In short, then ... "Sunlight, interacting with air molecules, scatters into different colors. Of all the colors, blue is the best for scattering. It turns out that he actually captures the airspace.

Now let's take a closer look

Only children can ask such simple questions that a fully grown person does not know how to answer. The most common question tormenting children's heads is: "Why is the sky blue?" However, not every parent knows the right answer even for himself. The science of physics and scientists who have been trying to answer it for more than one hundred years will help find it.

False Explanations

People have been searching for the answer to this question for centuries. People of antiquity believed that this color is a favorite for Zeus and Jupiter. At one time, explanations of the color of the sky excited such great minds as Leonardo da Vinci and Newton. Leonardo da Vinci believed that when combined, darkness and light form a lighter shade - blue. Newton associated the blue color with the accumulation of a large number of water droplets in the sky. However, it was not until the 19th century that a correct conclusion was reached.

Range

In order for a child to understand the correct explanation with the help of the science of physics, he first needs to understand that a beam of light is particles flying at high speed - segments of an electromagnetic wave. In a stream of light, long and short rays move together, and are perceived by the human eye together as white light. Penetrating in the atmosphere through the smallest drops of water and dust, they scatter into all colors of the spectrum (rainbow).

John William Rayleigh

Back in 1871, the British physicist Lord Rayleigh noticed the dependence of the intensity of scattered light on the wavelength. Scattering of the Sun's light by irregularities in the atmosphere explains why the sky is blue. According to Rayleigh's law, blue sun rays scatter much more intensely than orange and red ones, since they have a shorter wavelength.

The air near the surface of the Earth and high in the sky is made up of molecules, causing sunlight to scatter high in the air. It reaches the observer from all sides, even from the most remote ones. The spectrum of scattered air light differs markedly from direct sunlight. The energy of the first has been moved to the yellow-green part, and the second to the blue.

The more direct sunlight is scattered, the colder the color will appear. The strongest scattering, i.e. The shortest wavelength is for violet, the longest wavelength is for red. Therefore, during sunset, the distant parts of the sky appear blue, and the closest ones appear pink or scarlet.

Sunrises and sunsets

During sunset and dawn, a person most often sees pink and orange shades in the sky. This is because light from the sun travels very low to the surface of the earth. Because of this, the path that light needs to travel during sunset and dawn is much longer than during the day. Due to the fact that the rays travel the longest path through the atmosphere, most of the blue light is scattered, so the light from the sun and nearby clouds appear reddish or with a pink tint to a person.

"Why the sky is blue?" - This is one of the most popular children's questions. But, unfortunately, not every adult can answer it. First, you need to have knowledge of physics. And, secondly, to be able to explain complex information to a small child in an accessible way.

Let us try to briefly formulate the answer to this question from the point of view of physics, but in simple language.

Why the sky is blue can be explained in several ways:

Why the sky is blue - video for children

On the Internet there are special videos and presentations for children on the topic: “Why is the sky blue?”. They are created taking into account age, so the answer to the question will be simple and clear. Of course, any video must first be previewed. After watching, the child can play the game. Ask him to become a teacher and explain to you why the sky is blue. Thus, you can find out how the baby learned the information. In addition, the opportunity to be an adult will give the child a lot of positive emotions.

For example, some videos below.

Why the sky is blue - detailed explanation

Informative short cartoons for children about why the sky is blue

What color is the sun, sky and clouds? Explanation for children in terms of physics

Why is the sky blue in terms of physics?

Many researchers have tried to answer this question. However, only at the end of the 19th century, D. Rayleigh was able to give this phenomenon the best explanation. The sun studies rays of pure transparent light. Therefore, we should also see the sky as white. But on the way to the earth, the sun's rays change their shade. This is possible due to the fact that white color includes a spectrum of 7 shades. It is thanks to their combination that the white color is obtained.

Why does the white color break up into shades, but we see only blue? At first, scientists explained this by the special composition of the air, which consists of a large number of chemical components. The earth's atmosphere also contains water vapor, ice crystals, dust particles, and so on. Ozone is formed in the uppermost layer.

