Why does the center of the earth burn ? Isn t that a place where there is no oxygen?

The word combustion is only used to visualize the high internal temperature of the earth's core (about 4500 inside), and it is not what we often call combustion. Early theories held that the Earth began as a hot liquid and then slowly cooled to form a solid crust, while the core remained in a hot liquid state.

The prevailing view is that the Earth is made up of solid matter and that its temperature does not exceed 1,000 °C. Due to the decay of radioactive materials to generate heat, at the same time, the original earth material shrinks due to gravity, resulting in the release of gravitational energy, which causes the local temperature of the earth to rise. After the temperature exceeds the melting point of iron (1534), liquid iron flows to the center of the earth due to its high density, thus forming the hot core of the earth.

It is believed that the outer core of the Earth's core is mainly composed of iron and nickel, and the main substance of the inner core is iron. According to scientists' speculation, there are still radioactive materials in the earth's core that are decaying, and to a certain extent, maintaining the high temperature state of the earth's core.

But when the radioactive material is depleted, the Earth will slowly cool down like the Moon and Mars. When the heat is balanced inside and outside the earth, it will not be able to drive the movement of plates, nor can it cause the differential rotation of the earth's inner and outer cores, and the magnetic field will disappear. The magnetic field is the pulse of the planet, and without the magnetic field, the planet is close to death from an evolutionary point of view.

The Earth will become a lifeless planet.

First of all, oxygen is not necessarily needed for combustion. Chlorine and hydrogen, mixed together, can be burned without the need for oxygen. Secondly, the soil also contains a lot of oxygen. Therefore, the burning of the earth's core is not enough.

Not burning similar to the yolk of an egg when it is half-cooked.

Magma is formed by tremendous extrusion.

What do you mean by burning? Volcanic eruptions?

The Earth's atmosphere was initially oxygen-free. The primordial atmosphere was reductive and filled with gases such as methane, ammonia, etc. Since the emergence of green plants on the earth, the photosynthesis of green plants has produced a large amount of oxygen, so that the oxygen content on the earth has increased greatly;

The emergence of atmospheric oxygen stems from two actions, one is the photolysis of water with the participation of non-living things, and the other is the photosynthesis with the participation of living things.

The photosynthesis of living organisms has a huge impact on the atmosphere. It causes the atmosphere to change from a reducing atmosphere to an oxidizing atmosphere. The hydrogen produced by photolysis of water can be re-oxidized into water and returned to Earth without spreading into outer space, thus preventing the loss of water from Earth.

The increase in oxygen content improves the living environment of living organisms, which in turn promotes the prosperity of organisms, including plants, forming a virtuous cycle, and finally making oxygen on the earth a gas second only to nitrogen in content.

The earth appeared 2.7 billion years ago in shallow water, oxygen-producing photosynthetic microorganisms. After some time, they fill the atmosphere with oxygen. The data documents this conversion.

There is also oxygen on other planets, it's just a matter of how much. Because oxygen is one of the elements in the universe with a high content in addition to hydrogen, helium, carbon and other elements. In the solar system, oxygen is found on various planets, including their moons.

For example, Mercury, the closest planet to the Sun, has oxygen on it. Mercury has an extremely thin atmosphere, one ten-ten-millionth of Earth's atmosphere. The composition is 42% helium, 42% sodium, 15% oxygen, and the rest is some trace gas.

Because its atmosphere is so thin, it is generally believed that Mercury has no atmosphere.

Titan is the only moon in the solar system with a dense atmosphere that has a surface atmospheric pressure about twice that of Earth. Titan's atmosphere is nitrogen, the only nitrogen-rich star in the solar system other than Earth, and there are large residues of different kinds of hydrocarbons (including methane, ethane, acetylene, propane, etc.), as well as carbon dioxide and water vapor. Where there is water vapor, there will be oxygen.

The origin of oxygen on the earth is a long-term chemical reaction process, the early earth (before there were no animals) air human beings could not survive, and later the microorganisms that consumed carbon dioxide and other harmful gases appeared, such as seaweed, they absorbed carbon dioxide and released oxygen, and there were organisms on the bottom of the sea near the submarine volcano that survived on sulfides, which gradually changed the composition of the earth's atmosphere, and the oxygen concentration in the age of the dinosaurs was greater than the current 21% oxygen concentration At that time, dragonflies were more than one meter. The energy of animals** is produced by the reaction of oxygen and sugar. In fact, the composition of the air is also changing.

