Editing Newton's laws of motion (section)

==== Aristotle and "violent" motion ====
[[File:Statue at the Aristotle University of Thessaloniki (cropped).jpg|alt=Statue of Aristotle|thumb|205x205px|Aristotle <br/>(384–322 [[BCE]])]]
The subject of physics is often traced back to [[Aristotle]], but the history of the concepts involved is obscured by multiple factors. An exact correspondence between Aristotelian and modern concepts is not simple to establish: Aristotle did not clearly distinguish what we would call speed and force, used the same term for [[density]] and [[viscosity]], and conceived of motion as always through a medium, rather than through space. In addition, some concepts often termed "Aristotelian" might better be attributed to his followers and commentators upon him.<ref>{{Cite journal |last=Ugaglia |first=Monica |date=2015 |title=Aristotle's Hydrostatical Physics |url=https://www.jstor.org/stable/43915795 |journal=Annali della Scuola Normale Superiore di Pisa. Classe di Lettere e Filosofia |volume=7 |issue=1 |pages=169–199 |jstor=43915795 |issn=0392-095X}}</ref> These commentators found that Aristotelian physics had difficulty explaining projectile motion.{{refn|group=note|Aristotelian physics also had difficulty explaining buoyancy, a point that Galileo tried to resolve without complete success.<ref>{{Cite journal |last1=Straulino |first1=S. |last2=Gambi |first2=C. M. C. |last3=Righini |first3=A. |date=January 2011 |title=Experiments on buoyancy and surface tension following Galileo Galilei |url=http://aapt.scitation.org/doi/10.1119/1.3492721 |journal=[[American Journal of Physics]] |language=en |volume=79 |issue=1 |pages=32–36 |doi=10.1119/1.3492721 |bibcode=2011AmJPh..79...32S |hdl=2158/530056 |issn=0002-9505 |quote=Aristotle in his ''Physics'' affirmed that solid water should have a greater weight than liquid water for the same volume. We know that this statement is incorrect because the density of ice is lower than that of water (hydrogen bonds create an open crystal structure in the solid phase), and for this reason ice can float. [...] The Aristotelian theory of buoyancy affirms that bodies in a fluid are supported by the resistance of the fluid to being divided by the penetrating object, just as a large piece of wood supports an axe striking it or honey supports a spoon. According to this theory, a boat should sink in shallow water more than in high seas, just as an axe can easily penetrate and even break a small piece of wood, but cannot penetrate a large piece.|hdl-access=free }}</ref>}} Aristotle divided motion into two types: "natural" and "violent". The "natural" motion of terrestrial solid matter was to fall downwards, whereas a "violent" motion could push a body sideways. Moreover, in Aristotelian physics, a "violent" motion requires an immediate cause; separated from the cause of its "violent" motion, a body would revert to its "natural" behavior. Yet, a javelin continues moving after it leaves the thrower's hand. Aristotle concluded that the air around the javelin must be imparted with the ability to move the javelin forward.