From red to violet, which are the main colors of the spectrum. Color, visible to the eye, is explained by the wavelength of the light. Accordingly, red color gives the longest light, and violet gives the shortest.

During sunset, a person can observe a disk quickly approaching the horizon. Wherein sunlight passes through increasing thickness. The longer the light wavelength, the less susceptible it is to absorption by the atmospheric layer and the aerosol suspensions present in it. To explain this phenomenon, we need to consider the physical properties of blue and red colors, the usual shades of the sky.

When the sun is at its zenith, an observer can say that the sky is blue. This is due to differences in the optical properties of blue and red colors, namely their scattering and absorption abilities. Blue color is absorbed more strongly than red, but its ability to dissipate is much higher (four times) than that of red color. The ratio of wavelength to light intensity is a proven physical law called “Rayleigh’s blue sky law.”

When the sun is high, the layer of atmosphere and suspended matter separating the sky from the observer’s eyes is relatively small, the short wavelength of blue light is not completely absorbed, and the high scattering ability “drowns out” other colors. That's why the sky appears blue during the day.

When sunset comes, the sun begins to rapidly descend towards the true horizon, and the layer of atmosphere increases sharply. After a certain time, the layer becomes so dense that the blue color is almost completely absorbed, and the red color, due to its high resistance to absorption, comes to the fore.

Thus, at sunset, the sky and the luminary itself appear to the human eye in various shades of red, from orange to bright scarlet. It should be noted that the same thing is observed at sunrise and for the same reasons.

It's nice to look into the dazzling blue sky or enjoy the crimson sunset. Many people enjoy admiring the beauty of the world around them, but not everyone understands the nature of what they observe. In particular, it is difficult for them to answer the question why the sky is blue and the sunset is red.

The sun emits pure white light. It seems that the sky should be white, but it appears bright blue. Why is this happening?

Scientists for several centuries could not explain the blue color of the sky. From a school physics course, everything that white light can be decomposed into its component colors using a prism. There is even a simple phrase for them: “Every Hunter Wants to Know Where the Pheasant Sits.” The initial words of this phrase allow you to remember the order of colors: red, yellow, green, blue, indigo, violet.

Scientists have suggested that the blue color of the sky is caused by the fact that the blue component of the solar spectrum best reaches the Earth's surface, while other colors are absorbed by ozone or dust scattered in the atmosphere. The explanations were quite interesting, but they were not confirmed by experiments and calculations.

Attempts to explain the blue color of the sky continued, and in 1899 Lord Rayleigh put forward a theory that finally answered this question. It turned out that the blue color of the sky is caused by the properties of air molecules. A certain amount of rays coming from the Sun reaches the Earth's surface without interference, but most of them are absorbed by air molecules. By absorbing photons, air molecules become charged (excited) and then emit photons themselves. But these photons have a different wavelength, and photons that produce blue color predominate among them. This is why the sky looks blue: the sunnier the day and the less cloudy it is, the more saturated this blue color of the sky becomes.

But if the sky is blue, then why does it turn crimson during sunset? The reason for this is very simple. The red component of the solar spectrum is absorbed much worse by air molecules than other colors. During the day, the sun's rays enter the Earth's atmosphere at an angle that directly depends on the latitude at which the observer is located. At the equator this angle will be close to a right angle, closer to the poles it will decrease. As the Sun moves, the layer of air that light rays must pass through before reaching the observer’s eye increases - after all, the Sun is no longer overhead, but is leaning towards the horizon. A thick layer of air absorbs most of the rays of the solar spectrum, but red rays reach the observer almost without loss. This is why the sunset looks red.

On April 26, 2012, strange greenish clouds appeared in the sky over Moscow. An inexplicable phenomenon alarmed residents of the capital and agitated the Russian Internet. It was suggested that an accident occurred at one of the enterprises, which was accompanied by the release of harmful substances into the atmosphere. chemical substances. Fortunately, the information was not confirmed.

Instructions

The chief sanitary doctor of the Russian Federation, Gennady Onishchenko, said that according to official data, there were no accidents at chemical plants in the Moscow region and nearby regions. Meanwhile, in some areas of Moscow, people really felt worse. Allergy sufferers and asthmatics understood the reason for this anomalous phenomenon.