At the beginning of the formation of various planets, there was no shortage of oxygen, but because oxygen was relatively active, oxygen on other planets basically turned into compounds after 2 billion years old, so the elemental oxygen gradually disappeared on other planets. When the earth was 2 billion years old, life was born, and plants were produced, and plants are a natural large factory for reducing oxygen, which continuously recycles the oxygen in carbon dioxide like a wheel, and has been maintained at a proportion of oxygen that needs to maintain civilization.

Because there are plants on the earth that carry out photosynthesis and convert carbon dioxide into oxygen, !Other planets are not without oxygen but very little!Hardly!And there are no plants on other planets, so they can't generate oxygen!

In fact, this statement is false, other planets also have or have had oxygen. For example, on Mars, the detection of oxides on the surface of the earth has shown that oxygen was present in the past, and liquid water was also present in the past. However, due to other factors (possibly star collisions), the composition of the atmosphere changes, and the molecular state of the atmosphere ionizes and escapes.

Other planets also have it, but it is relatively rare, like the moon, which has a drop of oxygen, so humans can't breathe it directly.

2.4 billion years ago, it was arguably the most turbulent period in the history of life. Life has been thriving on Earth for more than a billion years, but a new single-celled organism has emerged. They can harness solar energy, but in the process they produce a toxic by-product, oxygen.

This single-celled organism quickly multiplied in an incredible number in the primeval oceans, and the composition of the atmosphere changed as a result.

See: 2.4 billion years ago, where did the oxygen that poisoned life on Earth come from?

As for whether there is oxygen on other planets, it can only be said that it has not been discovered at present, which does not mean that there is none.

In fact, the earth originally did not have oxygen, but the earth has green plants that can produce oxygen, while other planets do not, so it is still the same as it was.

Because the earth has an ozone layer.

Because it is the photosynthesis of plants that produces oxygen.

If you think about it this way, it's much simpler. Why is oxygen on Earth and not on other planets?

This kind of problem is not known to many people now, and most of the time it is not clear!

Oxygen was born from nuclear fusion reactions in stars and is ubiquitous in space. Especially on solid planets like Earth, Venus, and the Moon, oxygen is a major building element.

On other planets, oxygen exists in the form of metal or non-metal oxides, with no elemental or free oxygen. This is because oxygen is a reactive element that is very prone to chemical reactions with other elements to form compounds. So on other planets, or in space, there is no or almost no free oxygen.

For example, in the atmosphere of Venus, carbon dioxide is the main component.

Oxygen is also a major component when the Earth is formed, but oxygen on Earth, like other planets, exists as compounds formed with other elements, and there is no free oxygen. Oxygen on Earth is completely separated from carbon dioxide by plants or photosynthetic algae through photosynthesis after organisms have evolved photosynthesis.

Without the photosynthesis of living things, there would be no oxygen on Earth.

A: Of course not, other planets with atmospheres have more or less oxygen, but they are far less oxygen than the Earth's atmosphere (21%), for example, the Martian atmosphere has about an oxygen content.

As for the solar system.

other planets and moons with atmospheres have lower oxygen content; The earth has a high oxygen content, which is mainly used by the earth's organisms, especially plants and some can carry out photosynthesis.

of microorganisms. As for the solar system, other planets and moons with atmospheres have lower oxygen levels; The earth has a high oxygen content, which is mainly due to the dominant role of the earth's organisms, especially plants and some microorganisms that can carry out photosynthesis.

Among chemical substances, oxygen is a chemically very active Mingchai gas, except for gold, platinum, silver and other very few metals and rare gases.

In addition, most of the elements can react with oxygen, which we call oxidation reaction.

This property of oxygen determines that oxygen cannot exist in large quantities on many planets, because if there is no oxygen supplement, the oxygen on the planet will be gradually consumed, and eventually the oxygen content of the planet will be close to zero.

in a variety of chemical reactions.

