Quite simply you cannot. It is widely stated you would need to be at a height of at least 40,000 ft to get even a hint of curvature if earth were round. Commercial aircraft are not allowed to fly this high. They are only allowed to fly just under this altitude. 36,000ft might be typical. In addition, the windows on commercial aircraft are small and heavily curved. Even if they flew high enough for a person to see curvature, it would still not be visible to passengers.
If the Earth were a globe, it would, unquestionably, have the same general characteristics - no matter its size - as a small globe that may be stood upon the table. As the small globe has top, bottom, and sides, so must also the large one - no matter how large it be. But, as the Earth, which is "supposed" to be a large globe, bas no sides or bottom as the small globe has, the conclusion is irresistible that it is a proof that the Earth is not a globe.
113) The idea that people are standing, ships are sailing and planes are flying upside down on certain parts of Earth while others tilted at 90 degrees and all other impossible angles is complete absurdity. The idea that a man digging a hole straight down could eventually reach sky on the other side is ludicrous. Common sense tells every free-thinking person correctly that there truly is an “up” and “down” in nature, unlike the “everything is relative” rhetoric of the Newtonian/Einsteinian paradigm.
93.) We have seen that astronomers – to give us a level surface on which to live – have cut off one-half of the "globe" in a certain picture in their books. [See page 6.] Now, astronomers having done this, one-half of the substance of their "spherical theory" is given up! Since, then, the theory must stand or fall in its entirety, it has really fallen when the half is gone. Nothing remains, then, but a plane Earth, which is, of course, a proof that the Earth is not a globe.
4) If Earth were a ball 25,000 miles in circumference as NASA and modern astronomy claim, spherical trigonometry dictates the surface of all standing water must curve downward an easily measurable 8 inches per mile multiplied by the square of the distance. This means along a 6 mile channel of standing water, the Earth would dip 6 feet on either end from the central peak. Every time such experiments have been conducted, however, standing water has proven to be perfectly level.

With increasing distance from the object, the earth’s curvature causes the surface of the water to fall away from the beam of light. Over one mile, the amount of drop is eight inches, but the drop increases quadratically with distance. Consequently, after three miles the drop is six feet, and after six miles the drop is 24 feet. This is the point of the Bedford level experiment—the curvature of the earth ought to intervene to prevent the mast of the boat being visible from much more than three miles, let alone six miles. However, for the light from the distant object not to be visible, it would have to travel in a straight line. But with a temperature inversion, straight-line motion would carry the light from a cooler layer of air into a warmer layer of air at nearly a grazing angle. The light cannot do this, so it continually is internally reflected, causing the light to bend around the edge of the earth. Therefore, with a temperature inversion, one can see objects that lie well beyond the edge of the earth’s curvature when viewing close to the surface of water.
In the next photograph and succeeding photographs, the ship is farther away, as indicated by the decreasing apparent size of the ship. In Figure 5, an inferior mirage is starting to show up. At the edge of the water, you can see a gray line, which is an inferior mirage of the row of gray containers right above the hull. On the right side of the ship, you can see the inferior mirage of the bow. The hull protrudes forward there, and the small white patch just above is a small portion of the forecastle. Notice that the inferior mirage of the bow is inverted, as one would expect. It is difficult to see here, but the lettering on the hull also is undergoing an inferior mirage too.
97.) Mr. Hind, the English astronomer, says – "The simplicity, with which the seasons are explained by the revolution of the Earth in her orbit and the obliquity of the ecliptic, may certainly be adduced as a strong presumptive proof of the correctness" – of the Newtonian theory; "for on no other rational suppositions with respect to the relations of the Earth and Sun, can these and other as well-known phenomena, be accounted for." But, as true philosophy has no "suppositions" at all – and has nothing to do with, "suppositions" – and the phenomena spoken of are thoroughly explained by facts, the "presumptive proof" falls to the ground, covered with the ridicule it the dust of Mr. Hind's "rational suppositions" we are standing before us a proof that Earth is not a globe.

If you are a Christian and you believe the Bible is the True Word of God, then you need to set aside all previous beliefs and accept what the Bible says, not what the world and the media say. Remember, the Bible tells us that we have an enemy, called Satan. It says in John 8:44 about Satan, that, “He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.” And also in Revelation 12:9 it describes what happened to Satan and what he is doing on earth: “And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.”

