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In the answer to this question, a user provided a quote from the 1638 novel The Man in the Moone by Bishop Francis Godwin:

The manner of our Travel to the Palace of Pylonas was more strange and incredible than any thing we have related, for at our first setting forth there were delivered to each of us two Feather Fans, like those our Ladies in Spain cool themselves with in Summer: You must understand, that the Globe of the Moon has likewise an attractive Power, yet so much weaker than the Earth, that if a Man do but spring upward with all his Strength, as Dancers do in shewing their Tricks, he will be able to mount fifty or sixty Foot high; and being then above all Attraction from the Moon's Earth, he falls down no more, but by the Help of these Fans, as with Wings, they convey themselves in the Air in a short Space, (though not quite so swift as Birds) whither they please. In two hours Time (as I could guess) by the Help of these Fans, we were carried through the Air those five Leagues, in all about sixty Persons.

How is it possible that Godwin was aware that the force of gravity would be reduced on the Moon? As far as I am aware, the idea that mass and gravity were related was Newton's invention, and at the time of this novel's writing Newton had not yet been born.

tbrookside
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    See History of Gravitational Theory. For example, in Aristotle's concept of gravitas, heavier object possess more attractive power. – nwr Aug 05 '19 at 19:30
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    The conjectures about attraction between celestial bodies were widely discussed before Newton. (Newton's contribution was to proving the exact law of this attraction and deriving verifiable new consequences from this law). – Alexandre Eremenko Aug 05 '19 at 21:02
  • Physics did not start with Newton, you know. – Chrystomath Aug 06 '19 at 07:58
  • This question might be better rephrased as "what was the state of understanding of gravity in 1638" – Carl Witthoft Aug 06 '19 at 13:16
  • @NickR Nowhere does Aristotle imply that gravity is stronger on Earth than on the Moon. – fdb Aug 12 '19 at 23:32
  • @fdb No, obviously not. But the moon, to a 17th century man such as Godwin, being smaller than the earth and so less "heavy", would possess less "attractive power". This would explain the ability to "spring upward with all his Strength, as Dancers do in shewing their Tricks, he will be able to mount fifty or sixty Foot high" etc. Admittedly, my comment appears rather cryptic now and the reference to History of Gravitational Theory should have been sufficient. – nwr Aug 13 '19 at 04:43
  • Newton's big idea was the apple fell for the same reason as celestial bodies and that is an amazing concept for sure -- he is a genius just from that and working out the math thereof. However, Kepler and Galileo I am pretty sure thought of attraction between the sun and the planets -- they did not attribute it to the same thing that makes fruit fall. I do think reduced gravity on the moon is very interesting and insightful and I wonder who first thought of low gravity on the moon, separate from gravity being a celestial force also. – releseabe Sep 15 '23 at 11:28

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