What is the sun made of? Why does nuclear fusion occur spontaneously?

What material is the sun made of? On the topic of why the nuclear fusion reaction occurs spontaneously, my personal opinion is that what the sun has at present is an organic combustible substance with high intensity, high density and high purity, and its essence is an organic carbide that can store heat and burn, which can continuously produce the ultra-high temperature combustion phenomenon of nuclear fusion. This substance can also be called nuclear energy substance. Why do you say that? Because:

Judging from the performance of solar energy, it is a combustible substance. All substances that can spontaneously burn in nature are energy substances with different burning abilities, which are evolved from organic carbides. The energy substances owned by the sun are also the highest expression of nuclear energy substances with strong burning abilities.

However, the volume and mass of the sun is a huge celestial body, and there are also a lot of high-intensity, high-density and high-purity nuclear energy substances. Because of its high density, it will gradually burn from the outside to the inside, and the burning process will continuously produce ultra-high temperature nuclear fusion, which can continuously release light and heat and huge amounts of dust particles for the solar system and create natural conditions for the birth and growth of all things in the solar system.

Under the irradiation of solar nuclear fusion, our solar system has gone through a long period of about 5 billion years, and at this stage it has formed a star state of the solar system. With the passage of the arrow of time, the nuclear material currently possessed by the sun can spontaneously glow for about 5 billion years.

According to the current mainstream theory "Big Bang Model", we know that the universe originated from a big bang. This theory is supported by three evidences:

In the early days of BIGBANG, the temperature decreased with time, and material particles gradually formed.

You know, today's so-called "everything is made of atoms", but atoms are not inseparable particles. Atoms are composed of nuclei and electrons, and nuclei are divided into neutrons and protons. (Of course, the actual situation is far more complicated than this, so I won't go into details here. )

Protons and neutrons can actually be subdivided. They are made up of quarks.

Quarks and electrons are inseparable particles as we know them at present. A hydrogen atom has only one proton in the nucleus and only one electron outside the nucleus.

Therefore, the easiest atom to form is hydrogen. The second easy to form is helium atom. So most of the atoms in the universe are hydrogen atoms and helium atoms, accounting for more than 99% of the total. So most celestial bodies in the universe are composed of hydrogen atoms and helium atoms. The sun is mainly composed of hydrogen and helium.

I guess you will question me, after all, the earth is not like this. But we should know that the sun accounts for more than 99.86% of the total mass of the whole solar system, and the earth is just an ordinary planet and a very small one among the planets. Those big planets are also mainly composed of hydrogen and helium.

The question "Why does the sun spontaneously fuse" can be summarized in one sentence, which must be: the mass of the sun is large enough.

In fact, whether a celestial body can become a star depends entirely on its own quality. The minimum standard for becoming a star is at least 7%~8% of the mass of the sun (although this value is still controversial at present). Jupiter is the most massive planet in the solar system, but it is still a little far from becoming a star.

Under the action of the sun's own gravity, the temperature of the sun's core reaches 15 million degrees, and the pressure reaches more than 2 million atmospheres.

This makes the sun not a simple gas, liquid and solid, but a plasma.

In this state, the structure of the atom cannot be preserved, and the nucleus and electrons are freely strung around the core of the sun, just like a pot of porridge.

As we all know, the nuclear fusion reaction actually takes place in the inner core of the sun and actually takes place at the nuclear level. Based on the plasma state of the solar core, it is not impossible for nuclear fusion to occur between nuclei, but there are actually obstacles, specifically Coulomb repulsion. We all know that like charges repel and opposite charges attract. Nuclei are positively charged, so there is repulsion between them.

Because of the existence of coulomb force, it is necessary to overcome this force to react, so it is not easy to carry out nuclear fusion reaction. That's why it's also nuclear fusion. To detonate a hydrogen bomb on the earth, it is necessary to detonate an atomic bomb in advance to provide the necessary conditions for nuclear fusion reaction, that is, the temperature of 1 100 million degrees.

But we all know that the core of the sun is 65.438+05 billion degrees, which is far from 65.438+00 billion degrees. But there is a phenomenon in the quantum world called tunneling effect. To put it bluntly, it is something that needs to be overcome at a great cost, and there is a certain probability that it will happen in the quantum world.

However, this probability is really low, which is probably that a pair of hydrogen nuclei can only have a nuclear fusion reaction once every 65.438 billion years on average. Although the probability is low, there are enough particles in the core of the sun, so nuclear fusion can happen. But it is precisely because of the low probability that the nuclear fusion reaction will be very slow and will not be completely blown up like a hydrogen bomb. In the beginning, stars burn hydrogen nuclei to produce helium nuclei.

