Albert Einstein (14 March 1879 – 18 April 1955) was a German-born American Jewish scientist. He worked on theoretical physics. He developed the theory of relativity. He won the Nobel Prize in Physics in 1921 for theoretical physics.
His most famous equation is \displaystyle{ E=mc^2 } in which E is for Energy, m for mass, c is the speed of light is therefore Energy equals mass multiplied by the speed of light squared.
At the start of his career, Einstein didn't think that Newtonian mechanics was enough to bring together the laws of classical mechanics and the laws of the electromagnetic field. Between 1902 and 1909 he made the theory of special relativity to fix it.