The flat Earth collective has made the battle against the established powers its own. Their enemies are legion and they govern science, politics and the society. Their most effective weapons are lies and disinformation with which they enslave us. Because Truth will set us free. And that “Truth” includes the true appearance of our planet and the universe, or at least this is what the followers of the flat Earth theory hold. They have come so far in their defense that they have elaborated a broad argument to raise the pillars of their doctrine. The objective of this article and its future continuation will be to conscientiously analyze the topics most used by them. Are flat earthers right about the deliberate concealment of the most important knowledge of all times or are we facing an elaborate fraud born and feed by the Internet and globalization?
Since the resurgence of the flat Earth theory in the 19th century, as we have already seen, from the rhetoric of Samuel Birley Rowbotham (1816-1884) and his disciples, it has not ceased to gain followers and inflate his influence. It has not succeeded alone. The Age of the Internet has had much to do with the spread of these ideals throughout our planet, reaching every corner of the world.
We have already made a brief exploration of the fundamental features of the Flat Earth Theory. Now it is the turn to study and contrast these basis in order to elaborate a kind of personal profile of the modern flat Earth movement. Let us begin…
Rowbotham’s experiment discredited by a biologist
In the first part of this series of posts we write a brief biography of Samuel Birley Rowbotham (1816-1884), alias Parallax, father of zetetic astronomy and the modern flat Earth theory. Let us remember that to make his assertions he relied on certain biblical passages often interpreted in his own way. He was also the one who carried out the first experiment to try to demonstrate that the Earth was flat, certainly a point in his favor. Next, we extract the fragment from the previous article where we described the experiment:
“[…] in 1838 he went to the Old Bedford River, near Cambridgeshire, an artificial drainage canal that presents a couple of curiosities: it is practically straight and flat along its 24 miles of distance. The experiment consisted of the following: he chose a stretch of about 6 miles delimited by the Welney bridge and Welche’s dam and suggested that, if the Earth was round as astronomers claimed, a boat located at one end could not be seen from the other, as the Earth’s curvature would hide it. Samuel placed himself at one end with a telescope 20 cm above the water to test this principle. We can imagine him with a supremely grimace when he put his eye on the lens and could see that the ship was still there even though it had exceeded the limit he had imposed. It was clear then: the Earth is flat […].”
It seemed that Rowbotham had confirmed what the Bible was supposed to say. But what flat earthers don’t usually recognize is that this experiment was refuted years later. We have to go back to January 12, 1870. That day an advertisement appeared in Scientific Opinion magazine signed by John Hampden in which he made the following challenge:
“What is to be said of the pretended philosophy of the 19th century, when not one educated man in ten thousand knows the shape of the earth on which he dwells? Why, it must be a huge sham! The undersigned is willing to deposit from ₤50 to ₤500, on reciprocal terms, and defies all the philosophers, divines and scientific professors in the United Kingdom to prove the rotundity and revolution of the world from Scripture, from reason or from fact. He will acknowledge that he has forfeited his deposit, if his opponent can exhibit, to the satisfaction of any intelligent referee, a convex railway, river, canal or lake.”
Hampden was a staunch follower of Rowbotham and other zetetists. He was the eldest son of the Protestant rector of a parish in Dorset County, England. He signed up for a university degree in divinity at Oxford University, but he completed only two years. His conversion to the zetetist movement came after encountering Theoretical Astronomy Examined and Exposed, whose author was another Rowbotham follower, William Carpenter (1830-1896). He was so impressed with its contents that he paid 100 pounds to reissue the pamphlet. From then on, he eagerly devoured any treatise on zetetic astronomy including, obviously, the works of Rowbotham (he also bought the rights of Zetetic Astronomy). He regarded these books as the perfect weapons for fighting scientific heresy.
Well, regarding the challenge proposed by Hampden, this was accepted by one of the best scientists of all times: Alfred Russell Wallace (1823-1913), the naturalist co-discoverer of evolution through natural selection together with Charles Darwin. Wallace sought advice from another great scientist, Charles Lyell (1797-1875), father of modern geology to proceed better. Finally, he came to the conclusion that the best way to win the bet was through a practical and experimental demonstration, in order to transcend the typical epistemological discussions of his time about the shape of the Earth. In this way he could also convince Hampden more solidly whether he was wrong or not. Moreover, if he won the bet it would not only benefit him economically (at that time he had scarce economic resources) but also intellectually. So, without further ado, he wrote a letter to Hampden accepting his proposal.
The reins of the challenge were constantly held by Hampden, who decided at all times the place where the experiment would take place and under what circumstances. In fact, Wallace originally chose Lake Bullet (Wales), which was large and flat enough for his demonstration. But Hampden flatly refused and strategically chose a similar 9 Km stretch, this time bounded by the Old Bedford and Welney bridges, to that which Rowbotham had used previously. The naturalist did not know this information. Wallace humbly offered to perform the demonstration privately, so as not to make a fool of him in front of the public in case he showed the Earth curvature. Again, Hampden refused. He had an overwhelming assurance that Wallace had nothing to do to refute the flat Earth model.
Both deposited their respective 500 pounds at Coutts’s Bank and made an appointment for March 1, 1870. It is curious that a few days earlier Hampden suddenly retracted his decision to attend the experiment in person, sending a substitute of his confidence. He did not want to travel that far, not even to meet his own challenge. Wallace offered to meet him privately to observe the experiment and, if he was not convinced, to go to the referees for the final evaluation (so as to avoid public scorn as well), but Hampden insisted on his rotundity. So there was no choice but to choose the referees. Wallace suggested John Henry Walsh, editor of a sports magazine and surgeon, and Hampden agreed. The other referee, Wallace insisted, should be a person who was impartial and not known to any of the challengers. Hampden agreed… but he played dirty again, because he sent none other than one of his colleagues, William Carpenter.
Wallace met Carpenter at the station on February 28. Hampden was pretty wily. He gave a brief note to Carpenter in which Hampden informed him that he was going to send his printer and zetetist acolyte Alfred Bull to accompany him and to have someone else on his side in case he had to consult or plan anything. He also warned him that Wallace could cheat to win. On the contrary, we see that the only one with a hint of humility was the naturalist. Finally, John Hampden made his star appearance at the last minute after having been convinced by his colleagues that he had to be present at his own challenge.
On March 1, Wallace’s experiment was attempted. His proposal was very simple: he wanted to install six 1.82 metre long poles with black and red circles attached to them on the river bank along the 6 miles agreed of the Old Bedford River, one in each mile. His hypothesis was very simple and could be contrasted by anyone:
“If water is straight and flat, the tops of the poles will of course be straight and flat too. But if the earth and water has a curvature of 4000 miles radius, then the tops of the poles will be equally convex, and they will be seen rising higher and higher to the middle point, and thence sinking lower and lower to the furthest one. With a good telescope curvature will be easily seen if it exists.”