Finally, to sum up, the sun is mainly composed of hydrogen and helium, and Coulomb repulsion between nuclei is an obstacle to the spontaneous nuclear fusion reaction of the sun. Due to the existence of quantum tunneling effect, the reaction can occur, but the reaction speed is very slow.

The sun is mainly composed of hydrogen (H) and helium (he). By mass, the composition of the sun is 75% hydrogen and 25% helium, and various metals account for less than 0. 1% of the sun's mass.

Nuclear fusion is a reaction in which two or more nuclei combine to form one or more different nuclei and subatomic particles (neutrons or protons). The quality difference between reactants and products is manifested in the release or absorption of energy. This mass difference is due to the difference of atomic "binding energy" of the nucleus before and after the reaction, which releases huge energy.

The sun is the great tension of nuclear fusion in the core area, which is against the gravitational pressure of the sun's huge volume, and nuclear fusion has always been in this balance.

According to scientific research, three-quarters of the material in the sun is hydrogen, the rest is almost all helium, and of course there are a few other heavier elements, such as oxygen, carbon and even iron!

The spontaneous nuclear fusion of the sun is closely related to the huge mass of the sun, which means that super gravity, especially in the core of the sun, has strong temperature and pressure!

The core temperature of the sun is as high as 15 million degrees Celsius, and the pressure reaches 300 billion atmospheres. Such high temperature and pressure will make the core hydrogen spontaneously fuse into helium!

The huge outward thrust generated by nuclear fusion is not to blow up the sun, but to maintain the balance between the huge gravity and the external thrust of nuclear fusion, so the sun can run stably for billions of years!

The "artificial sun" we make works the same as the sun, but it is difficult for human beings to meet the terrible conditions of the sun's core, such as 300 billion atmospheres, so we can only work hard on the temperature. For example, the artificial sun temperature in China is as high as 100 million degrees!

To put it bluntly, the artificial sun is controlled nuclear fusion, which is considered to be the most likely clean and efficient energy source to replace the traditional chemical energy source in the future, and it is also likely to open the real interstellar travel era!

From the chemical composition, about three-quarters of the mass of the sun is hydrogen, and the rest is almost helium, including oxygen, carbon, neon, iron and other heavy elements with mass less than 2%.

For most of the time after the formation of the sun, the energy of nuclear fusion is produced through a series of processes called proton-proton chain reaction; This process changes hydrogen into helium, and only 65,438+0.7% of helium is produced through the cycle of carbon, nitrogen and oxygen. The nuclear fusion of the sun's core reaches a balance under negative feedback: as long as the speed is slightly increased, the temperature and pressure of the core will increase, which can better resist the pressure of peripheral substances, so the core will expand, thus reducing the nuclear fusion rate and correcting the disturbance caused by the increase of the previous nuclear fusion rate; If the reaction rate drops slightly, it will lead to a slight drop in temperature and pressure, so that the inner core will shrink and the rate of nuclear fusion will increase again, returning to the previous level.

The solar core is undergoing about 9.2× 1037 proton-proton chain reactions every second. This reaction is to fuse four free protons (hydrogen nuclei) into helium nuclei (alpha particles), and about 3.7× 1038 protons per second become alpha particles (the sun has about 8.9× 1056 free protons), which is equivalent to about 6.2× 1065438 per second.

Every time hydrogen nuclei polymerize into helium, about 0.7% of the mass is converted into energy.

Therefore, the mass-energy conversion rate of the sun is 4.26 million tons per second (the mass leaves in the form of radiant energy, referring to the mass-energy equivalent), releasing 384.6 uwt (3.846× 1026 W), which is equivalent to 9.192×10/kloc-per second.

The early sun was almost entirely composed of hydrogen, and then with the beginning of fusion, helium was gradually produced. So at present, the elements of the sun are composed of hydrogen and helium, but hydrogen accounts for more than 90% and helium is less than 9%.

