That struck me as an interesting question. The father of the theory of gravity was of course Isaac Newton (he wasn’t thinking about apples falling, he was thinking about planets and moons rotating around a larger mass). So I checked.
Newton went to school in Grantham and then went to Trinity College Cambridge. Up until he obtained his masters degree it seems he was not a notable student. But in completing his bachelors degree his work was recognised as outstanding scientific and mathematical developments - mainly gravity and calculus.
So, yes, it seems he really did want to do on to study such stuff when he left school.
1 Like
Someone one dumb it down so could understand it. In the big picture the sun rotates around the Galaxy. The plants rotate around the Sun. Ok, here it is. If the sun did not move the planet would be sucked into the Sun. But since the Sun keeps moving, the planets are headed to where the Sun is but by the time the planets get to were the sun was, it’s not there anymore more. So it’s a continuous cycle. The planters keep heading toward the sun but it keeps moving out of the way.
Not sure if that cleared it up?
2 Likes
Sounds good to me Robin…
1 Like
Not entirely correct. The Sun is not spherical, but an oblate spheroid. If it were to stop rotating, it would have virtually no effect because its mass and gravity would remain the same, spinning or not. Because of the Sun’s shape and it’s effect on localised space/time, the shift in planetary orbit would be something in the order of fraction of an arcsecond per hundred years. If the sun were to ‘disappear’, the planets would wander off on a tangential path with respect to their position/velocity.
1 Like
I agree, but like I said they dumb it down form me. It wasn’t about the spin as much, but more about forward movement/rotation around the larger object.
This might clarify it a little better. The moon is getting farther away from the earth every year, by about an inch a year. But, if the arthritis stopped moving in a forward direction or any direction, and the moon stopped it forward movement, rotation being irrelevant, the moon would be pulled into the Earth’s gravity. Sort of like satellites. Most have the forward momentum and distance correct and some don’t and by being off by a fraction can bring them back to earth or sent if into space.
1 Like
Satellites fall to Earth as a result of atmospheric drag slowing them down and being overcome with gravity due to their mass. This atmosphere can vary and changes as a result of solar radiation. If a body is placed in HEO (High Earth Orbit), around 1,240 miles above the Earth, the atmospheric drag is virtually zero. So any object placed there will stay in orbit for somewhere between 1,000 years to indefinitely. Only if there is some significant external force enough to overcome the Moon’s mass/inertia would cause it impact the Earth.
2 Likes
This Geezer Hung around.
And Did It.
All’s well, though.
Azz & Matron have sent him some Toothpaste. JIC. 
.
1 Like
I have rarely read a series of posts that demonstrate such a lack of knowledge and understanding of planetary dynamics. Throw in some glorious misspellings (plants and planters??) and we have a fulsome display of dumb parading as intellectual…
2 Likes
Don’t tell me Lincs, I used to think that all the stars was just light from our sun reflecting off distant planets. It wasn’t until a good friend (?) told me that they were in fact suns like ours but trillions of light years away…
It took me a long time to believe him. I’m still wondering…
1 Like