According to the physicists who were the first to deal with this issue, ozone and water molecules absorb red rays, while blue rays pass through. However, after making precise calculations, the scientists ruled out that explanation, because there simply isn't enough ozone and water in the atmosphere to make the sky blue.

After 70 years, the scientist D. Tyindall suggested that the light is scattered due to dust and other particles present in the air. Blue light is scattered the least, which is why the phenomenon of a blue sky is created. The scientist argued that if the air were absolutely clean, then the sky would also seem white to us.

Soon, D. Rayleigh also revised his attitude to why the sky is blue. He suggested that the sky is colored blue not by particles of smoke, smog or dust, but directly by the air. Some of the rays reach the Earth without changing their color. But most of it still comes into contact with gas molecules and is absorbed by them.

In such an interaction, the molecules are filled with energy, excited, and again emit energy in the form of photons. The resulting photons can be of any color. They scatter in any direction. The color of the rays will then depend on the predominance of quanta of one or another shade. During the collision of photons and gas molecules, there are 8 blue quanta for one secondary red quantum. From this, the scientist concluded: we see the sky blue due to the refraction of color due to gas molecules.

How to explain to a child why the sky is blue?

For a small child, information about a question of interest to him should be presented as simply and accessible as possible. The best option is to resort to the help of fairy tales and metaphors. The smaller the child, the less scientific information he needs to be given. Consider how to explain to a child why the sky is blue at different ages.

Explanation for a child 2-3 years old

It will be difficult for a kid of this age to understand information about spectra, wavelengths and other intricacies of physics. Tell your child that there are many different water bodies on our Earth: rivers, seas, lakes. Be sure to show him in the pictures. When it is warm and sunny outside, the water is reflected in the sky, as if in a mirror. The water in the river and the lake is blue, so the sky is also blue. You can take any blue object and demonstrate how it is reflected in the mirror. Better yet, go to the pond and bring a mirror to it. The child will see real confirmation of your words.

Explanation for a child 3-4 years old

To a child of this age to explain everything more realistically. You can tell him that the white color is not very simple. It includes 7 other shades at once: orange, green, blue, purple, blue, yellow and red. Show a picture of a rainbow. All rays "get" to the ground through a dense layer of air, like through a sieve. Each sunbeam is splashed and split into separate parts along the way. However, the blue color is the most persistent, so it persists. It is he who paints the sky blue.

Explanation for a child 4-5 years old

The air seems transparent to us. But he's only up close. But his real color is blue. Invite the child to look at the sky. Explain to the baby that the air is very dense, which is why it seems blue to us from afar. To visually demonstrate this effect to him, take a piece of a plastic bag. Fold the package several times and give it to the baby. Let him look through it at the sun and make sure that the rays have changed transparency and hue.

Explanation for a child 5-6 years old

Air is a mixture of different particles (steam, dust, gas). They are very small, so it is not easy to see them. This can only be done with a microscope. The rays of the sun consist of 7 shades. Making their way through the air stream, they collide with small particles, and therefore disintegrate. But blue is the most persistent color, which is why the firmament seems to us just like that.

And here is another answer. The sun's rays appear short and yellow to us. The air that is around us is made up of a huge number of particles that we cannot see. When the sun sends its rays to the Earth, not all of them reach the surface. The rays of blue are the shortest, they do not have time to get to us, so they dissolve along the way and turn blue.

What to answer the child if he asked a question unexpectedly?

Little “why” ask their parents several dozen questions a day. It is not always possible to answer them truthfully and easily. After all, not every parent reads encyclopedias about technology, the world around them and other things that are so interesting to the baby. Walking away from the conversation is not the best option. What to do in this situation?

If the question "has got you into a dead end," tell your child that you will answer it later. But your promise must be kept, so that the baby does not lose the desire to know this world. It is useful to have a children's encyclopedia on hand, which will provide answers to many questions.

