A selenelion occurs during a lunar eclipse when the sun and moon are observed above the horizon. Atmospheric refraction bends light rays and lifts the image of the sun, and the moon typically up to 0.6°, so both can appear above the horizon.
Flat-Earthers assert that a selenelion should not be possible if Earth is a sphere due to the fact during a lunar eclipse, the sun and moon are 180° apart. In reality, a selenelion is possible because Earth’s atmosphere refracts light.
Continue reading “Selenelion: The Phenomenon Where Both the Sun and Moon Are Visible During a Total Lunar Eclipse”
Visibility range is a measure of the distance at which an object can be clearly discerned. Angular resolution is the ability of an optical system to resolve detail in the object.
Unlike the claim from flat-Earthers, there is no such thing as the “maximum range” of a camera. A germ on our hand is well within the visibility range, yet a regular camera lacks sufficient angular resolution to see it. On the other hand, an airplane is much farther away, but it has a larger angular size and can be seen by the camera.
Continue reading “Visibility Range vs Angular Resolution”
An inferior mirage is a phenomenon in which atmospheric refraction bends light rays to produce a mirrored image below a real object. It occurs when a hot surface heats the layer of air above it, placing it below a colder & denser layer of air.
Flat-Earthers like to use inferior mirages to “explain” how a distant object can appear partly obstructed if the Earth is flat. In reality, an inferior mirage cannot produce an appearance similar to an object partially obscured by Earth’s curvature.
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In 2019, scientists discovered that Earth’s atmosphere consists of a hydrogen cloud called the geocorona that extends to the Moon and beyond. Its density is minuscule, practically vacuum, and does not affect space travel.
Flat-Earthers claim this is an “admission” as the Moon has always been “inside the dome” in their flat Earth model. In reality, the discovery does not change much about what we already know.
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Flat-Earthers use the phenomenon of refraction as a catch-all “explanation” every time they observe something not appearing in the expected position if the Earth is flat. They use the term “refraction” as mere technobabble without any underlying explanation.
The following are how we can distinguish real-world, scientific refraction from the technobabble used by flat-Earthers:
Continue reading “Refraction: Only a Baseless Technobabble in Flat Earth Community”
Earth’s shadow is the shadow that Earth casts into its atmosphere, toward the opposite point from the sun. Above Earth’s shadow is the Belt of Venus, a pink band from the scattering of sunlight through the atmosphere.
Earth’s shadow lies at the antisolar point —the point opposite the sun. It rises when the sun sets and sets when the sun rises. The phenomenon shows us that the sun really goes below the horizon and disproves the flat Earth model.
Continue reading “Earth’s Shadow and the Belt of Venus”
Atmospheric pressure decreases as altitude increases. There is no visible boundary between Earth’s atmosphere and space in terms of pressure. There is no abrupt drop in pressure where space begins.
Flat-Earthers assert that it is impossible for the pressurized atmosphere to meet the vacuum of space without any barrier. In reality, the pressure changes gradually. There is no sudden pressure drop between the atmosphere and space.
Continue reading “Atmospheric Pressure and the Vacuum in Space”
Polar areas have a lower temperature than areas closer to the equator because the same amount of solar radiation is dispersed over a larger area, and the surface of ice and snow reflects more sunlight than darker surfaces.
In the spherical Earth model, the distance to the Sun from the poles and the equator is practically the same because the sun is much farther than the distance between any two locations on Earth. Because of that reason, flat-Earthers then claim that the temperature in polar and equatorial areas should be the same. In reality, the distance to the sun is not the only factor that can determine temperature.
Continue reading “Temperature Differences Between the Equatorial & Polar Areas”
We cannot feel the Earth rotating, and to explain the phenomenon, we usually use the moving vehicle analogy. If the vehicle is moving at a constant speed, we will not be able to sense the motion. We cannot feel the motion of Earth because of the same reason.
Flat-Earthers invented the excuse that we are standing on Earth, not inside it, to falsely reject the explanation.
Continue reading “Moving Vehicle Analogy and the Physical Barrier Excuse”
If a distant boat is not visible, then it is because of at least one of these reasons:
- Our eyes have limited angular resolution and are unable to resolve the ship at that distance.
- The atmospheric condition is limiting our visibility.
- The curvature of the Earth obscures the ship.
Flat-Earthers like to demonstrate that a previously invisible ship at a distance can be made visible by zooming in. They would use it to disprove Earth’s curvature. They are wrong. There are reasons other than Earth’s curvature that can obscure a distant boat.
