Why does the sun shine and why does the sun shine

The sun is a red-hot gas planet that shines on its own. The temperature on its surface is about 6,000 degrees Celsius, and the core temperature is as high as 15 million degrees Celsius. The radius of the Sun is about 696,000 kilometers, which is about 109 times the radius of the Earth.

Its mass is tons, which is about 332,000 times that of the Earth. The average density of the Sun is grams per cubic centimeter, which is about 1 4 of the density of the Earth. The average distance between the Sun and our Earth is about 100 million kilometers.

The structure of the sun is mainly divided from the inside to the outside: the center is the thermonuclear reaction zone, the core is the radiation layer, the radiation layer is the troposphere, and the troposphere is the solar atmosphere outside the troposphere.

According to the theory of nuclear physics, the center of the sun is a thermonuclear reaction zone. The central region of the Sun occupies 1 4 of the entire radius of the Sun and is more than half of the mass of the entire Sun. This indicates that the density of matter in the central region of the Sun is very high.

Up to 160 grams per cubic centimeter. Under the attraction of the sun's own strong gravity, the central region of the sun is in a state of high density, high temperature and high pressure. It is the birthplace of the sun's immense energy.

The energy generated in the central region of the Sun is mainly transmitted in the form of radiation. Beyond the central region of the sun is the radiant layer, which extends from the radius of the sun at the top of the thermonuclear center to the radius of the sun, where the temperature, density, and pressure decrease from the inside out. In terms of volume, the radiant layer accounts for the vast majority of the total volume of the Sun.

Through thermonuclear fusion, the sun emits light by burning large amounts of hydrogen concentrated at its core, consuming an average of 6 million tons of hydrogen per second. After another 5 billion years, the Sun will deplete its hydrogen reserves, and then the nuclear region will shrink and the nuclear reaction will expand to the outside, where its temperature can reach more than 100 million degrees, leading to helium fusion.

Thermonuclear reactions are constantly taking place in the sun's nuclear reaction zone, and the energy produced is radiated into space. Among them, only one part of 2.2 billion energy radiates to the earth, becoming the main light and heat on the earth, solar radiation is released in the form of electromagnetic waves, and the electromagnetic waves in the visible light area are seen by the naked eye as sunlight.

Solar flares are intensely active and produce light. It is generally believed to occur in the chromosphere, so it is also called "chromosphere explosion".

Its main observation feature is that the rapidly developing bright spots suddenly appear on the surface of the sun (often over the sunspot group), and its lifetime is only between a few minutes and tens of minutes, and the brightness rises rapidly and decreases slowly. Especially in peak solar years, flares occur frequently and the intensity of rolling perturbation becomes stronger.

Once it appeared, it was simply an earth-shattering explosion. The energy released by this brightening is equivalent to the total energy of 100,000 to 1 million strong volcanic eruptions, or equivalent to tens of billions of 100-ton hydrogen bombs**; And a large flare eruption can release 10 of the 25th power joules of energy in one or two minutes.

Even at this stage when the Sun is still in the main sequence zone, the luminosity of the Sun is still slowly increasing (about 10% per billion years), and the surface temperature is slowly rising. The light of the sun used to be dim, which may be the reason why life only appeared on land 1 billion years ago.

If the temperature of the Sun increases at this rate, the Earth may become too hot in the next 1 billion years for water to exist on the surface of the Earth in a liquid state, and all life on Earth will become extinct. Dazhongdan.

Following the red giant phase, intense thermal pulsations will cause gas from the Sun's outer layers to escape, forming planetary nebulae. After the outer layers were stripped away, the only thing that remained was the scorching core of the star, the white dwarf, which gradually cooled and dimmed over billions of years. This is typical of low-mass vs. intermediate-mass star evolution.

The sun shines because it produces excess energy during the fusion of hydrogen into helium, which is eventually released in the form of light and heat, which is the real reason why the sun shines.

The Sun is a giant nuclear fusion reactor (nuclear fusion is a nuclear reaction in which two lighter nuclei combine to form a heavier nucleus and a very light nucleus or particle. In this process, the nuclear fusion reaction converts the mass of some of the reactants into energy), and the artificial sun mimics the sun's nuclear fusion principle to provide humans with an inexhaustible source of energy.