Finally, they placed a heavy telescope on a barge, located at the height of the poles, and tried to balance it as they could. However, they observed that the poles were not aligned and the unevenness Wallace had predicted could not be appreciated. After much discussion, they aborted the experiment for another day. Wallace bought a theodolite, a cartographic instrument to measure the real level of any object seen at a distance with a fairly tight precision. The results were delayed several more days due to different circumstances, such as bad weather or the abandonment of the referee John Henry Walsh, who had to continue his work as editor. He was replaced by surgeon Martin Wales Bedell Coulcher.
Finally, 5 March was the day when the conditions were right to carry out the experiment. There was a slight redesign to adapt it to the new conditions. They placed a large calico sheet with a thick black band painted accross its centre hanging from the Old Bedford Bridge. They installed the new telescope on the Welney Bridge, located at the opposite end of the Old Bedford River segment, at the same height of the water as the black band. At an intermediate distance between the two bridges (3 miles) a red post was placed, topped with two marker discs at the appropriate height so that the upper disc coincided with the heights of the black band and the telescope. The three points were located just over 4 meters above the water. It all depended on the height at which the marker discs appeared: if the upper disc appeared to be projected approximately on the black band and the lower disc below that band, it would be true that the watercourse, and therefore the Earth, were flat. In contrast, if the upper disc was seen above the black band and the lower disc projected on the black band it was due to the effect of the curvature of the Earth. To be more precise, Wallace predicted from his hypothesis that the upper disc had to appear approximately 1.5 metres above the black band, ignoring atmospheric refraction. And so it was, the central marker was about 1.5 metres above the black band, confirming his hypothesis and demonstrating that the Earth had curvature. However, the flat earther referee, William Carpenter, also looked through the theodolite, denying Wallace’s observation, as he claimed that both the marker discs and the black band of the other bridge were below the cross-hair of the telescope. Consequently, he refused to recognize the veracity of the experiment. Coulcher, on the other hand, as was to be expected in a man of science, confirmed that the experiment was well done and results were correctly interpreted.
However, Wallace had to convince the two referees to win the bet. Coulcher and Carpenter met at the former’s house, where Coulcher made a series of diagrams and plans that schematically showed the results. But Carpenter did not give in, he stood his ground, denying the obvious and not acknowledging his defeat. Carpenter sent a letter to Wallace asking him to call a different referee so that he could “sensibly” discuss the experiment. The naturalist, stunned by his opponent’s dishonesty, had no choice, so he called John Henry Walsh again. He kindly came again as a referee and analyzed the schemes of the experiment. He also had to give in to Hampden’s demands to send the documents to an expert ophthalmologist, Mr. Solomons. To make sure there were no pitfalls (there had already been plenty of them on his part), Hampden sent Carpenter to follow the evolution of the ophthalmologist’s analyses (although they were eventually carried out by an equally skilled apprentice). To his disgrace, the review concluded the obvious: that the experiment was well done and that it showed that the surface of the water was curved.
Finally, all the evidence pointed to Wallace’s victory, and so Henry Walsh put it in writing:
“Mr A. R. Wallace, by means of the experiment agreed on as satisfactory to Mr Hampden and his umpire by both of these gentlemen, has proved to my satisfaction “the curvature to and fro” of the Bedford Level Canal between Welney bridge and Wlech’s Dam (six miles) to the extent of five feet, more or less. I therefore propose top ay Mr A. R. Wallace the sum of ₤1000, now standing in my name at Coutts’s Bank to abide the result of the above test, next Thursday, unless I have notice to the contrary for Mr Hampden.”
From here on we reach the height of hypocrisy, because Carpenter refused to sign the document that granted Wallace victory. Zetetists, after all, refused to give in because their mentor Rowbotham had already “demonstrated” the flat shape of the Earth. They wasted Wallace’s time, because they would never recognize that he had won, they already had a fixed and immovable idea. Even so, Walsch, fed up with so much nonsense, gave Wallace the prize. Meanwhile, Carpenter took the opportunity to write a pamphlet to discredit Walsh and Wallace, shamelessly labeling them as frauds. For his part, Hampden tried for several years to socially destroy Wallace by sending letters to colleagues, relatives and friends of him, where he wrote all sorts of defamations about the naturalist. However, justice was done, as Hampden was denounced by Wallace for slander and for sullying his honour. Throughout that time, he was convicted up to four times, spending a few months in prison and forced to pay 600 pounds to Wallace, which he never did for declaring himself insolvent. He also sent death threat letters to Wallace’s wife, for which he was also tried:
“Madam, if your infernal thief, of a husband is brought home some day on a hurdle, with every bone in his head smashed to pulp, you will know the reason. Do… tell him from me he is a lying infernal thief, and as sure as his name is Wallace he never dies in his bed. You must be a miserable wretch to be obliged to live with a convicted felón. Do not think or let him think I have done with him.”
Besides, in 1876 Hampden denounced Henry Walsh under a law that forbade betting (when he was who made it). Unfortunately, in this case he did win the case and Wallace was forced to pay him the 500 pounds he justifiably earned in 1970. He did not have to pay it all, as Hampden still owed him 600 pounds for the previous complaint. Wallace also received criticism from his own scientific colleagues (even from Darwin) for having given more repercussion to the flat Earth madness because of this scandal and for having participated in a bet that discussed an indisputable scientific fact, the sphericity of the Earth.
Thus ended one of the most pathetic chapters in history. However, there is still a question to be clarified. Why did Rowbotham see during his experiment the ship beyond 6 miles if it should have been hidden by the curvature of the water? There is an explanation that agrees with his results and that we will mention on more occasions: he was a victim of atmospheric refraction, that is, the deviation of light rays reflected by bodies in certain atmospheric conditions and that allows us to see them even though they are not in our line of vision. What is clear is that his experiment was refuted. And not only by Wallace. Years later, specifically in the summer of 1900 and 1901, geography professor Henry Yule Oldham replicated the naturalist’s experiment exactly in the same stretch of the Old Bedford and using the same technique, only this time he used a more modern theodolite and a camera to verify the observation. His results perfectly corroborated Wallace’s.
The early refutation of the “foundational” proof of the modern flat Earth movement and the nefarious behavior of those first members (two facts that flat earthers often forget to mention) already tell us a lot about this movement… And now, we will analyze some of the most popular flat earther topics. If the reader wants to investigate more about the bases of flat earthers, we recommend reading two books: 200 Proofs Earth Is Not a Spinning Ball by Eric Dubay, one of the best compilations of topics about the Flat Earth Theory, which is also free access, and Tierra plana. La mayor conspiración de la historia of the Spanish youtuber Óliver Ibáñez, a book that is a literal copy of the previous one but in which the author has introduced some reflections of his invention.
