In the section on the question Why the clouds are white black storm clouds? given by the author Natalia Natalia the best answer is In ordinary clouds, there are usually few drops of water, rather there are not drops, but very small particles. Sunlight is reflected from the outside of such particles. With such a reflection, refraction does not occur, respectively, the reflected light remains white. AT thunderclouds(even in large dense clouds) there is much more water, correspondingly more light is absorbed, but it also increases the likelihood that light is reflected to the point that it is reflected upward from the ground - therefore clouds from below appear dark ... In the clouds (clouds) there is nothing except water (in the form of steam or ice crystals), in fact, this is the essence of the cloud / cloud. Blacker clouds can also appear due to the relatively low "flight" height, and the sun can shine more to the side than to the center from above.

Answer from Pmuuuuuuuuuets mkemeuts[newbie]
because the rays of the sun do not pass through it

Answer from Leonid[guru]
It's all about the size of the CLOUD ITSELF, and last but not least, the size of the water droplets. Just if you look closely, even ordinary clouds come in different shades - with a transition from white to gray. That is, it is clear that 1) white differs from gray simply by the amount of light reaching the bottom of the cloud, and 2) the key factor here is how much sunlight needs to go through the cloud. The thicker the cloud thunderclouds- this is several kilometers of thickness!), the more light is scattered / absorbed. This means that the less it reaches the lower boundary of the cloud. So, the darker it looks from below. If you look at a thundercloud from above (it’s easy from an airplane), then all the clouds are white there, because reflection occurs in the same way, and absorption, when you look from the SIDE OF THE LIGHT SOURCE, does not affect.

Answer from Lexus Fleet[guru]
Since white clouds are mostly made up of large water droplets, the sunlight passing through them is not separated into its constituents and remains white. Thunderclouds are denser and reflect the rays of light back up, thus it seems to us that the clouds are black.

Answer from Fourth Dimension[guru]
The size of the water droplets in the cloud is large enough, and light is reflected from their outer surface. With this reflection, the light does not decompose into its component colors, but remains white. Very dense clouds appear black because they let through little sunlight- it is either absorbed by the water droplets in the cloud or reflected upward.

Do you know how clouds appear, why some become clouds, while others remain lush snow-white lambs? Our amazing novelty “Clouds. We observe and study ”- it is for true lovers of clouds and whys of all ages.

Why are clouds white and clouds black, how are clouds and mirages born, and is it true that there is a Society of Cloud Lovers? We tell.

This is the motto of The Cloud Appreciation Society - international organization founded in 2004 in England by Gavin Praetor-Pinney. It brings together 30,000 cloud lovers from 94 countries. These are people who dream of discovering the beauty of the cloudy sky to others. Join now!

You just need to lie on the grass and watch the clouds. Or just look up. Whenever you want.

How is a cloud born?

When hot air mixes with cold air, it cools down and can reach the dew point. Condensation occurs. Water vapor, settling on a particle in the air, turns into drops or ice crystals, which, gathering together, form a cloud.

Most often, this happens when hot air rises from the ground and meets cold air above in the atmosphere. A cloud-like phenomenon can also be observed near the surface of the earth. Earth or water, heated during the day, cools more slowly than air. When cold night air comes into contact with warm air, fog forms near the surface of the earth or water.

Illustration from the book

Yes, fog also consists of cloud elements. In fact, this is a large cloud lying on the ground.

Why are clouds white and clouds black

If clouds are made of drops, why are they white? Because cloudy elements reflect light: crystals and drops glisten in the rays of the sun. And the smaller the elements in size and the more of them in number, the whiter the cloud.

Grey, bluish and black thunderclouds are composed of the same drops. It's just that they - with strong cloudiness - can cast a shadow on each other (and even on themselves), which is why they seem darker. There are also denser clouds - they consist of large crystals and drops, so the sun's rays cannot penetrate through them. They appear dark and sinister when viewed from the ground.

Illustration from the book

But if you fly over them, for example by plane, they will be absolutely white.

How is a mirage formed?

A cloud forms when warm air rises. This hot updraft is called a thermal. Birds and gliders soar on it.

The thermal can be seen if you look at the paved road on a hot day. It seems that the air above the asphalt trembles, and the road seems to be covered with puddles. This phenomenon is called a mirage.

A mirage can be seen when hot and cold air which have different densities. At the boundary of media with different densities, a beam of light is refracted, and we see a mirage.

Clouds are not just cotton tufts that cover the sun. They are no less beautiful than the stars. After reading this book, you will see for yourself.

Many of us, back in childhood, at least once, but asked a similar question, why the sky blue above us After all, the light that reaches us straight from the Sun is, in fact, white, not blue at all. However, as they grow older, people certainly have not lost interest in this issue. Many would not mind pacifying their curiosity and still find out why the vault of heaven is blue.

Why the sky is blue: physics

Physics will help to delve into all the subtleties of this issue in more detail, where scientists have long figured out the reasons and have thoroughly studied everything. We can only taste the fruits of their hard work.

