to see him to find out more, and ended up with a pictorial introduction to partial differential equations.

**Josefina Alvarez**describes the workings of the most famous search engine of them all. You'll need some linear algebra for this one, but it's worth the while!

**Chris Budd and Cathryn Mitchell**look at the maths that isn't only responsible for these medical techniques, but also for much of the digital revolution.

**Stefan Kopieczek**explores his story.