Cavendish Experiment

The Cavendish experiment was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant.

Flat-Earthers are in a constant effort to discredit the Cavendish experiment. They would invent various “explanations” to “explain” the result of the experiments. However, the experiment was not only done once by Henry Cavendish in 1797-1798, and has been replicated numerous times by multiple independent parties for centuries, all yielding consistent results.

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Bottled Water: A Simple Device for Observing the Dip of the Horizon

On many flights, they would give away leveling devices to all passengers for free, so that everyone would be able to observe the dip of the horizon and proves Earth is a sphere. And as a nice side effect, to quench our thirsts, too!

Such devices are called ‘bottled water’. Using these simple ‘instruments’ on a flight, we can demonstrate that Earth is a sphere.

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In photography, bokeh is the way a camera lens renders out-of-focus points of lights. The shape of bokeh depends on the camera lens more than the out-of-focus objects themselves.

Some flat-Earthers do not know how to take correctly focused pictures of distant planets and stars due to their lack of knowledge and the unsuitability of their camera for the purpose. All they are getting are bokeh, which does not tell us much about the intended objects.

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Remedy Drive’s “Commodity” Album Cover Image Confusion

In 2014, the Christian rock band Remedy Drive released the album “Commodity”. Its cover image is a small hole from NASA’s Solar Max Satellite that was caused by space debris. NASA first published the original photos in 2006.

In 2018, astronaut Chris Hadfield showed the picture to illustrate how space debris can do to a spacecraft. Flat-Earthers were happy to accuse Hadfield of stealing the cover image from the “Commodity” album. They were simply looking for any reason do discredit space flight and did not realize NASA published the image first before anyone else, including Remedy Drive.

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Rayleigh Scattering

Earth’s atmosphere glows in blue because of Rayleigh scattering. It scatters sunlight to every direction. Bluish colors are scattered more than reddish colors. This results in the bright blue color of the sky in the daytime.

There are many misconceptions in the flat Earth community that arise from the lack of understanding of Rayleigh scattering.

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Direct and Indirect Measurements

Measurement can be direct measurement, like measuring length using a measuring tape; or indirect measurement, which is measuring something by measuring another.

Flat-Earthers love to discredit results of measurement which they deem ‘impossible’ or not supporting their beliefs; for example the distance to the Sun, the distance to stars, Sun’s temperature, the orbital and rotational velocity of the Earth, etc. Their usual excuse is that such measurements were not done directly, but indirectly. In reality, most measurement instruments we use every day do their measurements indirectly.

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Sun Glitter

Sun glitter is a bright, sparkling light formed when sunlight reflects from water waves. A rippled by a locally smooth surface such as water with waves will reflect the sun at different angles at each point on the surface of the waves. As a result, a viewer in the right position will see many small images of the sun, formed by portions of waves that are oriented correctly to reflect the sun’s light to the viewer.

Flat-Earthers take the long shape of the reflection of a sunset on an ocean surface as ‘proof’ that Earth is flat. They are wrong. Sun glitter is the result of rippling water. The difference in curvature between the flat and spherical Earth model is not that far to cause the difference in the shape of sun glitter.

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One Single Proof Fallacy

The fallacy of “one single proof” occurs when someone rejects overwhelming evidence because of the lack of specific evidence and declare the entire argument invalid.

A common trick of flat-Earthers is to demand unrealistic evidence of spherical Earth. After their demand is not met, they would proclaim Earth is not a sphere, and conveniently ignore all the other evidence of spherical Earth.

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Crossing the Continent of Antarctica

Crossing the continent of Antarctica is a feat that has been achieved multiple times. And it is only possible if Earth is a sphere. If Earth were flat, the expeditions would have to travel impossibly far, all the way to the other side of Earth.

Flat-Earthers claim that no such expedition has been attempted before. They are wrong. Crossing Antarctica has been done numerous times by multiple independent parties and using different methods.

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The ‘Destroyed Technology’ to go to the Moon

In an interview, Donald Pettit —a NASA astronaut— mentioned that he’d go the moon, but they no longer have the technology to do that. All the technology from the Apollo mission has been destroyed, and it is a painful process to build it back again.

Flat-Earthers interpreted the statement rather too freely and took that as “proof” we never had the technology in the first place. In reality, the word “technology” is polyseme. It has two different related meanings. Flat-Earthers misinterpreted Don’s statement as one meaning, while Don’s intention was another.

