AI IMAGE - Portrait of Albert Einstein, 1950s, (2023). German-born mathematician and theoretical physicist. Einstein's main contribution to science was the theory of relativity, regarded by many as the most important theory in the history of physics. His special (1905) and general (1916) theories of relativity, proved the concept that time does not exist at the same rate for everyone and everything. Special Relativity produced the equation which expresses the equivalence between matter and energy: E=mc squared. In 1921, Einstein received the Nobel Prize for Physics. His Jewishness meant that he had to leave Germany when the Nazis came to power, emigrating to the USA and taking American citizenship.