De motu corporum in gyrum [SEP] inception
De motu corporum in gyrum
De motu corporum in gyrum ("On the motion of bodies in an orbit") is the presumed title of a manuscript by Isaac Newton sent to Edmond Halley in November 1684. The manuscript was prompted by a visit from Halley earlier that year when he had questioned Newton about problems then occupying the minds of Halley and his scientific circle in London, including Sir Christopher Wren and Robert Hooke.
The title of the document is only presumed because the original is now lost. Its contents are
text is available online.
For ease of cross-reference to the contents of "De Motu" that appeared again in the "Principia", there are online sources for the "Principia" in English translation, as well as in Latin.
"De motu corporum in gyrum" is short enough to set out here the contents of its different sections. It contains 11 propositions, labelled as 'theorems' and 'problems', some with corollaries. Before reaching this core subject-matter, Newton begins with