Because the sky is blue. Why is the sky blue and the sunset red? Description, photo and video. Sunburst color

10.10.2020

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

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

However, "average" parents do not know what to say to the 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 the school physics course. Colors are distinguished by their ability to scatter (due to wavelength) in the gaseous envelope surrounding the Earth. So, the red color has a low ability, which is why it is used, for example, as external side lighting for aircraft.

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

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

We argue further. The blue and blue "branch" of the spectrum lies between green and violet. All these shades have a high scattering power. And the maximum scattering of a certain shade in a particular medium colors it in this color.

Now we need to explain the following fact: if the purple hue is better diffused in the air, why is the sky blue, and, for example, not purple. This phenomenon is explained by the fact that the organs of vision of a person with equal brightness “prefer” exactly blue shades, and not violet or green.

Who paints the sky?

How to answer a child who looks at the parent with enthusiasm and expects a clear and quite clear answer. The parent's departure from the question can offend the baby or dissuade him of the "omnipotence" of mom or dad. What are possible explanations?

Answer number 1. Like in a mirror

It is extremely difficult for a child of 2-3 years old to tell about spectra, wavelengths and other physical wisdom. But there is no need to dismiss it, it is better to give the maximum simple explanation, 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 is sunny outside, the water is reflected, as in a mirror, in heaven. That's why the sky is as blue as the water in the lake. You can show the child in the mirror any blue object.

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

Answer number 2. Spray in a sieve

An older child can be given a more realistic explanation. Tell him that a sunbeam has seven hues: red, orange, yellow, green, blue, indigo, and violet. At this point, show the drawing of the rainbow.

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

Answer number 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 when looking 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 the child to see how it changed color and degree of transparency.

Answer number 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, litter, water vapor). They are so small that people with special equipment - microscopes - can see them.

The rays of the sun include seven shades. Passing through the air masses, the beam collides with small particles, as a result of which all colors decay. Since the blue tint is the most persistent, we distinguish it in the sky.

Answer number 5. Short rays

The sun warms us with its rays, and they seem yellow to us, as 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 celestial body sends rays to Earth, not all of them reach their destination. Part of the rays (which is blue) is very short and does not have time to get to the Earth, so it dissolves in the air and becomes lighter. Heaven is the same air, only being very high.

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

It is very important for children to get a quick explanation, but it is not always possible to remember or come up with a simple and understandable answer. Avoiding the conversation - of course, not the most the best option developments, but it is still better to prepare.

Try to explain to the child what you will tell, but do it a little later. It is necessary to specify exact time, otherwise the baby will think that you are deceiving him. You can do the following:

Think of the planetariums, where experts explain the history of the Earth's appearance in a very entertaining way and talk about the starry sky. The kid will definitely like this fascinating story. And even if the guide does not explain where the blueness of the sky came from, he will learn a lot of new and unusual things.
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 net. Just choose an explanation, focusing on the age and level of intellectual development of children. And do not forget to thank the child, because it is he who helps you develop.

Why the sky is blue? Similar questions worry many kids-why-why who get acquainted with the world around them. It is good if the parent himself knows where the blue above his head comes from. This will help our answer options.

Before you tell your version, invite your child to reflect and put forward their own idea.

In such a simple way, you can bring up an inquisitive baby who always strives to find an explanation for every fact that excites him.

Hello, I'm Nadezhda Plotnikova. Having successfully studied at SUSU as a special psychologist, she devoted several years to working with children with developmental problems and advising parents on raising children. I apply the experience gained, among other things, in the creation of psychological articles. Of course, by no means do I pretend to be the ultimate truth, but I hope that my articles will help dear readers deal with any difficulties.