53.) Every year the Sun is as long south of the equator as he is north; and if the Earth were not "stretched out" as it is, in fact, but turned under, as the Newtonian theory suggests it would certainly get as intensive a share of the Sun's rays south as north; but the Southern region being, in consequence of the fact stated, – far more extensive than the region North, the Sun, having to complete his journey round every twenty-four hours, travels quicker as he goes further south, from September to December, and his influence has less time in which to accumulate at any given point. Since, then the facts could not be as they are if the Earth were a globe, it is a proof that the Earth is not a globe.
132) The Sun’s light is golden, warm, drying, preservative and antiseptic, while the Moon’s light is silver, cool, damp, putrefying and septic. The Sun’s rays decrease the combustion of a bonfire, while the Moon’s rays increase combustion. Plant and animal substances exposed to sunlight quickly dry, shrink, coagulate, and lose the tendency to decompose and putrify; grapes and other fruits become solid, partially candied and preserved like raisins, dates, and prunes; animal flesh coagulates, loses its volatile gaseous constituents, becomes firm, dry, and slow to decay. When exposed to moonlight, however, plant and animal substances tend to show symptoms of putrefaction and decay. This proves that Sun and Moon light are different, unique, and opposites as they are in the geocentric flat model.
74.) As to the supposed "motion of the whole Solar system in space," the Astronomer Royal of England once said: "The matter is left in a most delightful state of uncertainty, and I Shall be very glad if anyone can help us out of it." But, since the whole Newtonian scheme is, today, in a most deplorable state of uncertainty – for, whether the Moon goes round the Earth or the Earth round the Moon has, for years, been a matter of "raging" controversy it follows that, root and branch, the whole thing, is wrong; and, all hot from the furnace of philosophical phrensy, we find a glowing proof that the Earth is not a globe.
140) Foucault’s Pendulums are often quoted as proof of a rotating Earth but upon closer investigation prove the opposite. To begin with, Foucault’s pendulums do not uniformly swing in any one direction. Sometimes they rotate clockwise and sometimes counter-clockwise, sometimes they fail to rotate and sometimes they rotate far too much. The behavior of the pendulum actually depends on 1) the initial force beginning its swing and, 2) the ball-and-socket joint used which most-readily facilitates circular motion over any other. The supposed rotation of the Earth is completely inconsequential and irrelevant to the pendulum’s swing. If the alleged constant rotation of the Earth affected pendulums in any way, then there should be no need to manually start pendulums in motion. If the Earth’s diurnal rotation caused the 360 degree uniform diurnal rotation of pendulums, then there should not exist a stationary pendulum anywhere on Earth!
56.) The Sun and Moon may often be seen high in the heavens at the same time – the Sun rising in the east and the Moon setting in the west – the Sun's light positively putting the Moon's light out by sheer contrast! If the Newtonian theory were correct, and the moon had her light from the Sun, she ought to be getting more of it when face to face with that luminary – if it were possible for a sphere to act as a reflector all over its face! But as the Moon's light pales before the rising Sun, it is a proof that the theory fails; and is gives us a proof that the Earth is not a globe.
