Flat earth is the belief that Earth is not a sphere but a flat disk, typically envisioned as a circular plane with the North Pole at the center and a massive wall of ice around the edges where Antarctica would be. While the idea sounds ancient, the modern movement traces back to 19th-century England and has grown significantly through social media, with major flat earth Facebook pages attracting over 225,000 followers. The belief requires rejecting not just the shape of the planet but also gravity, space travel, and satellite imagery as fabrications.
What the Flat Earth Model Looks Like
The most common version of the flat earth model uses something resembling an azimuthal equidistant projection, the same kind of map you see on the United Nations flag. The North Pole sits at the center, and the continents spread outward from it. Antarctica isn’t a continent at the bottom of a globe. Instead, it forms a towering ice wall ringing the entire outer edge of the disk, holding the oceans in place.
Above this disk, many flat earthers propose a dome or “firmament,” a solid structure covering the world like a lid. The sun, moon, and stars are thought to move inside or just beneath this dome, only a few thousand miles overhead rather than millions of miles away. Some believers claim that rocket footage shows objects striking this dome at high altitude, though aerospace engineers have pointed out that any rocket hitting a solid barrier at speed would be destroyed on impact, not gently stopped. The concept draws heavily from biblical cosmology, where the firmament separates the earthly realm from the heavens.
Not all flat earthers agree on the details. Some believe Antarctica extends infinitely in every direction beyond the ice wall. Others reject the dome idea entirely but still insist the earth is a plane. The movement has no single authority, so models vary widely from one community to the next.
How Flat Earthers Explain Gravity
Gravity is the most immediate problem for a flat earth model. If the earth is a disk, why do objects fall downward? The two most popular explanations are density/buoyancy and upward acceleration.
The density argument claims that objects don’t fall because of gravitational attraction. Instead, heavier (denser) things simply sink below lighter things. A rock falls through air because the rock is denser than air, not because the earth pulls it. This sounds intuitive at first, but it can’t explain why “down” is always toward the ground regardless of where you stand. Buoyancy and density describe how objects behave relative to each other inside a gravitational field. Without some force defining which direction is “down,” there’s no reason dense objects would move in any particular direction at all.
The upward acceleration model proposes that the flat disk of the earth constantly accelerates upward at 9.8 meters per second squared, pressing into everything on its surface the way the floor of an accelerating elevator presses into your feet. This would mimic the sensation of gravity, but it raises its own set of problems, including what force drives that acceleration and why it never stops.
Where the Modern Movement Began
The modern flat earth movement started with Samuel Rowbotham, an English writer who published a 16-page pamphlet called “Zetetic Astronomy” in 1849, later expanded into a full book. Rowbotham developed his conviction after conducting experiments along the Bedford Level, a six-mile stretch of straight drainage canal in England. He claimed the water showed no curvature over that distance, which he took as proof the earth was flat.
In 1870, the naturalist Alfred Russel Wallace repeated the experiment with more precise instruments. Wallace measured the apparent position of marker posts set at equal heights along the canal and found that the middle marker appeared roughly five and a half feet higher than a straight line drawn between the two endpoints three miles apart. Over the full six miles, the deviation matched what you’d expect from a sphere with earth’s known radius, leaving less than two feet of discrepancy attributable to atmospheric refraction. The results confirmed curvature. Rowbotham’s supporters rejected the findings, setting a pattern that continues today.
Rowbotham’s ideas were carried forward by the Universal Zetetic Society and eventually the Flat Earth Society, founded in the mid-20th century. The movement remained small and fringe until YouTube and social media gave it a new audience in the 2010s.
Why People Believe It
Research conducted at Flat Earth International Conferences found that the community operates with a strong confirmation bias, both motivated and unmotivated. Evidence supporting a flat earth is accepted uncritically, while counterevidence is distrusted and quickly dismissed. This isn’t unique to flat earthers. It’s a well-documented pattern in conspiracy communities, where group norms actively encourage members to reject mainstream sources.
A deep distrust of institutions sits at the core. NASA is the primary target. Flat earthers point out that many iconic images of Earth from space are composite images, assembled from multiple satellite passes and processed digitally. This is true, and NASA has never hidden it, since photographing an entire hemisphere in a single unedited shot requires being far enough away (like the Apollo missions were). But for flat earthers, the compositing process is evidence of fabrication. If the images are edited at all, the reasoning goes, they can’t be trusted at all.
The movement also draws people who feel excluded from or skeptical of scientific authority. Researchers have noted that flat earth communities promote what they call a “contagious sense of understanding,” making members feel they’re doing real science by questioning everything. The Zetetic method Rowbotham championed, relying only on direct sensory observation, appeals to people who distrust anything they can’t personally verify.
How We Know the Earth Is Round
The spherical shape of the earth has been demonstrated for over two thousand years. Around 240 BCE, the Greek scholar Eratosthenes measured the angle of a shadow cast by a sundial in Alexandria at noon on the summer solstice, when the sun was known to be directly overhead in Syene (modern Aswan) to the south. The shadow’s angle was one-fiftieth of a full circle. Since the distance between the two cities was about 5,000 stadia, he calculated the earth’s total circumference at roughly 250,000 stadia. Depending on which version of the stadion he used, this works out to within a few percent of the actual circumference of about 40,075 kilometers.
More accessible evidence is visible in everyday life. Ships disappear hull-first over the horizon, exactly as you’d expect on a curved surface. Different constellations are visible from different latitudes: the Southern Cross is permanently above the horizon at 35 degrees south latitude and farther south, circling close to the south celestial pole, yet it never rises above the horizon for most of the United States. When European sailors first crossed the equator, they watched the North Star sink below the horizon behind them. On a flat plane, every star would be visible from every location.
Time zones, the way gravity varies slightly with latitude, the circular shadow Earth casts on the moon during lunar eclipses, the behavior of long-haul flight paths, and thousands of photos and videos from the International Space Station all reinforce the same conclusion. The flat earth model requires each of these to be explained away individually, which is why alternative explanations multiply and often contradict each other within the movement itself.
The Scale of the Movement Today
Despite being easily disproven, flat earth belief has a surprisingly visible online presence. The American Flat Earth Society’s Facebook page has more than 225,000 followers. Prominent YouTube channels dedicated to the topic have tens of thousands of subscribers. International communities exist in Italian, Portuguese, Spanish, and other languages, with active Telegram and Facebook groups hosting thousands of members each.
Flat Earth International Conferences have been held in the United States and elsewhere, drawing hundreds of attendees. Surveys suggest that actual belief in a flat earth remains very rare in the general population, but awareness of the movement and casual engagement with its content is far more widespread. For many people, flat earth content functions as entertainment or as a gateway into broader conspiracy thinking, where distrust of one institution leads to distrust of many others.