## Velocity is Measured From Specific Frame of Reference

A widespread misunderstanding within the flat-Earth victims is related to velocity/speed. They seem to think velocity is absolute, while in reality it is measured from a specific frame of reference. Example:

“If the Earth is in motion around the Sun at 30 km/s, and Apollo traveled at only 11 km/s, then how could Apollo astronauts possibly make it back to the Earth?”

We used to measure velocity/speed relative to the surface of the Earth. But it is not always like that.

## The Aether Experiments are Never Evidence of Flat and Stationary Earth

Aether was the hypothetical material that fills the region of space. It was assumed to be the medium that allows light and gravity to propagate in space. Throughout the late 1800s and early 1900s, some experiments were carried out to prove if the aether exists.

Flat-Earthers (and geocentrists alike) often use the results of these experiments to support their case that the Earth is stationary. But they are wrong. These experiments were conducted to prove if the Aether theory, or if one of its competing hypotheses —like the Special Relativity— better explains reality.

## Lunar Phase and Lunar Eclipse

Apparently it is a very common misconception that the phases of the Moon is caused by the Earth’s shadow. Not only among flat-Earthers, but the general public as well. The difference is that flat-Earthers will usually jump to conclusion, and have some outlandish interpretation about this.

In reality, the phases of the Moon happen because we see a different sunlit part of the Moon at different time. Not because it is over the shadow of the Earth.

## Star Trail: Evidence the Earth is a Sphere and Rotating Around Its Axis

In the northern hemisphere, if we look at the sky to the north, we can observe stars rotate counter-clockwise around a point. This axis of rotation is not visible from observers in the southern hemisphere.

On the other hand, in the southern hemisphere, if we look at the sky to the south, we can observe stars rotate in the opposite direction. Conversely, this axis of rotation is not visible from observers in the northern hemisphere.

This motion of the stars cannot possibly happen in a flat-Earth. The motion of the stars is a proof that the Earth is round and rotates around its axis.

## ‘The Principle’: A Documentary Without Principle

‘The Principle’ is a pseudoscientific documentary that promotes geocentrism, that the Earth is stationary and the center of the universe. Despite the fact that the film has almost nothing to do with flat-Earth, some flat-Earthers decide to use this film to bolster their beliefs. Because after all, in the flat-Earth model, the Earth is stationary and the center of the universe, right?

This actually gets more complicated than that. We are dealing with two forms of pseudoscience, that sometimes even goes against each other.

## Midnight Sun in Both Polar Regions Proves Spherical Earth

Midnight Sun is a phenomenon where the Sun remains visible at midnight. This phenomenon occurs in the summer months north of Arctic Circle, and south of the Antarctic Circle.

The apparent motion of the Sun in both polar regions is different. In the north polar region, the Sun moves from left to right. On the other hand, in Antarctica, the Sun moves from right to left. There is no explanation other than that Earth is a sphere.

## The False Analogy of a Spinning Tennis Ball

The mass of the Earth exerts the gravitational acceleration of about 9.82 m/s² to everything on Earth’s surface toward the center of the Earth. On the other hand, the rotational motion of the Earth generates the centrifugal acceleration of about 0.03 m/s² away from the Earth. The net acceleration is about 9.79 m/s² toward the center of the Earth. That is why everything on Earth’s surface stays on the surface, not flying away to space.

Flat-Earthers often make a false comparison using a wet & spinning ball. Water on the surface of a wet & spinning ball does not stick to the ball, but the Earth is also round, wet, and spins, yet everything stays on the surface. Then they make the erroneous conclusion that the Earth cannot be a spinning ball.