SHIRLEY GRIFFITH: This is Shirley Griffith.
STEVE EMBER: And this is Steve Ember with the VOA Special
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SHIRLEY GRIFFITH: Much of today's science of physics is based on (可连读) Newton's discovery of the three laws of motion and his theory of gravity. Newton also developed one of the most powerful tools（off) of mathematics. It is the method we call calculus.
Late in his life, Newton said of his work: "If I saw further than other men, it was because I stood on (可连读 )the shoulders of giants. "