So, let's start with what distinguishes our planet from others - it is the presence of air that living organisms can breathe. Although its composition includes nitrogen, oxygen, carbon dioxide, water vapor, various dust particles that are constantly in motion, it nevertheless remains absolutely transparent. But on the other hand, sunlight has a huge number of colors, they are familiar to us as the colors of the rainbow. Each of the seven colors has its own wave, ray, and they are all different in length.

In order for sunlight to reach the earth, it needs to break through a huge layer of air. It is during the passage of light through the air that the rays begin to scatter, and this process occurs more intensively precisely with blue. This is explained very simply - the wavelength of blue light is the shortest. This is how, from the point of view of physics, the blueness of the sky is explained.

Physics answered our question "why the sky is blue", but what about the clouds, because they have a white tint, although they are in the air. It would be logical to assume that the rays of sunlight would scatter through the clouds in the same way as when passing through the thickness of the air. But this issue needs to be approached from a slightly different angle.

Clouds, first of all, are the smallest particles of water that have evaporated from the surface of the earth and grouped into a gaseous mass. But no matter how small these particles are, they will still be much larger in size than an air molecule. It is in the size of the molecules that the answer to this question lies.

As we have learned, the sun's rays, penetrating the Earth's atmosphere, encounter an obstacle on their way - air, which can only be overcome by scattering. But with clouds, this method does not work all because of the same size of the molecules. Light, meeting with a micro-droplet of water, is not refracted, but rather reflected from its surface.

This allows sunbeam remain in their original color palette, that is, white, while coloring the cloud molecules white.

One of distinguishing features man is curiosity. Probably everyone, as a child, looked at the sky and wondered: “why is the sky blue?”. As it turns out, the answers to such seemingly simple questions require some knowledge in the field of physics, and therefore not every parent will be able to correctly explain to the child the reason for this phenomenon.

Consider this issue from a scientific point of view.

The wavelength range of electromagnetic radiation covers almost the entire spectrum of electromagnetic radiation, which includes radiation visible to humans. The image below shows the dependence of the intensity of solar radiation on the wavelength of this radiation.

Analyzing this image, one can note the fact that visible radiation is also represented by uneven intensity for radiation of different wavelengths. So a relatively small contribution to visible radiation makes the violet color, and the largest - blue and green colors.

Why the sky is blue?

First of all, we are led to this question by the fact that air is a colorless gas and should not emit blue light. It is obvious that the cause of such radiation is our star.

As you know, white light is actually a combination of radiation of all colors of the visible spectrum. Using a prism, you can explicitly decompose light into the entire range of colors. A similar effect occurs in the sky after rain and forms a rainbow. When the sunlight hits earth's atmosphere, it begins to dissipate, i.e. radiation changes its direction. However, the peculiarity of the composition of air is such that when light enters it, radiation with a short wavelength is scattered more than long-wave radiation. Thus, taking into account the spectrum shown earlier, it can be seen that red and orange light will practically not change its trajectory, passing through the air, while violet and blue radiation will noticeably change their direction. For this reason, a kind of "wandering" short-wave light appears in the air, which is constantly scattered in this medium. As a result of the described phenomenon, it seems that short-wave radiation of the visible spectrum (violet, blue, blue) is emitted at every point in the sky.

The well-known fact of the perception of radiation is that the human eye can catch, see, radiation only if it directly hits the eye. Then, looking at the sky, you will most likely see the shades of that visible radiation, the wavelength of which is the smallest, since it is it that scatters best in the air.

Why don't you see a distinctly red color when you look at the Sun? Firstly, a person is unlikely to be able to carefully examine the Sun, since intense radiation can damage the visual organ. Secondly, despite the existence of such a phenomenon as the scattering of light in the air, nevertheless, most of the light emitted by the Sun reaches the surface of the Earth without being scattered. Therefore, all the colors of the visible spectrum of radiation are combined, forming light with a more pronounced white color.

Let us return to the light scattered by the air, the color of which, as we have already determined, should have the smallest wavelength. Violet has the shortest wavelength of visible radiation. next comes blue, and a slightly longer wavelength is blue. Taking into account the uneven intensity of the solar radiation, it becomes clear that the contribution of the violet color is negligible. Therefore, the largest contribution to the radiation scattered by the air is blue, followed by blue.

Why is the sunset red?

In the case when the Sun hides behind the horizon, we can observe the same long-wave radiation of red-orange color. AT this case light from the Sun must travel a noticeably greater distance in the Earth's atmosphere before reaching the observer's eye. In the place where the radiation of the Sun begins to interact with the atmosphere, blue and blue colors are most pronounced. However, with distance, shortwave radiation loses its intensity, as it is significantly scattered along the way. While longwave radiation does an excellent job of overcoming such large distances. This is why the Sun is red at sunset.

As mentioned earlier, although long-wave radiation is weakly scattered in air, there is still scattering. Therefore, being on the horizon, the Sun emits light, from which only the radiation of red-orange hues reaches the observer, which has time to dissipate somewhat in the atmosphere, forming the previously mentioned "stray" light. The latter paints the sky in variegated shades of red and orange.

Why are clouds white?

