These outlined a theory of the photoelectric effect, explained Brownian motion, introduced his special theory of relativity-a theory which addressed the inability of classical mechanics to account satisfactorily for the behavior of the electromagnetic field-and demonstrated that if the special theory is correct, mass and energy are equivalent to each other. In 1905, a year sometimes described as his annus mirabilis (miracle year), Einstein published four groundbreaking papers. His intellectual achievements and originality have made Einstein synonymous with genius.

In a 1999 poll of 130 leading physicists worldwide by the British journal Physics World, Einstein was ranked the greatest physicist of all time. His work is also known for its influence on the philosophy of science. He received the 1921 Nobel Prize in Physics 'for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect', a pivotal step in the development of quantum theory. His mass–energy equivalence formula E = mc 2, which arises from relativity theory, has been called 'the world's most famous equation'. Best known for developing the theory of relativity, he also made important contributions to quantum mechanics, and was thus a central figure in the revolutionary reshaping of the scientific understanding of nature that modern physics accomplished in the first decades of the twentieth century. Albert Einstein ( / ˈ aɪ n s t aɪ n/ EYEN-styne German: ( listen) 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely held to be one of the greatest and most influential scientists of all time.

Albert einstein drawing sketch