The invisible curvature
The horizon is always perfectly flat regardless of the height at which the observer is standing and where he or she looks.
The fact is that it’s not. From a certain height, you can see the curvature of our planet. In order to observe this curvature, we would have to fly at heights that very few can reach: more than 30 Km away, and yet the curvature is almost imperceptible. Why? Let’s go to mathematics.
Our planet has a radius of approximately 6371 km. The following formula is used to calculate the length of a circumference:
Circunference = 2 * r * π
That is to say, we have to obtain the product of the number pi multiplied by twice the radius, or what is the same, the diameter. In this way we know that the circumference of our planet would measure about 40030,17 km. Considering the Earth as an almost perfect sphere, the imaginary circles that form the earth’s surface have 360º, so we can know the length that one degree of curvature has by making a simple division:
40030,17 Km / 360º = 111,19 Km occupy 1 degree of curvature
This shows that our blue sphere is immense, we only have to see the distance that occupies a degree of curvature that, on the other hand, remains almost imperceptible. It is estimated that at 30000 meters of altitude our sight would reach to contemplate 6º of arc, and even so it is difficult to appreciate the curvature, so imagine if we stay on land, where obviously we will not see any curvature. Therefore, the best evidence of the curvature of our planet are provided by space satellites or the International Space Station, which orbits at an altitude of 400 km, although according to flat earthers these arguments are not valid since there is no technology orbiting around the Earth. The reader can get a better idea by watching the following video, a perfect example of how height and distance from a surface alter our perception of it
It is striking that flat earthers consider the sunset as a sensory illusion (as we will see in a few moments) and do not do the same with the flat appearance of the horizon.
If the Earth were a globe, rivers would have to rise and fall constantly because of the curvature, which would be imposible. The fluvial system we are contemplating can only be explained from the model of a flat Earth.
This topic is repeated several times in Eric Dubay’s book. First of all, an error must be clarified. It is not correct to speak of “above” or “below” in relation to the curvature of something, in any case and taking our planet as a reference, we can only speak of “above” when we move away from the center of the Earth and of “below” when we approach to the center. Having said that, it is well known that watercourses always travel from top to bottom (towards the sea) for a mere energetic matter. The higher the altitude, the more potential gravitational energy there is, which decreases as the altitude decreases. The corresponding formula would be the following one (in which we observe that also the mass influences):
Graviational potential energy = Height * Local gravitational field * Mass
As the potential energy therefore depends on the distance to the centre of the Earth (or the height), all points that are at the same distance from that centre are equipotential, i.e. they harbour the same potential gravitational energy. Therefore, the curvature would not impede the current flow of the rivers.
Several photographers have captured geographic points that should not be seen from certain distances. If the Earth is a sphere of 40000 Km these locations should be hidden by the terrestrial curvature. See, for example, photographs of Chicago taken by photographer Joshua Nowicki in 2016 from St. Joseph, Michigan, showing the illuminated cliffs of the highest skyscrapers. Nor should the Philadelphia skyline be seen from Apple Pie Hill in New Jersey. All these points should be hidden by several hundred meters of the Earth’s curvature if the Earth is truly spherical.
Firstly, we should note that these arguments are often accompanied by errors and biases, and continue to be disseminated with them. For example, both Ibáñez and Dubay state openly that Nowicki took his beautiful photographs in 2016 at an altitude of 1.8 meters above Lake Michigan (practically from its shore), when taking a cursory look at the description of his Youtube channel’s video we see that this is not the case. Nowicki was then in a neighboring building, the Witcomb Senior Living Community, whose base is about 11 meters above the lake. If the photographer made the time-lapse from the roof, let’s add some more meters in which to place the height of the eye (about 46 meters in total). According to flat earthers’ calculations, the top of Chicago’s tallest building, the Willis Tower, 442 meters high, would have to be hidden behind 208 meters of curvature. Calculating the hidden part of a body by the curvature of the Earth is simple, and even more when we have online tools that are programmed for this purpose, such as the one provided below:
Adding the data correctly, we obtain that almost 400 meters of the Willis Tower would be hidden by the curvature of the Earth. Therefore, in optimal atmospheric conditions and with a suitable optical instrument, we could see the top of the building even ignoring the effect of atmospheric refraction. However, thanks to refraction we can see Chicago as Nowicki saw it from Lake Michigan. It is curious that flat earthers also ignore the testimony of the photographer himself, who explained that that day there was an important thermal inversion, that is, when the air temperature increases with altitude and vice versa (in normal conditions, the air temperature decreases as we rise in altitude), a phenomenon that increases the index of refraction of light. If this is not enough, it can be observed that the time-lapse was performed during the sunset, when the solar wavelengths must pass through a thicker section of the atmosphere. In these moments of the day the red wavelengths predominate, which are precisely the ones that suffer the most refraction. Even so, several flat earthers, including Óliver Ibáñez, continue to deny this fact, claiming that mirages and other optical illusions are distorted. It is enough to watch Nowicki’s video to corroborate that. The profile of Chicago’s skyscrapers staggers, shakes and distorts with the passage of time, clearly indicating that we are facing an illusion provoked by the refraction of light. Flat earthers have once again succumbed to the same error as Rowbotham with his experiment on the Old Bedford canal.
This phenomenon is not anomalous at all. We see it every day when we contemplate a sunset. When we observe the Sun hiding in the horizon, we are not really seeing the real image of the Sun, which is already hidden under the geometric horizon of our planet, but an optical illusion. Atmospheric refraction causes that we see the stars in a higher position than they actually occupy. If the atmosphere did not exist, we could contemplate the stars in their real position. That is why astronomers distinguish between the “apparent position” and the “real position” of the stars considering the presence or absence of atmosphere.
In the case of the alleged problem of Philadelphia’s visibility from Apple Pie Hill, the distance separating the two points is about 50 km (Eric Dubay notes in his book erroneously that they are 64 km). The hill is 62 metres high and Philadelphia is 12 metres above sea level on average. Also, some of its buildings are several hundred meters high. Introducing these data into the application, we get that 37 meters of Philadelphia are hidden under the curvature (and not the 102 meters indicated by Eric Dubay). From that distance and at that height we could easily see the colossal Philadelphia’s buildings that surpass that altitude.
Large engineering works, such as canals, roads, highways, bridges, etc. are always built horizontally and flat and without taking into account the presumed curvature of the Earth, which match with a flat Earth.
