In pictures: Stephen Hawking at 70

Professor Stephen Hawking was forced to miss a symposium yesterday that was held to mark his 70th birthday. The Cambridge theoretical physicist had been discharged from hospital only two days earlier and was still too unwell to attend. A recording of his speech was played instead to an audience of his peers and the public at Cambridge University instead. In his talk, entitled 'A Brief History of Mine', he again warned that humans must colonise space to survive and remarked that it had been "a glorious time to be alive, and doing research in theoretical physics".