36.) If we take a journey down the Chesapeake Bay, by night, we shall see the "light" exhibited at Sharpe's Island for an hour before the steamer gets to it. We may take up a position on the deck so that the rail of the vessel's side will be in a line with the "light" and in the line of sight; and we shall find that in the whole journey the light will won't vary in the slightest degree in its apparent elevation. But, say that a distance of thirteen miles has been traversed, the astronomers' theory of "curvature" demands a difference (one way or the other!) in the apparent elevation of the light, of 112 feet 8 inches! Since, however, there is not a difference of 100 hair's breadths, we have a plain proof that the water of the Chesapeake Bay is not curved, which is a proof that the Earth is not a globe.
In the Libyan desert there is a mysterious glass, the purest natural silica glass ever found on earth. No other substance like it exists. Since natural glass, such as Libyan Desert Glass, can be formed only by lightning strike, volcanic activity, or meteorites striking the earth, it is a mystery to scientists how the glass got there. But none of these events make any sense since the glass dates thousands of years old and is spread out all over the desert, plus there is no sign of a crater and no volcanos.
125) Another proof the Sun is not millions of miles away is found by tracing the angle of sun-rays back to their source above the clouds. There are thousands of pictures showing how sunlight comes down through cloud-cover at a variance of converging angles. The area of convergence is of course the Sun, and is clearly NOT millions of miles away, but rather relatively close to Earth just above the clouds.
195) Astronomers say the magical magnetism of gravity is what keeps all the oceans of the world stuck to the ball-Earth. They claim that because the Earth is so massive, by virtue of this mass it creates a magic force able to hold people, oceans and atmosphere tightly clung to the underside of the spinning ball. Unfortunately, however, they cannot provide any practical example of this on a scale smaller than the planetary. A spinning wet tennis ball, for instance, has the exact opposite effect of the supposed ball-Earth! Any water poured over it simply falls off the sides, and giving it a spin results in water flying off 360 degrees like a dog shaking after a bath. Astronomers concede the wet tennis ball example displays the opposite effect of their supposed ball-Earth, but claim that at some unknown mass, the magic adhesive properties of gravity suddenly kick in allowing the spinning wet tennis ball-Earth to keep every drop of “gravitized” water stuck to the surface. When such an unproven theory goes against all experiments, experience and common sense, it is high time to drop the theory.
The Ball Earth, heliocentric model is the foundation for Satan’s Babylon. He has brainwashed the world to believe in a Sun centered universe (Pagan Sun worship) that is the foundation for Evolution, the Big Bang, Atheism, the NWO, the alien deception, and many false religions. He is the father of lies (John 8:44)! The Flat Earth Truth reveals Satan’s deceptions and reveals that only God, the great Designer, could have created and designed such a perfect masterpiece as the Flat Earth.
69) The New York City skyline is clearly visible from Harriman State Park’s Bear Mountain 60 miles away. If Earth were a ball 25,000 miles in circumference, viewing from Bear Mountain’s 1,283 foot summit, the Pythagorean Theorem determining distance to the horizon being 1.23 times the square root of the height in feet, the NYC skyline should be invisible behind 170 feet of curved Earth.