About 600 million tons of hydrogen is implanted into the core of the sun every second, producing nuclear fusion and 596 million tons of helium. The static mass lost 4 million tons of hydrogen. It is this 4 million tons of hydrogen that is completely converted into heat and light according to the transformation law of mass-energy equation, which makes our earth have enough energy to maintain the ecological environment. According to the current burning rate of the sun, the core hydrogen reserves of the sun can be consumed for 5-6 billion years. Later, due to the consumption of hydrogen, helium in the sun's core will replace hydrogen for nuclear fusion. The fusion of this helium element is much more intense than hydrogen, extremely fast, completely out of control, and there is a high probability of helium flash. In the event of helium flash, the sun will instantly release huge energy, and the shock wave may give a devastating blow to the earth, so human beings must escape from the solar system and find a second home before the helium flash occurs in the sun. After the helium flash, the sun will enter the red giant stage, at this time, due to helium fusion, a large number of carbon elements will be produced.

As for why the sun spontaneously carries out nuclear fusion, it is because the mass of the sun is too great and the gravity generated is extremely great. The big ones can only resist the huge gravity by nuclear fusion at the core. It can also be said that the compressed hydrogen atoms have to undergo nuclear fusion (nuclear fusion) because of the great gravity of the sun itself. The original hydrogen of the sun came from the universe. After the big bang, a large number of substances were produced in the universe, which are some basic particles. Such as electrons, neutrons, protons and so on. After that, due to the attraction of charge, protons and electrons combine with each other, thus eliminating the simplest element in the universe-hydrogen. Hydrogen will fuse again and then generate other types of nuclei and elements. It's a little similar to the Taoist feeling of two lives and two lives.

The material that makes up the sun is not special. About 98.2% of the total mass of the sun is hydrogen and helium (mainly hydrogen, accounting for about 765,438+0%), while the remaining less than 2% is composed of oxygen, carbon, iron, neon, nitrogen, silicon, magnesium and other elements.

However, almost all the material forms on the sun appear in plasma state, which is another state different from the common solid, liquid and gas states and widely exists in the universe.

The energy source of the sun, such as the title, is nuclear fusion, so why did this nuclear fusion start? Why don't the eight-star planets such as Earth, Mars and Jupiter spontaneously start nuclear fusion?

The key for the sun to start nuclear fusion lies in its huge mass. We know that the mass of the sun accounts for 99.86% of the entire solar system, equivalent to 330,000 earths. Such amazing quality, the pressure on its core area is amazing. According to scientists' estimation, the temperature in its core working area has reached 15 million degrees Celsius, and the pressure is equivalent to 250 billion atmospheres.

On this basis, coupled with the existence of quantum tunneling effect, continuous nuclear fusion reaction can be carried out in the core of the sun. Hydrogen continues to fuse into helium, releasing a lot of energy in the process. According to the measured surface temperature of the sun, it is calculated that the energy released by the sun is 3.8 *10.26 joules per second, which is equivalent to 420 tons of matter being completely annihilated per second according to the mass energy equation.

However, the available hydrogen on the sun is also limited, which means that the sun will one day break away from the stage of the main sequence star, and the subsequent evolution is to become a red giant → a white dwarf → a black dwarf.

According to the theory of star formation, stars are born because of the contraction, aggregation and compression of gravity, and the composition of nebulae is a large amount of hydrogen and a small amount of helium produced during the Big Bang, and of course there are also a very small amount of elements such as carbon, nitrogen, oxygen and iron. The composition of nebulae is basically the material composition when stars form. With the progress of the stellar nuclear reaction, that is, the amount of hydrogen condensed into helium increases, the proportion of hydrogen and helium in the star will change. So is our sun. Three quarters of it is hydrogen, the rest is helium, and it will also include a small amount of carbon, nitrogen, oxygen and iron.

Generally speaking, as soon as a star is formed, it will be formed piece by piece, not one by one, because a nebula cannot only produce a density concentration point. Density concentration points will gather and compress the surrounding nebulae due to gravity, and the nebulae squeezed by gravity will produce high temperature. When the temperature squeezed by gravity reaches 40000 degrees, the nuclear fusion reaction will start and the nebula will become a star.

When the hydrogen in the core of a star is consumed, as long as the mass of the star is large enough, it will stop cooling because of the hydrogen fusion reaction, so the gravity will continue to shrink. The contraction of gravity continues to squeeze the inner core of the star, making the inner core produce higher temperature. At a higher temperature, the core of a star can start the nuclear fusion reaction of helium gathering into carbon and oxygen again.

As long as the star's nuclear fusion stops, gravity will contract and squeeze, forcing it to carry out the next nuclear reaction. Without gravity, the nuclear fusion of stars cannot be carried out, so it can be said that the nuclear fusion of stars is completely forced by gravity, not spontaneous.

