De Motu Corporum in Gyrum - Role of Robert Hooke

Role of Robert Hooke

Newton acknowledged in 1686 that an initial stimulus on him in 1679/80 to extend his investigations of the movements of heavenly bodies had arisen from correspondence with Robert Hooke in 1679/80.

Hooke had started an exchange of correspondence in November 1679 by writing to Newton, to tell Newton that Hooke had been appointed to manage the Royal Society's correspondence. Hooke therefore wanted to hear from members about their researches, or their views about the researches of others; and as if to whet Newton's interest, he asked what Newton thought about various matters, and then gave a whole list, mentioning "compounding the celestial motions of the planetts of a direct motion by the tangent and an attractive motion towards the central body", and "my hypothesis of the lawes or causes of springinesse", and then a new hypothesis from Paris about planetary motions (which Hooke described at length), and then efforts to carry out or improve national surveys, the difference of latitude between London and Cambridge, and other items. Newton replied with "a fansy of my own" about determining the Earth's motion, using a falling body. Hooke disagreed with Newton's idea of how the falling body would move, and a short correspondence developed.

Later, in 1686, when Newton's 'Principia' had been presented to the Royal Society, Hooke claimed from this correspondence the credit for some of Newton's content in the 'Principia', and said Newton owed the idea of an inverse-square law of attraction to him – although at the same time, Hooke disclaimed any credit for the curves and trajectories that Newton had demonstrated on the basis of the inverse square law.

Newton, who heard of this from Halley, rebutted Hooke's claim in letters to Halley, acknowledging only an occasion of reawakened interest. Newton did acknowledge some prior work of others, including Bullialdus, who suggested (but without demonstration) that there was an attractive force from the Sun in the inverse square proportion to the distance, and Borelli, who suggested (again without demonstration) that there was a tendency towards the Sun like gravity or magnetism that would make the planets move in ellipses; but that the elements Hooke claimed were due either to Newton himself, or to other predecessors of them both such as Bullialdus and Borelli, but not Hooke. Wren and Halley were both sceptical of Hooke's claims, recalling an occasion when Hooke had claimed to have a derivation of planetary motions under an inverse square law, but had failed to produce it even under the incentive of a prize.

There has been scholarly controversy over exactly what if anything Newton really gained from Hooke, apart from the stimulus that Newton acknowledged.

About thirty years after Newton's death in 1727, Alexis Clairaut, one of Newton's early and eminent successors in the field of gravitational studies, wrote after reviewing Hooke's work that it showed "what a distance there is between a truth that is glimpsed and a truth that is demonstrated".