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The Varying Earth-Moon Proportions in Different Pictures

How an object appears in a photograph depends on perspective —the position of the camera relative to the object—, and field of view of the camera. The farther the object, the smaller the object will appear in the resulting image; and conversely, the closer the object, the larger it will appear. The narrower the field of view, the larger the object will appear in the image; and conversely the wider the field of view, the smaller the object will appear.

Flat-Earthers take the varying proportions of the Earth & Moon in different pictures as a glaring inconsistency. They are wrong. The pictures were simply taken from a different perspective and field of view.

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The Antarctic Treaty Conspiracy Theory

According to flat-Earthers, the shape of Earth is a flat circle. In the center is the north pole in the Arctic Ocean and Antarctica is not a continent, but instead an ice perimeter surrounding the ‘flat Earth.’

The problem is that there are people who visited Antarctica, and their information about Antarctica does not fit the flat Earth narration. To ‘deal with the problem,’ they invented conspiracy theory and assumed every person who claimed to have visited Antarctica is a part of the grand conspiracy; and they spread the information to deceive us. This way, flat-Earthers’ narration about Antarctica is no longer falsifiable. If something stands against them, their ‘solution’ is merely to add more people to the list of persons that are part of the grand conspiracy.

The existence of the Antarctic Treaty System is convenient. Flat-Earthers use it to support their narration.

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How They Try to Deceive Us Using Footage From High-Altitude Balloons

A large amount of flat Earth memes present an image taken from a high-altitude balloon, showing the appearance of a flat horizon. Such images evidently cannot be regarded as “proof” of a flat Earth. The horizon appears flat only because of the barrel distortion from the fisheye lens.

The following is how any unscrupulous flat-Earther try to deceive us using footages from high-altitude balloons.

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Ring Laser Gyroscopes are Sensitive Enough to Measure Earth’s Rotation

A ring laser gyroscope (RLG) is an instrument for measuring the change in orientation and rotational velocity. It is sensitive enough to measure Earth’s rotation easily.

Flat-Earthers claim that there is no instrument able to measure Earth’s rotation. Such claim arose from their ignorance. Ring laser gyroscopes —which are installed in some airplanes and ships— can easily detect and measure Earth’s rotation.

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Visibility of the Sun on a Flat Earth

If the Earth were flat, then the Sun has to be visible above the horizon all the time, from the entire Earth. This does not occur, and the simple fact should have been sufficient to rule out any possibility of a flat-Earth.

But instead, flat-Earthers invented various convoluted chain of ad-hoc hypotheses and presented them as “explanations” to prevent the flat-Earth model from being falsified. None of the “explanations” are proven nor correspond to the way our world works.

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The Apparent Size of the Moon

The apparent size of the Moon remains constant in a single day. This can only happen if the Moon is practically at the same distance all day.

In the flat-Earth model, the Moon is thought to be moving in a circle above the flat Earth. Such a notion should cause the Moon apparent size to vary in a day. However, in reality, the Moon appears in the same size all day, and it proves that the flat-Earth model does not represent reality and that the Moon is much farther.

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Weight = Gravitational Force

The weight of an object is the force exerted on the object by gravity. The gravitational force exerted by the Earth on an object is what we refer to as ‘weight’.

Many flat-Earthers fail to understand that the gravitational force is just another name for ‘weight’. Many misconceptions in the communities of flat Earth victims arise from such a misunderstanding.

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Horizontal Motion of Smoke

Smoke rises due to convection current. The solid particles emitted from a combustion process are carried by the hot air that rises because of its lower density than the surrounding air. The horizontal motion of smoke itself is affected by the movement of air surrounding it.

Flat-Earthers claim that a rising smoke without horizontal motion “proves” a stationary Earth. They are wrong. The horizontal motion of smoke is an effect of the horizontal motion of air relative to the smoke, and the motion of the object emitting the smoke is inconsequential.

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NASA and Other Space Agencies

There are many space agencies from multiple countries. Some are from countries that are rivals or even enemies at some point in history. Even so, practically all their findings corroborate each other. Any made up claims or fabrications would have been noticeable and found very quickly.

Flat-Earthers accuse NASA of being part of the so-called globe Earth conspiracy, with the purpose of spreading “globe Earth propaganda” to the world population. However, there other space agencies, which are independent and employ thousands of staffs. And every one of them practically confirms NASA’s findings.

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