If the child is interested in information about the sky, stars, planets, etc., go with him to the planetarium. Experienced guides will simply and clearly tell the little researcher about the history of the appearance of the Earth, stars, clouds, the solar system, etc.

When choosing information and answering a child’s question, be guided by his age. If the search for an answer to a child's question took a lot of time and made you "sweat", be sure to thank the baby for the fact that you also learned a lot of new things.

Why is the sunset red?

Red rays are the longest. In addition, they are the least scattered by gas molecules. During the day, the sun rises high above the earth. The sun's rays are directed vertically. But in the evening, the heavenly body descends beyond the horizon and illuminates the earth at an angle. That is why the rays have to travel a longer distance than in the daytime. The blue-blue spectrum is absorbed in a dense layer of the atmosphere and does not reach the surface. But the red-yellow rays, due to their length, reach the Earth and paint the sky red.

Why are clouds white?

Why the sky is blue became clear. But a natural question immediately arises: “Why are clouds white?”. To give the best answer, you need to understand how they are formed. Moist air, which contains invisible vapor, heats up in the ground area and rises. At the top, atmospheric pressure is less than near the ground, so the air expands and cools.

As soon as the temperature of the steam reaches a certain temperature, its droplets condense around solid particles and grains of dust that are in the atmosphere. This is how clouds form. Water particles are quite small, but they are much larger than gas molecules. When the rays of the sun meet air molecules, they are scattered. And if with water drops, then they are reflected. At the same time, its natural color is preserved, so it also colors cloud molecules with white.

When the wind throws a white fluffy transparent cape over the beautiful blue sky, people begin to look up more and more often. If at the same time it also puts on a large gray fur coat with silver threads of rain, then those around hide from it under umbrellas. If the outfit is dark purple, then everyone is sitting at home and wanting to see the sunny blue sky.

And only when such a long-awaited sunny blue sky appears, which puts on a dazzling blue dress decorated with golden sunbeams, people rejoice - and smiling, leave their homes in anticipation of good weather.

The question of why the sky is blue has puzzled people's minds since time immemorial. Greek legends have found their answer. They claimed that this shade is given to it by the purest rock crystal.

At the time of Leonardo da Vinci and Goethe, they were also looking for an answer to the question why the sky is blue. They believed that the blue color of the sky is obtained by mixing light with darkness. But later this theory was refuted as untenable, since it turned out that by combining these colors, you can get only the tones of the gray spectrum, but not the color one.

After some time, the answer to the question of why the sky is blue was tried to be explained in the 18th century by Mariotte, Bouguer and Euler. They believed that this was the natural color of the particles that make up the air. This theory was popular even at the beginning of the next century, especially when it was found that liquid oxygen is blue, and liquid ozone is blue.

The first more or less sensible idea was given by Saussure, who suggested that if the air were completely clean, without impurities, the sky would turn out to be black. But since the atmosphere contains various elements (for example, steam or water drops), they, by reflecting color, give the sky the desired shade.

After that, scientists began to get closer and closer to the truth. Arago discovered polarization, one of the characteristics of scattered light that bounces off the sky. In this discovery, the scientist was definitely helped by physics. Later, other researchers began to look for the answer. At the same time, the question of why the sky is blue was so interesting for scientists that a huge number of different experiments were carried out to find it out, which led to the idea that the main reason for the appearance of the blue color is that the rays of our Sun simply scatter in the atmosphere.

Explanation

Rayleigh, a British researcher, was the first to create a mathematically sound answer to molecular light scattering. He suggested that light is scattered not because of the impurities that the atmosphere possesses, but because of the air molecules themselves. His theory was developed - and here are the conclusions scientists came to.

The sun's rays make their way to the Earth through its atmosphere (a thick layer of air), the so-called air shell of the planet. The dark sky is completely filled with air, which, despite being completely transparent, is not a void, but consists of gas molecules - nitrogen (78%) and oxygen (21%), as well as water droplets, steam, ice crystals and small pieces of solid material (for example, particles of dust, soot, ash, ocean salt, etc.).

