Robert Hooke's seminal contribution to orbital dynamics (Q1780872)

To understand the physical basis for Kepler's laws describing the orbital motion of a planet, Robert Hooke proposed in the middle of the 1660s that a planet's motion is determined by compounding its tangential velocity with the change in radial velocity and described his physical concept in a letter to Isaac Newton in 1679. Newton denied having heard of Hooke's novel concept but shortly after their correspondence he implemented it by a geometric construction. Three years later Newton deposited a preliminary draft at the Royal Society of London, which Hooke apparently was able to examine. He applied Newton's construction in a novel way to obtain the path of a body under the action of a certain force. The author shows that Hooke's construction corresponds to Newton's for his proof of Kepler's area law.