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Before Newton many phycisists try to understand nature and the rotations of planets. But Newton founded his laws of gravity. But was he the first who used the word gravity or when was it first used? And comes the word gravity from the word 'grievous'? Or was Aristotle or Galilei before him using that word? Of course they spoke another language but perhaps the already used βαρύτητα or gravità?

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    $\begingroup$ No it was not. It existed in English language since the times immemorial. It is of Latin origin. $\endgroup$ – Alexandre Eremenko Feb 19 '16 at 18:29
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    $\begingroup$ Hi, welcome to hsm. This question is answered on English SE english.stackexchange.com/questions/48469/… $\endgroup$ – Conifold Feb 19 '16 at 19:37
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    $\begingroup$ So maybe we should improve the question. "Gravity" formerly meant: the tendency of objects to fall toward the center of the earth. Was Newton the first to change that to: the tendency of two objects to attract each other? $\endgroup$ – Gerald Edgar Feb 21 '16 at 2:44
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Gravitas is the latin word used by Medieval natural philosophers to translate the Aristotelian heaviness, i.e. the quality of a body "having weight" (pondus):

Let us then apply the term ‘heavy’ (βάρος) to that which naturally moves towards the centre, and ‘light’ to that which moves naturally away from the centre. (De Caelo, 269b)


Isaac Newton uses gravity in his Philosophiae Naturalis Principia Mathematica (1687, 3rd Latin ed, 1726):

DEFINITION V

A centripetal force is that by which bodies are drawn or impelled, or any way tend, towards a point as to a centre.

Of this sort is gravity [gravitas], by which bodies tend to the centre of the earth.


Thus, Newton did not invent the word, but was the author of a crucial "shift of meaning": previously "gravity" denoted a quality, then a force.

For sure, Newton "invented" the force of gravity [vi gravitatis].



Note. Galileo Galilei in his Dialogue (in Italian) uses: gravità and leggerezza for heaviness and lightness, respectively.

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Gravity meant weight or heaviness before Newton. Thus Newton writes: “That force by which the moon is held back in its orbit is that very force which we usually call ‘gravity’.” (Principia, Book III, Prop. IV.)

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  • $\begingroup$ what does he mean by saying: 'we usually call gravity'? Who is 'we' and why said he 'usually'? $\endgroup$ – Marijn Feb 19 '16 at 16:31
  • $\begingroup$ @Marijn He means that "gravity" is a common word in general usage by speakers of the English language. The Oxford English Dictionary lists many examples of pre-Newtonian uses of "gravity" in the sense of weight, such as for example: "1646 Sir T. Browne Pseudodoxia Epidemica ii. iii. 72 To overcome the resistance of its gravity and to lift it up from the earth." $\endgroup$ – Viktor Blasjo Feb 19 '16 at 17:57
  • $\begingroup$ Do you think Aristotels also used βαρύτητα for his explanatioin why earthy heavy things falls to earth? $\endgroup$ – Marijn Feb 19 '16 at 19:49
  • $\begingroup$ @ViktorBlasjo. Except that the Principia are in Latin, not English. $\endgroup$ – fdb Feb 20 '16 at 17:38
  • $\begingroup$ @fdb yes yes, but the point is the same in either language. $\endgroup$ – Viktor Blasjo Feb 20 '16 at 17:48

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