The "free-range mathematician" and "architect of particle physics" has passed away in Princeton.

In February this year we were lucky enough to interview Freeman Dyson at the Institute for Advanced Studies in Princeton, USA. Dyson is now 89 and still does physics every day in his first floor office at the Institute. Here is an edited version of our interview that we hope conveys his generous nature, wit and intellect.

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.