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* ”'[[National Advisory Committee for Aeronautics|NACA]]”’ — [[United States]] National Advisory Committee for Aeronautics, replaced by [[NASA]] in 1958.

* ”'[[National Advisory Committee for Aeronautics|NACA]]”’ — [[United States]] National Advisory Committee for Aeronautics, replaced by [[NASA]] in 1958.

* ”'[[Nanotechnology]]”’ —

* ”'[[NASA]]”’ — [[United States]] National Aeronautics and Space Administration.

* ”'[[NASA]]”’ — [[United States]] National Aeronautics and Space Administration.

* ”'[[Navier–Stokes equations]]”’ —

* ”'[[Navier–Stokes equations]]”’ —

* ”'[[Newton (unit)]]”’ —

* ”'[[Newton (unit)]]”’ —

* ”'[[Newton’s law of universal gravitation]]”’ — is usually stated as that every [[particle]] attracts every other particle in the universe with a [[force]] that is [[Proportionality (mathematics)#Direct proportionality|directly proportional]] to the product of their masses and [[Proportionality (mathematics)#Inverse proportionality|inversely proportional]] to the square of the distance between their centers.<ref group=”note”>It was shown separately that separated spherically symmetrical masses attract and are attracted [[Shell theorem|as if all their mass were concentrated at their centers]].</ref> The publication of the theory has become known as the “[[Unification (physics)|first great unification]]”, as it marked the unification of the previously described phenomena of gravity on Earth with known astronomical behaviors.<ref>{{cite book|author=Fritz Rohrlich|title=From Paradox to Reality: Our Basic Concepts of the Physical World|url=https://books.google.com/books?id=3TqA1394OVcC&pg=PA28|date=25 August 1989|publisher=Cambridge University Press|isbn=978-0-521-37605-1|pages=28–}}</ref><ref>{{cite book|author=Klaus Mainzer|title=Symmetries of Nature: A Handbook for Philosophy of Nature and Science|url=https://books.google.com/books?id=QekhAAAAQBAJ&pg=PA8|date=2 December 2013|publisher=Walter de Gruyter|isbn=978-3-11-088693-1|pages=8–}}</ref><ref>{{Cite web|url=https://www.encyclopedia.com/science/science-magazines/physics-fundamental-forces-and-synthesis-theory|title=Physics: Fundamental Forces and the Synthesis of Theory &#124; Encyclopedia.com|website=www.encyclopedia.com}}</ref>

* ”'[[Newton’s law of universal gravitation]]”’ —

:This is a general [[physical law]] derived from [[empirical observation]]s by what [[Isaac Newton]] called [[inductive reasoning]].<ref>Isaac Newton: “In [experimental] philosophy particular propositions are inferred from the phenomena and afterwards rendered general by induction”: “[[Philosophiae Naturalis Principia Mathematica|Principia]]”, Book 3, General Scholium, at p.392 in Volume 2 of Andrew Motte’s English translation published 1729.</ref> It is a part of [[classical mechanics]] and was formulated in Newton’s work ”[[Philosophiæ Naturalis Principia Mathematica]]” (“the ”Principia””), first published on 5 July 1687. When Newton presented Book 1 of the unpublished text in April 1686 to the [[Royal Society]], [[Robert Hooke]] made a claim that Newton had obtained the inverse square law from him.

:In today’s language, the law states that every [[Point particle|point]] [[mass]] attracts every other point mass by a [[force]] acting along the [[Line (mathematics)|line]] intersecting the two points. The force is [[Proportionality (mathematics)|proportional]] to the [[Product (mathematics)|product]] of the two masses, and inversely proportional to the [[Square (algebra)|square]] of the distance between them.<ref name=”Newton1″/>

:The equation for universal gravitation thus takes the form:

:<math>F=G\frac{m_1m_2}{r^2},</math>

:where ”F” is the gravitational force acting between two objects, ”m₁” and ”m₂” are the masses of the objects, ”r” is the distance between the [[Center of mass|centers of their masses]], and ”G” is the [[gravitational constant]].

* ”'[[Newton’s laws of motion]]”’ —

* ”'[[Newton’s laws of motion]]”’ —