Eric Dubay and Óliver Ibáñez emphasize this point on several occasions. Moreover, both cite the testimonies of several engineers who confirm this premise, since they have never had to take into consideration the curvature of our planet, which would be enough to conclude that the Earth is flat, wouldn’t it? The problem is that they do not provide sources. In fact, when we try to trace the history of the only engineer that has a name, someone called W. Winckler, who suggests that engineers do not need to calculate the curvature of the planet, it is not possible to find the original source. In all the forums and blogs only the paragraph from Dubay’s book is mentioned, a problem that has also been echoed by a user of the Flat Earth Society forums.
Leaving this aside, it is true that when it comes to raising these engineering wonders the earth curvature is not taken into account. Interestedly, Ibáñez and Dubay cite in their corresponding books a conveniently biased fragment of a statement made by the Office of Engineers of the Manchester Ship Canal of 19 February 1892:
“In the construction of railways and canals, it is the norm that the reference point for all surfaces is a horizontal line. In practice, no curvature of the earth is taken into account when planning and carrying out public works.”
Surely, if they had offered the whole text, we could see why engineers say this. Everything has to do again with the immense size of our planet. Let us remember that one degree of curvature of our planet occupies about 111 Km. Let us imagine for a moment that we have to install a 1 Km long railroad simultaneously. With a simple rule of three we obtain that the curvature that engineers would have to take into account would be approximately 0.009º of arc, a negligible figure. That is the key. Engineers omit the curvature of the Earth not because it does not exist, but because they work in sections at a scale where the curvature is negligible, therefore these sections are built considering the surface as if it were flat. What engineers really have to adapt to is the local orography.
By the way, the authors mentioned above have made another mistake because, in effect, there are many engineering works that are neither flat nor horizontal. See for example the Golden Gate or the Danyang-Kunshan Bridge.
The Law of Perspective on flat surfaces refutes Earth curvature. Every body that disappears in the distance from the bottom to the top is due to this principle.
This presumed law, which must be framed exclusively within the flat earther thesis, is repeatedly used to explain phenomena such as the sunset and rising of the Sun or the disappearance of any other body on the horizon. Basically it states that our eyes have a very limited capacity for depth vision, so that any object that hides behind the horizon is not because there is a curvature, but because it has moved away to a great extent and is imperceptible from our point of observation. Eric Dubay exemplifies this phenomenon with a woman in a dress that moves away from an observer. After a certain distance, states Dubay, we will only see the highest part of the woman’s body, while her feet will have disappeared in the distance. The same goes for the hulls of boats, which are the first to disappear on the horizon. All this would be an illusion, because if we used a telescope we would recover the complete vision of the woman or the ship.
This is simply absurd and is completely opposed to the much-appreciated empiricism for flat earthers. When a body moves away, all its parts are proportionally dwarfed, not some before others. In any case, if the lower parts begin to disappear before the upper ones, it is because an obstacle has been placed between the observer and the lower part of that body. Besides, if this “law” were true, how is it possible then that the sizes of the Sun or the Moon are the same along their celestial paths? Should they not be dwarfed when they hide on the horizon because, according to the flat earther model, they are moving away from us until they become invisible? Here is a fascinating video of the path of the Moon and the Sun, where we can observe that their sizes do not vary:
On the contrary, the way in which a ship disappears on the horizon corresponds precisely to the model of a spherical world. Indeed, when a boat is far enough we only see its masts and sails while the hull is hidden. On the other hand, when a ship approaches from the horizon, the first thing that is visualized is its highest part, which was already witnessed in Aristotle’s time and wielded as empirical evidence of terrestrial sphericity and curvature. This phenomenon is obviated by flat earthers, although they like to rescue ancestral “truths”.
If the Earth were really a sphere with a circumference of 25000 miles, airplane pilots would have to constantly correct their altitudes downwards in order not to fly directly into “outer space”.
First of all, the confusion of “flying straight” implicit in this argument must be clarified. Flat earthers believe that airplanes would fly in the following manner taking as a reference a curved land if they did not implement various corrections during their trajectory, facing the danger of entering space:
However, this is not a “straight” flight at all. Rather, the aircraft is following a tangential trajectory with respect to the Earth’s surface. A “straight” trajectory on our planet involves following the curvature of the earth’s surface:
This is the trajectory that aircrafts follow. If we are talking about commercial flights, the planes will fly following the terrestrial curvature at a constant height of approximately 10 Km. Anyway, if a pilot committed the foolishness of trying to fly into space, he would not get very far. The density of air decreases with height, so the plane would have to reach higher speeds to ensure an air cushion to support it, a situation that a conventional plane can not reach.
During a flight, corrections are made to avoid problems and tragedies indeed. One of these corrections pursues a constant height along the journey to ensure the aerial lift of the aircraft (10 km high above the sea level in the case of commercial flights). In this respect, long-haul flights, for example, do take into account the curvature of the earth. But this factor is implicit and is not usually mentioned. By correcting and maintaining a constant altitude during a flight, the earth’s curvature is automatically included in that equation. In other words, by maintaining a constant height above the Earth’s surface the plane follows the curvature of the Earth.
“And yet it moves…”
If the Earth were really a giant sphere that moves through space, the water would be wobbling everywhere, instead of remaining level and stable just as we see it. One proof that the Earth is flat is that the water remains leveled regardless of the container.
Precisely what prevents the water from escaping is the gravity (non-existent for many flat earthers). Nor is it true that water is always flat. In a microgravity scenario, water takes on spheroidal forms, for example. Likewise, the dew that is deposited on the surface of leaves or flowers in the morning does so in the form of drops. Actually, what determines the “shape” of water are the interactions between the H2O molecules that compose it and other forces such as the eternal gravity, causing the water to adopt that “shape” that supposes the least amount of energy and that is equal to the shape of the equipotential surface of the gravitational field.
If the Earth were really spinning eastwards at over 1609 Km/h, helicopters and balloons could hover in place and wait for their destinations to come to them; a vertically fired cannonball would fall farther from the cannon than it actually does; an airplane flying eastwards at a speed slower than the rotation of the Earth would never reach its destination, because it would constantly escape from it, etc.
Inertia. It is the cause of none of the above happens. The mere fact of being in our planet implies that we move with it. Although it may seem crazy, a reader who lives on the equator is spinning at about 1600 Km/h with respect to the center of the Earth at the moment he is reading these lines (although this angular velocity is reduced to nullify as we approach the poles). It is not strange at all. The same thing happens when we jump in a moving train or in an airplane, we are not going to move from our site because we are moving with the vehicle at its same speed. The truth is that if inertia did not exist it would be much easier to travel by plane and would save a lot of fuel. Flying westward (the opposite direction of rotation) we would arrive in the blink of an eye at our destinations, which would inevitably moving towards us. On the contrary, we fly faster to the east than to the west. When we move eastwards, i.e. following the direction of rotation, our speed is added to that of the rotation and the opposite happens if we move westwards, the speeds are subtracted.
