Argument to the Future

The fallacy of argument to the future occurs when someone claims their argument is true because of the false assumption that the evidence is in the making, and it will soon be proven true.

Flat-Earthers are sometimes forced to concede that they cannot prove a flat Earth, but they believe it anyway because they claim it will be proven in the future. In reality, something like the shape of the Earth has been thoroughly proven to be a sphere. No amount of “research” will eventually prove a flat Earth.

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Direct and Indirect Measurements

Measurement can be direct, like measuring length directly with tape or a ruler. But it can also be indirect, like measuring distance by emitting a sound, listening for it, and measuring the delay the sound is received after being bounced back by an object.

Flat-Earthers like to discredit measurement results —like the distance to the Sun— by mentioning these are just results of calculation, not measured directly. In reality, many everyday instruments do measure indirectly. They measure a different value, then use calculations to get the desired calculation.

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Controlled Opposition or Psyop

Believers of a less ridiculous conspiracy theory often wrongly claim that a more ridiculous one, like flat Earth, is a psyop or controlled opposition intentionally created by the authorities to undermine and discredit all the other conspiracy theories.

In reality, conspiracy theories like flat-Earth can form due to ignorance, emotion, and prejudice. It is not necessary to invent a conspiracy theory to explain the existence of another. Moreover, all conspiracy theories are more similar than different from each other, including flat-Earth. They differ only in the severity of ignorance, emotion, and prejudice needed for someone to become a victim of a specific conspiracy theory.

Bedford Level Experiment Confirmed the Curvature of the Earth

In 1870, Alfred Russell Wallace took a challenge from a flat-Earther and successfully confirmed the existence of Earth’s curvature in the Bedford level experiment.

Wallace did the experiment on the Bedford Canal. Wallace fixed a black band on the Old Bedford Bridge and observed it with a telescope from the Welney Bridge 6 miles away. Right in the middle, he placed a pole with two discs on it. The telescope, the top disc, and the black band are at the same height above the water.

From the telescope, both discs were seen above the black band, proving the existence of Earth’s curvature.

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Contextualism: How to Debunk Flat Earth in a Reasonable Way

Contextualism is the treatment of knowledge as context-sensitive. In discussions about the shape of Earth, flat-Earthers like to use the extreme denialist context in which if there is any tiny possibility that we might be wrong, then we do not know it at all. But if we apply the same context to everyday scenarios, we will fail to function as normal human beings.

To avoid unreasonable arguments, we can shift the context back to what applies to everyday scenarios. If these people ask, “How can you be certain of <something> if you haven’t proven it yourself?” we can reply, “The same way you are certain that North Korea is real.” In an everyday context, we all know North Korea is real although most of us cannot personally prove it.

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Non-Stop, Long-Haul Flight Routes in the Southern Hemisphere

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There are many non-stop, long-haul flight routes between different continents in the southern hemisphere, without crossing the northern hemisphere. These routes are only possible if Earth is a sphere, and impossible if Earth is flat.

Flat-Earthers claim that all long-haul flights south of the Equator always do a stop north of the Equator. In reality, there are plenty of non-stop routes between these locations, showing that Earth is a sphere.

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Refraction of Laser Beam

Lasers are distinguished from other light sources by their coherence, or that their frequency and waveform are identical, and the output being a narrow beam. But lasers are still a form of light and exhibit the same characteristics as other light sources.

Flat-Earthers assume lasers always travel in a straight line, not affected by the medium. They use this incorrect assumption in their “experiments” to “prove” a flat Earth. In reality, like other light sources, atmospheric refraction can bend laser beams.

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Southern Hemisphere: Where Many Flat-Earth Claims are Disproven

Flat-Earth is a con initially designed to appeal to the potential victims in the Northern hemisphere. At a glance, some of the claims are seemingly in line with observation in the Northern hemisphere, but they are easily disproven when tested in the Southern hemisphere.

90% of all humans live in the Northern hemisphere. And it made sense of these con artists to invent the “facts” with the northern markets in mind while hoping nobody would bother going to the Southern hemisphere only to verify them. It was realistic in the 19th century, but today, everyone can verify the southern facts. There is no excuse for us to become flat-Earth victims, especially those already living in the Southern hemisphere.

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Flat-Earthers’ Excuse to Dismiss Observation of the Sky

Flat-Earthers like to dismiss evidence of spherical Earth if it is in the form of an observation of the sky. In reality, many of the observed motions of celestial objects can only be explained if Earth is a sphere. These observations are sufficient to prove that Earth is a sphere and rule out a flat Earth.

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Horizontal Motion of Smoke

The horizontal motion of a rising smoke occurs due to the horizontal motion of air relative to the object releasing the object. If the air is stationary relative to the object releasing the smoke, then the smoke will rise straight upward.

Flat-Earthers claim the motion of smoke rising straight up “proves” Earth is stationary. In reality, the horizontal motion of smoke is caused by the motion of surrounding air, relative to the object releasing the smoke, not the motion of the object itself.

