Stars emit enormous amounts of heat and light over many billions of years, requiring enormous fuel consumption. Until the twentieth century, no one could imagine what kind of fuel it was. The biggest problem in physics was the big question: where do stars get their energy? All we could do was look at the sky and realize that there was a huge “hole” in our knowledge. To understand the secret of the stars, a new engine of discovery was needed.
Helium was needed to unlock the secret. Albert Einstein's theory proved that stars can obtain energy from within atoms. The secret of the stars is Einstein's equation, which is the formula E = ms 2. In a sense, the number of atoms that make up our body is concentrated energy, compressed energy, energy compressed into atoms (cosmic dust particles) that make up our universe. Einstein proved that this energy could be released by colliding two atoms. This process is called thermonuclear fusion, and it is this force that powers stars.
Imagine, but the physical properties of a small, subatomic particle determine the structure of stars. Thanks to Einstein's theory, we have learned how to release this energy inside the atom. Now scientists are trying to simulate the source of stellar energy to gain control of the power of fusion in the laboratory.
Within the walls of the laboratory, near Oxford in England, there is a machine that Andrew Kirk and his team are turning into a “star” laboratory. This installation is called Tokamak. In essence, it is a large magnetic bottle that holds very hot plasma, thanks to which it is possible to simulate conditions similar to those inside a star.
Inside the Tokamak, hydrogen atoms confront each other. To smash atoms into each other, the Tokamak heats them to 166 million degrees, at which temperature the atoms move so fast that they cannot avoid colliding with each other. Heating is movement; the movement of heated particles is sufficient to overcome the repulsive force. Flying at thousands of kilometers per second, these hydrogen atoms crash into each other and combine to form a new chemical element, helium, and a small amount of pure energy.
Hydrogen weighs slightly more than helium; during combustion, mass is lost, and the lost mass is converted into energy. A tokamak can support fusion for a fraction of a second, but in the interior of a star the fusion of nuclei does not stop for billions of years, the reason is simple - the size of the star.
A star lives by gravity. That's why stars are big, huge. To collapse a star, a huge force of gravity is needed in order to release an incredible amount of energy, sufficient for thermonuclear fusion. This is the secret of the stars, this is why they glow.
Fusion in the core of the Sun's star generates enough power every second to power a billion nuclear bombs. A star is a giant hydrogen “bomb”. Why then doesn't she just fly to pieces? The fact is that gravity compresses the outer layers of the star. Gravity and synthesis are waging a grandiose war, the gravity of which wants to crush the star and the energy of synthesis, which seeks to destroy the star from the inside, this conflict and this balance create the star.
This struggle for power continues throughout the star’s life. It is these battles on the stars that create light and each ray of star travel makes an incredible journey, the light travels 1080 million kilometers per hour. In one second, a beam of light can circle the earth seven times; nothing in the universe moves so fast.
Since most stars are very far away, light takes hundreds, thousands, millions and even billions of years to reach us. When the orbiting Hubble Space Station peers into the far reaches of our universe, it sees light that has been traveling for billions of years. The light of the star Etequilia, which we see today, set off 8 thousand years ago, the light of Betelgeuse has been traveling since Columbus discovered America 500 years ago. Even the light of the Sun flies to us for 8 minutes.
When the sun synthesizes helium from hydrogen, a particle of light is created - a photon. This ray of light has a long and difficult path to the surface of the Sun. The whole star prevents him, when a photon appears, it crashes into another atom, another proton, another neutron, it doesn’t matter, it is absorbed, then reflected in another direction, and moving so chaotically inside the Sun, it must break out.
The photon will have to rush around madly, crash into gas atoms billions of times and desperately rush out. It's funny, it takes a photon thousands of years to get out of the Sun's core and only 8 minutes to fly from the surface of the Sun to the Earth. Photons are sources of heat and light that support the diverse and amazing life on our planet Earth!
