Earth’s atmosphere scatters sunlight in every direction. Bluish colors are scattered stronger than reddish tones. As a result, the sky is glowing in bright blue during the day. The phenomenon is called the Rayleigh scattering.
Sometimes the Moon is visible during the day. The bright part of the Moon is bright because it is lit by the sunlight. On the other hand, its dark part does not receive sunlight, and thus barely emit any light. Because of these reasons, the dark part of the Moon is dominated by the blue color of the sky.
Continue reading “The Moon in Daytime and the ‘Transparent Moon’ Misconception”
Sunlight can be broken into its constituent colors using a prism. The colors are the optical spectrum of the Sun. They are the same colors on rainbows. On careful observation, the spectrum is not perfectly continuous, but it has dark lines scattered over the entire spectrum. It turned out that from the lines, we can tell the composition of the Sun without physically getting there.
Some flat-Earthers think that it is impossible for us to determine the composition of the Sun, as it is impossible for anyone to visit the Sun without getting roasted in the process. They are wrong. The composition of the Sun can be determined from the spectral lines, or more specifically for the Sun: the Fraunhofer lines.
Continue reading “Fraunhofer Lines”
Before sunrise or after sunset, the Sun is below the horizon and not directly visible. But the sky and clouds above are illuminated because they are high above, and sunlight can reach them.
If there’s a mountain between the Sun and the clouds, it can cast a shadow on the clouds. The flat-Earth model assumes the Sun is always high above, and thus, this phenomenon cannot possibly occur in a flat-Earth.
The fact that a mountain can cast its shadow on clouds far above it is evidence that the Earth is spherical.
Continue reading “Shadow on Clouds”
If the Earth is flat, then the Sun would have been visible from the entire Earth, but that’s not the reality. So, to rescue the concept of the flat-Earth from being falsified, they invented an ad-hoc hypothesis that the Sun appears to set because of perspective and refraction.
Continue reading “Atmospheric Refraction and the Position of the Sun in the Flat-Earth Model”
The Sun appears to be in the angular size of about 0.53°, and it is constant throughout the day. But sunlight is very intense and causes glare that surrounds the Sun. Because of the intensity, we are unable to distinguish the Sun from its glare.
During a sunset, sunlight’s intensity is reduced as sunlight traverses the atmosphere at an angle. Because of the reduced intensity, the amount of glare will also be reduced, and the Sun can look as if it is shrinking.
Flat-Earthers often see this phenomenon as ‘evidence’ of a receding Sun during a sunset. They are wrong.
Continue reading “Sun Glare Makes The Sun Appear Larger”
Light waves are not always moving in a straight line. When it passes through a medium of a different refractive index, the waves will deviate. The phenomenon is called refraction and described according to Snell’s Law.
Earth’s atmosphere has variation in air density that depends on the altitude. As the refractive index changes with the density of the medium, light waves passing through Earth’s atmosphere also experience refraction.
Continue reading “Atmospheric Refraction”
Sometimes, we can see clouds appearing as if they are behind the Sun or the Moon. Obviously, this is simply an illusion. But some flat-Earthers regard this as ‘evidence’ that the Sun and the Moon are close, closer than clouds ‘above’ them. They are wrong.
Continue reading “The Illusion of Clouds Appearing ‘Behind’ the Sun or the Moon”
During a total solar eclipse, the Moon is right between the Earth and the Sun. Thus, the near side of the Moon does not receive any sunlight. But while it is dark, it still gets some light reflected by the surface of the Earth. This phenomenon is called Earthshine.
Some flat-Earthers argue that a solar eclipse is not caused by the blocking of the Sun by the Moon, but by another, mysterious celestial body. The reason is that eclipses are incompatible with their beliefs about the motion of the Sun and the Moon.
Earthshine proves that they are wrong.
Continue reading “Earthshine Proves the Moon Obscures the Sun During a Total Solar Eclipse”
Some flat-Earthers consider crepuscular rays as evidence that the Sun is not far. In their mind, the Sun is only about ±5000 km circling above us. In reality, the actual distance of the Sun is ±150 million km.
Continue reading “Crepuscular Rays”
“The Sun and the Moon have been observed to appear in the sky at the same time during a total lunar eclipse. This cannot happen if the Earth is round because the Sun, Earth and Moon are supposed to be in a straight line during a total lunar eclipse. So, the globe Earth model is wrong!”
Some flat-Earthers observed the Sun and Moon appear at the same time during a total lunar eclipse. Predictably enough, they pick the most far-fetched explanation, and conclude the Earth is not round. But in reality, this phenomenon is well documented and clearly explained.
Continue reading “Selenelion: The Phenomenon Where The Sun and Moon Are Visible During a Total Lunar Eclipse”