A pr 2 00 5 Hooke ’ s Memorandum on the development of orbital dynamics

I discuss a memorandum entitled " A True state of the Case and Controversy between Sir Isaak Newton & Dr Robert Hooke as the Priority of that Noble Hypothesis of Motion of ye Planets about ye Sun as their Centers " , where Robert Hooke summarized his seminal contributions to the physics of orbital motion and to the theory of universal gravitation. In a brief handwritten but undated memorandum entitled " A True state of the Case and Controversy between S r Isaak Newton & D r Robert Hooke as the Priority of that Noble Hypothesis of Motion of ye Planets about ye Sun as their Centers " [1], Hooke recounted his hypothesis for the physics of orbital motion and his theory of universal gravitation. Hooke's memorandum , which remained unpublished during his lifetime, is historically quite accurate, contradicting numerous criticisms of his contemporaries and historians of science that Hooke always claimed for himself more credit than he actually deserved. In fact, to support his " priority " Hooke quoted verbatim from several extant documents: the transcript of his lecture on Planetary Movements as a Mechanical Problem given at the Royal Society on May 23, 1666 [2], his short (28 pages) monograph, An Attempt to prove the motion of the Earth by Observations published in 1674 [3], and his lengthy correspondence in the Fall of 1679 with Isaac Newton [4]. However, Hooke did not mention his remarkable geometrical implementation of orbital motion for central force motion, see Fig. 1, based on the application of his physical principles , which was found only recently in a manuscript dated Sept. 1685 [6] [7]. Unfortunately, Hooke did not publish this manuscript and related work in spite of Edmond Halley's urging him " ... that unless he produce another 1