After a long winter, in early April there was a sharp warming, which caused rapid melting of the snow cover, early leafing out of trees and flowering of several species at once: birch, alder,

We are all accustomed to the fact that the color of the sky is a variable characteristic. Fog, clouds, time of day - everything affects the color of the dome overhead. Its daily shift does not occupy the minds of most adults, which cannot be said about children. They are constantly wondering why the sky is physically blue or what makes a sunset red. Let's try to understand these not so simple questions.

Changeable

It’s worth starting by answering the question of what the sky actually represents. In the ancient world, it was truly seen as a dome covering the Earth. Today, however, hardly anyone does not know that, no matter how high the curious explorer rises, he will not be able to reach this dome. The sky is not a thing, but rather a panorama that opens up when viewed from the surface of the planet, a kind of appearance woven from light. Moreover, if observed from different points, it may look different. So, from rising above the clouds, a completely different view opens up than from the ground at this time.

A clear sky is blue, but as soon as clouds come in, it becomes gray, leaden or dirty white. The night sky is black, sometimes you can see reddish areas on it. This is the reflection of the artificial lighting of the city. The reason for all such changes is light and its interaction with air and particles of various substances in it.

The nature of color

In order to answer the question of why the sky is blue from a physics point of view, we need to remember what color is. This is a wave of a certain length. Light coming from the Sun to the Earth is seen as white. It has been known since Newton's experiments that it is a beam of seven rays: red, orange, yellow, green, blue, indigo and violet. Colors differ in wavelength. The red-orange spectrum includes waves that are the most impressive in this parameter. parts of the spectrum are characterized by short wavelengths. The decomposition of light into a spectrum occurs when it collides with molecules of various substances, and some of the waves can be absorbed, and some can be scattered.

Investigation of the cause

Many scientists have tried to explain why the sky is blue in terms of physics. All researchers sought to discover a phenomenon or process that scatters light in the planet's atmosphere in such a way that, as a result, only blue light reaches us. The first candidates for the role of such particles were water. It was believed that they absorb red light and transmit blue light, and as a result we see a blue sky. Subsequent calculations, however, showed that the amount of ozone, ice crystals and water vapor molecules in the atmosphere is not enough to give the sky blue color.

The reason is pollution

At the next stage of research, John Tyndall suggested that dust plays the role of the desired particles. Blue light has the greatest resistance to scattering, and therefore is able to pass through all layers of dust and other suspended particles. Tindall conducted an experiment that confirmed his assumption. He created a smog model in the laboratory and illuminated it with bright white light. The smog took on a blue tint. The scientist made an unambiguous conclusion from his research: the color of the sky is determined by dust particles, that is, if the Earth’s air was clean, then not blue, but white skies would glow above people’s heads.

Lord's Research

The final point on the question of why the sky is blue (from the point of view of physics) was put by the English scientist, Lord D. Rayleigh. He proved that it is not dust or smog that colors the space above our heads in the shade we are familiar with. It's in the air itself. Gas molecules absorb most and primarily the longest wavelengths, equivalent to red. The blue dissipates. This is precisely how today we explain the color of the sky we see in clear weather.

Those attentive will notice that, following the logic of scientists, the dome overhead should be purple, since this color has the shortest wavelength in the visible range. However, this is not a mistake: the proportion of violet in the spectrum is much smaller than blue, and human eyes are more sensitive to the latter. In fact, the blue we see is the result of mixing blue with violet and some other colors.

Sunsets and clouds

Everyone knows that in different time day you can see different colors of the sky. Photos of beautiful sunsets over the sea or lake are a perfect illustration of this. All kinds of shades of red and yellow combined with blue and dark blue make such a spectacle unforgettable. And it is explained by the same scattering of light. The fact is that during sunset and dawn, the sun's rays have to travel a much longer path through the atmosphere than at the height of the day. In this case, the light from the blue-green part of the spectrum is scattered in different directions and clouds located near the horizon become colored in shades of red.

