In the first of a new series 'Imaging Maths', Plus takes an illustrated tour of an extraordinary geometric construction: the Klein bottle.
The 2003 Dirac Lecturer, distinguished physicist Freeman Dyson, tells Plus why he is an optimist, what makes life interesting and why old-fashioned maths is what you need for physics.
  • Plus looks different! - Redesigning the website
  • Beauty is truth, truth beauty - The aesthetics of mathematics
  • Readers' corner - Rolling with money revisited: The Pyramid Puzzle
If you had a crystal ball that allowed you to see your future, what would you arrange differently about your finances? Plus talks to the Government Actuary, Chris Daykin about the pensions crisis, and how actuaries use statistical and modelling techniques to plan for all our futures.
  • Optional maths - should students be able to give up maths at age 14?
  • Outer space - In what will now be a regular feature, mathematician and cosmologist John D. Barrow shares some maths that's amused and intrigued him.
  • Readers' corner- More Strange activities for last issue's Ship of Fools!
One million dollars is waiting to be won by anyone who can solve one of the grand mathematical challenges of the 21st century. In the second of two articles, Chris Budd looks at the well-posedness of the Navier-Stokes equations.