Albert Einstein (1879 – April 1955) - German-born theoretical physicist best known for developing the theory of relativity and his important contributions to quantum mechanics. His mass–energy equivalence formula E = mc2, which arises from special relativity, has been called "the world's most famous equation". He received the Nobel Prize in Physics in 1921, "for his services to Theoretical Physics and especially for his discovery of the law of the photoelectric effect" More