'A corpuscle...is attracted to the centre of the sphere', 1687.
© Science Museum / Science & Society Picture Library
Proposition 71, Theorem 31, concerning the attractive forces of spherical bodies, from Newton's 'Principia Mathematica' (1687). This proposition posits that 'a corpuscle placed outside the spherical surface is attracted to the centre of the sphere by a force inversely proportional to the square of its distance from that same centre.' The discoveries of English physicist and mathematician Isaac Newton (1642-1727) were prolific and hugely influential on science and thought. His work included the three laws of motion, the theory of gravitation, the law of cooling, the binomial theorem and the calculus.