When the sky becomes clouded, the picture changes completely. unable to overcome the dense layer, and most of them simply do not reach the ground. The rays that managed to pass through the clouds meet with water drops of rain and clouds, which again distort the light. As a result of all these transformations, white light reaches the ground if the clouds are small in size, and gray light when the sky is covered by impressive clouds that absorb part of the rays for the second time.

Other skies

It's interesting that on other planets solar system When viewed from the surface, one can see a sky very different from that on Earth. On space objects deprived of an atmosphere, the sun's rays freely reach the surface. As a result, the sky here is black, without any shade. This picture can be seen on the Moon, Mercury and Pluto.

The Martian sky has a red-orange hue. The reason for this lies in the dust that fills the planet’s atmosphere. It is painted in different shades of red and orange. When the Sun rises above the horizon, the Martian sky turns pinkish-red, while the area immediately surrounding the disk of the luminary appears blue or even violet.

The sky above Saturn is the same color as on Earth. Aquamarine skies stretch over Uranus. The reason lies in the methane haze located in the upper planets.

Venus is hidden from the eyes of researchers by a dense layer of clouds. It does not allow rays of the blue-green spectrum to reach the surface of the planet, so the sky here is yellow-orange with a gray stripe along the horizon.

Exploring the space overhead during the day reveals no less wonders than studying the starry sky. Understanding the processes occurring in the clouds and behind them helps to understand the reason for things that are quite familiar to the average person, which, however, not everyone can explain right away.

“Dad, mom, why is the sky blue?” – how many times have parents and the older generation been embarrassed when they heard a similar question from a small child.

It seems that people with higher education know almost everything, but such interest often baffles children. Perhaps the physicist will easily find an explanation that satisfies the baby.

However, “average” parents do not know what to answer their child. You need to figure out which explanation is suitable for children and which for an adult.

To understand the blueness of the sky, you need to remember your school physics course. Colors differ in their ability to be scattered (due to wavelength) in the gas envelope surrounding the Earth. Thus, red color has a low ability, which is why it is used, for example, as external on-board lighting of aircraft.

Thus, those colors that have an increased ability to disperse in the air are actively used to camouflage any objects from air and ground enemies. Typically these are the blue and violet parts of the spectrum.

Let's look at scattering using the example of a sunset. Since red color has a low scattering ability, the departure of the sun is accompanied by crimson, scarlet flashes and other shades of red. What is this connected with? Let's look at it in order.

Let's discuss further. The blue and blue “compartment” of the spectrum is located between green and violet colors. All these shades are characterized by high scattering ability. And the maximum scattering of a certain shade in a specific environment colors it in this color.

Now we need to explain the following fact: if the violet hue is better scattered in the air, why is the sky blue, and, for example, not violet. This phenomenon is explained by the fact that the human visual organs, with equal brightness, “prefer” precisely blue shades, not violet or green.

Who paints the sky?

How to answer a child who looks at his parent with enthusiasm and expects an understandable and quite clear answer. A parent’s avoidance of the question may offend the child or disabuse him of the “omnipotence” of mom or dad. What are the possible explanations?

Answer No. 1. Like in a mirror

It is extremely difficult to tell a 2-3 year old child about spectra, wavelengths and other physical wisdom. But there is no need to brush it off; it is better to give the most simple explanation possible, satisfying the natural curiosity inherent in a tiny child.

There are many bodies of water on our Earth: there are rivers, lakes, and seas (we show the child a map). When it’s sunny outside, the water is reflected in the sky, like in a mirror. That's why the sky is as blue as the water in the lake. You can show your child a blue object in the mirror.

For children early age such an explanation can be considered sufficient.

Answer No. 2. Splashes in the sieve

An older child can be given a more realistic explanation. Tell him that the sun's ray has seven shades: red, orange, yellow, green, blue, indigo and violet. At this moment, show a drawing of a rainbow.

All rays penetrate to the Earth through a dense air layer, as if through a magic sieve. Each ray begins to splash into its component parts, but the blue color remains because it is the most persistent.

Answer No. 3. The sky is cellophane

The air near us seems transparent, like a thin plastic bag, but its real color is blue. This is especially noticeable if you look at the heavens. Invite the child to lift his head and explain that since the air layer is very dense, it takes on a bluish tint.