The main material components of our whole universe are hydrogen and helium. If calculated by the total number of atoms, hydrogen and helium account for more than 99% of the total number of atoms in the universe, and other elements add up to less than 1%.

This is because the earliest elements since BIGBANG are hydrogen and helium, and a small amount of lithium. These elements are the purest and most primitive elements in our universe, and also the lightest elements.

At present, there are 1 18 elements in our universe. Those elements heavier than hydrogen and helium are gradually generated in the evolution of the universe, mainly through the evolution of stars and supernova explosions, which are fused at high temperature and high pressure. Therefore, it can be said that these heavier elements are the remnants of the universe.

Therefore, human society is full of thirst for money and many dirty desires. Haha, these are all free play. If you are lofty, don't take it seriously.

Our earth is the main member of terrestrial planets in the solar system. It can be seen from us that the sun is not the first generation star in the universe, but was born from the dregs left by the death of many generations of old stars, so there are so many impurities.

But in any case, there are few impurities. The sun is mainly composed of hydrogen and helium. If calculated by atomic number, it is similar to the abundance of elements in the universe, in which hydrogen accounts for 90%, helium accounts for about 9%, and the rest elements are a little more than 1%. According to density and specific gravity, the main elements of the sun account for about 73.46% of hydrogen, 24.85% of helium, 0.77% of oxygen, 0.29% of carbon, 0.6% of iron, 0.2% of neon and 0.09% of nitrogen.

The nuclear fusion of all stars is excited by the core high temperature and high pressure caused by the star's own gravity.

The central temperature of the sun is 654.38+05 million degrees, and the pressure is equivalent to 300 billion atmospheres. Under this temperature and pressure, the extranuclear electrons of hydrogen atoms are stripped into free electrons, and the nuclei are squeezed and fused together, forming four hydrogen nuclei fused into 654.38+0 helium nuclei.

There are 600 million tons of hydrogen participating in the nuclear fusion reaction in the solar center every second, and the fusion is 595.7 million tons of helium, releasing 4.3 million tons of energy converted by mass, which is equivalent to releasing 3.8×10.26 joules of electromagnetic radiation into space every second. Our earth can accept and enjoy these energies 1/2.

At present, about 5 billion years have passed since the sun's main sequence star stage. In another 5 billion years, the hydrogen in the sun's core will burn out, which will not meet the continuous supply of solar nuclear fusion fuel, and the sun will become unstable, and eventually the central nuclear fusion will be extinguished. Great gravity pressure will cause matter to collapse toward the center.

At this stage, the radius of the sun can be expanded by 200 to 300 times, and the outer edge of its surface will reach the orbit of Venus or even Mars, and the planets along the way will be swallowed up into gas, so it is difficult to predict whether our earth will be swallowed up in that terrible era.

But one thing is certain, even if the earth is not swallowed, it will be burnt and turned into a potato buried in the fire. Fortunately, at that time, there was no life on the earth long ago, and human beings had either emigrated to other planets or died long ago, and would not suffer that kind of suffering.

Helium nuclear fusion is more violent and faster than light nuclear fusion, and soon helium is exhausted and all condenses into carbon. After the red giant stage, the sun has been unable to stimulate carbon nuclear fusion, and the fire of fusion is gradually extinguished.

This is the cause and result of solar nuclear fusion, and it is also the cause of nuclear fusion of all stars, but the outcomes of different stars are different. This problem of time-space communication has been discussed a lot in the past, and interested friends can go and have a look.

Hello, everyone, I am the home of deep technology. As a creator in the field of science, let me take you into this question. Now let's discuss it together.

First of all, if the number of atoms is calculated, the sun is composed of 90% hydrogen, 9% helium and 1% other elements. Calculated by density and specific gravity, it is composed of hydrogen 73.46%, helium 24.85%, oxygen 0.77%, carbon 0.29%, iron 0. 16%, neon 0. 12% and nitrogen 0.09%.

Secondly, the nuclear fusion reaction of the sun is under the action of the sun's own gravity, which leads to the increase of the temperature in the center of the sun and the strengthening of the air pressure. Under the influence of high temperature and high pressure, hydrogen atoms undergo hydrogen nuclear fusion.

Finally, after 5 billion years, the solar hydrogen will burn out, and due to the tension of hydrogen nuclear fusion, more intense helium nuclear fusion will occur inside the sun.

The answers to this question shared above are all personal opinions and suggestions. I hope the answer to this question I shared can help everyone.

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