It turns out that very few people know the answer to this seemingly "always hanging in the air question." Children often ask about this, but adults are not ready to give an explanation. Many people think that this question is one of a series of questions that we cannot answer at all, such as "where is the end of the universe." There are people who believe that this is the color of a mixture of nitrogen and oxygen when there are many of these gases and they are illuminated by the Sun. There are those who associate the color of the sky with the refraction of light in the layers of the atmosphere. Those who were excellent students at school will say that, they say, the air scatters Blue colour more intense than all other colors of the spectrum according to Rayleigh's law, often without understanding the essence of this scattering. By the way, the question of the color of the sky was solved by physicists only in the twentieth century. Therefore, we should not be especially ashamed.

And although this issue is not directly related to temperature, let's try to figure it out. We will not dig very deep into physics, but we will recall the basic provisions about light and air.

Sunlight is a mixture of radiations of all colors of the rainbow, i.e. electromagnetic waves with oscillation frequencies such that they can affect the human retina. Violet corresponds to a wavelength of 380 nm, red - 720 nm. The retina contains cones responsible for color perception. There are three types of cones: blue (responsible for high frequencies), green (responsible for mid frequencies) and red (for low frequencies). The sensitivity ranges of cones overlap, but the maximum falls on a certain color.

air molecules in normal condition have no charge, they are neutral. However, they consist of charged particles - electrons and nuclei. Under the influence of the electric field, the nuclei are shifted in one direction, the electrons in the other, and a dipole with its own electromagnetic field. If the dipole enters an alternating electromagnetic field, then it begins to oscillate, that is, the positive and negative charges shift back and forth and the dipole itself begins to radiate an electromagnetic wave. In our case, the electromagnetic wave of sunlight causes air molecules to turn into dipoles that emit electromagnetic waves. Moreover, the directions of studying dipoles can be various. According to the law of conservation of energy light wave loses intensity in the original direction. This is the main mechanism of light scattering in air. It is more correct to speak not even about scattering, but about the glow of air molecules under the action of light. We look through the atmosphere and actually see the light from the sun and the light emitted by the molecules in our atmosphere. Why is it not white, but blue?

The fact is that the intensity of the dipole radiation is proportional to the fourth power of the radiation frequency. The most intensely emitted by dipoles are waves with maximum frequency and energy, corresponding to blue light. Waves of red light interact less with air molecules. Those. when passing through the atmosphere, it is as if white color is filtered along the spectrum. Air molecules emit mainly blue light, i.e. light that excites the blue and green cones of the retina much more strongly than the red cones.

John Tyndall was the first to take a step towards a correct explanation of the color of the sky in 1865. He discovered that when light rays pass through a medium in which small particles of impurities are suspended, the blue color is scattered more intensely than red. As a result, we see the coloration of the transmitted light in a blue tint. This can be observed when looking sideways at a beam of light passing through water slightly clouded with milk. If you look not from the side, but in the direction of the beam, then the light acquires a reddish tint, because. the blue component is scattered.

A few years later, the British scientist Lord Rayleigh studied this effect in more detail. He showed that the intensity of light scattering by very small particles is inversely proportional to the fourth power of the radiation wavelength. From this it followed that blue light scatters 10 times more intensely than red.

Tyndall and Rayleigh thought that the blueness of the sky was due to the presence of small particles of dust and water vapor in the atmosphere. Later, scientists realized that if this were true, then we would observe significantly more variations in the color of the sky with changes in humidity, nebula, and air pollution than we see now. The problem was solved by Einstein, who in 1911 derived a formula describing the scattering of light by molecules. The formula confirmed all previous experiments. It was proved that it is not dust and vapor, but air molecules that scatter light, since (as mentioned above) the electromagnetic field of light initiates electric dipole moments in molecules.

Why is the sky not purple, but blue? After all, purple waves are shorter than blue ones. The first reason is that the spectrum of solar radiation is not uniform. There is less purple. In addition, violet rays are scattered even in the uppermost layers of the atmosphere. The second reason is that our cones are less sensitive to violet than to blue. The third reason is that the blue color irritates not only the blue cones in the retina, but also slightly red and green ones. Therefore, the color of the sky is not pale, but saturated blue, especially when the air is transparent.