For greater effect, take a plastic bag and fold it several times, inviting your child to see how it changes color and degree of transparency.

Answer No. 4. Air is small particles

For children preschool age The following explanation is suitable: air masses are a “mixture” of various moving particles (gas, dust, debris, water vapor). They are so small that people with special equipment - microscopes - can see them.

The sun's rays include seven shades. Passing through air masses, the beam collides with small particles, causing all colors to disintegrate. Since the blue tint is the most persistent, this is what we distinguish in the sky.

Answer No. 5. Short rays

The sun warms us with its rays, and they seem yellow to us, like in children's drawings. However, each ray actually resembles a bright rainbow. But the air around us includes many particles invisible to the eye.

When a heavenly body sends rays to Earth, not all of them reach their destination. Some of the rays (which are blue) are very short and do not have time to hit the Earth, so they dissolve in the air and become lighter. Heaven is the same air, only located very high.

That is why when a child raises his head, he sees the sun’s rays dissolved in the air above. This is why the sky turns blue.

It is very important for children to receive a quick explanation, but it is not always possible to remember or come up with a simple and easy-to-understand answer. Avoiding a conversation is, of course, not the best the best option developments, however, it is better to be prepared.

Try to explain to your child that you will tell him, but you will do it a little later. Be sure to indicate the exact time, otherwise the baby will think that you are deceiving him. You can do the following:

1. Remember the planetariums, where experts very captivatingly explain the history of the appearance of the Earth and talk about the starry sky. Your little one will definitely love this fascinating story. And even if the guide doesn’t explain where the blue sky came from, he will learn a lot of new and unusual things.
2. If it is not possible to go to the planetarium or the question remains unanswered, you will have time to search in any sources, for example, on the Internet. Just choose an explanation based on the age and level of intellectual development of the children. And don’t forget to thank your child, because he is the one who helps you develop.

Why the sky is blue? Similar questions worry many little kids who are getting to know the world around them. It’s good if the parent himself knows where the blue above his head comes from. Our answer options will help with this.

Before telling your version, invite your child to think and come up with his own idea.

On a clear sunny day, the sky above us looks bright blue. In the evening, the sunset colors the sky in red, pink and orange. So why is the sky blue and what makes the sunset red?

What color is the sun?

Of course the sun is yellow! All the inhabitants of the earth will answer and the inhabitants of the Moon will disagree with them.

From Earth, the Sun appears yellow. But in space or on the Moon, the Sun would appear white to us. There is no atmosphere in space to scatter sunlight.

On Earth, some of the short wavelengths of sunlight (blue and violet) are absorbed by scattering. The rest of the spectrum appears yellow.

And in space, the sky looks dark or black instead of blue. This is the result of the absence of an atmosphere, therefore the light is not scattered in any way.

But if you ask about the color of the sun in the evening. Sometimes the answer is the sun is RED. But why?

Why is the sun red at sunset?

As the Sun moves toward sunset, sunlight has to travel a greater distance in the atmosphere to reach the observer. Less direct light reaches our eyes and the Sun appears less bright.

Since sunlight has to travel longer distances, more scattering occurs. The red part of the spectrum of sunlight passes through the air better than the blue part. And we see a red sun. The lower the Sun descends to the horizon, the larger the airy “magnifying glass” through which we see it, and the redder it is.

For the same reason, the Sun appears to us to be much larger in diameter than during the day: the air layer plays the role of a magnifying glass for an earthly observer.

The sky around the setting sun can have different colors. The sky is most beautiful when the air contains many small particles of dust or water. These particles reflect light in all directions. In this case, shorter light waves are scattered. The observer sees light rays of longer wavelengths, which is why the sky appears red, pink or orange.

Visible light is a type of energy that can travel through space. Light from the Sun or an incandescent lamp appears white, although in reality it is a mixture of all colors. The primary colors that make up white are red, orange, yellow, green, blue, indigo and violet. These colors continuously transform into one another, so in addition to the primary colors there are also a huge number of various shades. All these colors and shades can be observed in the sky in the form of a rainbow that appears in an area of ​​high humidity.

The air that fills the entire sky is a mixture of tiny gas molecules and small solid particles such as dust.

