An atmospheric duct is a horizontal layer in the lower atmosphere in which a thermal inversion causes light rays to be trapped and continuously guided near Earth’s surface. They tend to follow Earth’s curvature without escaping to space.
Water heats up slower than air and will be cooler than air most of the time. In turn, the colder water cools down the layer of air just above it, creating a thermal inversion that can form a duct.
It is the reason flat-Earthers like to perform observations from very close to the water’s surface. It will be easier for light to bend, revealing objects that are geometrically behind the curvature. Then, they will incorrectly attribute it to “the lack of curvature.”
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Earth is tilted relative to its orbital plane. The Northern Hemisphere experiences more sunlight in the months around June. The same is true of the Southern Hemisphere around December. This causes an annual temperature cycle and the seasons.
Flat-Earthers claim the Equator is the hottest place on Earth and use it to disprove Earth’s tilt. In reality, the Equator is not necessarily the hottest place on Earth. Earth’s temperature caused by the axial tilt has an annual cycle and cannot be shown in a single image. Additionally, the Earth is rotating, and therefore the Sun affects the same latitude similarly.
Continue reading “Temperature and Earth’s Axial Tilt”
Clouds are moved by the wind. The average wind speed at the altitude of clouds is only about 18–70 km/h, relatively slow compared to the size of visible Earth’s surface from space.
Flat-Earthers use the lack of an apparent cloud movement to discredit videos taken from space. In reality, the clouds are moving far too slowly to appear moving in videos taken from space. To observe the cloud’s motion, we need to speed up the video.
Continue reading “Cloud Movements Seen From Space”
The distance to the horizon depends on the height of the observer and atmospheric refraction. The variability in atmospheric refraction can make the horizon appear in front of a distant object sometimes, and behind it in other times.
Some flat-Earthers raised a case —dubbed the “black swan” case— in which the horizon appears to be behind a distant object which is farther than the distance to the horizon according to calculation, and they use the fact to “disprove” Earth’s curvature. In reality, they did not account for atmospheric refraction, and that the amount of refraction varies.
Continue reading “Distance to the Horizon & the Black Swan Observation”
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”
Different locations on a comparable latitude can have some similarities. However, the latitude is not the only factor that decides seasonal changes, biodiversity, temperatures, and other conditions. The conditions can be vastly different even on places on the similar latitudes.
Flat-Earthers highlight the differences between locations on a similar latitude to the North and South of the Equator and conclude Earth must be flat. They are wrong. There are factors other than latitude that determine the differences.
Continue reading “Locations on a Similar Latitude and the Differences in their Conditions”
A sun dog is an atmospheric optical phenomenon that consists of a bright spot separated by 22° from the Sun to one or both sides of the Sun. It is caused by the refraction of sunlight by ice crystals in the atmosphere.
Flat-Earthers claim that a sun dog is caused by the reflection of sunlight by the mythical dome enclosing the flat Earth, that there are multiple suns, or other equally implausible reasons. They are wrong. A sun dog is simply an optical phenomenon that occurs in cold locations where ice crystals can accumulate in the atmosphere.
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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.
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A cyclone or hurricane rotates in a different direction depending on which hemisphere it occurs. A cyclone rotates counterclockwise in the Northern Hemisphere, and clockwise in the Southern Hemisphere.
The phenomenon happens because of the Coriolis effect, which in turn occurs because the Earth is spherical and rotating.
Continue reading “Cyclonic Rotation: The Direction a Cyclone or Hurricane Rotates”
Sometimes, we can see clouds appearing as if they are behind the Sun or the Moon. Obviously, this is merely an illusion. But some flat-Earthers regard this as ‘evidence’ that the Sun and the Moon are close and apparently closer than some clouds. They are wrong.
Continue reading “The Illusion of Clouds Appearing ‘Behind’ the Sun or the Moon”