The color of the sunset is also explained by the scattering of light by air molecules. Having traveled a long way from the Sun tangentially to the Earth, the beam loses all blue hues. Only yellow and red tones reach the eye. Near the sea, the sunset can even be orange, thanks to the salt particles in the air that are responsible for Tyndall's scattering.

Note that the composition of the atmosphere, i.e. the presence of nitrogen and oxygen, the color of the sky is practically independent. If the planet has a transparent atmosphere of sufficient thickness and density, illuminated by a luminary whose spectrum is white, like that of the Sun, then the sky there will be blue.

How, then, to explain that the pictures from spacecraft who have landed on Mars say that the sky is pink and red there? This is because the atmosphere of Mars is very thin and polluted with dust. Scattering of sunlight occurs not on molecules, but mainly on suspended impurities of dust. Many dust particles are larger than the wavelengths of light and are made up of iron oxide, which is red in color.

Now you know that the answer to the question "why is the sky blue" is not very simple. We understand, but what to say to the children? It is likely that our beautiful atmosphere consists of air that glows blue when the Sun warms it. Because blue is the strongest of all the colors of the rainbow.

Why the sky is blue?

“Dad, why is the sky blue and not, say, green or purple?”
Children when they start learning the world are very active in asking questions. Hundreds of questions a day about anything that comes under the spotlight. All you hear is "why-why". And dad (or mom) by no means can "fall face down" and lose authority, saying "I don't know." How can this even be, because he has been living for a very long time and knows such elementary things for sure from his childhood?
And dad, of course, knows why this sky is suddenly blue 😉, and if he suddenly forgot something, he carefully reads what is written below.

What color is sunlight?

To understand the color of the sky, and understand why it is, you first need to find out what color the sunlight has. This question seems elementary.
"Yellow" - the baby will tell you, but here he will have to be surprised for the first time.
"But it's not yellow!"
O_O - the baby will have approximately the same eyes (something is clearly wrong with dad).
“Come on, raise your head, dad! It's yellow! Why is it not? Very much yes!”
“But no!” Then dad makes an authoritative face and says:
“In fact, the color of the sun and its rays is white, and the fact that we see it yellow is because it becomes so after passing through the air.”

What is white made up of?

"What colors do you know?" the child's father asks.
"Green, yellow, red, white ..." - the kid begins to list.
“Clever! All those colors that you listed, except for white, are simple colors. But the white one is special! In nature, there is no just white, but it appears if you put together all the simple colors.
It's like in a game when you need to collect parts of an object. Here you take one part, the second, the third, etc., and when you collect everything - TADAM! You get the whole item! So is white - it consists of all colors, and if at least some shade is taken away from it, it will no longer be white. It's clear?"
"Yeah," the kid nods.

So what's up with the color of the sky? Why is it blue?

“All this is very interesting, but, in my opinion, you are moving away from the topic. How about the color of the sky? Why is it like this?
“I'm just getting there. I told you elementary things so that more complex ones could be explained on the fingers.
As for the sky, I must say this. Scientists have not yet found an absolutely exact answer, but there are two simple theories that explain why the shade of the sky is blue. I'll tell you both.

First theory:

In the air that surrounds the earth flies a large number of particles are different gases, dust particles, water particles, etc. When a white ray from the sun (and, as you remember, it is not by itself, but all the colors together) enters the air, then colliding with particles of air and particles that fly in the air, it begins to crumble into the colors of which it consisted.
It turned out that not all of them are equally fast, some are very clumsy, they disperse in the air, colliding with some particles, while others, very fast, dodge collisions and reach the Earth.
Blue rays are clumsy, they most often fall on obstacles and scatter (scatter) in all directions, illuminating the air with blue light.

Second theory a little more complicated:

Scientists suggest that particles of the air that surrounds the Earth absorb the sun's rays. They, as it were, are charged from these rays, and then begin to radiate their own light in all directions.