Continue reading “Zooming In On Distant Boats Does Not Disprove Earth’s Curvature”
The Earth retains an atmosphere because gravity pulls air particles toward the center of the Earth. Without something affecting the air —like gravity— air particles would move toward lower pressure, and Earth would lose its atmosphere.
Flat-Earthers claim that Earth should not be able to have an atmosphere because without any barrier separating Earth’s atmosphere and space, it would have been sucked by the vacuum in space. They are wrong. Gravity pulls air and allows Earth to retain an atmosphere.
Continue reading “Vacuum in Space and Earth’s Atmospheric Retention”
When aboard an airplane flying at cruising speed, we will not be able to feel that the plane is, in fact, moving at speed of more than 900 km/h. But if the plane changes its speed, turns or changes its altitude, we can easily feel it.
The same thing happens with the motion of the Earth. Due to Earth’s rotation, the surface of the Earth is moving at 1656 km/h near the equator. We never feel it because the speed is constant, or in other words, the acceleration is zero.
Continue reading “Human Perception of Speed and Acceleration”
An airplane exists on Earth. It has the same motion as the surface of the Earth, including the Earth’s rotating motion. The motion of the airplane itself is measured relative to the surface of the Earth.
Flat-Earthers think that due to Earth’s rotation, an airplane should not be able to fly east or land. They are wrong. The speed of an airplane is relative to the surface. It retains the motion of the Earth and does not need to chase Earth’s rotation.
Continue reading “Airplane and Earth’s Rotation”
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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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.
Continue reading “Rayleigh Scattering”
In most situations, atmospheric refraction bends light downwards and causes objects to appear higher than they actually are. The strength of atmospheric refraction is not constant. It depends on weather condition and varies on the different seasons, different days, and even different times of the day.
Because of the variability of atmospheric refraction, a distant object that is usually obstructed by Earth’s curvature can sometimes be visible. Some flat-Earthers would cherry-pick moments when the object is visible. They would show such specific moments to everyone and use them to “disprove” Earth’s curvature; happily ignoring the cases where Earth’s curvature partly or entirely obstructs the object.
Continue reading “Variability of Atmospheric Refraction”
Troposcatter is a signal propagation method using the scattering phenomenon in the upper troposphere. As the signal pass through the upper troposphere, some of the energy is scattered back toward Earth, allowing the receiver station at the correct location to pick up the signal.
White Alice is a decommissioned troposcatter network in North America. Some flat-Earthers invented the “explanation” that the various satellite-based services we enjoy today are using White Alice. They are wrong. White Alice and other troposcatter networks cannot possibly replace all the services provided by satellites.
Continue reading “White Alice and the Troposcatter Propagation”
On Earth, daylight sky is glowing in bright blue due to Rayleigh scattering. Sunlight is scattered in every direction by the oxygen and nitrogen molecules in Earth’s atmosphere.
Such the phenomenon does not happen on the Moon, causing the dark sky of the Moon. Flat-Earthers claim that the dark sky of the Moon captured by photos and videos taken from the Moon are “proof” there is misconduct. They are wrong. Just because Earth’s sky is bright blue, it does not mean it will be like that on the Moon and other planets.
Continue reading “The Dark Sky on the Lunar Daytime”
Earth’s atmosphere is part of the Earth. It practically follows Earth’s rotating motion like the rest of the Earth. Due to various factors, Earth’s atmosphere has relatively small and uneven movement relative to the surface. We call it ‘wind.’ The fastest wind ever recorded is about 408 km/h, relative to Earth’s surface.
Many misconceptions about Earth arise from the wrong idea that only Earth’s solid body is rotating, but the atmosphere is not. If it is true, then we should always feel the wind with the speed of 1674 km/h near the equator, or more than 4× the fastest wind ever recorded. We don’t feel such a wind, and thus we know our atmosphere is moving at practically at the same speed as Earth’s surface.
Continue reading “Earth’s Atmosphere Rotation”
Buoyancy is an upward force exerted by a fluid (liquid or gas) that opposes the weight of an immersed object. Buoyancy happens because the fluid has a pressure gradient. Pressure gradient occurs because the fluid is affected by acceleration, such as the Earth’s gravitational acceleration.
Flat-Earthers makes buoyancy as an “explanations” on how things fall. They are wrong. Without Earth’s gravitational acceleration, buoyancy will not occur.
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