Albert Einstein, German mathematical physicist, 1933.
© Science Museum / Science & Society Picture Library
Albert Einstein (1879-1955), the German-Swis-American theoretical physicist whose major contribution was the theory of relativity. Einstein made fundamental contributions to physics which include his special (1905) and general (1915) theories of relativity, which posited the concept that time does not exist at the same rate for everyone and everything. Special Relativity produced the equation which expreses the equivalence between matter and energy: E=mc squared. In 1921, he received the Nobel Prize for Physics. During the Nazi period he was forced to leave Germany because he was Jewish, and went to live in the United States of America, taking citizenship.