The jump example can also be applied to a projectile that is fired vertically. The projectile will end up falling on or near the canyon because during its ascent and descent it is moving with the Earth, just like the canyon. In ideal conditions, the projectile would end up falling on the canyon, but due to the force exerted by the wind its trajectory is modified.
A frequent protest made by flat earthers against Earth movements is that, if they were true, their inhabitants would be fired by the resulting enormous centrifugal force (remember the sardonic comment that Orlando Ferguson captured in his peculiar map of the flat Earth). Once again this incomprehension proceeds by not taking gravity into account (or by denying it). Our planet is so massive and immense that the gravity it generates is very powerful, much more than the centrifugal force resulting from rotation. In fact, the latter would only constitute 3% if we compare it with gravity. On the other hand, if Earth were much smaller and kept its current angular velocity or if it is increased considerably, possibly we would be expelled by the air.
The experiment known as “Airy’s Failure” and the Michelson-Morley experiment proved that stars move in relation to a stationary Earth and not the other way around. Likewise, the “Olbers’ Paradox”, which states that if there were billions of stars the night sky would be completely filled with light, is another refutation of the heliocentric model.
George Biddell Airy (1801-1892) was a famous British astronomer. He was appointed royal astronomer and directed the Cambridge observatory. He bequeathed to us important discoveries, such as Airy’s disk, an interference pattern produced by the undulating nature of light when it passes through the circular aperture of an optical apparatus.
At his time, scientists were intensely discussing a very interesting idea known as “ether drag hypothesis”. Broadly speaking, ether would be a sort of ubiquitous substance in the universe. Its existence was suggested to try to justify the fixed speed at which electromagnetic waves move (300000 Km/s approximately), a prediction of the electromagnetic theory of the Scottish James Clark Maxwell. That measure could only be obtained by measuring against a reference system. That is, light has to move with respect to something at a fixed speed, but with respect to what? The scientists then looked at the sound waves and determined that the light waves would have to behave similarly. Sound waves are nothing more than undulations of the medium in which they are transmitted (air for example). From this it can be inferred that for their transmission a medium is obligatorily needed, which can be gaseous, solid or liquid, in consequence nothing is heard in space, because the sound waves do not have any means for their transmission. Therefore, by analogy, electromagnetic waves should also need a disturbing medium for their transmission, and this is where the ether or luminiferous ether comes into play. In the absence of air, there had to be something between the Sun and the Earth for its light to reach us. The light, therefore, was transmitted by undulating vibrations of the ether.
From here another complication arose: it was needed to determine what the ether was like, what its constitution was. This omnipresent substance had to be, on the one hand, very rigid. Sound is transmitted faster in solid media than in less rigid media. If light was similar in nature to sound and traveled at such huge speeds (300000 Km/s), then the ether had to be quite solid. On the other hand, the ether had to be very elastic. Otherwise, the friction with it would cause the stars moving in its bosom to gradually lose their speed until they stopped.
The luminiferous ether was originally conceived as a static medium and totally or partially independent of matter, i.e. it did not interact and was not affected (or very little) by the movement of matter in its bosom. Consequently, the planets and other celestial bodies that moved with respect to it. The existence of the “ether wind” was also postulated, whose direction changed with respect to the movement of the Earth around the Sun. To understand it a little better, we can imagine a cyclist riding on a calm day without wind. If the cyclist moves in a southward direction, he will encounter a “wind” or an opposing air resistance facing north and vice versa. This involved a fundamental question: measuring the speed of light would have to produce different results. It has logic, since if the Earth moves towards the ray of light (that is, perpendicularly), the measure of the speed of light will be slightly greater, since it will arrive earlier than if the ray of light follows the same direction and sense that the terrestrial movement (it is parallel to the same), since it will be stopped by that ether wind. Bearing this in mind, it was interesting to know what was the relative velocity of our planet in reference to the surrounding ether through the measurement of the velocity of light in the two circumstances just mentioned. For this, the physicist and Nobel Prize winner Abraham Michelson and the chemist Edward Williams Morley devised an experiment in 1887, considered one of the most important experiments in the history of physics.
For this experiment, Michelson built an interferometer, an optical device that uses the interferences of light waves to measure distances, such as wavelengths (interferences are an inherent property of all types of waves, according to which they can overlap to form a new wave of different amplitude). Specifically, the Michelson interferometer consisted of a light source, a pair of semi-transparent glass plates (A and B in the scheme) and a pair of mirrors arranged perpendicular to each other (M1 and M2). The experiment consisted of simulating a pair of light rays, one following the direction of the Earth’s orbit and the other perpendicular and opposite to it, in order to compare their speeds of arrival at a receiver or observer. To do this, one of the semi-transparent glass plates divided the ray of light in two: one part reflects it towards one of the mirrors and the other is transmitted towards the other. Finally, those rays of light will be reflected back and will gather to be captured by the receiver composing a diagram of interferences, i.e. alternating bands of light and shadow.
During the experiment, the interferometer spun slowly. In this way, they expected to observe the displacement of these bands of interference, a sign that there were differences in the speed of light depending on whether it follows a path parallel to the Earth’s orbit (or opposite to that of the ether wind) or perpendicular. However, the result was the opposite: the bands of interferences remained always the same. The experiment was replicated on several times and in different conditions so as not to leave any variable unsaid, but the result was always the same: the bands did not vary, which implied that the value measured for the speed of light was the same. The conclusions were clear and precise: there was no movement of the Earth relative to an immutable ether, but not because the Earth was stationary, which is what flat earthers and geocentrists argue, but because the ether did not exist. Subsequently, as we shall see below, the ether drag hypothesis was used. Perhaps the key was that not all the ether was static…
Although it seems that this refutation left some gaps unexplained, a few years later the eminent Albert Einstein would fill them with his theory of special relativity. In a somewhat simplistic way, as a result of these results Einstein reasoned that ether was not necessary in the universe, since the speed of light was independent of the relative movement between the source and the receiver. Therefore, we observe again an erroneous and interested interpretation of science and a malpractice on the part of the flat earthers that is suspiciously frequent among them.