Why does the sun shine? Probably every parent has encountered the curiosity of their children, who are ready to ask a thousand and one questions a day. While teaching a child to observe the environment, the child had a question: why does the sun burn, and what would happen if it stopped shining. It seems that every adult knows simple questions and answers to them.
But we cannot always answer them accurately and correctly. Many interesting stories and facts can be found in encyclopedias and the vastness of the World Wide Web. Let us remember from the school astronomy course that the Sun is many times larger than the Earth in terms of mass and size. It consists of hydrogen (mainly) and helium.
There are many different legends and myths around the daytime celestial body of every nation. In ancient times, they considered him the God of light and worshiped him, dedicated songs, and performed rituals. For example, it was called - Yarilo, in Ancient Egypt - Ra, in Greece - Helios in a golden chariot, in Australia - the image of a girl sitting on a tree, the ancient Slavs called the four faces of god - Khorsu, Yarilo, Jadbog, Svarog.
One legend says that its light and warmth are due to the constant burning of coal, but how much coal must be burned. According to the ancient myths of the Egyptian people, Ra sails daily in a boat along the Nile during the day, and fights in the underworld at night, returning victorious in the morning. The Greeks painted Helios wearing a golden helmet and considered him a resident of Olympus.
The peoples of Africa compared all phenomena of unknown origin to different parts of the human body. In their view, with glowing armpits he controlled time intervals. He lets go of his hand, it begins to get dark, he goes to bed and night comes. The Hindus, the inhabitants of India, deified Surya as a healer and guardian of the gates of heaven. His main attribute is a carriage with seven horses. Along with myths, superstitious people have come up with signs related specifically to the color of the sun.
A lot of time has passed and scientists have made many discoveries. For example, they proved that the Sun is a star, and not a satellite of our Earth. The day star plays the most important role on planet Earth. The life of not only a person, but also all living things around, depends on its rays and warmth. A long time ago, our ancestors noticed that in the morning the sun rises, it becomes warm and light.
Our planet is located in the solar system, therefore, the sun is the center of this system. And each planet makes its revolution around it, following its axis. If a planet in the solar system is a solid state, then a star called the Sun is a gaseous ball.
Like all stars, the sun is a collection of dust and gas, due to reactions constantly occurring inside the core of the conversion of hydrogen into helium at very high temperatures. This whole process is accompanied by the emission of light that we see. During the day, the sun's rays illuminate the entire earth, warming the population of different continents at different times.
Why does the sun shine during the day
The radiant sun smiles at us in the morning. When science was not developed and astronomy as a science was unknown, people simply observed celestial bodies. And at one time they made the discovery that with the rising of one luminary, day comes, and with its setting, night. Various legends were composed about the daylight and given various names.
Attempts were made to figure out why it only happens during the day. Explaining the movement of the deity Ra (personified the sun god), Egypt composed a beautiful legend. In the morning he swam along the river, carrying with him peace and tranquility. At night he went down into the dungeon, fought a battle and won, returning the next day, giving a new dawn.
After a long time, scientists have refuted not a few facts. They proved that the Sun is a star and all the planets of its system revolve around it. It is the brightest and largest star in relation to the planets, which is closest to the blue planet.
So, why does the sun shine during the day and not at night, and if it is a star, then why don’t we see it in the night sky. The answers to these questions are very simple. The planet not only revolves around the Sun, it rotates around its own axis. Whether morning or night comes depends on which side it is turned to the light source. Its rise depends on the rotation of the Earth.
Our morning comes and our day begins when the sun appears over the horizon. During the day, we cannot observe night stars in the sky, this is due to the fact that the sun's rays are scattered, eclipsing their faded flicker.
Why does the sun shine brightly
For humans, the topic of space, celestial bodies, and the universe will always remain incompletely studied. It has captivated people with its obscurity and mystery for thousands of years. Scientists from different eras tried to unravel the mystery of day and night. They came up with various ways to observe the movements of bodies in the sky, created observatories and telescopes, and conquered space. All of the above actions did not help a person get closer to the main source of life. The surface of the moon has been studied, but it is not possible to fly up to the Sun.
