First Image of Earth From Space Taken By a V-2 Rocket

The first image of Earth from space was taken by the V-2 No. 13 rocket in 1946 using the DeFry 35mm movie film camera and a 50mm lens attached to the rocket. The camera had a relatively narrow field of view. As a result, Earth’s curvature is only very slightly visible.

Flat-Earthers claim the flat appearance in the photo “proves” a flat Earth. In reality, 1. by careful examination, we can see the curve, 2. the camera has a narrow field of view, reducing the visible curvature, 3. the photo shown by flat-Earthers is usually a cropped version, further reducing the visible curve, and 4. the photo matches the expected curvature according to simulation.

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Theories of Gravity

Gravity is a natural phenomenon by which all things with mass or energy are brought toward one another. Today, gravity is explained by two theories: Newton’s law of universal gravitation and Einstein’s general relativity.

Flat-Earthers treat the existence of the two theories as a supposed conflict, and they use it as “evidence” of wrongdoing. In reality, these are two separate theories that explain the phenomenon of gravity. Einstein’s is more accurate yet more complex. In contrast, Newton’s is simpler but less accurate. Despite having been superseded, Newton’s gravity continues to be used as an excellent approximation of the effect of gravity in most applications.

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The Wallace Method

In 1870, Alfred Russel Wallace proved Earth’s curvature in the Bedford level experiment. His method was straightforward & effective and can be easily used in a similar experiment.

Wallace’s method fixes the common issues with similar experiments done by flat-Earthers. They usually fail to control, and even disregard, the effect of atmospheric refraction. Using Wallace’s simple method, we can easily prove Earth is a sphere.

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Magnitude of Visible Earth’s Curvature in a Photograph

The magnitude of the curvature that appears in a photograph of Earth’s curvature depends on several factors:

  1. The observer’s altitude.
  2. The camera’s field of view or focal length.
  3. The distortion characteristics of the camera lens.

Flat-Earthers like to dismiss a photo of Earth’s curvature by comparing it to another photo showing a different amount of curvature. In reality, to compare the visible curvature, we need to ensure all the images were taken from the same altitude, same field of view, and account for the lens’ distortion.

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Unhealthy Skepticism

Flat-Earthers like to employ an extreme, unhealthy “skepticism” toward scientific concepts. We can demonstrate its absurdity by applying the same level of unhealthy “skepticism” toward everyday things that we have taken for granted. We would not be able to know these things and cease to function like normal humans.

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Danyang–Kunshan Grand Bridge

As of 2021, the Danyang–Kunshan Grand Bridge is considered the longest bridge in the world. It is a 164.8-km-long viaduct bridge in China, consisting of 2000 spans of ~80 m long each. Like every other bridge, it is constructed following Earth’s curvature.

A hoax in flat Earth communities claims the Danyang–Kunshan Grand Bridge somehow “proves” flat Earth. In reality, it is just a claim asserted without evidence and then spread as a hoax.

The bridge is a viaduct with many short spans, and therefore, accounting for Earth’s curve is less critical than in the case of longer-spanning bridges. Nevertheless, it is still built to follow Earth’s curvature.

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Perth–Johannesburg Flight Route

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By comparing the duration of the non-stop Perth–Johannesburg flight route with the same route with a stop, we can conclude the route is only possible if Earth is a sphere.

There are other Perth–Johannesburg flights but with a stop, like in Dubai. Flat-Earthers use it to “prove” a flat Earth. In reality, it does not mean the non-stop route does not exist. And it is easy to verify the existence of the non-stop route. These are consistent only with a spherical Earth and can never be explained if the Earth is flat.

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Cost of the Apollo Lunar Roving Vehicle (LRV)

The Apollo Lunar Roving Vehicle (LRV) cost $38 million, equivalent to $260 million in 2021. Flat-Earthers claim the cost was too much for such a “dune buggy” & use it to discredit the Apollo mission. In reality, the cost was reasonable for such a project.

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Quote Mining

Quote-mining is the fallacious tactic of taking quotes out of context to make them seemingly agree with one’s position.

Quote-mining is a common flat-Earthers’ tactic. They take statements from scientists, pick a small part, and remove the surrounding context. The information no longer resembles the initial meaning, but then it is attributed to the original author or speaker to exploit or discredit their names and reputations.

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Big Diomede and Little Diomede Islands

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The Big Diomede and Little Diomede are islands in the middle of the Bering Strait. Although only 4 km apart, they belong to different countries and have a 21-hours time zone difference.

