A Jewish-born German, later naturalised as a US citizen, Einstein became the most influential physicist of the 20th century.
He developed his special theory of relativity in response to problems he saw with Newtonian mechanics. His mass–energy equivalence formula E = mc2 has been called the "the world's most famous equation".
He was awarded the Nobel Prize for Physics in 1921 and later warned President Roosevelt of the dangers of bombs being developed, later protesting against their use as weapons.