Not only favorable weather, good mood, but in general the entire life support of living organisms depend on sunny days. It has been proven that the Sun is gaseous. This is evidenced by the temperature inside the core. Its surface is covered with high temperature, due to which various transformation reactions occur. Thermonuclear reactions require large amounts of energy.
Therefore, we see a small circle in the daytime sky, warming everything around and giving life. Today, the world does not know a single metal, not a single substance, not a single matter that can tolerate temperatures of several thousand Celsius.
No one knows how long it will shine, modern technologies suggest that hydrogen reserves should last for several billion years, no one knows for sure. During the combustion process, not only physical, but also chemical substances expand. The minds of science have put forward a version when the reserves of hydrogen and helium begin to run out, the core will shrink, the surface will expand, an explosion will occur, a bright star will die, turning into fog. The vital activity of all living things will stop.
Despite the simple formulation of the question “Why does the Sun shine?” the answer to it requires some base of physical knowledge and to present it in one sentence is a difficult task. We will try to solve it towards the end of the article, which we will begin with historical background.
Story
One of the first who tried to explain the nature of the Sun from a scientific point of view was the ancient Greek astronomer and mathematician Anaxagoras, according to whom the Sun is a hot metal ball. For this, the philosopher was imprisoned. Before the instrumental study of the Sun began in the 17th century, there was still a lot of speculation about the nature of sunlight, even to the constantly burning forests on the surface.
Since the 17th century, scientists have discovered such a phenomenon as sunspots, and it becomes possible to calculate the period of rotation of the Sun. It becomes clear that our star is a kind of physical body with a complex structure. In the 19th century, spectroscopy appeared, with the help of which it was possible to decompose a sunbeam into its component colors. Thus, thanks to the absorption lines, Fraunhofer manages to detect a new chemical element that is part of the star - helium.
In the mid-19th century, scientists were already trying to describe the glow of the Sun using more complex scientific hypotheses. So Robert Mayer suggested that the star is heating up due to bombardment by meteorites. Somewhat later, in 1853, a more plausible idea of the so-called “Kelvin-Helmholtz mechanism” arose, according to which the Sun heated up due to gravitational compression. However, in this case, the age of the star would be much less than it actually is, which contradicts some geological studies.
Why does the sun shine
The British physicist Ernest Rutherford was the first to come up with the correct answer to this question, who suggested that radioactive decay occurs in the Sun and it is this that is the source of the star’s energy. Later, in 1920, the English astrophysicist Arthur Eddington developed Rutherford's idea, arguing that a thermonuclear fusion reaction could occur in the Sun's core under the influence of the internal pressure of the Sun's own mass. After 10 years, the main fusion reactions generating the observed amount of energy were calculated.
Briefly, the thermonuclear reaction that causes the Sun to shine can be described as the fusion of protons (hydrogen nuclei) into a helium-4 nucleus. Since the helium-4 nucleus has less mass than the hydrogen nucleus, the energy difference (free energy) is emitted in the form of photons - particles that are electromagnetic radiation.
Thermonuclear reaction
Proton-proton thermonuclear fusion reactions occurring inside stars with a solar mass or less can be divided into three chains: ppI, ppII, ppIII. Of these, ppl accounts for more than 84% of the Sun's energy. The proton-proton reaction consists of three cycles, where the first is the interaction of two protons (two hydrogen nuclei). With enough energy to overcome the Coulomb barrier, the two protons merge to form a deuteron. Since the deuteron nucleus, consisting of two protons, has less mass than two individual protons, free energy is generated, due to which a positron and an electron neutrino are created, which are emitted from the region where the reaction took place.
Next, due to the interaction of a deuteron and another proton, helium-3 is formed with the release of energy in the form of electromagnetic radiation. Further stages of the reaction can be clearly seen in the diagram below.
Reactions taking place inside the sun
In addition to the proton-proton thermonuclear fusion reaction, a small contribution to the energy released by the Sun is made by a reaction of the proton-electron-proton type (0.23%).
