On the face of it, symmetry may seem simple, but diving beneath the surface reveals a whole new world. Over the last 100 years, the mathematical idea of symmetry has proved to be a guiding light for the world of physics. But what does a mathematician mean by symmetry? How does this link in with the world around us? And could it be the key to the mysterious 'Theory of Everything'? Plus, in the news, a new MRI-based cancer treatment, zero-emission highways and the curious case of Whistled Turkish.