Well, for example, like a door on a stove. Remember, I showed you how the door was black at first, and then warmed up, warmed up and began to glow red? Do you remember?
“Yeah, I remember. And why did you remember the stove? .
“Yes, because it is the same here. Particles of air receive energy from the sun's rays, and then begin to glow. Different gases glow differently. The fact that we see the sky blue, according to this theory, it is thanks to the gases that make up our air (oxygen and nitrogen) that they emit a blue color. But if instead of them there would be, for example, neon (there is such a gas), then the sky would glow red-orange, but we would not be able to enjoy this spectacle, because. couldn't breathe.
Therefore, I think that even if it remains blue, blue is also okay, right?
“I agree,” the kid nodded, and after a minute, when he saw the dog, he asked the following vital question: “Dad, and

White sunlight is made up of the seven colors of the rainbow and comes to us in waves. Air dissipates these waves. Worst of all, it scatters long waves, and best of all - short waves. The blue light wave is short, so we see the sky as blue.

A detailed answer in terms of physics

The sun's rays reach our planet through a thick layer of the atmosphere, which itself is transparent, but not at all empty: it consists of 78% nitrogen and 21% oxygen, and also includes steam, water droplets, tiny ice crystals and solid particles. earth dust and sea salt, soot and ash. Breaking through the heterogeneous layers of the atmosphere, the rays of the Sun are scattered - diffraction occurs, that is, the splitting of light into components.

White light consists of the seven colors of the spectrum—red, orange, yellow, green, blue, indigo, and violet—and travels in waves. Each color has its own wavelength.

Blue, blue, violet colors are from the short-wavelength part of the spectrum, therefore they are very strongly scattered in the atmosphere. To our eye, a mixture of these colors is seen as blue. At sunrise and sunset, the rays of the sun become longer and go to the earth under more acute angle- and we observe how the blueness completely dissipates for a while: it is replaced by red and yellow tones from the long wavelength part of the spectrum.

The blue overflows that can sometimes be observed in the sky are explained by the heterogeneity of the composition of the atmosphere - passing through it, even blue light waves are not scattered in the same way.

The physical law of light scattering is called the Rayleigh law in honor of the English physicist who discovered it and states that the intensity of scattered light is inversely proportional to the fourth power of the wavelength of light. The formula looks like this: I ~ 1/λ4

For the designer and programmer: the color of the blue sky

The interesting thing is that for every designer and programmer, color blue sky will be designated differently - depending on personal perception, because blue is the collective name for a whole group of light shades of blue - and sometimes even with a subtle shift towards green. Each of these shades has its own color coordinates.

The closest thing to spectral blue is hue 130 in the Windows color system, denoted 00BFFF.

Interestingly, in the CMYK system, one of the main system colors, cyan, can be called cyan, although it contains a shade of green. In Russian, the color of cyan best corresponds to the definition of "color of the sea wave." But the sea is often called blue.

Song "Under the blue sky there is a city of gold"

The most famous song, which was performed by Boris Grebenshchikov and his group "Aquarium" under the name "City", does not belong to either BG or the group. Yes, and it was called in the original "Paradise". The author of the text, the immigrant poet Anri Volokhonsky, composed these verses in 1972, having heard a string melody performed by V. Vavilov on the record. On the cover of the disc, the melody was shamelessly attributed to Francesco da Milano, who does not have such a work. Traces of the author of the original melody are now lost, and different performers have interpreted it in different ways.

And we hear Volokhonsky's text in Grebenshchikov's version. As everyone knows, BG sings: "Under the blue sky ..." In the original - "Above". The poet was inspired by the book of the prophet Ezekiel, and the city above the sky is, of course, the heavenly Jerusalem, “Earthly I had not yet seen,” said Volokhonsky.

Aquarium - "Under the blue sky"

On a clear sunny day, the sky above us looks bright blue. In the evening, the sunset colors the sky in reds, pinks and oranges. Why is the sky blue? What makes a sunset red?