Thus, summarizing the above, the Sun emits electromagnetic waves of various frequencies, including in the region of visible light, which are formed by particles born as a result of released energy during the proton-proton (proton-electron-proton) thermonuclear fusion reaction.
1.The light of the Sun reaches the surface of the Earth in just 8 minutes. During this time, it covers a distance of 150 million kilometers. The sun is responsible for the weather, disasters, and life on the planet.
2. The temperature of the Sun is not the same in different parts of it. It ranges from 6 thousand to 15 million degrees C. The lowest temperature is on the surface, and the highest is in the core. This is explained by the fact that almost all the energy of the star is generated in the center and only then transferred to the upper layers. 3. If a drop of matter from the core of the Sun fell on the surface of the Earth, then not a single living creature would survive at a distance of 150 km from the fall. 4. An interesting period of history was the time from 1640 to 1700. During these years, there were no sunspots on the sun, that is, the celestial body decreased its activity. This period of history was called the "Maunder" minimum. Also, the disappearance of the spots influenced the occurrence of the Little Ice Age, due to which rivers that had never frozen before froze, and the overall air temperature dropped. At the moment, the sun is at its peak. 5. There is much more water on the Sun than on Earth. Existing in the form of vapor, water molecules are concentrated mainly in “sunspots” and in a narrow layer under the surface of the star.
6. In honor of the total solar eclipse of 1999, which was best observed in Romania, the authorities of this country issued a plastic banknote of 2000 Romanian lei. The bill had a transparent window through which one could look at the Sun during an eclipse. 7.The sun also emits electrons and protons, known as the solar wind, its speed is 450 kilometers per second. 8. The distance between the earth and the sun is ideal. The temperature on the planet ranges from approximately -50° to +50° The Earth is removed from the sun as much as necessary for this “eternal fire” to properly warm us, no more, no less! If the Earth were a little further from the Sun, we would freeze, a little closer, we would burn. Any slight change in distance in one direction or another - and life on Earth would be impossible. And the rotation of the Earth around its axis every day makes it possible for the entire surface of the planet to heat up and cool down sufficiently. 9. The Earth receives 94 billion megawatts of energy from the Sun. This is 40,000 times the annual requirement of the United States. 10.Sunset on the Red Planet, Mars, is blue.
11. The sun rotates around its axis, and the layers of stellar matter at the equator rotate almost a third faster than the layers in the polar regions. 12. In the sky we see the sun as an orange or yellow circle, but this is just a trick of light, in fact the sun is white. Our sun is not the hottest, but not the coldest either; more than 15% of the other stars known to us are brighter than our sun. 13. The sun is a ball consisting of gas, which is held together by its own force of gravity. And flickering is a process of nuclear fusion that occurs inside a Star. 14.Solar eclipses also have a certain periodicity. In general, once every 200-300 years, an eclipse can be observed at any specific point on the globe, but if we talk about an annual eclipse, then it happens 1-2 times, but always at different points on the Earth. 15. The sun is the cause of the northern lights. Astronomers call it the “solar wind.” From Earth you can see a beautiful twinkle across the sky. When this happens, the Sun ejects a large number of charged particles along with heat. Thanks to our planet's magnetic field, some of them are reflected, but some pass through it, they interact with the gases that make up our atmosphere. As a result of this “cooperation”, a glow appears. This is how you get the aurora.
16. Here is what Professor David Block notes: “If the distance from the earth to the sun were reduced by 5%, then the earth would turn into a solid steak (of people and animals). And if the distance from the earth to the sun increased by only 1%, then the earth would freeze. 17.The US flag, planted on the Moon, has “faded” due to solar radiation - now it consists of white and blue colors. 18. It was only in 1992 that the Vatican publicly acknowledged that the Earth actually revolves around the Sun. 19.Sooner or later our planet will die and all because of the sun. For 5 billion years, the sun has been giving our planet the necessary heat and burning 700 billion tons of hydrogen every second. Moreover, the mass of the sun is so great that it will “burn” for about 5 billion years. After this, the sun will end its life becoming a small white celestial body, but before that the sun will increase in size and push all the planets away from itself, thereby destroying their atmosphere and evaporating all the water. 20. The diameter of our sun is 109 times larger than the diameter of the Earth, while it is 1,392,000 km. The sun also rotates, but around the center of our galaxy, and makes a full revolution in just 225-250 million years.
