Why does the sun shine for so many years? Why does the sun shine? How does it "work" and how does it affect our planet? Why doesn't the sun shine

The light of the Sun is one of the most important things on Earth. It supports life in every organism on our planet, and without it we simply would not exist. But how does it affect us? And why does the sun shine at all? Let's find out how these processes work.

Another star in the sky

In ancient times, people did not know why the sun shines. But even then they noticed that it appears early in the morning and disappears in the evening, and bright stars come to replace it. He was considered a diurnal deity, a symbol of light, goodness and power. Now science has stepped far forward and the Sun is no longer so mysterious to us. Dozens of websites and books will tell you a lot of details about him, and NASA will even show him pictures from space.

Today we can safely say that the Sun is not some special and unique object, but a star. Just like the thousands of others we see in the night sky. But other stars are very far away from us, so from Earth they seem like tiny lights.

The sun is much closer to us, and its radiance can be seen much better. It is the center of the star system. Planets, comets, asteroids, meteoroids and other space bodies revolve around it. Each object moves in its own orbit. The planet Mercury has the smallest distance to the Sun, the farthest parts of the system have not been explored. One of the distant objects is Sedna, which makes a complete revolution around the star in 3420 years.

Why does the sun shine?

Like all other stars, the Sun is a huge hot ball. It is thought to have formed from the remains of other stars about 4.5 billion years ago. The gas and dust released from them began to compress into a cloud, the temperature and pressure of which constantly increased. Having "warmed up" to about ten million degrees, the cloud turned into a star, which became a giant energy generator.

So why does the sun shine? All this is due to thermonuclear reactions inside it. In the center of our star, hydrogen is continuously converted into helium, under the influence of a very high temperature - about 15.7 million degrees. As a result of this process, a huge amount of thermal energy is produced, accompanied by a glow.

Thermonuclear reactions take place only in the solar core. The radiation it produces spreads around the star, forming several outer layers:

radiant transfer zone;
convective zone;
photosphere;
chromosphere;
crown.

Sunlight

Most of the visible light is produced in the photosphere. This is an opaque shell, which is identified with the surface of the Sun. The temperature in Celsius of the photosphere is 5,000 degrees, but there are also "colder" areas on it, called spots. In the upper shells, the temperature increases again.

Our luminary belongs to the yellow dwarfs. This is far from the oldest and not the largest star in the universe. In its evolution, it has reached about half the way and will live in this state for about another five billion years. Then the Sun will turn into a red giant. And then sheds off the outer shell and becomes a dim dwarf.

The light it emits now is almost white. But from the surface of our planet, it is visible yellow, as it dissipates and passes through the layers of the earth's atmosphere. The color of the radiation becomes close to the real one in very clear weather.

Interaction with the Earth

The location of the Earth and the Sun relative to each other is not the same. Our planet is constantly moving around the star in its orbit. It makes a complete revolution in one year or approximately 365 days. During this time, it covers a distance of 940 million kilometers. On the planet itself, movement is not felt, although every hour it passes about 108 kilometers. The consequences of such a journey are manifested on Earth in the form of a change of seasons.

However, the seasons are determined not only by the movement around the Sun, but also by the tilt of the earth's axis. Relative to the orbit, it is inclined by 23.4 degrees, so different parts of the planet are illuminated and warmed by the star in different ways. When the Northern Hemisphere is turned towards the Sun, it is summer there, and in the Southern Hemisphere at the same time it is winter. Six months later, everything changes exactly the opposite.

We often say that the Sun appears during the day. But this is just an expression, because it creates the day for us. Its rays penetrate the atmosphere, illuminating the planet from morning to evening. Their brightness is so strong that we simply do not see the rest of the stars during the day. At night, the Sun does not stop shining, it's just that the Earth turns to it first one side, then the other, because it rotates not only in orbit, but also around its own axis. It makes a complete revolution in 24 hours. On the side turned to the star - day, on the opposite side - night, every 12 hours they change.

Irreplaceable Energy

From our planet, the distance to the Sun is 8.31 light years, or 1.496 10 8 kilometers, which is quite enough for the existence of life. A closer location would make the Earth look like a lifeless Venus or Mercury. However, in a billion years the star should become 10% hotter, and in another 2.5 billion years it will be able to literally dry up all life on the planet.

At present, the temperature of the sun suits us perfectly. Thanks to this, a huge variety of life forms appeared on our planet, ranging from plants and bacteria to humans. They all need sunlight and warmth, and will easily die if left unattended for a long time. The light of the star promotes plant photosynthesis, which produces vital oxygen. Its ultraviolet radiation enhances the functioning of the immune system, promotes the production of vitamin D, and helps to self-purify the atmosphere from harmful substances.

