Is the earth made in its entirety? How did the earth come out

About 4.7 billion years ago, dust gathered in the universe to form the Earth and the other planets of the solar system in which it is located. At that time, the air did not contain oxygen, but contained a lot of carbon dioxide (carbon dioxide gas) and nitrogen.

Originally, the Earth was small, but it continued to increase in size due to the constant impact of small stars in the universe. And when it hits, the energy gathers, the temperature rises, and eventually melts into a liquid.

Soon, the number of star impacts decreased, and the temperature of the Earth's surface decreased, forming the Earth's crust. This is the surface of the earth today. However, magma in the Earth's interior is constantly erupting, forming a large number of volcanoes. The water vapor in the volcanic ash cools and condenses into water, which forms the ocean.

In the early days of the formation of the sun, the dust and gravel around the stars collided and contracted over a long period of time, and finally formed 8 planets...

About 4.5 billion years ago, some gases, dust, ice particles and other materials gathered together to gradually form the prototype of the earth, which is only 1 kilometer in size, which is very small compared to the vast universe.

But it was this "little earth" that kept rotating, absorbing and gathering other materials around it, and after tens of millions of years of accumulation, it gradually formed the size of the current earth, but the earth at that time was completely different from the earth now.

It is said that the universe collapsed greatly

What is above the earth as we know it? Plants, animals, humans. But who was born first of these three things? It's a plant.

The ancestors of plants were born hundreds of millions of years ago, and it is they who changed the earth and made it possible for us and animals to exist.

What does the Earth look like now? Is it blue plus green? But this was not the case on Earth in the past.

In the past, the earth was not only harsh, but also dead. There are no plants, no animals, and no humans. But with the birth of the ocean, all that changed gradually.

Bacteria that are present in the ocean, which are purple in color at first. They are spread over most of the world, making the earth look purple. It wasn't until later that sunlight reached deeper into the ocean, causing some evolution of the species.

Purple bacteria turn green, but it's not just a matter of color, the main thing is that these bacteria can produce oxygen.

Over time, leafless plants have emerged. These plants do not have leaves and can only survive along the coast. It doesn't grow into the piles of strange rocks on Earth.

To overcome this difficulty, plants evolved leaves and developed what is known as light deficit with sunlight. Each leaf contains something called chlorophyll, which was the direct grandson of the green bacteria of the time. They react to sunlight and photosynthesize, absorbing several litres of carbon dioxide a day and excreting a lot of oxygen.

Sugar is an essential ingredient when plants are growing, and plants use water to absorb sugar. So this attracted a lot of animals to climb ashore. First were animals that could breathe with lungs, then amphibians, and later land animals.

But at this time, a new species evolved, dinosaurs.

At that time, dinosaurs 2 and 3 were all vegetarians, and they were occupied by vegetarians. The largest of these are sauropod dinosaurs. They are about 30 times the size of the largest herbivores living on land, and eat twice as much as elephants.

Because of this, plants are under great threat. If this continues, plants may not be able to provide more oxygen, and the earth will not be able to breed more species, and may even be in danger of extinction. So the plants also began their evolution, and evolved a lot of powerful killer features.

For example, plants with thorns, or plants that are active, and a series of poisonous plants, and so on. There are also plants that grow their leaves upwards, such as giant sequoias, whose branches can grow very long and large, and nearly a square meter of wood is covered with them every year. So the dinosaurs and the plants began to balance a bit.

If the star hadn't fallen to the surface of the earth that time, maybe the dinosaurs and plants would have survived peacefully like this. But the fall of the planet eventually led to the demise of the dinosaurs.

When it comes to giant sequoias, let's go back to the present day. The giant sequoia trees that are so large are all grown from seeds of less than one cubic centimeter. So let's wait and see if there will be any new species or new evolutions in the future.

The Earth is an irregular elliptical sphere with slightly flattened poles and a slightly bulging equator.

Earth is the third planet in the solar system from the inside and outside, and it is also the terrestrial planet with the largest diameter, mass and density in the solar system, about 100 million kilometers (1 astronomical unit) from the sun.

The radius of the Earth's equator is kilometers, the polar radius is kilometers, the average radius is about 6371 kilometers, and the equatorial circumference is about 40075 kilometers. The Earth's surface area is 100 million square kilometers, of which 71% is oceans and 29% is land. The main components of the atmosphere are nitrogen and oxygen, as well as small amounts of carbon dioxide and argon.

