14 March 1951: Arthur Sasse was amongst the pack of photographers hounding Albert Einstein as he left his 72nd birthday celebration but the only one to get this shot of him playfully sticking his tongue out. This crop (from a wider image showing his companions in the back of a car) was chosen by Einstein himself to put on greetings cards to be sent out to friends. The photograph, arguably one of the best known press photographs of any 20th century personality, established a public image of Einstein as the 'nutty professor' rather than the nobel prize-winning physicist who developed the theory of general relativity