The uneven heating of the Earth by the Sun creates the movement of air masses, which, in turn, creates the climate and weather on the planet. Light from a star affects the establishment of circadian rhythms in living organisms. That is, a strict dependence of their activity on the change of time of day is developed. So, some animals are active only during the day, others only at night.

Sun observation

Among the star systems closest to us, the Sun is not the brightest. It occupies only the fourth place in this indicator. For example, the star Sirius, which is perfectly visible in the night sky, surpasses it in brightness by as much as 22 times.

Despite this, we cannot look at the Sun with the naked eye. It is too close to the Earth and to observe it without special instruments is detrimental to vision. For us, it is about 400 thousand times brighter than the light reflected by the moon. We can look at it with the naked eye only at sunset and dawn, when its angle is small and the luminosity drops by a thousand times.

The rest of the time, to see the Sun, you need to use special solar telescopes or light filters. If at the same time we project the image onto a white screen, then it is possible to see spots and flashes on our star even with non-professional equipment. But this must be done carefully so as not to damage it.

It's hard to believe, but those stars that shine at night from the sky, and the Sun that illuminates us during the day, are one and the same. Why does the Sun shine during the day and not at night like "normal" stars? Let's dive into the science.

The sun is the star closest to our planet. The Sun is the center of our planetary system, which got its name from the name of the star - Solar. The distance from the Earth to the Sun is approximately 150,000,000 kilometers. The mass of a star named the Sun is 330,000 times greater than the mass of our planet. At the same time, the Sun is not a solid body, like the Earth, but is a spherical accumulation of hot gases. If someone does not believe in the gaseous nature of the Sun, then just imagine: the temperature on its surface is approximately 6000 degrees Celsius. The core (central part) of the Sun is heated to millions of temperatures. No material, alloy or element currently known to science will be able to maintain a solid state at such temperatures.

Why the Sun Shines: A Scientific Explanation Previously, it was believed that the Sun shines due to the burning of the elements that make up its composition. But according to rough estimates, even rough ones, it cannot “burn out” for billions of years, the Sun should have gone out a long time ago, having lost mass, thereby breaking the gravitational balance in the system of planets and letting them float freely across the expanses of the Galaxy. But this does not happen, the Sun has been shining for billions of years and does not think to dry up. What makes the sun shine? Scientists have found and proved that the glow of the Sun is the result of the release of colossal amounts of energy obtained as a result of thermonuclear processes occurring in it. Thermonuclear processes are remarkable in that when matter is consumed, millions of times more energy is released than during combustion. Yes, that's why thermonuclear energy is the future, its minus is the difficulty of starting the reaction. To start a thermonuclear reaction requires a huge amount of energy and complex types of consumables, such as synthetic uranium or plutonium.

Why the Sun shines during the day and not at night Everything is simple here. The very phenomenon of night is the turn of a part of the planet with its "back" to the Sun. And since the planet rotates uniformly around its axis, and the revolution takes about 24 hours, it is easy to calculate the time allotted for the night - 12 hours. So it turns out that half of the Earth is turned towards the Sun for 12 hours and it illuminates it, and in the remaining 12 hours it is on the other side of the globe, not illuminated by the Sun. It turns out that when the Sun shines, we have day, and when the Sun does not illuminate our part of the Earth, we have night. Phenomena such as morning and evening are side effects caused by the ambiguous nature of light and the concomitant effect of diffraction. So, knowing now why the Sun shines, you should also find out how much he has left to please us. This is about 5 billion years, after losing about a percent of its mass, the Sun will lose stability and go out.

Read more on Elhow: http://elhow.ru/ucheba/astronomija/pochemu-svetit-solnce?utm_source=users&utm_medium=ct&utm_campaign=ct

Sections: Primary School , Competition "Presentation for the lesson"

Presentation for the lesson

Back forward

Attention! The slide preview is for informational purposes only and may not represent the full extent of the presentation. If you are interested in this work, please download the full version.

Lesson Objectives:

form an idea of the stars;
develop ideas about the shape, size, color of objects;
cultivate the ability to work in a team.

Equipment: textbook "The world around" grade 1 author A.A. Pleshakov, workbook, projector, presentation, plasticine.

DURING THE CLASSES

1. Organizational stage

2. Motivation for learning activities

- Guys, today the Ant came to say thank you. You have answered many of his questions, But he cannot guess the riddle. And having guessed the riddle, we will find out the topic of our lesson.
(2 slide)

Mystery

The grain crumbled by night,
Looked in the morning - there is nothing.
What's this? (Stars)

– Today we will look for the answer to the question “Why does the Sun shine during the day, and the stars at night?” And for this we will go on a space journey.

