Albert Einstein (March 14, 1879 - April 18, 1955) was a theoretical physicist widely regarded as the most important scientist of the 20th century. He was the author of the general theory of relativity and made important contributions to the special theory of relativity, quantum mechanics, statistical mechanics, and cosmology. He was awarded the 1921 Nobel Prize for Physics for his explanation of the photoelectric effect in 1905 (his "wonderful year") and "for his services to Theoretical Physics".
After British solar eclipse expeditions in 1919 confirmed that light rays from distant stars were deflected by the gravity of the Sun by the amount he had predicted in his theory of relativity, Einstein became world-famous, an unusual achievement for a scientist. In his later years, his fame perhaps exceeded that of any other scientist in history. In popular culture, his name has become synonymous with great intelligence and genius.