In 1610, Galileo Galilei observed the moons of Jupiter rotating around it. He described them as small planets orbiting a larger planet—a description (and observation) that was very difficult for the church to accept, as it challenged a geocentric model where everything was supposed to revolve around the Earth. This observation also showed that the planets (Jupiter, Neptune, and later Venus was observed too) are all spherical, and all orbit the sun.

of the intervening object. This conclusion is forced upon, us by the evidence; but it involves the admission that the moon shines with light of its own–that it is not a reflector of the sun’s light, but absolutely self-luminous. Although this admission is logically compulsory, it will be useful and strictly Zetetic to collect all the evidence possible which bears upon it.”- Samuel Rowbathom, Zetetic Astronomy (1)
78) From Anchorage, Alaska at an elevation of 102 feet, on clear days Mount Foraker can be seen with the naked eye 120 miles away. If Earth were a ball 25,000 miles in circumference, Mount Foraker’s 17,400 summit should be leaning back away from the observer covered by 7,719 feet of curved Earth. In reality, however, the entire mountain can be quite easily seen standing straight from base to summit.
Considerably more than a million Earths would be required to make up a body like the Sun -the astronomers tell us: and more than 53,000 suns would be wanted to equal the cubic contents of the star Vega. And Vega is a "small star!" And there are countless millions of these stars! And it takes 30,000,000 years for the light of some of those stars to reach us at 12,000,000 miles in a minute! And, says Mr. Proctor, "I think a moderate estimate of the age of the Earth would be 500,000,000 years! "Its weight," says the same individual, "is 6,000,000,000,000,000,000,060 tons!" Now, since no human being is able to comprehend these things, the giving of them to the world is an insult - an outrage. And though they have all risen from the one assumption that Earth is a planet, instead of upholding the assumption, they drag it down by the weight of their own absurdity, and leave it lying in the dust - a proof that Earth is not a globe.
19) Tycho Brahe famously argued against the heliocentric theory in his time, positing that if the Earth revolved around the Sun, the change in relative position of the stars after 6 months orbital motion could not fail to be seen. He argued that the stars should seem to separate as we approach and come together as we recede. In actual fact, however, after 190,000,000 miles of supposed orbit around the Sun, not a single inch of parallax can be detected in the stars, proving we have not moved at all.
A flat planet (ours or any other planet) would be such an incredible observation that it would pretty much go against everything we know about how planets form and behave. It would not only change everything we know about planet formation, but also about star formation (our sun would have to behave quite differently to accommodate the flat-earth theory) and what we know of speeds and movements in space (like planets' orbits and the effects of gravity). In short, we don’t just suspect that our planet is spherical. We know it.

I am new to flat earth and see way more logical proof to this idea than the spinning globe. I have often wondered about what we are taught as it didn't make sense but we believe because that's what we been taught. One item I have not seen in my research and maybe you can address. If one were to stand precisely at the point where the imaginary axis is that the globe spins on, at the North Pole area, or even say 1/4 mile away,or ten feet away, what the person would see or experience I think would be bizarre....essentially rotating in a 1/4 mile or ten foot circle during the 24 hr day...more bizarre if they were on the exact axis point. This I think could be proven easily by going there, but it seems to not have been, which to me adds more proof to flat earth.I am sure if one were to go there, they would not see any following a circular pattern as the 24 hrs pass. They would be stationary!

65.) The Rev. D. Olmsted, in describing a diagram whish is supposed to represent the Earth as a globe, with a figure of a man sticking out at each side and one hanging head downwards, says "We should dwell on this point until it appears to us as truly up," In the direction given to these figures as it does with regard to a figure which he has placed on the top! Now, a system of philosophy which requires us to do something which is, really, the going out of our minds, by dwelling on an absurdity until we think it is a fact, Cannot be a system based on God's truth, which never requires anything of the kind. Since, then, the popular theoretical astronomy of the day requires this, it is evident that it is the wrong thing, and that this conclusion furnishes us with a proof that the Earth is not a globe.
“1 In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. 2 And the Spirit of God moved upon the face of the waters. 3 And God said, Let there be light: and there was light. 4 And God saw the light, that it was good: and God divided the light from the darkness. 5 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
In Figure 12, the ship now appears beyond the pier. Notice that the inferior mirage of the lettering on the hull is much more obvious now. In Figure 13, the lettering and its inferior mirage have not merged. In Figure 14, the lettering is difficult to see. This probably is because most of the lettering is below the horizon, and what appears to be the bottom of the hull is an inferior mirage of the top of the hull. This is clearly seen by the inferior mirage of the first layer of red containers below the turquoise. In Figure 15, the inferior mirage of the bottom layer of containers is more obvious, and the inferior mirage of the bottom of the bridge castle is beginning to show up. Clearly, at least half of the turquoise visible here is an inferior mirage. Most of the hull is below the curvature of the earth. Unfortunately, at this point the sun was about to set, so light levels were dropping quickly, forcing me to use longer exposures. At that point, I stopped taking photographs.
136) Many people think that modern astronomy’s ability to accurately predict lunar and solar eclipses is a result and proof positive of the heliocentric theory of the universe. The fact of the matter however is that eclipses have been accurately predicted by cultures worldwide for thousands of years before the “heliocentric ball-Earth” was even a glimmer in Copernicus’ imagination. Ptolemy in the 1st century A.D. accurately predicted eclipses for six hundred years on the basis of a flat, stationary Earth with equal precision as anyone living today. All the way back in 600 B.C. Thales accurately predicted an eclipse which ended the war between the Medes and Lydians. Eclipses happen regularly with precision in 18 year cycles, so regardless of geocentric or heliocentric, flat or globe Earth cosmologies, eclipses can be accurately calculated independent of such factors.
As the mariners' compass points north and south at one time, and as the North, to which it is attracted is that part of the Earth situated where the North Star is in the zenith, it follows that there is no south "point" or "pole" but that, while the centre is North, a vast circumference must be South in its whole extent. This is a proof that the Earth is not a globe.
121) When you observe the Sun and Moon you see two equally-sized equidistant circles tracing similar paths at similar speeds around a flat, stationary Earth. The “experts” at NASA, however, claim your common sense every day experience is false on all counts! To begin with, they say the Earth is not flat but a big ball; not stationary but spinning around 19 miles per second; they say the Sun does not revolve around the Earth as it appears, but Earth revolves around the Sun; the Moon, on the other hand, does revolve around the Earth, though not East to West as it appears, rather West to East; and the Sun is actually 400 times larger than the Moon and 400 times farther away! You can clearly see they are the same size and distance, you can see the Earth is flat, you can feel the Earth is stationary, but according to the gospel of modern astronomy, you are wrong and a simpleton worthy of endless ridicule if you dare to trust your own eyes and experience.