21. The Sun has existed for more than 4.5 billion years. Every second it produces a huge flow of energy. Scientists estimate that this is about 390 billion trillion kilowatts. 22. Light coming from the sun travels 150 million kilometers in just 8 minutes, while the nearest star Proxima Centauri is 4 such distances. 23.The estimated age of the Sun is 4.6 billion years. The sun will live another 4-5 billion years. 24.The sunniest cities are: Nice, Monte Carlo, Morocco, Ussuriysk, Brisbane and Nice. These cities have 300 out of 365 sunny days. 25. The luminosity of the Sun (i.e., the amount of energy released per second) is approximately 3.86 * 1020 Megawatts. It is produced by thermochemical reactions converting hydrogen into helium. The Earth receives only 94 billion megawatts of solar energy. However, if this energy is fully used, it will be enough for all of humanity for many thousands of years.
26. Solar radiation is deadly due to the radiation accompanying it, but the Earth’s atmosphere blocks it. 27. The sun gives different amounts of its light to all cities, so residents of the city of Kirun, which is located above the Arctic Circle, see the sun 24 hours a day, although in winter the sun is not visible at all. Malta can boast of only 10 hours of daylight, while Stockholm already has 18, and in Samarkand the sun rises for 15 hours. The day (24 hours) was borrowed from the Egyptians. According to their beliefs, the god Ra (the sun god) moves in his chariot across the sky for 12 hours, checking his possessions. 28. The weight of the Sun is more than 99.5% of the mass of the entire solar system; it exceeds the weight of our planet by 330,000 times. 29.Occurs annually from two solar eclipses. It is almost impossible to see them in the same place. The eclipse can only be seen from a narrow strip of the lunar shadow. At a certain point on the globe it can be observed once every 200, or even 300 years. 30.The sun revolves around the center of the Milky Way, just as the Earth revolves around the sun. The rotation period of the Sun around the center of our galaxy is approximately 240 million years.
31.The brightness of the Sun is equivalent to the brightness of 4 trillion trillion 100-watt light bulbs. 32.Solar gravity is 28 times greater than Earth’s. On Earth, a person’s weight is 70 kilograms, on the Sun it increases, and will already be around 2 thousand (1960) kilograms. 33. Both “great luminaries”, the Sun and the Moon, have the same angular dimensions. They are the largest celestial objects (in terms of their visibility from Earth). The Sun is located from the Earth at a distance that is 400 times greater than the distance from the Earth to the Moon. It is also amazing that the solar ball is 400 times larger than the Moon. But visually, the Sun and Moon are the same size and occupy the same space in the sky. 34.If the Sun were the size of a football, Jupiter would be the size of a golf ball, and the Earth would be the size of a pea. 35.The solar wind travels from the Sun at a speed of about 450 kilometers per second.
36. Almost 700 billion tons of hydrogen burn on the Sun every second. Despite such large losses, the Star will still have enough energy for many years to come. About as long as it already exists. 37. In about a billion and a hundred million years, the brightness of the Sun will increase by ten percent, which will entail the end of all life on Earth. 38. From the Sun to the farthest planet, light and heat reach only 5.5 hours. 39.The magnetic field of the Sun is only twice as strong as the magnetic field of the Earth. 40.Lightning is 5 times hotter than the surface of the Sun.
