People who believe that Earth is flat aren't coming to that conclusion from the same types of observations. Instead, they believe that we are being misled and lied to, that scientists (including me) want you to believe that Earth is round, despite its flatness.

But in reality, humans have circumnavigated the planet in planes and ships, and no one has fallen into space. Rather, when ships traveling large distances on the ocean do appear and disappear on the horizon, they do so either mast or hull-first, respectively. If the Earth was flat, and you had the right optics, you could watch a ship sail from New York to Africa without losing sight of it. You can’t because the curve of the Earth makes the ship dip below the horizon. She said all conspiracy theories share a basic thrust: They present an alternative theory about an important issue or event, and construct an (often) vague explanation for why someone is covering up that "true" version of events. "One of the major points of appeal is that they explain a big event but often without going into details," she said. "A lot of the power lies in the fact that they are vague." When you follow this train of logic, it becomes clear that the only feasible conclusion is that Earth is indeed flat. Flatter than anyone has ever expected. Eric Oliver is a professor of Political Science at the University of Chicago. His research focuses on American politics, public opinion, political psychology, local politics, racial attitudes and self knowledge. He has published a number of books, the most recent of which was Enchanted America: How Intuition and Reason Divide Our Politics (The University of Chicago Press, 2018). He has also authored numerous articles in journals.Karen Douglas is professor of social psychology at the University of Kent in the U.K., specializing in the psychology of conspiracy theories. Karen’s research regularly features in the media, and she gives public talks. She is a founding member of an international network of conspiracy theory scholars. The question of belief and sincerity is one that comes up a lot," Wilmore said. "If I had to guess, I would probably say that at least some of our members see the Flat Earth Society and Flat Earth Theory as a kind of epistemological exercise, whether as a critique of the scientific method or as a kind of 'solipsism for beginners.' There are also probably some who thought the certificate would be kind of funny to have on their wall. That being said, I know many members personally, and I am fully convinced of their belief." During a lunar eclipse, Earth passes between the sun and the moon, allowing Earth to cast its shadow on the moon. That shadow is always, always, always a circle, no matter where you are on the planet, no matter the timing of the eclipse. Always.

You can learn more about the first photographs that clearly showed Earth's curvature in this NASA story. This explainer from Arizona State University lays out clearly and concisely the plentiful evidence for our planet's spherical shape. (Nearly spherical, rather: Earth's rotation causes it to be slightly squashed at the poles and swollen at the equator, a shape known as an oblate spheroid.) And this piece by fivethirtyeight.com explains why people believe in conspiracy theories such as the flat-Earth idea. Bibliography And when Columbus set sail from Spain in 1492, the question wasn't "Would he fall off the edge of the world?"—educated people knew the Earth was round—but rather, how long a westward voyage from Europe to Asia would take, and whether any new continents might be found along the way. During the Age of Exploration, European sailors noticed that, as they sailed south, "new" constellations came into view—stars that could never be seen from their home latitudes. If the world were flat, the same constellations would be visible from everywhere on the Earth's surface. For those who might not know, a “flat earther” refers to people who believe in the conspiracy theory that planet earth is flat, not spherical. But what could lead someone to believe that Suga was a part of such an absurd belief? There’s no such thing as a mountain, they’re just optical illusions caused by light refracting off all the mind-altering chemicals in the air. Photograph: PR But a fringe society founded in the 1950s, dedicated to insisting that the Earth is flat, has given rise to a modern ground of flat Earth adherents. These believers claim that the Earth is a flat disc, and that evidence that it is round — say, pictures taken from space — are an elaborate hoax involving multiple governments. Opinions differ on exactly how the flat Earth works, with believers concocting elaborate versions of physics and creative interpretations of the solar system to make their theories work.Well, the culprit was his outfit. During the first half of the Busan setlist, Suga wore a t-shirt that said, “The Earth is flat. Didn’t you know?” which prompted the funny-boned ARMYs to Tweet some hilarious takes, eventually landing in the phrase “Yoongi Flat Earther” on the trending list. | Weverse Live If the Earth were flat," Adhikari says, "the trajectory would be completely different." How different depends on which way the globe is sliced into a flattened map, but if it looked like it does on a Mercator-projection map, it might head east and pass over Africa. Engineers and architects also take the Earth's curvature into account when building large structures. A good example is the towers that support long suspension bridges such as the Verrazano Narrows bridge in New York City. Its towers are slightly out of parallel with each other, the tops being more than 1.5 inches further apart than their bases. If the Earth were flat, the bottom of the towers would be separated by the exact same distance as the top of the towers; the planet's curvature forces the tops of the towers apart. This flat Earth map drawn by Orlando Ferguson in 1893 is also considered the Bible Map of the World. (Image credit: CalimaX/ Alamy)

