The Earth is flat

The Earth is flat
	FALSE
	"The Earth is a flat disc rather than a sphere, and governments, space agencies and scientists conceal this truth through faked photographs and a global conspiracy."
Domain	Science & Environment
Tactic	Conspiracy Theory; Pseudoscience / Junk Science;
Era	Current
First seen	1849
Origin	The modern movement traces to Samuel Rowbotham's "zetetic astronomy" in nineteenth-century England, revived through online videos from about 2014
Last reviewed	2026-10-27
	Further reading: books on Science & Environment

The claim that the Earth is flat has experienced a surprising revival in the twenty-first century, spreading through online videos, social media and conferences. Modern flat Earth believers typically hold that the Earth is a disc with the North Pole at its center and Antarctica as an ice wall around the edge, and that space agencies fake photographs to hide the truth. The Earth's roughly spherical shape has been known since ancient Greece and has been confirmed by countless observations and measurements, from the shadow cast on the Moon during eclipses to satellite navigation and photographs from space. The claim is false.

The claim

Flat Earth proponents argue that the horizon always looks flat, that water does not curve, that people would feel the Earth spinning, and that photographs from space are fabricated. They often describe themselves as skeptics testing claims for themselves, and frame belief in a round Earth as blind trust in authority.

Origin

Contrary to a popular myth, educated people in medieval Europe did not generally believe the Earth was flat. The idea that Columbus had to convince people the Earth was round was largely popularized by Washington Irving's 1828 biography of Columbus. Ancient Greek thinkers, including Pythagoras and Aristotle, argued for a spherical Earth, and around 240 BC Eratosthenes estimated its circumference with remarkable accuracy by comparing the angles of shadows in two Egyptian cities.

The modern flat Earth movement began with Samuel Rowbotham, an English writer who in 1849 published a pamphlet, later expanded as Zetetic Astronomy: Earth Not a Globe, based partly on observations along a straight canal in England known as the Bedford Level. Later experiments on the same canal, accounting for refraction, supported curvature. The Flat Earth Society was founded in 1956. The idea gained a new audience from about 2014 through YouTube videos and social media, and attracted attention when some celebrities and athletes expressed doubts about the Earth's shape.

What the evidence shows

Eclipses. During a lunar eclipse, the Earth's shadow on the Moon is always curved, which only a sphere produces from every angle.
Ships and horizons. Ships disappear hull first over the horizon, and the distance to the horizon increases with height.
Different skies. Different stars are visible from different latitudes, and the Sun's angle varies by location, as Eratosthenes used.
Time zones. It is day in some places and night in others at the same time, consistent with a rotating sphere lit by the Sun.
Navigation and satellites. GPS, satellite communications and flight routes depend on a spherical Earth.
Direct observation. Hundreds of astronauts and cosmonauts from many countries have seen and photographed the Earth from space, and private companies and amateurs have sent cameras to high altitudes showing the curved horizon.

The 2018 documentary Behind the Curve followed flat Earth believers who conducted their own experiments, including one with a sensitive gyroscope and another with light beams. Both produced results consistent with a rotating, curved Earth, which the participants struggled to explain.

Why it persists

Researchers suggest that flat Earth belief is driven less by evidence than by distrust of authority, a sense of community among believers, and the satisfaction of seeing oneself as an independent thinker. Recommendation algorithms on video platforms have been criticized for steering viewers toward such content. A 2018 survey by YouGov found that about 2 percent of Americans said they firmly believed the Earth was flat, with a larger share of young adults expressing uncertainty.

Lessons for readers

Some facts can be checked with simple observations, such as eclipses and horizons.
Skepticism means following evidence, not rejecting all authority.
When your own experiments contradict your belief, update the belief.
Conspiracy theories often require implausibly large numbers of people to keep secrets.
Be aware of how online recommendation systems can amplify fringe ideas.

Sources

Jeffrey Burton Russell, Inventing the Flat Earth: Columbus and Modern Historians (Praeger, 1991).
Christine Garwood, Flat Earth: The History of an Infamous Idea (Macmillan, 2007).
Daniel J. Clark (director), Behind the Curve (2018).
YouGov, survey on belief in a flat Earth (2018).