One of the many evidences in favor of the Earth orbiting around the Sun is the phenomenon of Bradley’s aberration of light or stellar aberration. This implies that, when we observe a star, we are not really seeing it in its real position. It is another one of those wonderful paradoxes of our universe. The cause is the movement of our planet around the Sun and, to a lesser extent, the rotation upon itself. In other words, this phenomenon, in addition to the speed of light, depends on the speed at which the observer moves (approximately 30 Km/s around the Sun). Nowadays it has been stipulated with enough precision that the angular difference between the real position of a star and the illusory one that we contemplate is of 20,47 seconds of arc, although it is true that this value varies throughout a year, since the speed of the Earth movement around the Sun is not constant. In addition, it is something that can be checked individually. In a rainy day without wind, for a person who is under a static umbrella the rain will fall on it in a practically vertical way. What happens if we move and we increase the speed gradually keeping the umbrella vertical? We will soak and we will be forced to tilt the umbrella forward more and more. Suddenly, the rain has acquired an illusory angle regarding the observer.
And what about George Airy? This astronomer carried out an experiment that has become viral between flat earthers and geocentrists, since according to them the results obtained show without any kind of doubt that the Earth is static and does not move around the Sun, but quite the contrary, the stars move around our planet. As we will see below, this interpretation could be true… if we take things out of context. Airy’s essays are contextualized in the debate we mentioned earlier about the existence and nature of ether as a necessary medium for the transmission of light waves. Airy carried out its experiment in 1871, before Michelson and Morley, who helped to definitively discard the idea of the luminiferous ether. A few decades earlier, his colleague James Bradley provided one of the first definitive evidences of stellar aberration by periodically observing the star γ Draconis. Bradley realized that over the course of a year he had to slightly correct the inclination of the telescope in order to focus it. The peculiarity of γ Draconis is that it is very close to the zenith (that is, the point of the celestial hemisphere situated on the vertical of the observer) if observed from the Royal Observatory of Greenwich, England. Therefore, by orienting the telescope at 90º it should be possible to observe it, but this was not the case due to this phenomenon. This was the first confirmation of Bradley’s aberration and his logical prediction, that aberration is a phenomenon that occurs as a result of the Earth’s movement around the Sun. Airy thought that he could use the stellar aberration phenomenon to dispel doubts about Earth’s motion with respect to ether, and always with respect to this question. That is to say, Airy did not seek to prove whether the Earth moves around the Sun or not. In fact, he was heliocentrist.
Earlier we mentioned the ether drag hypothesis. This idea suggested that a completely or partially independent and unalterable ether was absurd, in fact the experimental results obtained until then did not fit with these premises. Therefore, the nature of the ether had to be, according to this hypothesis, precisely the opposite: the ether contained in matter or situated in its vicinity could be dragged along with it, while the ether of the rest of space remained static. Since the speed of light was a property of ether (remember that light was considered vibrations of ether), it would propagate along with that dragged ether. This hypothesis is directly linked to Airy’s experiment and to the aberration of light.
For his experiment, Airy used a telescope filled with water. The reason was to use a medium with a different refractive index to that of air to test a prediction inferred from the ether drag hypothesis: that light moves along with the moving ether. In this way, he thought, one could find the value of the absolute motion of the Earth with respect to ether. The water refracts the light more and it travels more slowly through it, therefore, to be able to see γ Draconis, the telescope with water should be inclined at a greater angle than the telescope full of air. The following video serves to illustrate this principle, although it has creationist influences:
To his surprise, this was not the case and the telescope with water did not need a greater inclination than an air telescope would require in order to observe the star. This showed that the Earth did not move with respect to the ether or drag it with it. But not because the Earth is static… but because the ether did not exist, as Michelson, Morley, Sagnac, Einstein and others later again demonstrated.
In fact, Michelson himself tried to prove this extreme. If the Earth was dragging the ether, he thought, then this dragging would be reduced as gravity decreases. A prediction that was already proposed by the physicist Augustin Jean Fresnel, one of the main defenders of the ether drag hypothesis. For this reason, he carried out his experiment with the interferometer at different altitudes, obtaining the same null results as the first time. On the other hand, if the Earth were static, it would not be necessary to incline the telescope to see γ Draconis, because the beam of light would reach the telescope’s lens being oriented at 90º. Consequently, the stationary Earth contradicts the phenomenon of aberration, which has been demonstrated numerous times empirically, a method so appreciated by flat earthers, who of course continue to use this experiment as a proof of a stationary Earth. And yet it moves.
Let’s continue with Olbers’ paradox. Heinrich Wilhelm Olbers (1758-1840) was a German astronomer who, like some of his predecessors, such as Johannes Kepler, reflected on an alleged anomaly in the model of the universe of his time. First of all, we must analyze how the universe was conceived in these centuries. Basically, the universe was supposed to be static and infinite in spatial and temporal extension, although in other more creationist spheres, in addition to static, it was supposed to have a certain divine origin. If the universe was infinite then it must have had an infinite amount of matter. Consequently, no matter where we looked, we would always have to run into a star. If the sky was full of stars, how was it possible then that night existed? Shouldn’t the sky be constantly and intensely illuminated by infinite stars? Why don’t we see something like that? Olbers then argued that the “few” stars we see in the sky are the nearest, because the light from the farthest ones would be absorbed by the opaque matter (stellar dust for example) that occupies the spaces between the stars. However, this leads to another problem: that matter would end up being just as radiant as stars because of the constant absorption of the energy that emanates from them.
We have to wait until 1929 to find a solution to this problem. This year, astronomer Edwin Hubble warned after a large number of observations that galaxies were moving away from us. In other words, the universe is not static, but expanding. On the contrary, if we go back in time we would see that galaxies would approach until they were concentrated in one point. This point is where everything started and from where the universe expanded thanks to the Big Bang. Therefore the history of the universe is finite (astrophysicists have established that the universe “was born” between 13 and 15 billion years) as well as its limits. Let us also remember that light has a finite velocity. Therefore, the light of all the stars of the universe has not yet reached us. On the other hand, if the stars constantly move away from us, the light they emit suffers what is known as redshift, i.e. the wavelength of light (the distance from one crest to another) increases and the light loses intensity. There is not much more mystery, really Olbers’ paradox does not serve to sustain the geocentrism in any way, although it always endows of seriousness to quote some scientist. But was not science an instrument of conspirators?
Tycho Brahe argued against the heliocentric theory of his time, stating that if the Earth orbits around the Sun, the stars must appear to separate as we approach and join together as we retreat, something he could not verify.
To this Danish astronomer (1546-1601) we owe important advances in astronomy. In addition to being the mentor of the famous Johannes Kepler (who was able to design his laws from Brahe’s data), he helped to establish the position of about 800 stars and increased the precision of various astronomical measurements using devices from his own invention. Brahe devised a model opposed to the Copernican model but with slight variants to the traditional geocentric model. According to this, the Sun and the Moon would orbit around a motionless Earth and the rest of the planets would orbit around the Sun. In other words, it is a sort of transition between geocentrism and heliocentrism.