The photograph showed the troposphere-stratosphere boundary and the actual curvature of the Earth and demonstrated the potential for long-range reconnaissance from high-altitude balloons," NASA officials wrote. But you don't need a ship to verify the Earth's shape. When the Sun is rising in, say, Moscow, it's setting in Los Angeles; when it's the middle of the night in New Delhi, the Sun is shining high in the sky in Chicago. These differences occur because the globe is constantly spinning, completing one revolution per day. If the Earth were flat, it would be daytime everywhere at once, followed by nighttime everywhere at once. If you use gravity to, say, trust your GPS to give you accurate positions and calculate trajectories, then that same force will form material the size of Earth into a ball. As objects recede from you, they begin to look smaller and slowly disappear in a very unique way: first their bottoms become hidden, and then their tops. If you've ever watched a ship on the horizon, you've seen this for yourself. Similarly, from a great distance, the tops of tall objects like mountains are visible well before their bases.

Artists

Not every celestial body is a sphere, but round objects are common in the universe: In addition to Earth and all other known large planets, stars and bigger moons are also ball-shaped. These objects, and billions of others, have the same shape because of gravity, which pulls everything toward everything else. All of that pulling makes an object as compact as it can be, and nothing is more compact than a sphere. Say, for example, you have a sphere of modeling clay that is exactly 10 inches in diameter. No part of the mass is more than 5 inches from the center. That's not the case with any other shape—some part of the material will be more than 5 inches from the center of the mass. A sphere is the smallest option. ARMYs feel that Suga chose the t-shirt for its satirical punch, which ended up creating a full-circle moment after BTS took a jab at their words being twisted by the media during the concert. Some also feel that the shirt ended up being complimentary to the controversial event that the concert itself had become over the past few months. The Andes Mountains, 287 miles [462 kilometers] away, and although taller than the plane's altitude, lay below the sensible horizon, marked by the white horizontal line in the photograph," NASA officials wrote in a description of the flight. "The Earth's curvature explains this phenomenon, as described in the diagram accompanying the photograph. The Earth's curvature is also visible laterally in the photograph, although the effect is subtle as the image encompasses only 1/360 of the Earth's circumference." And yet, the Earth isn't a perfect sphere; it bulges slightly at the equator. "Over a long time-scale, the Earth acts like a highly viscous fluid," says Surendra Adhikari, a geophysicist at the Jet Propulsion Laboratory in Pasadena, California. The Earth has been spinning since it was formed, and "if you have a spinning fluid, it will bulge out due to centrifugal forces." You can see evidence for this at the equator, where the Earth's diameter is 7926 miles—27 miles larger than at the poles (7899 miles). The difference is tiny—just one-third of 1 percent. THE SHADOW KNOWS The ancient Greeks also knew Earth's size, which they determined using the Earth's shape. In the 2nd century BCE, a thinker named Eratosthenes read that on a certain day, the people of Syene, in southern Egypt, reported seeing the Sun directly overhead at noon. But in Alexandria, in northern Egypt, on that same day at the same time, Eratosthenes had observed the Sun being several degrees away from overhead. If the Earth were flat, that would be impossible: The Sun would have to be the same height in the sky for observers everywhere, at each moment in time. By measuring the size of this angle, and knowing the distance between the two cities, Eratosthenes was able to calculate the Earth's diameter, coming up with a value within about 15 percent of the modern figure.

In Zetetic astronomy, the perception that Earth is flat leads to the deduction that it must actually be flat; the antimoon, NASA conspiracy and all the rest are just rationalizations for how that might work in practice.On YouTube, there are videos pointing to shadows in pictures of the moon and arguing that the moon is transparent, and thus just a light. One speaker at the 2018 conference attended by a Guardian reporter made a case for the moon as a projection. What is the Zetetic Method? The only way to always cast a circular shadow is if the thing casting the shadow — in this case, Earth — is a globe. It's a matter of geometry. Dean Burnett covers the neurological mechanisms leading to conspiracy theories and more in his debut book The Idiot Brain, So if you find yourself talking to a flat-Earther, skip the evidence and arguments and ask yourself how you can build trust. Additional resources