## relativity

Cambridge celebrates 25 years since the first very early Universe workshop

*string theory*have nudged their way into public consciousness. It's a theory of everything in which everything's made of strings — or something like that. But why strings? What do they do? Where did the idea come from and why do we need such a theory?

**David Berman**has an equation-free introduction for beginners.

**Shahn Majid**met up with

*Plus*to explain.

**Mario Livio**explains how not only shapes, but also laws of nature can be symmetrical, and how this aids our understanding of the universe.

**Hardeep Aiden**sets out to persuade readers that they too can understand an idea as elegantly simple as it was original.

*Plus*is very proud to present

**Professor Stephen Hawking**'s own Birthday Symposium address.

*Plus*is a special, marking the occasion of Stephen Hawking's 60th birthday. Plus attended his Birthday Conference in Cambridge, where we interviewed some of the world's most influential mathematicians and physicists.