The sun's rays, coming from space, begin to scatter under the influence of atmospheric gases, and this process occurs according to Rayleigh's Law of Scattering. As light travels through the atmosphere, most of the long wavelengths of the optical spectrum pass through unchanged. Only a small part of the red, orange and yellow colors interacts with the air, bumping into molecules and dust.

When light collides with gas molecules, light can be reflected in various directions. Some colors, such as red and orange, reach the observer directly by passing directly through the air. But most blue light is reflected from air molecules in all directions. This scatters blue light throughout the sky and makes it appear blue.

However, many shorter wavelengths of light are absorbed by gas molecules. Once absorbed, the blue color is emitted in all directions. It is scattered everywhere in the sky. No matter which direction you look, some of this scattered blue light reaches the observer. Since blue light is visible everywhere overhead, the sky appears blue.

If you look towards the horizon, the sky will have a paler hue. This is the result of light traveling a greater distance through the atmosphere to reach the observer. The scattered light is scattered again by the atmosphere and less blue light reaches the observer's eyes. Therefore, the color of the sky near the horizon appears paler or even appears completely white.

Why is space black?

There is no air in outer space. Since there are no obstacles from which the light could be reflected, the light travels directly. The rays of light are not scattered, and the “sky” appears dark and black.

Atmosphere.

The atmosphere is a mixture of gases and other substances that surround the Earth in the form of a thin, mostly transparent shell. The atmosphere is held in place by the Earth's gravity. The main components of the atmosphere are nitrogen (78.09%), oxygen (20.95%), argon (0.93%) and carbon dioxide (0.03%). The atmosphere also contains small amounts of water (in different places its concentration ranges from 0% to 4%), solid particles, gases neon, helium, methane, hydrogen, krypton, ozone and xenon. The science that studies the atmosphere is called meteorology.

Life on Earth would not be possible without the presence of an atmosphere, which supplies the oxygen we need to breathe. In addition, the atmosphere performs another important function - it equalizes the temperature throughout the planet. If there were no atmosphere, then in some places on the planet there could be sizzling heat, and in other places extreme cold, the temperature range could fluctuate from -170°C at night to +120°C during the day. The atmosphere also protects us from harmful radiation from the Sun and space, absorbing and dispersing it.

The structure of the atmosphere

The atmosphere consists of different layers, the division into these layers occurs according to their temperature, molecular composition and electrical properties. These layers do not have clearly defined boundaries; they change seasonally, and in addition, their parameters change at different latitudes.

Homosphere

• The lower 100 km, including the Troposphere, Stratosphere and Mesopause.
• Makes up 99% of the mass of the atmosphere.
• Molecules are not separated by molecular weight.
• The composition is fairly homogeneous, with the exception of some small local anomalies. Homogeneity is maintained by constant mixing, turbulence and turbulent diffusion.
• Water is one of two components that are unevenly distributed. As water vapor rises, it cools and condenses, then returning to the ground in the form of precipitation - snow and rain. The stratosphere itself is very dry.
• Ozone is another molecule whose distribution is uneven. (Read below about the ozone layer in the stratosphere.)

Heterosphere

• Extends above the homosphere and includes the Thermosphere and Exosphere.
• The separation of molecules in this layer is based on their molecular weights. Heavier molecules such as nitrogen and oxygen are concentrated at the bottom of the layer. Lighter ones, helium and hydrogen, predominate in the upper part of the heterosphere.

Division of the atmosphere into layers depending on their electrical properties.

Neutral atmosphere

• Below 100 km.

Ionosphere

• Approximately above 100 km.
• Contains electrically charged particles (ions) produced by absorption of ultraviolet light
• The degree of ionization changes with altitude.
• Different layers reflect long and short radio waves. This allows radio signals traveling in a straight line to bend around the spherical surface of the earth.
• Auroras occur in these atmospheric layers.
• Magnetosphere is the upper part of the ionosphere, extending to approximately 70,000 km altitude, this altitude depends on the intensity of the solar wind. The magnetosphere protects us from high-energy charged particles from the solar wind by keeping them in the Earth's magnetic field.