We must remember that the telescope began to be used by Galileo Galilei in the early seventeenth century to observe the cosmos. Therefore, Brahe did not have the opportunity to use it, which undoubtedly would have allowed him to increase his astronomical discoveries. It is not strange then that Tycho Brahe did not have precise data on stellar parallax, that is, the relative position of a star in the celestial vault in reference to the observation point, a phenomenon that has served astronomers to calculate distances between celestial bodies. This phenomenon can be reproduced by placing a finger near and in front of our eyes, closing one eye and opening the other alternately. We will see that the relative position of our finger changes regarding the background depending on the eye with which we look at it.
It’s very difficult to notice the stellar parallax at first sight. In fact, it was thanks to the telescope that this phenomenon could be accurately established. Consequently, it is not that there was no parallax produced by the terrestrial orbit around the Sun, but that Brahe could not observe it because he lacked the necessary instruments. Indeed, the results in this respect began to be obtained from 1610 by scientists such as Jean-Dominic Cassini, Jean Richer, Friedrich Wilhelm Bessel, Thomas Henderson, etc.
Why does the Polar Star stay fixed in the sky if the Earth moves around the Sun?
Polaris, Alpha Ursae Minoris, North Star or, simply, the Polar Star is one of the stars that have been most linked to the history of humanity. It belongs to the constellation of the Little Bear and has been fundamental to guide us through the great vastness of the northern hemisphere of our planet. So important is to us that it is part of legends of Greeks, Chinese and Arabs.
For about 4000 years, the Earth’s axis has been pointing directly at this star. However, Polaris has not always been the guide of our travels. For the ancient Egyptians for example, the Alpha star of the Dragon constellation or Thuban was their particular North Star. This is due to the movement known as the precession of equinoxes, which finds its raison d’être in the inclination of 23.5º of arc of the Earth’s axis. Every 25765 years approximately, the terrestrial axis draws a cone in the sky and during this journey it points to different stars in both hemispheres.
But why do we see Polaris located in the same place in the sky if our Earth supposedly orbits around the Sun? Shouldn’t it change its position? Precisely its position with respect to the axis of our planet is the key. It is like observing a disc spinning on a record player, the “immutable” center to which our planetary axis points would be Polaris and the rest of the disc would correspond with the other stars of the firmament that spin throughout the nights and the year around that center. Here is its usefulness to locate us in the northern hemisphere, its apparent immobility. And we insist that it is apparent, because obviously and like the rest of its celestial companions, Polaris orbits around the center of the Milky Way. Another question related to its “immobility” is the enormous distance that separates us from it, 323 light years. Since it is so far away, we cannot appreciate its movement, although its distance is also what allows us to know in which latitude we are making some simple trigonometric calculations.
And since we’re talking about stars, the observation of different stars in both hemispheres doesn’t fit with a flat Earth model. For example, both Polaris and the constellation of the Great Bear (with all the stars that compose it) are only visible from the northern hemisphere, while the Crux constellation is only visible from the southern hemisphere, as is Sigma Occitantis (or Polaris Australis), the analog of Polaris in this hemisphere. For this there is no discussion, because it can be empirically proven with our senses. On top of that, if the Earth were flat it would be a fiasco to be able to determine the latitude in the northern hemisphere, because the Polaris star would have different altitudes (something completely absurd).
Let’s take the flat Earth model according to which the North Pole is in the center of the disk and the Earth is covered with a dome where stars are glued (what was formerly known as the sphere of fixed stars). The Polar Star is in the vertical of the center of the pole and, therefore, forms an angle of 90º with the surface. Now imagine that we are in Russia about 3300 Km from the polar center. With the right instrumentation, we will find that from this point the Polar Star forms a 60º angle with the observer. We therefore have a right-angled triangle. With the formula to find values of tangents we can find the length of the leg that corresponds to the height of Polaris with respect to the surface:
As we know the value of the adjacent leg (3300 Km), it is only necessary to clear:
Height of Polaris = tg 60º * 3300 Km = 5716 Km
We’ve already found the height of Polaris. Let us now travel to Castellón de la Plana, in Valencia (Spain), which would be about 4820 Km from the center of the Pole to see if we would see this star at the same height. From this location, Polaris would form an approximate angle of 45º with the observer. With all these data we repeat the operation:
Height of Polaris = tg 45º * 4820 Km = 4820 Km
We see a very serious problem, as there is a difference of almost 1000 Km in the height of Polaris depending on where we observe it… We could continue taking more reference points and we would continue obtaining very different values.
Foucault’s pendulum and Coriolis effect show a series of inconsistencies that prevent them from being wielded as evidence of a rotating Earth.
Jean Bernard Léon Foucault (1819-1868) was a French wise who made remarkable advances in the field of astrophysics and mathematics. He studied the infrared solar spectrum and calculated a more precise value for the speed of light. He also invented the gyroscope. However, he is known worldwide for his magnanimous creation, Foucault’s pendulum. The results obtained with this apparatus are considered the first experimental proofs that the Earth rotates on itself.
The pendulum he built consisted of a 28 kg sphere supported by a 67 metre wire attached to the dome of the Paris Pantheon. Today we can see several replicas in science museums and universities. Conceptually, it is somewhat complex to understand, but we will try to synthesize it as far as possible. Once the oscillation of the pendulum was started, Foucault verified that the vertical oscillation plane was always the same and that this plane rotated clockwise at a rate of 11º15′ per hour, which implied that the Earth rotated on its axis and that the rotation of the oscillation plane was due to inertia. The current models in which several stakes are placed in the ground around the pendulum are very illustrative.
It is a matter of perspective and can be better understood in a scale model:
The clockwise movement of the plane is apparent, since what actually moves is the ground in an counterclockwise direction. Flat earthers claim that this experiment does not prove anything, because pendulums sometimes behave randomly (?) or move in the opposite direction to what one would expect. Perhaps because they have not taken into account the fact that Foucault’s pendulum rotates with a different rhythm and direction depending on where it is installed. If it were located right at the point of the North Pole that is crossed by the terrestrial axis, the plane of oscillation makes a complete turn in 24 hours. On the other hand, the Paris pendulum only completes a 270º turn in 24 hours. This indicates that the rate of rotation of the plane depends on latitude. As can be seen, the closer the pendulum is to the equator (latitude 0º), the longer it takes to make a complete turn. In fact, at the equator the turn stops and the pendulum always oscillates in the same plane. In the southern hemisphere the opposite happens, the plane of oscillation turns counterclockwise and turns faster as the latitude increases or, in other words, as we approach the South Pole. These changes correspond not only to a rotating Earth but also to a spherical Earth.