Some rays manage to freely pass between gas molecules, completely bypassing them, and therefore reach the surface of our planet without changes, but most of the rays collide with gas molecules that come into an excited state, receive energy and release multi-colored rays in different directions, completely coloring the sky, resulting in a sunny blue sky.

White light itself consists of all the colors of the rainbow, which can often be seen when it is broken down into its component parts. It so happens that blue and violet colors scatter the most because they are the shortest part of the spectrum, since they have the shortest wavelength.

When mixed in an atmosphere of blue and purple with a small amount of red, yellow and green, the sky begins to "glow" blue.

Since the atmosphere of our planet is not homogeneous, but quite different (it is denser near the Earth's surface than at the top), it has a different structure and properties, we can observe blue overflows. Before sunset or sunrise, when the length of the sun's rays increases significantly, blue and purple colors are scattered in the atmosphere and absolutely do not reach the surface of our planet. The yellow-red waves successfully reach, which we observe in the sky during this period of time.

At night, when the sun's rays, falling on a certain side of the planet, have no opportunity, the atmosphere there becomes transparent, and we see the "black" space. This is how astronauts above the atmosphere see it. It is worth noting that the astronauts were lucky, because when they are over 15 km above the earth's surface, during the day they can simultaneously observe the Sun and stars.

Sky color on other planets

Since the color of the sky is largely dependent on the atmosphere, it is not surprising that on different planets it is of different colors. Interestingly, the atmosphere of Saturn is the same color as on our planet.

Very beautiful aquamarine skies of Uranus. Its atmosphere consists mainly of helium and hydrogen. It also contains methane, which completely absorbs red and scatters green and blue. The blue skies of Neptune: in the atmosphere of this planet there is not as much helium and hydrogen as ours, but there is a lot of methane, which neutralizes the red light.

The atmosphere on the Moon, a satellite of the Earth, as well as on Mercury and Pluto, is completely absent, therefore, light rays are not reflected, so the sky is black here, and the stars are easily distinguishable. The blue and green colors of the sun's rays are completely absorbed by the atmosphere of Venus, and when the Sun is near the horizon, the skies here are yellow.

In the article you can find out a simple explanation of the blue (with shades) color of the sky. After all, the question is actually very interesting, especially for children. Let's find a simple explanation for this phenomenon, although it is not as easy to do as it seems.

The human eye can only see three colors, not as is commonly believed that the eye can see many colors. These are red, green and blue.

Introduction: why is the sky blue?

Photographic film is built exactly on the above principle. There are three surfaces in the frame, each perceives only its own light, changing color in accordance with the absorption of rays. When the light of an electric lamp passes through it, creating an image on the screen, we see millions of shades, due to their mixing in various proportions. Technology imitates nature. After all, the human eye works exactly on this principle. It contains such biological elements that react only to their own color.

And when these colors are mixed in the human brain, we observe the color that reflects the object. For example, when blue and yellow are mixed, green is formed. An interesting fact is that we see yellow as paler than blue or green. This is a color trick of the human eye. The black and white photo clearly shows that the yellow is not pale at all.

We see only the color that is reflected from the surface. For example, the skin of Europeans is white, while that of Africans is almost black. This only means that in some skin coloration is able to reflect all colors, which occurs when all three primary colors are mixed, while in others it can only absorb. After all, we see only reflected rays. Ideally, of course, absolutely white and absolutely black skin does not exist. But I wrote it to make it clearer.

Answer: Why is the sky blue?

“But what about the sky? - the reader, now wise by experience, will say, - is the sky capable of reflecting the rays? Agree. It passes them through, but the air surrounding the Earth, stretching for a thousand kilometers above the surface, does not pass all the rays. He partially delays red and green, and blue misses. Therefore, looking into the sky, we see it blue, blue, and in bad weather purple and even lead. The human eye, unlike various objects, practically does not reflect light, but only absorbs with its cones and rods that are sensitive to a certain color. And since the blue spectrum of rays predominates, we see it.

The sky looks blue because air scatters short wavelength light more than long wavelength light.