Division of the atmosphere into layers depending on their temperatures

Top border height troposphere depends on seasons and latitude. It extends from the earth's surface to an altitude of approximately 16 km at the equator, and to an altitude of 9 km at the North and South Poles.

• The prefix "tropo" means change. Changes in the parameters of the troposphere occur due to weather conditions - for example, due to the movement of atmospheric fronts.
• As altitude increases, the temperature drops. Warm air rises, then cools and falls back to Earth. This process is called convection, it occurs as a result of the movement of air masses. Winds in this layer blow predominantly vertically.
• This layer contains more molecules than all other layers combined.

Stratosphere- extends from approximately 11 km to 50 km altitude.

• Has a very thin layer of air.
• The prefix "strato" refers to layers or division into layers.
• The lower part of the Stratosphere is quite calm. Jet aircraft often fly into the lower stratosphere to avoid bad weather in the troposphere.
• At the top of the Stratosphere there are strong winds known as high-altitude jet streams. They blow horizontally at speeds of up to 480 km/h.
• The stratosphere contains the "ozone layer", located at an altitude of approximately 12 to 50 km (depending on latitude). Although the ozone concentration in this layer is only 8 ml/m 3, it is very effective at absorbing harmful ultraviolet rays from the sun, thereby protecting life on earth. The ozone molecule consists of three oxygen atoms. The oxygen molecules we breathe contain two oxygen atoms.
• The stratosphere is very cold, with a temperature of approximately -55°C at the bottom and increasing with altitude. The increase in temperature is due to the absorption of ultraviolet rays by oxygen and ozone.

Mesosphere- extends to altitudes of approximately 100 km.

Municipal budgetary educational institution

"Kislovskaya secondary school" Tomsk district

Research

Topic: “Why is the sunset red...”

(Light dispersion)

Work completed: ,

student of class 5A

Supervisor;

chemistry teacher

1. Introduction …………………………………………………………… 3

2. Main part………………………………………………………4

3. What is light……………………………………………………….. 4

Subject of study– sunset and sky.

Research hypotheses:

The sun has rays that color the sky in different colors;

Red color can be obtained in laboratory conditions.

The relevance of my topic lies in the fact that it will be interesting and useful for listeners because many people look at the clear blue sky and admire it, and few know why it is so blue during the day and red at sunset and what gives this is his color.

2. Main part

At first glance, this question seems simple, but in fact it affects deep aspects of the refraction of light in the atmosphere. Before you can understand the answer to this question, you need to have an idea of ​​what light is..jpg" align="left" height="1 src=">

What is light?

Sunlight is energy. The heat of the sun's rays, focused by the lens, turns into fire. Light and heat are reflected by white surfaces and absorbed by black ones. This is why white clothes are cooler than black clothes.

What is the nature of light? The first person to seriously attempt to study light was Isaac Newton. He believed that light consists of corpuscular particles that are fired like bullets. But some characteristics of light could not be explained by this theory.

Another scientist, Huygens, proposed a different explanation for the nature of light. He developed the "wave" theory of light. He believed that light formed pulses, or waves, in the same way that a stone thrown into a pond creates waves.

What views do scientists today hold on the origin of light? It is now believed that light waves have the characteristics of both particles and waves at the same time. Experiments are being conducted to confirm both theories.

Light is made up of photons, weightless, massless particles that travel at speeds of about 300,000 km/s and have the properties of waves. The wave frequency of light determines its color. In addition, the higher the oscillation frequency, the shorter the wavelength. Each color has its own vibration frequency and wavelength. White sunlight is made up of many colors that can be seen when it is refracted through a glass prism.

1. A prism decomposes light.

2. White light- difficult.

If you look closely at the passage of light through a triangular prism, you can see that the decomposition of white light begins as soon as the light passes from air into glass. Instead of glass, you can use other materials that are transparent to light.

It is remarkable that this experiment has survived centuries, and its methodology is still used in laboratories without significant changes.

dispersio (lat.) – scattering, dispersion - dispersion

Newton's dispersion.

