Some of these people are known for their academic brilliance and others for their bravery in standing up for what they believe is right. There is no particular order to the list that I present below. It is just as it comes.
Paul Erdős was a brilliant and eccentric Hungarian mathematician who had a long and productive career. He spent most of his adult life living out of a suitcase and worked ceaselessly. He was truly single-minded in his devotion to the subject.
Albert Einstein revolutionised physics in the twentieth century. He was responsible for shaking up its foundations and introducing relativity. The idea behind special relativity theory is very simple. The laws of physics must be the same as seen by any observer in the universe. He was also a respected social commentator. He believed in compromise as the best approach to any problem.