Flat-Earthers noticed the number of polar days is different on both islands during the summer solstice & they used it to discredit science. In reality, the islands are very close to the Arctic circle, & during the June solstice, the sun’s path is almost parallel to the horizon. A tiny change in latitude or height can result in a large change in sunrise & sunset times.

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Milky Way Visibility

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Because Earth is a sphere moving around the Sun, we can easily see the Milky Way’s center only in certain months. In other months, the Milky Way will be too close to the Sun in the sky, where sunlight will overwhelm and obscure it from view.

Flat-Earthers claim that the Milky Way is visible every night “proves” a flat Earth. In reality, we are inside the Milky Way, and some parts will be visible. However, a specific part of it, like its brighter center, will not be visible every night.

New York Journal’s Article in January 31, 1897

On January 31, 1897, the newspaper New York Journal wrote an article about the astonishing fact that many people still believe in a flat Earth and are trying to “prove” it.

The article was illustrated with an image of a flat Earth and today’s flat-Earthers use it as “evidence” we knew Earth is flat since centuries ago. In reality, the article was about the phenomenon there were people who still believed Earth is flat. The article did not endorse the notion that Earth is flat.

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Image Noise and The “Transparent Moon” Misinformation

Image noise is a random variation of brightness or color information produced by a photo film or digital sensor. Image noise is an undesirable by-product of photography and does not come from the actual objects in the picture.

Image noise can be in the salt-and-pepper type, forming bright dots in the dark parts of the image. When appearing in the dark part of the Moon, flat-Earthers incorrectly claim they are stars, “proving” that the Moon is transparent. In reality, these are just image noise, not part of the actual objects.

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Cult of Personality Accusations

Flat-Earthers like to accuse that science accepts ideas due to the cult of personality toward the people behind the ideas. In reality, science accepts ideas because of their merits, not because of the identity of the people behind the ideas.

Isaac Newton is considered one of the most influential scientists ever. But we have no problem saying that some of his ideas were just plain wrong and not scientific.

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An astrolabe is a device historically used to determine the date and time of day from the positions of the sun or stars. Astrolabe was used from classical antiquity, about the 2nd century BC,  until the age of discovery. It was superseded by the more accurate sextant, star charts, and time-keeping devices.

Flat-Earthers claim an astrolabe can work because Earth is flat. In reality, astrolabes are designed using the spherical Earth model. They could not possibly work if Earth is flat.

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Gleason Map

The so-called “Gleason Map” is an old map published in the 18th century. The author was a flat-Earther who claimed the map as the “flat Earth map.” In reality, the map is just a normal azimuthal equidistant map centered on the North Pole.

From the map’s patent, we know the author was aware and in full knowledge that the map was just a projection of the spherical Earth, contradictory to the claims in his book.

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Conformal vs Equal-Area Map

All map projections distort Earth’s surface in some way. They attempt to preserve some properties at the expense of other properties. A conformal map preserves shape at the expense of area. On the other hand, an equal-area map preserves area at the expense of shape.

Conspiracy theorists incorrectly claim that maps are designed to lie to us about the real area of countries. In reality, equal-area maps exist if we need a map that preserves area by sacrificing accurate shape.

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Operation Avalanche

Operation Avalanche is a conspiracy thriller film released in 2016. It is of a deconstructive parody genre that assumes as if the Apollo moon landings did not occur and gives a fictional backstory on how secret agents managed to “fake” the moon landings.

Flat-Earthers took footage from the movie, then modified them to make them more convincing, and presented the result as if it is a recently discovered video on how the moon landings were “faked.” The video then spread in flat-Earth communities as a hoax.

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Auguste Piccard, A Scientist Falsely Claimed by Flat-Earthers

In 1931, Auguste Piccard went up in a balloon to an altitude of 15781 m, not far above the cruising altitude of an airliner. At the altitude, Earth’s curvature is still very slight and difficult to see, especially through the small portholes in his chamber.

In a Popular Science interview, Piccard was reported to have said that Earth “seemed a flat disc with an upturned edge.” Flat-Earthers quickly interpreted his statement as if he was telling us Earth is flat. In reality, in another interview, it is clear that he is convinced that Earth is a sphere. In his writings about his expeditions, the word “globe” was also mentioned several times.

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Moon Phase and Earth Phase Relation

The phase of the moon seen from Earth is the opposite of the phase of Earth seen from the moon at the same time. If we see a crescent moon from Earth, then someone on the moon at the same time will see a gibbous Earth, and vice versa.

Flat-Earthers noticed the phase of the moon during an Apollo mission was different from the phase of Earth in photos from the mission. Then they used it to discredit the Moon landing, wrongly assuming both phases should be identical. In reality, the two phases are opposite each other, and they will check out.