To answer these questions, you need to know what light is and what the Earth's atmosphere consists of.

Atmosphere

The atmosphere is the mixture of gases and other particles that surround the earth. Basically, the atmosphere consists of gaseous nitrogen (78%) and oxygen (21%). Argon gas and water (in the form of steam, droplets and ice crystals) are the next most common in the atmosphere, their concentration does not exceed 0.93% and 0.001%, respectively. The Earth's atmosphere also contains small amounts of other gases, as well as the smallest particles of dust, soot, ash, pollen and salt that enter the atmosphere from the oceans.

The composition of the atmosphere varies within small limits depending on the place, weather, etc. The concentration of water in the atmosphere increases during torrential storms, as well as near the ocean. Volcanoes are capable of throwing huge amounts of ash high into the atmosphere. Technogenic pollution can also add various gases or dust and soot to the usual composition of the atmosphere.

Atmospheric density at low altitude near the Earth's surface is the highest, with increasing altitude it gradually decreases. There is no clear-cut boundary between the atmosphere and space.

light waves

Light is a form of energy that is carried by waves. In addition to light, waves carry other types of energy, for example, a sound wave is an air vibration. A light wave is an oscillation of electric and magnetic fields, this range is called the electromagnetic spectrum.

Electromagnetic waves propagate through airless space at a speed of 299.792 km/s. The speed of propagation of these waves is called the speed of light.

The radiation energy depends on the wavelength and its frequency. The wavelength is the distance between the two nearest peaks (or troughs) of a wave. Wave frequency is the number of wave oscillations per second. The longer the wave, the lower its frequency, and the less energy it carries.

Visible light colors

Visible light is the part of the electromagnetic spectrum that our eyes can see. The light emitted by the Sun or an incandescent lamp may have White color, but in fact it is a mixture of different colors. You can see the different colors of the visible spectrum of light by decomposing it into its components using a prism. This spectrum can also be observed in the sky in the form of a rainbow, which occurs due to the refraction of the light of the Sun in water droplets, acting as one giant prism.

The colors of the spectrum are mixed, continuously moving one into another. At one end of the spectrum is red or orange. These colors fade into yellow, green, blue, indigo and violet. Colors have different wavelengths, different frequencies, and different energies.

Propagation of light in the air

Light travels through space in a straight line as long as there are no obstacles in its path. When a light wave enters the atmosphere, light continues to propagate in a straight line until dust or gas molecules get in its way. In this case, what happens to the light will depend on its wavelength and the size of the particles in its path.

Dust particles and water droplets are much larger than the wavelength of visible light. Light is reflected in different directions when it collides with these large particles. Different colors of visible light are equally reflected by these particles. Reflected light appears white because it still contains the same colors it had before it was reflected.

Gas molecules are smaller than the wavelength of visible light. If a light wave collides with them, then the result of the collision can be different. When light collides with a molecule of any gas, some of it is absorbed. A little later, the molecule begins to emit light in various directions. The color of the emitted light is the same color that was absorbed. But colors of different wavelengths are absorbed differently. All colors can be absorbed, but higher frequencies (blue) are absorbed much more strongly than low frequencies(Red color). This process is called Rayleigh scattering, named after the British physicist John Rayleigh, who discovered this scattering phenomenon in the 1870s.

Why is the sky blue?

The sky is blue due to Rayleigh 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 flowers interacts with air.

However, many shorter wavelengths of light are absorbed by gas molecules. After absorption, the blue color is emitted in all directions. It is scattered all over the sky. In whatever direction you look, some of this scattered blue light reaches the observer. Since blue light is visible everywhere overhead, the sky looks blue.

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

Black sky and white sun

From Earth, the Sun appears yellow. If we were in space or on the Moon, the Sun would appear white to us. There is no atmosphere in space that scatters sunlight. On Earth, some of the short wavelengths of sunlight (blue and violet) are absorbed by scattering. The rest of the spectrum looks yellow.

