Is the Earth oval or round?

The earth is not absolutely round, at the end of the 17th century, the great British scientist Newton.

The rotation of the Earth was studied.

The influence on the shape of the earth is theoretically speculated that the earth is not a very round spherical shape, but a slightly uplifted spheroid at the equator, slightly flattened at the poles, and the equatorial radius is more than 20 kilometers longer than the polar radius. 1735 In 1744, the Academy of Sciences in Paris, France, sent two survey teams to Northern Europe.

and South America, where the results confirmed that the Earth was indeed an ellipsoid. If you look at it from a distance, you will see that the earth is shaped like a pear: its equatorial part is bulging, and it is its "pear body"; The North Pole is a bit pointed, like a "pear"; The South Pole is a bit concave, like a "pear navel", and the whole earth resembles a pear-shaped rotating body, so people call it "pear-shaped Earth".

In fact, the Earth is a triaxial ellipsoid, to be exact.

Whether the Earth is elliptical or round depends on what scale you are going to measure. If you want to discern very carefully, the earth is not a perfect circle, but an ellipsoid. But in a general sense, we assume that the Earth is perfectly circular.

So you see, the shape of the earth is different from different scales.

After long-term precise measurements, scientists have found that the earth is not a regular sphere, but an irregular elliptical sphere with slightly flattened equators at the poles, exaggeratedly speaking, a bit like a "pear", called a "pear-shaped body".

The Earth is an irregular elliptical sphere with slightly flattened poles and slightly bulging equators. Earth is one of the eight planets in the solar system, the third planet in order from near to far, and it is also the terrestrial planet with the largest diameter, mass and density in the solar system, 100 million kilometers away from the sun.

The diameter of the Earth is 12,742 kilometers. The Earth's equatorial radius is kilometers, the polar radius is kilometers, and the average radius is about 6371 kilometers. So the average diameter of the Earth is 2 6,371 = 12,742 km.

The Earth Empty Brother is an irregular sphere with a large diameter at the equator and a small diameter at the north and south poles.

The shape of the earth is an irregular sphere, which is neither a sphere nor an ellipse.

The earth is an irregular sphere with slightly flattened poles and slightly bulging equators, and scientists have found that the earth is not a regular sphere, but an irregular sphere with slightly flattened poles and a slightly pure equatorial The radius of the earth's equator is about 21 kilometers longer than the radius of the poles, which is very small compared with the average radius of the earth.

The Earth is a huge irregular sphere. Today, people can see the true shape of the earth through the Earth Guardian star** sent back from space, but before that, due to the limitations of science and technology, people could not see the whole picture of the earth and the understanding of the shape of the earth, and they went through a long and difficult process of exploration