user: Can you please provide a few observations that are disproving the flat earth theory with an explanation how exactly it contradicts the flatness argument and why.
Please make at least seven points and provide the easiest to understand first.

assistant: 1. Gravity: Gravity pulls objects towards the center of mass, which for a spherical Earth, would pull everything towards the center. If the Earth were flat, gravity would pull objects towards the edges, causing things to slide or roll in that direction. This does not happen, as objects fall straight down, consistent with a spherical Earth.
2. Curvature of the horizon: When observing the horizon from a high altitude, such as on an airplane or a tall building, it is evident that the horizon curves. This curvature is consistent with a spherical Earth, not a flat one. Additionally, as ships sail away from the viewer, they disappear over the horizon bottom-first, indicating a curved surface.
3. Earth's shadow on the Moon: During a lunar eclipse, Earth casts a round shadow on the Moon. This round shadow is consistent with a spherical Earth, not a flat one. A flat Earth would cast an elongated or irregular shadow on the Moon.
4. Time zones: As the Earth rotates, different parts of the world experience daylight and nighttime at different times. If the Earth were flat, the entire world would experience daylight or nighttime simultaneously. This does not happen, which supports the spherical Earth theory.
5. Satellite images and space travel: Astronauts, satellites, and space probes have provided countless images and videos of Earth from space, all showing a spherical Earth. If the Earth were flat, we would see a flat disc instead of a sphere.
6. Coriolis effect: The Coriolis effect causes moving objects to be deflected based on their location on Earth, with different deflections occurring in the Northern and Southern Hemispheres. This effect is due to the rotation of the Earth and would not be observed on a flat Earth.
7. Circumnavigation: People have traveled around the Earth, returning to their starting point without ever reversing direction. This is only possible because Earth is a sphere. On a flat Earth, it would be impossible to travel around the world and return to the starting point without turning around at some point.

user: Elaborate more on the "Gravity" item. Use academic language and make sure it refutes flat-earthers.

assistant: Gravity is one of the fundamental forces of the universe, which can occur between bodies of mass. By looking at Newton's law of universal gravitation, we can see that any two bodies of a given mass will experience the most gravitational force when they are close together- in fact, the force of gravity is inversely proportional to the distance between those two masses. 

Due to this fact, objects in space prefer to assume forms that are spherical in shape. This is because the gravitational force pulls equally from all sides, and so it will normalize, or smooth out, the outer shape of the sphere. Therefore, we can safely assume that a disk-shaped Earth could not form, as any object with enough mass would have sufficient gravitational force to normalize its surface and assume a spherical shape.