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Isaac Newton and the “Hypotheses non Fingo”

Isaac Newton formulated the law of universal gravitation, which adequately explained the motion of all bodies in space known at his time. He also showed it is the same law that is causing everyday objects to fall on Earth.

In his famous phrase “hypothesis non fingo,” Newton stated that he did not know what causes gravity and refused to speculate. Flat-Earthers use it to discredit him. In reality, just because he did not know what causes gravity, it does not mean his law of universal gravitation is wrong.

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Transporting the Apollo Lunar Roving Vehicle

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The Apollo Lunar Roving Vehicle (LRV) is a battery-powered rover used on the Moon in the last three Apollo missions. Each LRV was carried to the moon folded up in the Lunar Module’s quadrant 1 bay, which was kept open to space.

Flat-Earthers claim the LRV is too large to fit inside the Lunar Module and they use it to dismiss the mission as fake. In reality, the LRV was carried folded up in open cargo space, similar to transporting a bicycle using a bike carrier attached to a car.

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Geocentric Coordinate System Does not Imply Geocentrism

In astronomy, we use a celestial coordinate system to specify the position of celestial objects, like satellites, planets, stars, etc. Each of the coordinate systems has an origin, which can be the observer (topocentric), Earth (geocentric), the Sun (heliocentric), the Moon (selenocentric), or any other location. We choose a specific coordinate origin according to convenience and suitability for the problem at hand.

Some coordinate systems are described as “geocentric,” and flat-Earthers use it as “proof” of geocentrism, or that Earth is stationary and the center of the universe. In reality, it is just the origin of the coordinate. “Geocentric” here means Earth is the origin of the coordinate system. As we live on Earth, a geocentric coordinate is useful for many purposes.

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True Horizon and Linear Perspective

In graphical, linear perspective, the horizon is the horizontal line where the vanishing points for level objects lie. However, as the Earth is a sphere, the horizon of linear perspective is not the same as the true horizon, which is the line that we observe separating Earth from the sky.

Flat-Earthers claim that the observed horizon is produced by the law of perspective. In reality, from a high vantage point, we can try extending level and parallel lines to find their vanishing points. In many cases, they will end up above the true horizon.

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Salar de Uyuni and Other Salt Flats

Salt flats are flat expanses of ground covered with salt and other minerals. Salar de Uyuni in Bolivia is the world’s largest salt flat. Salt flats appear visibly flat, but they still follow the curvature of Earth.

Flat-Earthers claim the apparent flatness of Salar de Uyuni and other salt flats “proves” a flat Earth. In reality, while salt flats appear flat, they still follow Earth’s curvature. On a salt flat, the bottom part of a distant object will be obscured by Earth’s curvature, similar to at sea.

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Airplanes Going Over Earth’s Curvature

To an observer on the ground, an airplane at 36000 ft will start going over Earth’s curvature at a distance of 400 km. However, we are also limited by atmospheric visibility. In an extremely best-case scenario, we can only see up to 240 km.

We can easily see ships going over Earth’s curvature, and flat-Earthers like to demand us the same thing for airplanes. In reality, at the typical distance a plane does that, it is far out of visibility range. But if it is very low, like when approaching a runway to land, it is possible to see the plane going over the curvature of the Earth.

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Archimedes and the Surface of any Fluid

In the 3rd century BCE, Archimedes of Syracuse wrote what we now call the Archimedes’ principle in his book “On Floating Bodies” using the spherical Earth model.

Flat-Earthers like to misuse Archimedes’ principle as if it supports their claim that Earth is flat. In particular, they abuse Archimedes’ principle as if it is a competing explanation against gravity. In reality, Archimedes and other Greek scientists at the time already knew Earth is a sphere, and he explicitly mentioned it in his writings.

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Alignment of Planets

Planets are in motion around the Sun. Sometimes the planets’ positions are aligned that they appear close to each other in the sky, and less frequently, involving more than two planets.

One such alignment of planets occurred in May 2011 where Mercury, Venus, Mars, and Jupiter are all appeared close together. Mercury and Venus are closer to the Sun than Earth, while Mars and Jupiter are farther. Flat-Earthers cannot understand how all of these planets can appear close to each other in the sky, and they use it to discredit science. In reality, this diagram can easily explain the general positions of the planets during the phenomenon.

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Cellular Network vs Satellite Communications

A cellular network consists of several cells. Each of the cells is serviced by a base station operating with a specific frequency. Adjacent cells are each assigned a different frequency. A non-adjacent cell will be able to use the same frequency without interfering.

Flat-Earthers like to tell us that a single satellite can cover an entire country, yet phone operators choose to install base stations everywhere instead. Then they use the fact to “prove” that satellites do not exist. In reality, a cellular network has several advantages compared to one single base station, like a satellite.

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Observing Earth’s Curvature From a Flight

At the cruising altitude of a jet airliner, Earth’s curvature is too slight for us to notice casually. But with planning and careful observation, it is not impossible to see the curvature. Continue reading “Observing Earth’s Curvature From a Flight”