Plus.Maths.org
torus
This article describes how you can describe the entire universe of Riemann tori (surfaces that look like dooughnuts) in one go.
A Riemann torus is a surface that looks like a doughnut. This articles explored how you might tell Riemann tori apart.
In a previous article we found a Möbius strip in Bach's music. This time it's a doughnut shape.
The paths of billiard balls on a table can be long and complicated. To understand them mathematicians use a beautiful trick, turning tables into surfaces.
In the first of a new series 'Imaging Maths', Plus takes an illustrated tour of an extraordinary geometric construction: the Klein bottle.