Also, in space, the sky looks dark or black instead of blue. This is the result of the absence of an atmosphere, hence the light does not scatter in any way.

Why is the sunset red?

As the sun goes down, the sunlight has to travel a greater distance in the atmosphere to reach the observer, so more sunlight is reflected and scattered by the atmosphere. Since less direct light reaches the observer, the Sun appears less bright. The color of the Sun also appears to be different, ranging from orange to red. This is due to the fact that even more short-wavelength colors, blue and green, are scattered. Only the long-wavelength components of the optical spectrum remain, which reach the observer's eyes.

The sky around the setting sun can be colored in 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, and so the sky appears red, pink, or orange.

More about the atmosphere

What is 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 that 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 it would be extremely cold, the temperature range could range from -170 ° C at night to + 120 ° C during the day. The atmosphere also protects us from the harmful radiation of the Sun and space, absorbing and scattering it.

Of the total amount of solar energy reaching the Earth, approximately 30% is reflected by clouds and the earth's surface back into space. The atmosphere absorbs approximately 19% of the Sun's radiation, and only 51% is absorbed by the Earth's surface.

Air has weight, although we do not realize it, and do not feel the pressure of the air column. At sea level, this pressure is one atmosphere, or 760 mmHg (1013 millibars or 101.3 kPa). With increasing height Atmosphere pressure is rapidly declining. The pressure drops by a factor of 10 for every 16 km in altitude. This means that at a pressure of 1 atmosphere at sea level, at an altitude of 16 km, the pressure will be 0.1 atm, and at an altitude of 32 km - 0.01 atm.

The density of the atmosphere in its lowest layers is 1.2 kg/m 3 . Each cubic centimeter of air contains approximately 2.7 * 10 19 molecules. At ground level, each molecule travels at about 1,600 km/h, while colliding with other molecules at a rate of 5 billion times per second.

Air density also drops rapidly with altitude. At a height of 3 km, the air density decreases by 30%. People living near sea level experience temporary breathing problems when raised to this altitude. highest height, where people permanently live, is 4 km.

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 pronounced boundaries, they change seasonally, and in addition, their parameters change at different latitudes.

Separation of the atmosphere into layers depending on their molecular composition

Homosphere

Lower 100 km including Troposphere, Stratosphere and Mesopause.
Makes up 99% of the mass of the atmosphere.
Molecules are not separated by molecular weight.
The composition is quite 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 distributed unevenly. When water vapor rises, it cools and condenses, then returning to the earth in the form of precipitation - snow and rain. The stratosphere itself is very dry.
Ozone is another molecule whose distribution is uneven. (Read about the ozone layer in the stratosphere below.)

heterosphere

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

Separation 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 the absorption of ultraviolet light
The degree of ionization changes with altitude.
Different layers reflect long and short radio waves. This allows radio signals propagating 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 about 70,000 km, this height depends on the intensity of the solar wind. The magnetosphere protects us from the high-energy charged particles of the solar wind by keeping them in the Earth's magnetic field.

Separation of the atmosphere into layers depending on their temperatures

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

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

Stratosphere- extends approximately from a height of 11 km to 50 km.

It has a very thin layer of air.
The prefix "strato" refers to layers or layering.
The lower part of the Stratosphere is quite calm. Jet planes often fly in the lower Stratosphere in order to get around bad weather in the Troposphere.
Strong winds known as high-altitude jet streams blow in the upper part of the Stratosphere. They blow horizontally at speeds 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 concentration of ozone in this layer is only 8 ml/m 3 , it absorbs the sun's harmful ultraviolet rays very effectively, thereby protecting life on earth. The ozone molecule is made up of three oxygen atoms. The oxygen molecules we breathe contain two oxygen atoms.
The stratosphere is very cold, its temperature is about -55°C at the bottom and increases with height. The increase in temperature is due to the absorption of ultraviolet rays by oxygen and ozone.