Similarly, the Coriolis effect is directly fictitious for flat earthers, just like any other law or scientific phenomenon. The Coriolis effect is a phenomenon discovered by the French engineer and mathematician Gaspard Gustave de Coriolis (1792-1843). Like Foucault’s pendulum, its mechanics demonstrates and depends on the rotation of the Earth. It is defined as the “force” that is observed in any reference system in rotation on a body in movement with respect to this system. Coriolis realized that, in such a system, an additional inertial force must be applied to the moving object, which is perpendicular to the movement of the object. This force causes a relative and apparent acceleration in the moving object. And we emphasize “relative” and “apparent” because this force only occurs from the point of view of a rotating observer. In fact it is not a real force as such as there is nothing to produce it. It is what is known in physics as fictitious or inertial force, an element that is introduced to correct and obtain the correct results.
Even so, this effect is fundamental to us today. On the one hand, it is very much taken into account when establishing long air or sea routes. A pilot or a ship captain cannot follow the most obvious rectilinear route to reach their destination, since because the Earth continues to rotate below them they would not reach their planned location (as long as the path does not follow a parallel land). Therefore, they must plan a route that takes into account the Coriolis effect in order to reach their destination.
This effect is also essential in meteorology, oceanography and in the military field, as ocean currents, permanent winds, cyclones and tornadoes, and projectiles fired at great distances are affected by this effect. The Coriolis force depends not only on the distance travelled, but also on time, the speed of the moving object and the latitude of the Earth (also proportional to the rotation speed) to become evident. For example, objects that travel short distances at high speed do not suffer the effects of Coriolis force or these are negligible (imagine a ball that is kicked in a football match). At the equator this effect is negligible and increases in intensity in the direction of the poles.
Much has been said about its relationship with the direction of the water’s rotation in the drains in the two terrestrial hemispheres. It is said that in one hemisphere the water rotates clockwise and in the other counterclockwise. Although it has long been considered a myth (in fact, in the toilets of both hemispheres the water can rotate in both directions), the Coriolis effect has something to do with it, even if its effect is once again insignificant. Other factors significantly influence the sense of drainage, including the shape of the pile and the drainage orifice. As we have emphasized, the Coriolis effect is imperceptible since the drainage of water is a phenomenon that happens at high speed. Flat earthers argue that scientists attribute the Coriolis effect to the sense of drainage in both hemispheres. On the contrary, we observe that physicists are quite clear as to whether this is true or not.
So far, flat earther arguments leave much to be desired. In order not to make this post denser we stop here, but if you want to dig deeper into the flat Earth theses and see our conclusions, visit the next part:
Flat Earth (part 3): Round Earth VS flat Earth. Latest analysis of the “Flat Earth Theory” and conclusions
If the reader wants to delve into the keys of modern flat Earth theory, we invite him to visit the first part of this dossier:
Flat Earth (part 1). The phoenix of myths
REFERENCES
Airy, G.B. (1871). IV. On a suppossed alteration in the amount of Astronomical Aberration of Light, produced by the passage of the Light through a considerable thickness of Refracting Medium. Proceedings of the Royal Society of London 20, 35-39.
Alfonseca, M. (1998). Grandes científicos de la humanidad (a~l). Madrid: Espasa Calpe.
Asimov, I. (1991). Guía de la Tierra y el espacio. Barcelona: Ariel.
Barcero, J.I. (2009). Manual de astronomía. Managua: Asociación Nicaragüense de Astrónomos Aficionados.
Dubay, E. (2015). 200 Proofs Earth is Not a Spinning Ball.
Encyclopaedia Britannica (2019). A.A. Michelson [online] available in: https://www.britannica.com/biography/A-A-Michelson
Encyclopaedia Britannica (2019). Edward Williams Morley [online] available in: https://www.britannica.com/biography/Edward-Williams-Morley
Encyclopaedia Britannica (2019). Sir George Biddell Airy [online] available in: https://www.britannica.com/biography/George-Biddell-Airy
Fábrega, O. (2017). El delirante mito moderno de la Tierra plana. El Ojo Crítico, 85/86, 48-59.
Fernández, J.L. (2013). Representación gráfica del campo gravitatorio. Fisicalab [online] available in: https://www.fisicalab.com/apartado/graficas-campo-gravitatorio
Ferraro, R. & Sforza, D.M. (2004). Arago (1810): the first experimental result against the ether. European Journal of Physics 26(1), 195.
Garwood, C. (2010). Flat Earth. The History of an Infamous Idea. London: Pan Books.
Hawking, S. (2011). A Brief History of Time: From Big Bang to Black Holes. UKI: Corgi Transworld.
Hdz, J.M. (2011). Despreciable ¿quién? Mi de vez en cuando [online] April 13, available in: http://midevezencuando.blogspot.com/2011/04/despreciable-quien.html
Ibáñez, O. (2016). Tierra plana. La mayor conspiración de la historia.
JuanC (2010). El sorprendente experimento de Airy. Creacionismo especial [online] March 3, available in: http://creacinseisdas.blogspot.com/2010/03/el-sorpendente-experimento-de-airy.html
López, C.T. (2014). De la aberración estelar. Cuaderno de cultura científica [online] August 26, available in: https://culturacientifica.com/2014/08/26/de-la-aberracion-estelar/
MinutoDeFísica (2015). Why Isn’t Faster To Fly West? [Vídeo online]. Available in: https://www.youtube.com/watch?v=3gNkgj9h2oM&feature=youtu.be
Nieves, J.M. (2017). Si la Tierra gira a gran velocidad y saltamos, ¿por qué la Tierra no se mueve debajo de nosotros a gran velocidad? Quora [online] February 10, available in: https://es.quora.com/Si-la-Tierra-gira-a-gran-velocidad-y-saltamos-por-qu%C3%A9-la-Tierra-no-se-mueve-debajo-de-nosotros-a-gran-velocidad
Oldham, H.Y. (1901). The experimental demonstration of the curvature of the Earth’s surface. Annual Report of the British Asociation for the Advancement of Sciences, 725-726.
Parallax (1865). Zetetic Astronomy: Earth Not A Globe! London: Simpkin, Marshall, and Co
Refutando la Tierra Plana (2019). Página principal [online] available in: http://refutandotp.blogspot.com/
Ros, J. (2013). ¿El agua del lavabo gira en sentido opuesto en cada hemisferio? ABC [online] March 19, available in: https://www.abc.es/ciencia/20130319/abci-agua-lavabo-gira-sentido-201303191054.html
Sputnik Mundo (2016). ¿Por qué los aviones civiles siempre vuelan a una altura de 10 Km? [online] December 11, available in: https://mundo.sputniknews.com/tecnologia/201612111065478547-aviones-civiles-altura/