The conditions for the production of oxygen are harsh, and only with the help of biological photosynthesis can the energy of the sun be partially stored in the chemical bonds of oxygen.

Middle. In various chemical reactions, the conditions for the production of oxygen are harsh, and only with the help of biological photosynthesis, the energy of the sun can be partially stored in the chemical bonds of oxygen.

If the oxygen consumption on the planet is balanced by the output of photosynthesis, then the oxygen content of the planet can be maintained at a high level; It can also be seen that the high oxygen content may indicate the existence of life, such as the first sharp increase in oxygen on Earth from cyanobacteria more than 3 billion years ago.

Appear. Unfortunately, so far, scientists have not found extraterrestrial planets with high oxygen content.

Unfortunately, so far, scientists have not found extraterrestrial planets with high oxygen content.

All right! My answer.

Although we have very few observations of exoplanets, especially exoplanets and moons, we have reason to say that oxygen is not unique to Earth.

Not to mention anything else, Mars, the other planet that has been surveyed the most by human beings, has about oxygen in its atmosphere, doesn't this show that oxygen is not just the patent of the earth?

In fact, oxygen is very common in the universe, and it is said that the composition of our earth is also the first place. It's just that oxygen has a strange property that makes it difficult for it to exist in a single form, that is, oxidation.

Because oxygen is relatively reactive in nature (only relatively speaking, there are more things than oxygen), so on other planets where there is no oxygen cycle, the vast majority of oxygen can only exist in the form of compounds, or oxides. For example, the most common water in our lives is actually hydrogen oxide. Therefore, normally, unless there is one planet where oxygen occupies the vast majority, the oxygen in it will quickly undergo a chemical reaction.

But it's not a perfect thing, Mars is an example.

First of all, from a biological point of view, since the Earth is a vibrant scene, there is no reason to believe that there are no other planets in the distant world that have plants like the Earth. Plants, or chloroplasts, are important players in the carbon and oxygen cycle, so as long as there are plants or similar ones, there must be oxygen on the planet.

Secondly, from a chemical point of view, any reaction is relatively equilibrium, that is to say, even if the chemical change is unidirectional in the macro, but the change is bidirectional in the micro, in other words, even if a chemical reaction has occurred in a certain container, the container must also be the coexistence of reactants and products, but it is just a matter of how much. In this way, almost every planet where aerobic elements exist has oxygen elements or even oxygen.

Therefore, in any case, oxygen is by no means just the preserve of the earth, and it is not only unique to the earth. Or rather, there is oxygen on almost every planet!

Scientists at the Carnegie Institute and Penn State University in the United States recently discovered that Earth's microbes began adapting to aerobic life 2.72 billion years ago, at least 300 million years before atmospheric oxidation. This proves for the first time a long-standing hypothesis that the Earth's transformation into an oxygen-like atmosphere is a long-term process.

The results were published in the Oct. 16 issue of Proceeding of the National Academy of Science.

It is widely believed that the Earth's atmosphere 2.4 billion years ago did not contain oxygen. When and how photosynthesis, which produces oxygen, began to evolve and inject oxygen into the atmosphere has long been a topic of debate. Photosynthesis of plants, algae, cyanobacteria produces oxygen as waste.

Lead author Jennifer EigenBone said: "The Earth appeared 2.7 billion years ago with shallow, oxygen-producing photosynthetic microorganisms. After some time, they fill the atmosphere with oxygen. The data documents this conversion. ”

The researchers analysed changes in carbon isotopes in fossils by examining shallow- and deep-water sediments unearthed in Hamersley, Western Australia, in units of 100 million years. Carbon in nature includes carbon-12 and carbon-13. Only about 1% of carbon is 13 – one more neutron than carbon-12, which is key to understanding photosynthetic organisms.

"Photosynthetic microbes evolved in shallow sunny waters, where they used light and carbon dioxide to make food," EigenRode said. They ingest carbon-12 and carbon-13, which eventually become organisms.

A mixture of two carbons left in fossils can be caused by changes in the way microorganisms make food and energy. ”

Archean organisms are anaerobic, so the carbon 13 content is low. As the oxygen content increases, organisms begin to adapt to aerobic life, and the result is an increase in carbon-13, first in shallow water and then in deep water.