Mesosphere- extends to altitudes of about 100 km.

As the altitude increases, the temperature rises rapidly.

Thermosphere- extends to altitudes of about 400 km.

With increasing altitude, the temperature rises rapidly due to the absorption of very short wavelength ultraviolet radiation.
Meteors, or "shooting stars", begin to burn up at altitudes of about 110-130 km above the Earth's surface.

Exosphere- extends for hundreds of kilometers beyond the Thermosphere, gradually passing into outer space.

The air density here is so low that the use of the concept of temperature loses all meaning.
Molecules often fly off into space when they collide with each other.

Why is the color of the sky blue?

Visible light is a form of energy that can travel through space. Light from the sun or an incandescent lamp appears white when in reality it is a mixture of all colors. The main colors that make up the white color are red, orange, yellow, green, blue, indigo and violet. These colors continuously change into one another, therefore, in addition to the primary colors, there is 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 occurs in areas of high humidity.

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

As sunlight passes through the air, it bumps into molecules and dust. When light collides with gas molecules, the 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 of the blue light is re-reflected from air molecules in all directions. In this way, blue light is scattered throughout the sky and it appears blue.

When we look up, some of this blue light reaches our eyes from all over the sky. Since blue is visible everywhere overhead, the sky looks blue.

IN outer space there is no air. Since there are no obstacles from which light could be reflected, the light propagates directly. The rays of light do not scatter, and the "sky" looks dark and black.

Experiments with light

The first experiment - decomposition of light into a spectrum

For this experiment you will need:

a small mirror, a piece of white paper or cardboard, water;
a large shallow vessel such as a cuvette or bowl, or a plastic ice cream box;
sunny weather and a window facing the sunny side.

How to conduct an experiment:

Fill a cuvette or bowl 2/3 full with water, and place it on the floor or table so that direct sunlight reaches the water. The presence of direct sunlight is essential for the correct conduct of the experiment.
Place a mirror under water so that the sun's rays fall on it. Hold a piece of paper over the mirror so that the rays of the sun reflected by the mirror fall on the paper, if necessary, adjust their relative position. Observe the color spectrum on paper.

What's happening: The water and the mirror act like a prism, splitting the light into its color spectrum. This happens because the rays of light passing from one medium (air) to another (water) change their speed and direction. This phenomenon is called refraction. Different colors are refracted differently, violet rays are more strongly decelerated and change their direction more strongly. Red rays slow down and change their direction to a lesser extent. The light is split into its component colors and we can see the spectrum.

The second experiment - modeling the sky in a glass jar

Materials needed for the experiment:

a transparent tall glass or a transparent plastic or glass jar;
water, milk, teaspoon, flashlight;
a dark room;

Conducting an experiment:

Fill a glass or jar 2/3 full with water, approximately 300-400 ml.
Add 0.5 to one tablespoon of milk to the water, shake the mixture.
Taking a glass and a flashlight, go to a dark room.
Hold a flashlight over a glass of water and point the beam of light at the surface of the water, look at the glass from the side. In this case, the water will have a bluish tint. Now point the flashlight at the side of the glass, and look at the beam of light from the other side of the glass, so that the light passes through the water. This will give the water a reddish tint. Place a flashlight under the glass and point the beam of light upwards while looking at the water from above. In this case, the reddish tint near the water will look more saturated.

What happens in this experiment is that small particles of milk suspended in water scatter the light coming from a flashlight in the same way that particles and molecules in the air scatter sunlight. When the glass is illuminated from above, the water appears bluish due to the fact that the blue color is scattered in all directions. When you look directly at the light through the water, the flashlight appears red, as some of the blue rays have been removed due to light scattering.

The third experiment - mixing colors

You will need:

pencil, scissors, white cardboard or a piece of drawing paper;
colored pencils or felt-tip pens, a ruler;
a mug or a large cup with a diameter at the top of 7-10 cm or a caliper.
Paper cup.