That and when they realize his whole universe was held together by magic. And that he was a lying cheating thief whose accomplishments lie not on the shoulders of giants, but because he would actively discredit other scientists to then steal their work later. He was truly an awful human being.
I agree with some of what you say, yes from what I have read Hooke was on the verge coming up with the same "Law of Universal Gravitation". Whether Newton stole it I don't know. The fact the Hooke died 24 years before Newton certainly enabled Newton to claim most of the credit and his dealings with Hooke were certainly not friendly.
But on the matter of "when they realize his whole universe was held together by magic" I do have to wonder if you really are showing a sense of humour.
You think gravitation is magic yet happily accept:
electromagnetic and nuclear forces? universal acceleration propelled by an
almost infinite magic energy source? sun, moon, planets and "stars" moving around weird paths powerd by magic?
the sun seeming to set
behind the horizon when it is still
3000 miles high (and at an elevation of roughly 20°).
the sun and moon appear (almost)
the same size all day (and night) when their distances
vary by a factor of around 4.
I could go on and on about the causes of moon phases and eclipses and the phases and size variations of say Venus, but you whole "universe" is held together by pure coincidence! just the right (magical) "atmospheric magnification" to make the sun and moon
seem to stay the same size.
Also the distance to the moon has been estimated be the early Greeks, calculated using parallax by astromomers centuries ago and finally accurately measured by radar and then by laser - guess what, the answers came out fairly consistent - sure the Greeks figures were a bit rough. And the Flat Earth explanation for the radar figures - how do we know that light does not travel slower when that far away? Sure but one 80th the speed!
How has the height of the moon been measured over the Flat Earth? Well we are
TOLD!
The Moon
The moon is a sphere. It has a diameter of 32 miles and is located approximately 3000 miles above the surface of the earth.
Justification - NONE!
One coincidence could be just a coincidence, but when they start piling one on top of the other, it becomes simply unbelievable MAGIC!
Please don't talk about gravitation being magic till you explain about the evidence for things like "lunar bio-luminescence".