But this does not mean that the sky cannot be red, crimson, scarlet or pink. At least his parts. If you watch it at sunrise or sunset, you will be amazed by the riot of bloody colors. But you will not see the green, yellow sky. Why is this happening? At sunrise or sunset, the sun does not penetrate the atmosphere from above, but at a very small angle, so we see a bloody dawn or a crimson sunset.

The world around us is full of amazing wonders, but we often do not pay attention to them. Admiring the clear blue of the spring sky or the bright colors of the sunset, we do not even think about why the sky changes color with the change of time of day.


We are accustomed to bright blue on a fine sunny day and to the fact that in autumn the sky becomes hazy gray, losing its bright colors. But if you ask a modern person why this happens, then the vast majority of us, once armed with school knowledge of physics, are unlikely to be able to answer this simple question. Meanwhile, there is nothing complicated in the explanation.

What is color?

From a school course in physics, we should know that differences in the color perception of objects depend on the wavelength of light. Our eye can only distinguish a fairly narrow range of wave radiation, with blue being the shortest and red being the longest. Between these two primary colors lies our entire palette of color perception, expressed by wave radiation in different ranges.

A white sunbeam actually consists of waves of all color ranges, which is easy to verify by passing it through a glass prism - you probably remember this school experience. In order to remember the sequence of changing wavelengths, i.e. the sequence of colors in the spectrum of daylight, invented a funny phrase about a hunter that each of us learned in school: Every Hunter Wants to Know, etc.


Since red light waves are the longest, they are the least susceptible to scattering during transmission. Therefore, when you need to visually highlight an object, they use mainly red color, which is clearly visible from afar in any weather.

Therefore, a stop signal or any other warning light is red, not green or blue.

Why does the sky turn red at sunset?

In the evening hours before sunset, the sun's rays fall on the surface of the earth at an angle, and not directly. They have to overcome a much thicker layer of the atmosphere than in the daytime, when the surface of the earth is illuminated by the direct rays of the Sun.

At this time, the atmosphere acts as a color filter, which scatters the rays of almost the entire visible range, except for the red ones, which are the longest and therefore most resistant to interference. All other light waves are either scattered or absorbed by water vapor and dust particles present in the atmosphere.

The lower the sun drops in relation to the horizon, the thicker the layer of the atmosphere the light rays have to overcome. Therefore, their color is increasingly shifted towards the red part of the spectrum. A folk sign is associated with this phenomenon, saying that a red sunset portends a strong wind the next day.


The wind originates in the high layers of the atmosphere and at a great distance from the observer. Oblique solar rays highlight the outlined zone of atmospheric radiation, in which there is much more dust and vapor than in a calm atmosphere. Therefore, before a windy day, we see a particularly red, bright sunset.

Why is the sky blue during the day?

Differences in the length of light waves also explain the pure blue of the daytime sky. When the sun's rays fall directly on the surface of the earth, the layer of the atmosphere they overcome has the smallest thickness.

Scattering of light waves occurs when they collide with gas molecules that make up air, and in this situation, the short-wavelength light range is the most stable, i.e. blue and purple light waves. On a fine windless day, the sky acquires amazing depth and blueness. But why do we then see blue and not purple sky?

The fact is that the cells of the human eye, which are responsible for color perception, perceive blue much better than purple. Yet purple is too close to the edge of the perceptual range.

That is why we see the sky as bright blue if there are no scattering components in the atmosphere, except for air molecules. When a sufficiently large amount of dust appears in the atmosphere - for example, in a hot summer in a city - the sky seems to fade, losing its bright blue.

Gray sky of bad weather

Now it is clear why the autumn bad weather and winter slush make the sky hopelessly gray. A large amount of water vapor in the atmosphere leads to the dispersion of all components of the white light beam without exception. Light rays are crushed in the smallest droplets and water molecules, losing their direction and mixing over the entire range of the spectrum.


Therefore, light rays reach the surface, as if passed through a giant diffuser. We perceive this phenomenon as a grayish-white color of the sky. As soon as moisture is removed from the atmosphere, the sky turns bright blue again.