In terms of technical classification, artificial suns belong to controlled nuclear fusion, and the energy output process of nuclear fusion is artificially controlled to ensure that the energy output meets the dynamic demand for energy of human beings.

The quantum effect helps the sun burn slowly, which is the secret of the sun's longevity.

The Sun is large, not only in size, but also accounts for 99% of the total mass of the solar system. However, the solar energy burns for so long, not because it ***. Conversely, the greater the mass, the greater the stellar gravitational pull, the more intense the star burns, and the faster the hydrogen depletion inside the star.

As a result, massive stars have very short lifespans, and some of these short-lived stars have a lifespan of less than a million years. However, the mass of the sun is not great in the universe. Scientists estimate that the sun will live for about 10 billion years.

It is estimated that some stars with very small masses can live up to 1 trillion years.

Because the sun is a source of energy, a powerful source of energy. Non-stop nuclear transformation. Energy is emitted at different frequencies. We humans can see the sun because our eyes can react conditioned to some of the electromagnetic waves emitted by the sun at various frequencies.

The sun shines is not a simple sense of combustion, to put it simply, in fact, the sun is a huge nuclear reactor, which is carrying out polymerization reactions all the time, the principle is the same as the hydrogen bomb, but the energy released by the sun in 1 second is equivalent to a lot of hydrogen bombs at the same time, and the hydrogen bomb will produce strong light, so the sun is a huge nuclear reactor of course will glow.

Because the sun is a star, there is a heat source inside, and the heat source emits heat, and the heat produces light.

Why do jellyfish emit light.

At the end of the 19th century, Marie Curie's major discoveries in the field of radioactivity brought humanity into contact with the tremendous energy of atomic energy, and it was then that mankind realized that the sun shone through the fission of the nuclear material inside.

The sun shines because the thermonuclear reaction of hydrogen fusion into helium is going on inside the sun.

The Sun, which is mainly composed of hydrogen, has been able to shine steadily for billions of years because of the thermonuclear reaction of hydrogen fusion into helium that has been going on inside it. We can think of the fusion reaction inside the sun as a constant hydrogen bomb going on**. Every second, 600 million tons of hydrogen in the sun's core fuse into helium, converting nearly 4 million tons of matter into energy.

More specifically, in the interior of the Sun, protons fuse into helium-4 nuclei through a series of reactions, releasing energy. It is a fusion process known as a proton-proton chain, and in this process, positrons, gamma rays, and neutrinos are also released. Theories suggest that 99% of the sun's energy is released through a series of fusion reactions in the PP chain.

The longevity of the sun

Everything has a life cycle, and the sun is no exception. It is only compared to the evolutionary history of the sun that human history is only a drop in the ocean, and the sun that rises in the east and sets in the west every day will be mistaken for eternal change.

Based on a comparison of the existing hydrogen and helium levels in the sun, scientists have calculated that the sun will continue to "burn" for about another 5 billion years. At that point, the outer layer of the Sun will expand very large and become a giant red giant. Those planets that are close to it, such as Mercury, Venus, and even the Earth will be engulfed by this "big red fat man".

The Sun's life lasts millions more years during the Sunset Red phase, but once the Sun fuses the heaviest element it can fuse, its outer atmosphere will eventually disperse to form a magnificent planetary nebula, and its core will transform into a compact object, a white dwarf.

The above content reference: China Science Network - Sun, Here We Come: China's first comprehensive solar exploration satellite will be launched next year.

Why does the sun shine? The temperature of the sun's inner core is 15 million degrees Celsius, where hydrogen-helium fusion reactions take place. Nuclear fusion reactions consume about five million tons of matter per second and convert them into energy that is released in the form of photons.

It takes more than a million years for these photons to reach the surface of the sun from the center of the sun. After the photon travels from the center of the sun, it passes through the radiation belt, losing energy in collisions with atomic particles along the way. It then passes through the convection zone, where the photon's energy is absorbed by the hot gas, which transfers energy to the surface in the convection current.

By the time they reached the edge of the convection zone, the photons had cooled to 5,500 degrees Celsius...

