What I wonder about, is everyone always talks about the conservation of momentum... what is the original force that made Earth travel? I find it hard to believe or comprehend that planets remain in orbit without an actual force keeping them moving, gravity of the sun is often the ad hoc explanation.
But where did his initial momentum come from? Is this what the hypothetical big bang is supposed to explain?
Also... why would gravity make things orbit elliptically around an object... if the law of gravity states that a molecule is intrinsically pulled to every other molecule inversely squared to the distance between them... then why isn't everything careening into the Sun?
Even in the Flat Earth model "things" are moving. The sun, moon and shadow object orbit the earth in a strange spiral pattern, the planets orbit the sun and the stars orbit around Polaris, over the North Pole. If you want more detail on this ask "the Wiki", don't ask me.
So, flat or Globe, something started it all running!
You ask,
"why would gravity make things orbit elliptically around an object"? All I can say is that is what you get when you solve the equations involving gravitation and Newton's laws of motion. Actually Johannes Kepler working with the data largely gathered by Tycho Brahe (who as it happens did not accept Copernicus' ideas) found that the planets were moving in (almost) elliptical orbits. Newton in the meantime (actually I don't know all the dates off the top of my head) found that a single small object orbited a large one in an elliptical orbit - nicely tying it all Up.
Of course there are 8 full planets, a number of minor planets and an almost innumerable number of asteroids and comets etc orbiting the sun. This means that the orbits of the planets are
not quite elliptical because a given planet is affected by the others, though only the ones either side are significant. The orbits of Neptune and Pluto are an extreme case where sometimes Pluto is closer to the Sun than Neptune.
Then you ask "then why isn't everything careening into the Sun?". Simply because gravitation is only one of the forces involved. The acceleration due to say the Sun's gravitation is balanced by the centripetal acceleration of the planet moving in a curved orbit.
But, the bottom line is simply that Flat Earth or Globe, the Earth and all the Celestial objects are in motion.
At least for the Heliocentric Globe these motions are (in general) explainable.
But there seems no rational explanation of the movements of the Celestial objects in the Flat Earth model - in particular nothing to explain what makes Sun (Moon and shadow object) move the required spiral sort of motion.