It must have been a dress-down day at Princeton University, New Jersey, when the most famous scientist in the world stood for this photograph in March 1955. That would explain why he seems to be wearing a tracksuit! Albert Einstein provided many of the theories that physicians still use today when building theoretical models of the universe. The German was the man who came up with 'E=MC2', the theory of special relativity which made nuclear fusion possible. Both theory and practicality have come a long way in the seventy years since his death, but we would still probably benefit from having Einstein's mind around to help us interpret new discoveries.
Einstein was so famous that our stereotypical image of a 'mad professor' - the crazy white-haired man with the glasses - is based on him. He passed away on April 18th, 1955, a month after the photo was taken, due to an abdominal aneurysm. He was 76.