41. The Sun, like any star, has its own atmosphere. Its upper boundary goes far beyond the orbit of Pluto. 42. It is difficult for us to imagine how great the distance from the Earth to the Sun is. It is incredible - 150 million kilometers. If we draw an analogy with a highway, then when a car moves at a speed of 105 km/h, this distance can be covered in 163 years. Consequently, we could not travel such a distance by car in our entire lives. 43. A total solar eclipse cannot last longer than 7 minutes and 40 seconds. 44. It is believed that the Greek philosopher Aristarchus was the first to come to the idea that the Earth revolves around the sun. 45.Unlike the Earth, the Sun is completely gaseous; there is no solid surface on the Sun. It consists primarily of helium and hydrogen, and does not have a solid surface.
46. The Sun is very far from the Earth, but the Earth is located much closer to the Sun than the other planets. 47. In 8 billion years, the Sun will increase in size by 200 times from today's size. As a result, the planet Mercury will be absorbed. Ultimately, the Star's layers will begin to disintegrate into small particles, and it will become a "white dwarf" in the existing solar system. If any elements for life are preserved after its destruction, they will become the beginning for the birth of new planets, stars and new life in the galaxy. 48.When the Sun turns into a red giant, it will engulf Mercury and possibly Venus, Earth and Mars. 49.Energy in the solar interior is generated due to nuclear fusion. 50. The mass of the Sun is approximately 99.86 percent of the mass of the entire solar system.
Back forward
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Lesson objectives:
- form an idea of the stars;
- develop ideas about the shape, size, color of objects;
- develop the ability to work in a team.
Equipment: textbook “The world around us” 1st grade author A.A. Pleshakov, workbook, projector, presentation, plasticine.
DURING THE CLASSES
1. Organizational stage
2. Motivation for educational activities
- Guys, today Ant came to say thank you. You answered many of his questions, But he cannot solve the riddle. And having guessed the riddle, we will find out the topic of our lesson.
(2 slide)
Mystery
The grain scattered by night,
We looked in the morning - there was nothing.
What is 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
Whichever one we want
We'll fly to this one
Stars, wait for us to visit you.” (3 slide)"One two Three
You need to sit down carefully
So as not to touch the devices.
Take a chair,
Fasten your seat belts."
3. Updating knowledge
– We fly through outer space and see many luminous points. (4 slide)
- What is this? (These are the stars)
-What are stars?
Children express 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 cooler than white ones, red ones are cooler than yellow ones. The sizes of stars are different.
– Why do the stars shine at night and the Sun during the day?
– What do you guys think?
(Children's answers)
5. Modeling stars
(7 slide)
– Now we will create models of stars. What's the biggest star? (Aldebaran)
- And the smallest one? (Sun)
– Which star is colder? (Aldebaran)
– Which stars are very hot? (Regulus and Sirius)
– Why do stars seem small?
Conclusion. The sun is a star, a yellow dwarf.
6. Physical education minute
7. Consolidation of new knowledge
(9 slide)
The sun is a star that we see during the day.
– Why do we see the Sun, but not such a large star Aldebaran? (This is the closest star to Earth)
The sun is a huge ball of fire. The temperature on the surface of the Sun is 20 million degrees. The sun is 109 times larger than the Earth.
If you imagine that the ball is the Sun, then the pea is our Earth. The sun creates our day, its rays reach the surface of the Earth, warm it, and illuminate it. Without the Sun there would be no life on Earth. While the Sun is shining, the radiance of other stars is not visible.
8. Physical education minute
9. Work on page 89 of the textbook
Stars, stars, from a long time ago
Chained you forever
A man's greedy gaze.
People have been observing the stars for a long time. Previously, they were called stargazers, but now scientists are astronomers. (10 slide)
People, watching the stars, noticed that they formed different figures: birds, animals, people. These figures were called constellations and given names.
Mystery
From which bucket?
They don't drink, they don't eat,
But they just look at him. (Constellation Ursa Major)
Not far from this constellation, people discovered another constellation Leo. It consists of 70 stars.
10. Lesson summary
We returned from the flight
And they fell to Earth.
Questions. (12 slide)
11. Reflection
There are two suns on the board: happy and sad.
– Guys, if you worked actively in class and learned something new about the stars, then add a ray of cheerful sunshine, and if you were bored in class and didn’t learn anything new, then add a ray of sad sunshine.