189) The Bible, Koran, Srimad Bhagavatam, and many other holy books describe and purport the existence of a geocentric, stationary flat Earth. For example, 1 Chronicles 16:30 and Psalm 96:10 both read, “He has fixed the earth firm, immovable.” And Psalm 93:1 says, “The world also is stablished, that it cannot be moved.” The Bible also repeatedly affirms that the Earth is “outstretched” as a plane, with the outstretched heavens everywhere above (not all around) giving a scriptural proof the Earth is not a spinning ball.

The aeronaut is able to start in his balloon and remain for hours in the air, at an elevation of several miles, and come down again in the same county or parish from which he ascended. Now, unless the Earth drag the balloon along with it in its nineteen-miles-a-second motion, it must be left far behind, in space: but, since balloons have never been known thus to be left it is a proof that the Earth does not move, and, therefore, a proof that the Earth is not a globe.
38) To quote Reverend Thomas Milner, “In the southern hemisphere, navigators to India have often fancied themselves east of the Cape when still west, and have been driven ashore on the African coast, which, according to their reckoning, lay behind them. This misfortune happened to a fine frigate, the Challenger, in 1845. How came Her Majesty’s Ship ‘Conqueror,’ to be lost? How have so many other noble vessels, perfectly sound, perfectly manned, perfectly navigated, been wrecked in calm weather, not only in dark night, or in a fog, but in broad daylight and sunshine - in the former case upon the coasts, in the latter, upon sunken rocks - from being ‘out of reckoning?’” The simple answer is that Earth is not a ball.
If the Earth were a globe, it would, unquestionably, have the same general characteristics - no matter its size - as a small globe that may be stood upon the table. As the small globe has top, bottom, and sides, so must also the large one - no matter how large it be. But, as the Earth, which is "supposed" to be a large globe, bas no sides or bottom as the small globe has, the conclusion is irresistible that it is a proof that the Earth is not a globe.
52.) It is a well-known and indisputable fact that there is a far greater accumulation of ice south of the equator than is to be found at an equal latitude north: and it is said that at Kerguelen, 50 degrees south, 18 kinds of plants exist, whilst, in Iceland, 15 degrees nearer the northern centre, there are 870 species; and, indeed, all the facts in the case show that the Sun's power is less intense at places in the southern region than it is in corresponding latitudes north. Now, on the Newtonian hypothesis, all this is inexplicable, whilst it is strictly in accordance with the facts brought to light by the carrying out of the principles involved in the Zetetic Philosophy of "Parallax." This is a proof that the Earth is not a globe.
37.) If the Earth were a globe, there would, very likely, be (for nobody knows) six months day and six months night at the arctic and antarctic regions, as astronomers dare to assert there is: – for their theory demands it! But, as this fact – the six months day and six months night – is; nowhere found but in the arctic regions, it agrees perfectly with everything else that we know about the Earth as a plane, and, whilst it overthrows the "accepted theory," it furnishes a striking proof that Earth is not a globe.
7) The experiment known as “Airy’s Failure” proved that the stars move relative to a stationary Earth and not the other way around. By first filling a telescope with water to slow down the speed of light inside, then calculating the tilt necessary to get the starlight directly down the tube, Airy failed to prove the heliocentric theory since the starlight was already coming in the correct angle with no change necessary, and instead proved the geocentric model correct.
Astronomers tell us. that the Moon, goes round the Earth in about 28 days. Well, we may see her making her journey round every. day, if we make use of our eyes and these are about the best things we have to use. The Moon falls behind in her daily motion as compared with that of the Sun to the extent of one revolution in the time specified; but that is not making a revolution. Failing to go as fast as other bodies go in one direction does not constitute a going round in the opposite one - as the astronomers would have us believe! And, since all this absurdity has been rendered necessary for no other purpose than to help other absurdities along, it is clear that the astronomers are on the wrong track; and it needs no long train of reasoning to show that we have found a proof that the Earth is not a globe.
There is physical, scientific evidence that we do indeed live under a glass dome. Sun dogs are lines of light that reflect off glass. This can only happen if a light is shining on the glass.These can be seen in the sky when the sunlight is shining just right and reflecting off the glass dome above us. This wouldn’t happen without glass. They say it is from ice crystals in the air, but air and ice crystal move constantly and would not cause this temporarily fixed phenomenon. Furthermore, this would not be possible on a spinning ball with no barrier separating the air from the vacuum of “space and no glass for the sun to reflect off of. Sun dogs are proof of a flat earth dome made of glass.

117) Newton also theorized and it is now commonly taught that the Earth’s ocean tides are caused by gravitational lunar attraction. If the Moon is only 2,160 miles in diameter and the Earth 8,000 miles, however, using their own math and “law,” it follows that the Earth is 87 times more massive and therefore the larger object should attract the smaller to it, and not the other way around. If the Earth’s greater gravity is what keeps the Moon in orbit, it is impossible for the Moon’s lesser gravity to supersede the Earth’s gravity, especially at Earth’s sea-level, where its gravitational attraction would even further out-trump the Moon’s. And if the Moon’s gravity truly did supersede the Earth’s causing the tides to be drawn towards it, there should be nothing to stop them from continuing onwards and upwards towards their great attractor.
148) Quoting “Earth Not a Globe!” by Samuel Rowbotham, “It is found by observation that the stars come to the meridian about four minutes earlier every twenty-four hours than the sun, taking the solar time as the standard. This makes 120 minutes every thirty days, and twenty-four hours in the year. Hence all the constellations have passed before or in advance of the sun in that time. This is the simple fact as observed in nature, but the theory of rotundity and motion on axes and in an orbit has no place for it. Visible truth must be ignored, because this theory stands in the way, and prevents its votaries from understanding it.”

21.) Man's experience tells him that he is not constructed like the flies that can live said move upon the ceiling of a room with as much safety as on the floor: – and since the modern theory of a planetary earth necessitates a crowd of theories to keep company with it, and one of them is that men are really bound to. the earth by a force which fastens them to it "like needles round a spherical loadstone," a theory perfectly outrageous and opposed to all human experience, it follows that, unless we can trample upon common sense ane ignore the teachings of experience, we have an evident proof that the Earth is not a globe.