'Visionary' physicist Stephen Hawking dies aged 76

The world-renowned British physicist Stephen Hawking has died at the age of 76. While having motor neurone disease, Prof Hawking popularised theoretical physics with his books, including the best seller 'A Brief History of Time'. Fellow physicist Prof Carlo Rovelli knew Prof Hawking well. What sort of a man was he?

Picture: Prof Stephen Hawking speaks during the opening ceremony of the London 2012 Paralympics. Credit: Dan Kitwood/Getty Images