Children stand up and say the words:

"Fast rockets are waiting for us
To distant planets
Which one do we want
Let's fly to this
Stars, wait for us to visit. (3 slide)

"One two Three
Sit down carefully
So that the devices do not hurt.
Take a chair
Fasten your seatbelts."

3. Updating knowledge

- We fly in outer space and see a lot of luminous dots. (4 slide)
- What is it? (These are the stars)
- What are the stars?

The children make their guesses.

4. Presentation of new material

(5 slide)
Stars are huge flaming balls. They are far from the Earth and therefore appear small. They flicker in different colors: red, white, yellow, blue.
(6 slide)
White and blue stars are very hot. Yellow stars are colder than white ones, red ones are colder than yellow ones. Stars have different sizes.
Why do the stars shine at night and the sun during the day?
- What do you guys think?
(children's answers)

5. Simulation of stars

(7 slide)
– Now we will create models of stars. What is the biggest star? (Aldebaran)
- And the smallest one? (Sun)

Which star is colder? (Aldebaran)
What stars are very hot? (Regulus and Sirius)
Why do stars seem small?

Conclusion. The sun is a star, a yellow dwarf.

6. Physical education

7. Consolidation of new knowledge

(9 slide)
The sun is the star that we see during the day.
- Why do we see the Sun, but do not see such a large star Aldebaran? (This is the closest star to Earth)
The sun is a huge fireball. The temperature on the surface of the Sun is 20 million degrees. The Sun is 109 times larger than the Earth.
If we imagine that the ball is the Sun, then the pea is our Earth. The sun creates a day for us, its rays reach the surface of the Earth, warm it, illuminate it. Without the Sun, there would be no life on Earth. As long as the sun shines, the radiance of other stars is not visible.

8. Physical education

9. Work on page 89 of the textbook

Stars, stars, from a long time ago
you chained forever
Man's greedy gaze.

People have been watching the stars for a long time. They used to be called astrologers, but now scientists are astronomers. (10 slide)
People, watching the stars, noticed that they form different shapes: birds, animals, people. These figures were called constellations and gave them names.

Mystery

From which bucket
Don't drink, don't eat
And they just look at him. (Constellation Ursa Major)

Not far from this constellation, people have discovered another constellation of Leo. It consists of 70 stars.

10. Summary of the lesson

We returned from the flight
And they landed on the ground.

Questions. (12 slide)

11. Reflection

There are two suns on the board: cheerful and sad.

- Guys, if you worked actively in the lesson and learned something new about the stars, then add a ray to the cheerful sun, and if you were bored in the lesson and you didn’t learn anything new, then add a ray to the sad sun.

Details about the sun

The sun is the star closest to our planet. The Sun is the center of our planetary system, which got its name from the name of the star - Solar.

The distance from the Earth to the Sun is approximately 150,000,000 kilometers. The mass of a star named the Sun is 330,000 times greater than the mass of our planet. At the same time, the Sun is not a solid body, like the Earth, but is a spherical accumulation of hot gases.

If someone does not believe in the gaseous nature of the Sun, then just imagine: the temperature on its surface is approximately 6000 degrees Celsius. The core (central part) of the Sun is heated to millions of temperatures. No material, alloy or element currently known to science will be able to maintain a solid state at such temperatures.

Why the sun shines: a scientific explanation

It used to be believed that the Sun shines due to the burning of the elements that make up its composition. But according to rough estimates, even rough ones, it cannot “burn out” for billions of years, the Sun should have gone out a long time ago, having lost mass, thereby breaking the gravitational balance in the system of planets and letting them float freely across the expanses of the Galaxy. But this does not happen, the Sun has been shining for billions of years and does not think to dry up. What makes the sun shine?

Scientists have found and proved that the glow of the Sun is the result of the release of colossal amounts of energy obtained as a result of thermonuclear processes occurring in it.

Thermonuclear processes are remarkable in that when matter is consumed, millions of times more energy is released than during combustion. Yes, that's why thermonuclear energy is the future, its minus is the difficulty of starting the reaction. To start a thermonuclear reaction requires a huge amount of energy and complex types of consumables, such as synthetic uranium or plutonium.

Why does the sun shine during the day and not at night

Everything is simple here. The very phenomenon of night is the turn of a part of the planet with its "back" to the Sun. And since the planet rotates uniformly around its axis, and the revolution takes about 24 hours, it is easy to calculate the time allotted for the night - 12 hours. So it turns out that half of the Earth is turned towards the Sun for 12 hours and it illuminates it, and in the remaining 12 hours it is on the other side of the globe, not illuminated by the Sun. It turns out that when the Sun shines, we have day, and when the Sun does not illuminate our part of the Earth, we have night. Phenomena such as morning and evening are side effects caused by the ambiguous nature of light and the concomitant effect of diffraction.