I. Newton was the first to study the phenomenon of light dispersion and is considered one of his most important scientific achievements. It is not for nothing that on his tombstone, erected in 1731 and decorated with figures of young men who hold in their hands the emblems of his most important discoveries, one figure holds a prism, and the inscription on the monument contains the words: “He investigated the difference in light rays and the various properties that appeared at the same time, something no one suspected before.” The last statement is not entirely accurate. Dispersion was known earlier, but it was not studied in detail. While improving telescopes, Newton noticed that the image produced by the lens was colored at the edges. By examining edges colored by refraction, Newton made his discoveries in the field of optics.

Visible spectrum

When the beam decomposes white in the prism a spectrum is formed in which the radiation different lengths waves are refracted at different angles. Colors included in the spectrum, that is, those colors that can be produced by light waves of one wavelength (or a very narrow range), are called spectral colors. The main spectral colors (which have their own names), as well as the emission characteristics of these colors, are presented in the table:

Each “color” in the spectrum must be matched with a light wave of a certain length

The simplest idea of ​​the spectrum can be obtained by looking at a rainbow. White light, refracted in water droplets, forms a rainbow, since it consists of many rays of all colors, and they are refracted differently: red ones are the weakest, blue and violet are the strongest. Astronomers study the spectra of the Sun, stars, planets, and comets, since a lot can be learned from the spectra.

Nitrogen" href="/text/category/azot/" rel="bookmark">nitrogen. Red and blue light interact differently with oxygen. Since the wavelength of blue color approximately corresponds to the size of the oxygen atom and because of this blue light is scattered by oxygen in different directions, while red light easily passes through the atmospheric layer. In fact, violet light is scattered even more in the atmosphere, but the human eye is less sensitive to it than to blue light. The result is that the eye. a person is caught from all sides by blue light scattered by oxygen, which makes the sky appear blue to us.

Without an atmosphere on Earth, the Sun would appear to us as a bright white star and the sky would be black.

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Read more about sunset colors. Precisely because of poor dispersion ability red The light of the sun at sunset shimmers with all shades of this color. And the reason folk sign, which speaks of an upcoming stormy day preceded by a scarlet sunset, is quite understandable. Let's try to think logically.
At the moment when the sun is near the horizon, its rays on the way to our eye have to pass through a much thicker layer of atmosphere than usual. Under normal conditions, the color of the sun appears dazzling white when looking at it. When passing through a thick layer of atmosphere, colors, with the exception of all shades of red, are greatly scattered or absorbed by the atmosphere.
Accordingly, we can say that the sun on the horizon will be the redder, the thicker the layer of atmosphere lies between it and our eye, or the more restless and, accordingly, dustier this very layer of the atmosphere will be. Our assumptions turn out to be correct. The closer the sun is to the horizon, the thicker the layer of atmosphere through which its light tends to us, and the, accordingly, redder its shades. The following statement is also true: the more purple the sunset, the stormier and windier the next day will be.
Further logical reasoning will help us understand what causes blue sky color. Blue(same as blue) color lies in the spectrum between green And purple. All of them have the ability to disperse in the atmosphere. The scattering of any color in a certain medium leads to the coloring of the medium in this color.

The air is transparent and colorless, but in the thick atmosphere on a clear day it is blue, as the sun's rays are scattered in the air. Light, or sun rays, are propagating electromagnetic waves. Violet, blue and cyan are rays with a short wavelength. On a clear day, they are intensively scattered by air molecules and become accessible to the eye, and the rays of red and yellow colors have a wavelength almost twice as long, so they are scattered by air molecules much less. Clouds and fog contain many different impurities, water droplets, ice crystals, here rays of all wavelengths are scattered equally strongly, which is why clouds and fog are white. At sunset, the sky often turns red and yellow. This happens because in the evening the Sun is low above the horizon and the sun's rays travel a very long way through the atmosphere. They are actively scattering, now red and yellow rays become available to our eyes

Different colors of the sky.

The sky is not always blue. For example, at night, when the sun does not send rays, we see the sky not blue, the atmosphere seems transparent. And through the transparent air, a person can see planets and stars. And during the day, the blue color again hides cosmic bodies from our eyes.

The color of the sky can be red - at sunset, in cloudy weather, white or gray.

Color perception

Human perception of color is associated with great emotions. Green and yellow colors have the most beneficial effect: they sharpen vision, speed up reactions, and sharpen hearing. Green color helps to quickly relieve pain. Red color excites, it is the color of rise, victory. Prolonged exposure to red creates fatigue.

