If astronomical works be searched through and through, there will not be found a single instance of a bold, unhesitating, or manly ,statement respecting a proof of the Earth's " rotundity." Proctor speaks of "proofs which serve to show ... that the Earth is not flat," and says that man "finds reason to think that the Earth is not flat," and speaks of certain matters being "explained by supposing" that the Earth is a, globe; and says that people have "assured themselves that it is a globe;" but he says, also, that there is a " most complete proof that the Earth is a globe:" just as though anything in the world could possibly be wanted but a proof - a proof that proves and settles the whole question. This, however, all the money in the United States Treasury would not buy; and, unless the astronomers are all so rich that they don't want the cash, it is a sterling proof that the Earth is not a globe.
60.) There is no problem more important to the astronomer than that of the Sun's distance from the Earth. Every change in the estimate changes everything. NOW, since modern astronomers, in their estimate of this distance, have gone all the way along the line of figures from three millions of miles to a hundred and four millions – today, the distance being something over 91,000,000; it matters not how much: for, not many years ago, Mr. Hind gave the distance, "accurately," as 95,370,000! – it follows that they don't know, and that it is foolish for anyone to expect that they ever will know, the Sun's distance! And since all this speculation and absurdity is caused by the primary assumption that Earth is a wandering, heavenly body, and is all swept away by a knowledge of the fact that Earth is a, plane, it is a clear proof that Earth is not a globe.
Another container ship made its way outward, as shown in Figure 11, a photograph taken through the supports of the pier at Virginia Beach. You can clearly read the name of the shipping company, Maersk Line, on the turquoise hull. What appears to be stains under the letters are the beginnings of an inferior mirage of the letters. Instead of a level of gray containers immediately above the hull, the layer of containers right above the hull on this ship appear a deep red. As with the other ship, in each succeeding photograph this ship is farther away, as evidenced by the decreasing apparent sizes of the containers and the ship.
Aristotle (who made quite a lot of observations about the spherical nature of the Earth) noticed that during lunar eclipses (when the Earth’s orbit places it directly between the Sun and the Moon, creating a shadow in the process), the shadow on the Moon’s surface is round. This shadow is the planet's, and it’s a great clue about the spherical shape of the Earth.
Since temperature inversions are common over water, it is relatively easy to devise experiments in which distant objects beyond the curvature of the earth are visible. Perhaps the most famous are the photographs of the Chicago skyline taken across Lake Michigan, about 60 miles away. The photographer, Joshua Nowicki, does not promote the flat earth, but flat-earthers have used his photographs many times, such as here, as supposed proof that the earth is flat. Flat-earthers do not seem to be aware of just how rare these photographs are. If the earth were flat, then the Chicago skyline would be visible across Lake Michigan nearly every clear day, but it is not. If the earth is spherical, then the hulls of ships ought to disappear as the ships move away from the observer. Since the ship must move many miles away for this to become noticeable, it is difficult to see this with the naked eye.
After returning from a trip to Egypt, Aristotle noted, “There are stars seen in Egypt and…Cyprus which are not seen in the northerly regions.” This phenomenon can only be explained if humans were viewing the stars from a round surface, Aristotle continued, claiming that the sphere of the Earth is “of no great size, for otherwise the effect of so slight a change of place would not be quickly apparent.” (De caelo, 298a2-10)
Consider a flat plane. The center of mass of a flat plane is in its center, so the force of gravity will pull anything on the surface toward the middle of the plane. That means that if you stand on the edge of the plane, gravity will be pulling you sideways toward the plane's middle, not straight down like you usually experience when you stand on Earth.
79.) The remark is common enough that we can see the circle of the Earth if we cross the ocean, and that this proves it to be round. Now, if we tie a donkey to a stake on a level common, and he eats the grass all around him, it is only a circular disc that he has to do with, not a spherical mass. Since, then, circular discs may be seen anywhere – as well from a balloon in the air as from the deck of a ship, or from the standpoint of the donkey, it is a proof that the surface of the Earth is a plane surface, and, therefore, a proof that the Earth is not a globe.