(1920-92) a US scientist and writer, born in Russia, and famous for writing SCIENCE FICTION (= stories about life in the future and imaginary developments in science)
1773-1843 united States naval officer who commanded the 'Constitution' during the War of 1812 and won a series of brilliant victories against the British
(1642-1727) a British PHYSICIST and MATHEMATICIAN who discovered GRAVITY (=the force that causes things to fall towards the ground or to be pulled towards stars or PLANET s in space). He made many other important scientific discoveries, and is one of the most important scientists who ever lived. Until the early 20th century, modern PHYSICS was based on Newton's work, and it is sometimes called Newtonian PHYSICS .