Happy Birthday, Albert Einstein (14 March 1879 – 18 April 1955)! His 1915 General Theory of Relativity earned him worldwide fame and a firm place in history. He also won the Nibel Prize in 1921 for his contributions to photoelectric theory. Dissatisfied with Newton’s classical mechanics and their limitations in explaining the natural world and specifically the newly discovered microscopic world suggested by the electromagnetic field, Einstein proposed a theory that addressed mechanics, electromagnetic fields and gravity. The world relativity was first used in English as a noun in 1834 meaning simply the fact or condition of being relative, derived from the English adjective relative. It first had roughly the sense that Einstein used in the work of English scientist James Clerk Maxwell in 1876. The word relative was used in English in the 14th century to mean a relative pronoun-from the Late Latin relativusmeaning having reference or relation, which came from Latin relatus, the past participle of referre meaning to refer.
Portrait of Albert Einstein in 1921.