The Angle of a Shadow During Equinox

During an equinox (March 20 and September 22-23), the Sun is directly above the equator. If we are on the equator, an upright stick will not have a shadow in the middle of the day.

On any other location, the angle between the stick and the direction of sunlight will be the same as the observer’s latitude.

This fact can only occur if the Earth is a sphere, and only if the Sun is very far relative to the size of the Earth.

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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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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 Foucault Pendulum Proves Spherical and Rotating Earth

The Foucault Pendulum is an experiment to demonstrate Earth’s rotation, named after French physicist Léon Foucault. The Foucault pendulum is the first simple and direct evidence of the Earth’s rotation. It is a straightforward experiment: a huge pendulum is allowed to swing throughout the day, and it will slowly rotate because of Earth’s rotation.

For any flat-Earthers, the Foucault pendulum is one of the facts that must be discredited. They would invent various “explanations” to reject the conclusion of the experiment. They are wrong. Anyone is free to repeat the experiment, and when done correctly, it will result in a consistent result and in line with expectations.

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Total Lunar Eclipse, Drawn to Scale

Any diagram showing two or more celestial bodies is almost never drawn in the correct scale. The reason is that in most cases, any two celestial bodies are spaced too far away relative to their sizes. It is just not possible to draw them in the correct scale and still effectively describes what we want to explain. We don’t have much choice other than drawing them not to scale.

The perpetrators of flat-Earth disseminate the allegations that the diagrams were drawn not to scale because of evil intentions, and not because of legitimate technical reasons. Some people don’t understand this and fell victim to flat-Earth indoctrination.

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Orbital Inclination: The Reason an Eclipse Does Not Occur Every Month

The orbit of the Earth and that of the Moon are not perfectly aligned in the same plane. The orbital plane of the Moon is inclined 5.145° from the Earth’s orbital plane. This is the reason an eclipse does not happen every month.

Sometimes we see flat-Earthers claim that an eclipse should happen every month. But it does not, and they take that as ‘evidence’ of the failure of modern science to explain the occurrence of an eclipse. Their mistake is that they don’t account for the orbital inclination.

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Total Solar Eclipse, Drawn to Scale

Any diagram showing two or more celestial bodies is almost never drawn in the correct scale. The reason is that in most cases, any two celestial bodies are spaced too far away relative to their sizes. It is just not possible to draw them in the correct scale and still effectively describes what we want to explain. We don’t have much choice other than drawing them not to scale.

The perpetrators of flat-Earth disseminate the allegations that the diagrams were drawn not to scale because of evil intentions, and not because of legitimate technical reasons. Some people don’t understand this and fell victim to flat-Earth indoctrination.

Continue reading “Total Solar Eclipse, Drawn to Scale”

The Galileo Affair was Never About the Shape of the Earth

Flat-Earthers often bring Galileo into the discussion. They treat him as a ‘villain’ who supported the spherical Earth but unable to prove it as he failed to demonstrate the occurrence of stellar parallax.

They are wrong. The Galileo affair was in fact not about the shape of the Earth at all. It was about geocentrism vs. heliocentrism. Everyone involved already knew that the Earth is spherical.

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