Why does the sun shine? What we can see directly is the photosphere on the surface of the Sun. The photosphere is relatively active, with a temperature of about 6,000 degrees Celsius, which belongs to the "cooler" part.

There are undulating convection units called "grains of rice" in the photosphere. Each grain of rice is about 1,600 kilometers in diameter, and they are the culmination of the thermals that rise from the inside of the sun. It is in the constant convection activity that the sun releases the equivalent of 100 billion megaton nuclear bombs into space every second.

In some parts of the photosphere, the temperature is relatively low, and in the visible light range, these parts appear darker than other places, so people call them "sunspots". The photosphere is wrapped around the chromosphere, and the sun transfers energy outward through the chromosphere...

Why does the sun shine? There are solar flares in this layer, which are scorching hydrogen clouds that are produced before sunspots form. Beyond the chromosphere is the outermost corona of the Sun's atmosphere.

The corona is so large that it can stretch millions of kilometers into space, but it can only be seen during a total solar eclipse. One can see in the corona a huge flame "bait" that emerges from the top of the chromosphere. While radiating light and heat, the sun also produces a low-density stream of particles – the solar wind.

The solar wind radiates into space at a speed of 450 kilometers per second. Auroras from Earth and certain other planets are also brought by the solar wind. If the solar wind is unusually strong for a period of time, a solar storm is formed.

The Sun's magnetic field is extremely powerful and complex, and its range even extends beyond the orbit of Pluto...

Why does the sun shine? The sun is almost five billion years old, and it can continue to burn peacefully for about five billion years. Five billion years from now, the helium inside the Sun will be transformed into a heavier element, doubling its brightness, expanding in size, and Mercury, Venus, and Earth will all enter its atmosphere.

After a 100 million year red giant phase, the Sun will run out of energy and collapse into a white dwarf, forming a planetary nebula by projecting material into space. Among the cosmic celestial bodies, the most striking is the Sun. Although people see the sun almost every day, it is difficult for people to see its true face because it emits a dazzling light all the time

Astronomers have envisioned all sorts of possibilities. A simple idea is that the sun is a big briquette that is burning. But if you calculate carefully, a briquette the size of the sun (1.3 million times larger than the earth) will only burn for more than 3,000 years if it burns forever.

Because the history of human beings is hundreds of thousands of years, and the history of civilization recorded in writing is more than 5,000 years. The "age" of the sun cannot be shorter than human history. What's more, if the briquettes burn smaller and smaller, the sunlight will quickly become fainter and weaker.

But in fact, after nearly 100 years of measurements, the solar luminosity has not changed. Therefore, the idea of briquettes burning is definitely not right.

Another idea is that the ancient sun was large and shone due to contraction, but after calculations, it was thought that this idea could not be held either.

In the 20th century, with the development of atomic physics, people solved the problem of solar energy. The famous scientist Albert Einstein (1879-1955) discovered the relationship between the mass of an object and its energy. As long as a little bit of mass is converted into energy, the value is huge.

For example, the energy corresponding to 1 gram of matter is equivalent to the heat released by the combustion of 10,000 tons of coal.

The study of atomic energy has led to the idea that the energy source of the sun may be atomic energy. Observations and experiments have confirmed this idea.

It turns out that the sun is mainly composed of hydrogen, which accounts for more than 70% of the mass. Under the conditions of high temperature (above 10 million K) and high pressure (about 250 billion atmospheres) in the interior of the sun, hydrogen atoms undergo a "thermonuclear reaction", which combines four hydrogen nuclei into one helium nucleus. In this reaction, a portion of the mass is converted into energy, releasing a large amount of heat.

Thermonuclear reactions inside the sun, similar to a hydrogen bomb on the ground**. It is precisely because of the countless "hydrogen bomb" processes that continue to occur in the core area of the sun, so the light and heat radiated by the sun are continuously eliminated. Atomic energy is the energy of the sun.

There are many hydrogen nuclei in the sun, which interact with each other and combine to form helium nuclei, which emits light and heat at the same time, which is called thermonuclear reaction, and the sun is a furnace that uses atoms as fuel. One kilogram of atomic fuel is worth 3 billion kilograms of coal. The sun's atomic fuel, which will never burn for thousands of years, will provide us with light and heat forever.