Albert Einstein, German mathematical physicist, 22 February 1944.
© NMeM / Daily Herald Archive / Science & Society Picture Library
Profesor Einstein (1879-1955), who conceived the theory of relativity, is here shown laughing at a joke told by the photographer James Jarche. Einstein, enjoying the fun, is wearing his pullover inside-out. 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. Because of his political stand against the Nazis, Einstein had to leave Germany and went to live in the United States of America, taking citizenship.