So, knowing now why the Sun shines, you should also find out how much he has left to please us. This is about 5 billion years, after losing about a percent of its mass, the Sun will lose stability and go out.

The fourth state of matter.
Part six. Why does the sun shine

Why does the sun shine? The same exact answer is known today to this question. The sun shines because in its depths, as a result of a thermonuclear reaction of the transformation of 4 protons (nuclei of hydrogen atoms) into one helium nucleus, free energy remains (because the mass of the helium nucleus is less than the mass of four protons), which is emitted in the form of photons. Photons in the visible range - this is the sunlight that we see.

And now let's reason and imagine the path that scientists have traveled. And at the same time, let's think about what will happen when hydrogen is completely burned out on the Sun? Will it definitely go off? We advise you to read the article to the end - a very interesting assumption is made there.

Let's assume that the Sun burns the most calorific of all types of fuel - the purest carbon, which burns whole, without any ash. Let's do a simple calculation. It is known how much heat this “bonfire” sends to the Earth. The sun is a ball, so it radiates heat evenly in all directions. Knowing the size of the Earth and the Sun, it is easy to calculate that in order to maintain the flow of heat from the Sun, about 12 billion tons of coal must burn in it every second! The figure is huge on the earth's scale, but for the Sun, which is more than three hundred thousand times heavier than the Earth, this amount of coal is small. And yet all that coal in the sun would have to burn out in just six thousand years. But the data of many sciences - geology, biology, etc. - irrefutably testify that the bright Sun has been heating and illuminating our planet for at least several billion years.

The notion that the Sun burns with coal had to be rejected. But perhaps there are chemical reactions in which even more heat is released than when coal is burned? Let's assume they exist. But even these reactions could extend the life of the Sun by a thousand, two thousand years, even twice, but no more.

But if the Sun is not able to provide itself with fuel for any long time, then, perhaps, outer space does this from the outside? It has been suggested that meteorites are continuously falling on the Sun. We have already said that when meteorites approach the Earth, due to braking in the Earth's atmosphere, they often burn out completely, heating the air on their way. Why not assume that there is no atmosphere around the Sun, that the deceleration of meteorites occurs directly in the solar matter, and it is heated to a high temperature?

Let's go back to the calculations. How many meteorites must fall on the Sun to keep it burning for a long time? The calculation gives an absolutely incredible figure: even if the weight of all the meteorites that fell on the Sun is equal to the weight of the Sun itself, it would still shine for only about a million years.

But, perhaps, once such a huge number of meteorites nevertheless fell on the Sun, heated it to a huge temperature, and now the Sun is slowly cooling down? Nothing like this! There is a lot of evidence that the Sun shone and warmed a billion, and a million, and a thousand years ago, as it does today. So, the second assumption also fails.

The amazing constancy of solar activity also buried the third, most tempting assumption about the cause of the "burning" of the Sun. It came down to the following. According to the law of universal gravitation, all bodies approach each other. The Earth is attracted by the Sun and moves around it. The stone is attracted by the Earth and falls on it if it is released from the hands.

Let's imagine that the Sun is a huge vessel with gas. The molecules of this gas, subject to the action of mutual attraction, despite the collisions that throw them away from each other, should gradually attract each other and approach each other. The sun as a whole would then shrink, the pressure of the gas in it would increase, and this would lead to an increase in temperature and the release of heat.

If we consider that in 100 years the diameter of the Sun is reduced by only a few kilometers, then this phenomenon could fully explain the radiation of the Sun. However, such a slow contraction cannot be detected with the help of astronomical instruments.

But there is a “device” that works for a much longer time. This device is the Earth itself. During its existence, the Sun would have to shrink tenfold: from sizes many times larger than the length of the entire solar system to modern ones. Such compression would certainly affect the . Nothing like this, however, the history of the Earth knows. She knows major geological catastrophes in which the highest mountains perished, new oceans, entire continents were born, but all this can be fully explained by the activity of the Earth itself, and not the Sun.

So, all three mentioned hypotheses about the causes of the "burning" of the Sun turned out to be untenable. Science, which was able to explain many of the most complex phenomena on Earth, for a very long time lowered its hands before the mystery of the activity of the Sun. Now it has become clear that the solution to this riddle must be sought not in the depths of space, but in the depths of the Sun.

And here the science of the super-large - astronomy - came to the aid of the science of the super-small - the physics of the atomic nucleus.