Speaking of clouds, we know that they are made up of microscopic droplets of liquid that scatter visible light almost uniformly, regardless of the wavelength of the radiation. Then the scattered light, directed in all directions from the droplet, is scattered again on other droplets. In this case, the combination of radiation of all wavelengths is preserved, and the clouds "glow" (reflect) in white.

If the weather is cloudy, then solar radiation reaches the Earth's surface in an insignificant amount. In case of big clouds, or a large number of them, some of the sunlight is absorbed, because the sky dims and takes on a gray color.

The beauty of the sky has been depicted more than once by artists, described by writers and poets, even people who are very far from art look into this alluring abyss, admire it, not finding either words or sufficient emotions to express those feelings that stir the soul and mind. Height attracts a person in any role, it is beautiful with its crystal blue surface, no less attractive are its seething streams of white-gray clouds, replaced by light patches cirrus clouds or lush cumulus "lambs". And no matter how melancholic the cloudy sky may look, enveloping with its depth, deafening and crushing with its whole mass, it also causes a storm of emotions and experiences, casting thoughts on a special wave.

Beauty is seen by the beholder

Each person perceives the world differently. For some, it is gloomy and gray, while others, on the contrary, see only a blooming, green, full of colors planet. We also value the heavens above our heads differently. If we take into account a person with ordinary color perception, then he will see the sky as it is commonly believed - blue, gray, pinkish at sunset, smoky-gray at dawn.

In fact, these colors are just what our eyes and brain can convey to us. It is easiest for people to perceive an overcast sky as gray. In clear weather, we have endless azure above our heads, but in fact, the atmospheric dome is closer to a purple hue, if you look at it from the side of the Earth.

In this publication, we will find out why the sky on a cloudy day is gray and what determines the saturation of this color, we will also find out how its color changes throughout the day and year and what affects these processes.

Bottomless ocean above

Over territory European countries firmament in warm season years usually strikes with its saturated. Sometimes you can say about it that it is blue-blue. However, if you give at least one day to what is happening above our heads and carefully observe natural processes, you can notice a gradation of color that changes very much from the moment the sun rises until the moment it completely sets.

In summer, the sky seems so clear and visually high due to low humidity, the absence of a large number of clouds, which, accumulating water, gradually fall closer to the ground. In clear weather, our gaze does not even look hundreds of meters ahead, but at a distance equal to 1-1.5 km. Therefore, we perceive the sky as high and bright - the absence of interference in the path of light rays in the atmosphere ensures that they are not refracted, and the eyes perceive its color as blue.

Why does the sky change color

Such a change is described by science, though not as picturesquely as by writers, and is called the diffuse radiation of the sky. If we speak in a simple and accessible language for the reader, then the processes of color formation of the heavens can be explained as follows. The light that the sun emits passes through the air gap around the Earth, it scatters it. This process is easier with short wavelengths. During the maximum rise of the celestial body above our planet, at a point located outside its direction, the brightest and most saturated blue color will be observed.

However, when the sun sets or rises, its rays pass tangentially to the surface of the Earth, the light emitted by them needs to travel a longer path, which means that they are scattered in the air to a much greater extent than during the day. As a result, a person perceives the sky in pink and red colors in the morning and evening. This phenomenon is most visible when there is an overcast sky above us. Clouds and clouds then become very bright, the glow of the setting sun colors them into stunning

thunder steel

But what is an overcast sky? Why does it become like this? This phenomenon is one of the links in the water cycle in nature. Rising up in the form of steam, water particles enter the atmospheric layer with a lower temperature. Accumulating and cooling at high altitude, they combine with each other, turning into drops. At the moment when these particles are still very small, and beautiful white Cumulus clouds. However, the larger the drops become, the more gray there is in the clouds.

Sometimes, looking at the sky, through which these huge “lambs” are swimming, you can see that one part of them is painted gray, while others even acquire a steel thunder hue. This transformation is explained by the fact that the drops in the clouds have different sizes and shapes, so they refract light in different ways. When the sky is completely overcast, it is completely painted in mouse-gray tones, only white light reaches us.

Vast smoky spaces

There are days when the gray overcast sky has not a single gap. This happens when the concentration of clouds and clouds is very high, they envelop the entire visual space above. Sometimes they are perceived as a huge pressing mass, ready to fall on the head. Moreover, this phenomenon is most characteristically demonstrated in autumn and winter, when the air temperature is low, but the humidity, on the contrary, is high and is at the level of 80-90%.

On such days, the clouds are very close to the earth's surface, they are located only a hundred or two meters from it. The description of an overcast sky often has melancholic and depressing notes, and this is most likely due to precisely the sensations that arise when you feel alone with this gloomy hulk, ready to fall down on you with rain and cold.

And everything could be different ...

What tones the sky plays depends on the intensity of light radiation and the wavelength reaching the planet, so in winter even in clear days he is bluish blue. But the closer spring is and the higher the location of the sun, the brighter its blue, especially on days when the haze dissipates in the upper atmosphere, distorting the light.

Scientists have found that on other planets the sky may not have the usual blue and gray colors for us; on Mars, for example, it is pink even at the height of daylight.