Editing Scientific Revolution (section)

==== Gravitation ====
[[File:NewtonsPrincipia.jpg|thumb|[[Isaac Newton]]'s ''[[Philosophiæ Naturalis Principia Mathematica|Principia]]'' developed the first set of unified scientific laws.]]

Newton also developed the theory of gravitation. In 1679, Newton began to consider gravitation and its effect on the orbits of planets with reference to Kepler's laws of planetary motion. This followed stimulation by a brief exchange of letters in 1679–80 with Hooke, opened a correspondence intended to elicit contributions from Newton to Royal Society transactions.<ref>''Correspondence of Isaac Newton, vol. 2, 1676–1687'' ed. H.W. Turnbull, Cambridge University Press 1960; at page 297, document No. 235, letter from Hooke to Newton dated 24 November 1679.</ref> Newton's reawakening interest in astronomical matters received further stimulus by the appearance of a comet in the winter of 1680–81, on which he corresponded with [[John Flamsteed]].<ref>[[#Westfall|Westfall]], pp. 391–92</ref> After the exchanges with Hooke, Newton worked out proof that the elliptical form of planetary orbits would result from a [[centripetal force]] [[inverse-square law|inversely proportional to the square of the radius vector]]. Newton communicated his results to [[Edmond Halley]] and to the Royal Society in ''[[De motu corporum in gyrum]]'' in 1684.<ref>Whiteside D.T. (ed.) (1974) ''Mathematical Papers of Isaac Newton'', vol. 6, 1684–1691, Cambridge University Press. p. 30.</ref> This tract contained the nucleus that Newton developed and expanded to form the ''Principia''.<ref>[https://www.bbc.co.uk/history/historic_figures/newton_isaac.shtml Isaac Newton (1643–1727)] {{Webarchive|url=https://web.archive.org/web/20150310093436/http://www.bbc.co.uk/history/historic_figures/newton_isaac.shtml |date=10 March 2015 }}, BBC – History</ref>

The ''Principia'' was published on 5 July 1687 with encouragement and financial help from Halley.<ref>[http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Halley.html Halley biography] {{Webarchive|url=https://web.archive.org/web/20090213164959/http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Halley.html |date=13 February 2009 }}. Groups.dcs.st-and.ac.uk. Retrieved on 26 September 2011.</ref> In this work, Newton states the [[Newton's laws of motion|three universal laws of motion]] that contributed to many advances during the [[Industrial Revolution]] which soon followed and were not to be improved upon for more than 200 years. Many of these advancements continue to be the underpinnings of non-relativistic technologies in the modern world. He used the Latin word ''gravitas'' (weight) for the effect that would become known as [[gravity]] and defined the law of universal gravitation.

Newton's postulate of an invisible [[action at a distance|force able to act over vast distances]] led to him being criticised for introducing "[[occult]] agencies" into science.<ref>Edelglass et al., ''Matter and Mind'', {{ISBN|0-940262-45-2}}. p. 54</ref> Later, in the second edition of the ''Principia'' (1713), Newton firmly rejected such criticisms in a concluding "[[General Scholium]]," writing that it was enough that the phenomena implied a gravitational attraction, as they did; but they did not so far indicate its cause, and it was both unnecessary and improper to frame hypotheses of things that were not implied by the phenomena. (Here Newton used what became his famous expression "''[[hypotheses non fingo]]''").<ref>On the meaning and origins of this expression, see Kirsten Walsh, [https://blogs.otago.ac.nz/emxphi/2010/10/does-newton-feign-an-hypothesis/ Does Newton feign an hypothesis?] {{Webarchive|url=https://web.archive.org/web/20140714120054/https://blogs.otago.ac.nz/emxphi/2010/10/does-newton-feign-an-hypothesis/ |date=14 July 2014 }}, [https://blogs.otago.ac.nz/emxphi/ Early Modern Experimental Philosophy] {{Webarchive|url=https://web.archive.org/web/20110721051523/https://blogs.otago.ac.nz/emxphi/ |date=21 July 2011 }}, 18 October 2010.</ref>