Recognized as one of the greatest physicists of all time, Albert Einstein’s achievements include his work in the development of quantum theory, for which he was awarded the Nobel Prize in 1921. But he is best known for his formulation of the theory of relativity, which recognizes that mass and energy are equal. Deprived of his German citizenship by the Nazis, he fled to America and became instrumental in the development of the atom bomb, but later actively promoted disarmament