How Aristotle proved that the earth is spherical

The shape of the earth must be spherical. Because each part of the earth has weight up to the center, when a smaller part is propelled by a larger part, the smaller part cannot fluctuate around the larger part, but is pressed and merged with it until they reach the center. To understand the meaning of this statement, we must imagine that the earth was in the process of being generated, as some natural philosophers have claimed.

It's just that they believe that the downward movement is caused by external coercion; We would rather say that centripetal motion is due to the nature of weighty objects. In the theoretical system of these natural philosophers, while the mixture is still in a latent state, the particles also move centripetally from all directions during the decomposition. Regardless of whether the surrounding parts are evenly distributed or not, they are concentrated from the extremes to the center and produce the same result.

Therefore, it is clear that, first, if all the particles move from all directions to one point (i.e., the center), then the clump formed must be the same in all respects. For, if you add equal quantities to the surroundings, then there must be an invariant between the extreme and the center. Such a shape is, of course, a ball.

The above evidence applies even if the parts of the earth are not uniformly concentrated from all directions to the center. A larger mass must push a smaller mass in front of it, and if both tendencies are centripetal, then the lighter thing, by being propelled by the heavier thing, will always go to that center. Evidence based on sensation can also be further demonstrated.

If the Earth is not spherical, then the eclipse will not show a bow-shaped shadow, but this bow-shaped shadow does exist. The phases of the moon from month to month are varied, sometimes semicircular, sometimes convex, and sometimes concave; But the boundaries of the shadows during a lunar eclipse are always convex. Therefore, if the eclipse is due to the position of the Earth between the Sun and the Moon, then the shape of the shadow must be due to the circumference of the Earth, and therefore the Earth must be round.

The observation of the stars also shows that the Earth is not only spherical, but also not very large, because if we change our position slightly to the south or north, the circumference of the horizon circle will be significantly changed, so that the stars above us will also change their position greatly, and thus, when we move north or south, we will not see the same stars. Some of the stars, which can be seen near Egypt and Cyprus, are not visible in the northerners, while the stars that are continuously visible in the northern countries can be observed in other countries. This proves that the Earth is not only spherical, but also that the circumference of the Earth is not large, because otherwise a slight change in position would not have caused such a direct result.

On the basis of these arguments, we must conclude that the Earth is not only spherical, but also small compared to other planets.

Aristotle.

Do experiments. He was in Alexandria.

Have the students go to a city farther south (** can't remember exactly). Make an appointment at noon on the same day, and measure the shadow length of the pole at the same height together (i.e., indirectly measure the height of the sun).

If the ground is flat, the sun should be at the same height. And if it is different, the roundness and size of the earth can be calculated according to the difference. Of course, the results were different, and he also calculated the radius of the Earth, which was accurate at the time.

Evidence that the Earth is a sphere has an arc on the horizon; When a ship on the sea level comes from afar, it always sees the mast first and then the hull; During solar and lunar eclipses, observe the moon, and the solar eclipse always has a certain arc; Magellan's circumnavigation of the world; During a partial lunar eclipse, the Earth blocks a portion of the daylight, causing the Earth's shadow to be cast on the surface of the Moon, allowing us to see the shape of the Earth's sphere.

1. The horizon is arc-shaped.

2. Ships on the sea level always see the mast first and then the hull when they come from afar, which proves that the earth is spherical.

3. During solar and lunar eclipses, observe the moon, and the solar eclipse always has a certain arc, which proves that the earth is round.

4. Magellan's circumnavigation of the world.

5. When a partial lunar eclipse occurs, the earth blocks a part of the daylight, so that the shadow of the earth is projected on the surface of the moon, just like looking in a mirror for the earth, so that we can see the shape of the earth's sphere.

The shape of the earth.

The earth is an irregular shape, it is slightly flattened, at first some people think it is round, oval, all kinds of speculation, but after some measurement data, with the midpoint of the earth as the center, the measured radius is about 40,000 kilometers, and its surface area is basically about 500 million square kilometers.

Newton's theories and laws were also opposed by other scientists, who believed that the earth was like an oval-shaped egg and a watermelon. Therefore, it is thought that French scientists sent two teams to actually measure the curvature of the earth, and through actual measurements, they confirmed Mr. Newton's theory that the earth is an irregular oblate sphere. Thus it was recognized.

Hello, very concerned about your question, the three proofs that prove that the earth is round are as follows pro, 1The horizon is arc-shaped; 2.Ships on the sea level always see the mast first and then the hull when they come from afar, proving that the earth is spherical; 3.

During solar and lunar eclipses, observe the moon, and the solar eclipse always has a certain arc; Proof that the Earth is round, that the Earth is the third planet in the solar system from the inside out, and that it is also the terrestrial planet with the largest diameter, mass, and density in the solar system. It is also often referred to as the world.

The earth is 4,446 billion years old, and there is a natural satellite, the moon, which revolves around the earth in a celestial cycle, and the earth rotates in a cycle of 23h, 56min, 4s (close to a solar day of 24h) and orbits the sun in a one-year cycle<>

Summary. Dear, glad to answer for you! Prove that the Earth is a sphere: Ships on the sea level always see the mast first and then the hull when they come from afar, proving that the Earth is spherical.

Dear, glad to answer for you! The reason for proving that the earth is the only big sphere: the ship on the sea level shed always sees the mast first and then the hull chain when it comes from afar, which proves that the earth is spherical.

Extended information: The head of the people talks about renting the time with facts that prove that the earth is a sphere. It's because Magellan set out from where he was, and his round-the-world voyage returned to where he was.

If, as you mentioned, it is a cone, a cylinder, a polyhedron, or something else, then it is very likely that it will deviate from the course on the way.