Helicopter and Earth’s Rotating Motion

We cannot travel to another location by hovering inside a helicopter and wait for the Earth to rotate below us until we are above our destination. The reason is the phenomenon of inertia.

Flat-Earthers claim that we cannot do such a thing as ‘proof’ of a motionless Earth. They are wrong. When on the ground, the helicopter itself is already moving at the same velocity as Earth’s surface.

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Temperature Variations at the Different Times During the Day

The variation of the temperature at the different times during the day is the result of two primary causes: the difference of the thickness of the atmosphere the sunlight must traverse to reach the surface; and the change of the concentration of sunlight over the same surface area of the Earth.

Flat-Earthers claim that the change in Sun’s distance caused such a difference in temperature and that it can only be explained in a flat Earth. They are wrong.

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The Moving Vehicle Analogy

“If the Earth is rotating, why when we throw a rock upward, it would fall to the original location?” The explanation is that the rock maintains the momentum before it is thrown. Before it is thrown, the rock has the same velocity as the surface of the Earth, it does not suddenly lose its momentum after being thrown, and there’s nothing exerting a force to alter its trajectory.

We usually use the moving vehicle analogy to illustrate this. If we throw the rock upward inside a moving vehicle, it would also fall to the original location, despite the fact that the vehicle is moving.

Flat-Earthers reject the analogy. Their usual excuse is that the atmosphere is not separated from space, and the rock is thrown “inside” the vehicle, separated by the body of the vehicle from the outside. They offer the analogy of being on the top of a moving vehicle as the correct analogy. They are wrong.

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The Moon in Daytime and the ‘Transparent Moon’ Misconception

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.

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Atmospheric Refraction

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.

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Zooming In On Distant Ships Does Not Disprove Earth’s Curvature

If we can’t see a distant ship, then it is because of 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 are keen to demonstrate that a previously invisible ship at a distance can be made visible by zooming in. They take this fact as ‘proof’ that the curvature of the Earth doesn’t exist. They are wrong. The curvature of the Earth is not the only reason a distant object is not visible.

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Our Ability to Perceive Speed and Acceleration

When we are aboard a plane 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 speed, turns or changes its altitude, we can easily feel it.

Same thing happens with the motion of the Earth. Because of the Earth’s rotation, the surface of the Earths moves at a speed of 1656 km/h near the equator. It also travels around the Sun at a speed of about 107000 km/h. We never feel any of these because the speed is constant, or in other words, the acceleration is zero.

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