Unusual phenomena

https://pandia.ru/text/80/039/images/image008_21.jpg" alt="Aurora" align="left" width="140" height="217 src=">!} Auroras Since ancient times, people have admired the majestic picture of the auroras and wondered about their origin. One of the earliest mentions of auroras is found in Aristotle. In his “Meteorology”, written 2300 years ago, you can read: “Sometimes on clear nights many phenomena are observed in the sky - gaps, gaps, blood-red color...

It looks like there's a fire burning."

Why does a clear beam ripple at night?

What thin flame spreads into the firmament?

Like lightning without threatening clouds

Striving from the ground to the zenith?

How can it be that a frozen ball

Was there a fire in the middle of winter?

What are aurora borealis? How is it formed?

Answer. The aurora is a luminescent glow resulting from the interaction of charged particles (electrons and protons) flying from the Sun with atoms and molecules of the earth's atmosphere. The appearance of these charged particles in certain regions of the atmosphere and at certain altitudes is the result of the interaction of the solar wind with the Earth’s magnetic field.

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10. The main thing is that now I know why the sky is painted red at sunset. My hypothesis was partially confirmed; the sun has rays that paint the sky this color.

11. While studying the topic I chose, I learned to work with literary sources, collect information, and analyze the data obtained.

3.Conclusion

In his research work I found out - Why is the sunset red?

At first glance, my question seemed simple. But already at the beginning of the study, I realized that this was not so.

The whole secret turned out to be in our atmosphere. The sun's rays must pass through a huge layer of air before hitting the ground. The color of the sun at its zenith is perceived by the human eye as white. In fact, the spectrum of sunlight consists of seven primary colors (spectrum colors) and their shades. Any color represents an electromagnetic wave of a given length, perceived by the human eye. The quality of spectral scattering will be affected by the thickness of the layer of atmospheric air located between the eyes and the object emitting light(by the sun). The air is filled with invisible aerosol scatterings of dust and moisture, and they are the main cause of the decomposition of solar color (dispersion). At the zenith position, the incidence of the sun's ray on the aerosol components of the air occurs almost at a right angle, their layer between the observer's eyes and the sun is insignificant. The lower the sun descends to the horizon, the more the thickness of the layer of atmospheric air and the amount of aerosol suspension in it increases. The sun's rays, relative to the observer, change the angle of incidence on suspended particles, and then dispersion of sunlight is observed. So, as mentioned above, sunlight is made up of seven primary colors. Each color, like an electromagnetic wave, has its own length and ability to dissipate in the atmosphere. The primary colors of the spectrum are arranged in order on a scale, from red to violet. The color red has the least ability to dissipate (and therefore absorb) in the atmosphere. With the phenomenon of dispersion, all colors that follow red on the scale are scattered by the components of the aerosol suspension and absorbed by them. The observer sees only red color. This means that the thicker the layer of atmospheric air, the higher the density of the suspended matter, the more rays of the spectrum will be scattered and absorbed. A well-known natural phenomenon: after the powerful eruption of the Krakatoa volcano in 1883, unusually bright, red sunsets were observed in different places on the planet for several years. This is explained by the powerful release of volcanic dust into the atmosphere during the eruption.

I think that my research will not end here. I still have questions. I want to know:

What happens when light rays pass through various liquids and solutions;

How light is reflected and absorbed.

Having completed this work, I became convinced how much amazing and useful for practical activities can be contained in the phenomenon of light refraction. It was this that allowed me to understand why the sunset is red.

Literature

1. Physics. Chemistry. 5-6 grades Textbook. M.: Bustard, 2009, p.106

2. Damask steel phenomena in nature. M.: Education, 1974, 143 p.

3. “Who makes the rainbow?” – Kvant 1988, No. 6, p. 46.

4. Lectures on optics. Tarasov in nature. – M.: Education, 1988

Internet resources:

1. http://potomy. ru/ Why is the sky blue?

2. http://www. voprosy-kak-i-pochemu. ru Why is the sky blue?

3. http://expirience. ru/category/education/