The Earth is an irregular elliptical sphere with slightly flattened poles and a slightly bulging equator.

The Earth is not a regular sphere, but an irregular elliptical sphere with slightly flattened equators at the poles, exaggeratedly, a bit like"Pears", call it"Pear-shaped"。The Earth's equatorial radius is about long, which is so small compared to the average radius of the Earth that it can still be regarded as a regular sphere when viewed from the perspective of space. If a globe with a radius of 1 meter is made according to this scale, the equatorial radius is only about 3 mm longer than the polar radius, which is difficult to detect with the human eye, so it is always made into a regular sphere when making a globe.

Earth Overview:

The total area of the earth is about 100 million square kilometersOf these, about 100 million square kilometers) are land, and the remaining 100 million square kilometers) are water. The land mass is mainly in the northern hemisphere, with five continents: Eurasia, Africa, the Americas, Australia and Antarctica, as well as many islands.

The ocean includes the Pacific, Atlantic, Indian, Arctic and Southern Oceans and their affiliated seas. The coastline is 10,000 kilometers long.

The rotation of the Earth

The earth has a rotation from west to east around the axis of rotation. At the Earth's equator, the linear velocity of rotation is 465 meters per second. The phenomenon of various celestial bodies rising in the sky rising in the east and setting in the west is a reflection of the rotation of the earth.

The Earth's rotation was the first to be used as a benchmark for measuring time. Since the 20th century, due to the development of astronomical observation technology, it has been discovered that the rotation of the earth is uneven. In 1967, the international community began to establish atoms that were more accurate and stable than the Earth's rotation.

Due to the establishment and adoption of atomic time, various changes in the rotation of the earth have been discovered one after another. Astronomers already know that there are long-term slowdowns, irregular changes, and periodic changes in the Earth's rotational speed.

The cyclical changes of the Earth's rotation mainly include changes in annual cycles, changes in monthly cycles, semi-monthly cycles, and changes in near-Sunday and semi-Sunday cycles. The annual cycle change, also known as the seasonal change, was discovered in the 30s of the 20th century, which is manifested by the slow rotation of the earth in the spring and the acceleration of the earth's rotation in the autumn, which also carries the change of the semi-annual cycle. The amplitude of the annual variation is 20 25 milliseconds and is mainly caused by seasonal changes in the wind.

The amplitude of the semi-annual variation is 8 9 milliseconds, which is mainly caused by the tidal action of the sun. In addition, the amplitude of the change in the monthly and semi-lunar cycles is about 1 millisecond and is caused by the tidal forces of the moon. The Earth's rotation has a sundial and semi-sundial variation that has only been discovered and confirmed in the last decade, with an amplitude of only about milliseconds, mainly caused by the sun-day and semi-sun-day tidal action of the moon.

The earth revolves

The orbit of the Earth's revolution is elliptical, the half-long diameter of the orbit is 149597870 km, the eccentricity of the orbit is the average orbital velocity of the orbit is km per second; The angle between the orbital plane (ecliptic plane) and the Earth's equatorial plane is 23°27', known as the yellow-red cross.

The rotation of the earth produces the diurnal variation of the earth, and the rotation of the earth and the existence of the yellow and red angles cause the alternation of the seasons.

The appearance of the earth: the earth is not a regular sphere, but an irregular sphere with slightly flattened poles and slightly bulging equators, with an average radius of 6,371 kilometers, a maximum circumference of about 40,000 kilometers, and a surface area of about 100 million square kilometers.

On the earth's surface, there are mountains, basins, rivers, lakes, and oceans, among others. It can be said that the surface of the earth is an extremely irregular curved surface, but these ups and downs are small relative to the whole earth. The area of the earth is 100 million km2, the area of the ocean is about 100 million km2 of the earth's surface, and the land area is only about 100 million km2.

The maximum undulation of the surface landform is 840 m in average elevation, most of which account for 75% of the total area and are below 1000 m.

The composition of the planet.

The Earth's atmosphere is mainly made up of nitrogen and oxygen. The tropics receive more solar energy than the polar regions and redistribute it through atmospheric and oceanic circulation. Greenhouse gases also play an important role in regulating the surface temperature.

The climate of a region is determined not only by latitude but also by factors such as altitude and proximity to the region and the ocean. Severe weather such as tropical cyclones, thunderstorms, and heat waves often occur in a wide area and have a great impact on life.