Experience why snow is white. Why is snow white? What is snow

The question of why snow is white is familiar to every person since childhood. But not all children, and even adults, know the correct answer why small snowflakes are blue or green. Everyone knows that snow is frozen water, or rather ice. But since ice is transparent and capable of transmitting light through it, why are the snowdrifts that cover the ground far from being opaque, but having a very distinct color?

In past centuries, when there were no such developed technologies that made it possible to study all natural processes, scientists struggled with the question of why snow is white. However, the answer was never found. Only when the entire process of creating snow from the very beginning to the end became clear, some guesses about the “snow-white cover” appeared.

It all starts with the fact that under the influence of warm sunlight, water from rivers, lakes and seas turns into steam and rises high into the atmospheric layers where permafrost predominates. Steam, in turn, having the properties of liquid water, due to the high subzero temperature, begins to solidify and turns into ice crystals. These are snowflakes that are ready to fall to the ground over time. For the most part, in places where it is warm, pieces of ice fall in the form of wet precipitation, melting while still in the air.

How snow is formed is now clear, but why, when it falls to the ground, does it suddenly turn white?

The question is relevant, because snowflakes, while still in the air, have the same properties of transmitting light through themselves as ice. But one thing should not be forgotten: the edges of the lenses are located at chaotic angles, which randomly refracts sunlight, and they do not absorb it, but transmit it further. And when the snowflakes gather into a “snow-white blanket,” the rays of the sun, refracting from one snowflake to another, pass through the entire cover. Many rays are reflected into our eyes, which is why often when you look at the snow you have to squint. Sunlight is too bright to be perceived by unprotected eyes.

But it is not entirely correct to ask the question of why snow is white, because it is not always “clean”. People see him like this only when the rays of sunlight fall on him. For example, at sunset it may turn pinkish, and in the light of a yellow lantern it may be slightly grayish, just like in cloudy weather.

Changes in the color of the snow are also possible in the air layers, when the snowflakes are just beginning to “fall to the ground.” For example, various pollen from trees and flowers, dust from arid land rises and meets grains of snow in air currents. If such snow does not have time to melt and is preserved by a small cover, then its color will certainly have different shades. Under these conditions, asking why the snow is white is inappropriate.

However, snowflakes are not just pieces of ice flying chaotically downwards, which for unknown reasons decided to cover the ground with a “white blanket”.

The main properties of snow are to protect the earth from the cold by covering it with a thick blanket. Yes, yes, it would seem paradoxical to warm and preserve the crop and soil from freezing, but it is true. It has poor thermal conductivity, allowing it to contain heat escaping from the ground and create a “thermal cushion”. It’s not for nothing that igloos were built by residents of the far north. Ice, like snow, retains heat well, creating unique favorable conditions for life.

You should not lose sight of the fact that the size of snowflakes depends on the weather conditions outside the window. If it’s cold enough, the ice flakes are small, almost invisible. But if the sun is shining and the air is not so cold, then the size of a snowflake can reach several centimeters. So, in 1944, ten-centimeter “grains of ice” fell in Moscow.

Our Ksyusha has become a bitch. And mom and dad became walking mini-encyclopedias. Therefore, to help parents of the same children, we decided to create a new section “” and publish answers to the most common children’s questions in it. We will try to adapt all the answers as much as possible for preschool children, so that it is easier for parents to explain to them the complex laws of nature.

It's winter now and therefore, of course, questions about why are in the TOP :) That's why we publish our answers to the snowiest questions.

What is snow?

Snowflakes are formed in the same way as raindrops: water evaporates from the seas and oceans and rises to the sky, where it cools and collects into droplets. When it is very cold, water droplets freeze into ice crystals. They fall to the ground in the form of snow. The melted snow evaporates or flows into streams, from where it again begins its path to the sky.

Why is snow white?

If snowflakes and droplets are of the same nature, then why are the droplets transparent and the snowflakes white? The fact is that each individual snowflake is transparent in itself, but together they fall to the ground in a chaotic manner and form a loose mass. Snowflakes lie to each other at different angles. Sunlight is reflected first in one snowflake, then in another, and so on, until it is directed back. It turns out that the snow completely reflects sunlight, and since the rays of the sun are white, the snow is white. If the rays of our Sun were yellow and red, then the snow would also be yellow or red. At sunset or sunrise, when we see the pink rays of the sun, the snow also turns pink.

Why do snow and ice melt from salt?

Snow and ice are water that freezes (becomes solid) at 0 degrees Celsius. If you add salt to water, you get a salt solution that freezes at temperatures below 0. If you sprinkle ice or snow with salt, we will make them melt, since salt dissolves in water and lowers its freezing point.

First, the ice around the salt crystal will melt, and then the melting process will spread further from this point.

Which snow melts faster?

Dirty snow melts faster because:

1. There are also salts in the mud, which speed up the process of snow melting.
2. Mud is usually dark, which means it absorbs the sun's rays and, as a result, quickly heats up, warming the snow in its wake.

Is it possible to eat snow?

Snow tends to collect dust. City dust, in addition to ordinary natural dirt and bacteria, contains many heavy metals and other toxic substances that are very dangerous for humans. By eating snow, a person absorbs all these toxic substances and puts his life at risk of poisoning.

High in the mountains, pure snow falls without dangerous impurities, but such water is also unhealthful for the body, since it lacks the most important salts that are usually found in drinking water. There is only one conclusion: eating snow is not only unhealthy, but also dangerous to health.

Are there any identical snowflakes in the world?

More than a hundred years ago, when the first cameras first appeared, one man nicknamed “Snezhika” decided to photograph snowflakes under a microscope. He took 5,000 pictures, but not a single snowflake pattern was repeated. Many years have passed, and scientists are still arguing whether there are identical snowflakes. They even created 2 twin snowflakes in their laboratory, but this still did not put an end to their dispute. Having started another study, scientists came to the conclusion that snowflakes may differ not only in their external pattern, but also in their internal structure. This means that even if snowflakes are identical in appearance, most likely their internal structure is still different.

Have you ever wondered why snow is white? After all, when snow melts, it turns into water, and the water is clear. Why is snow white?

A little about color

Different things have different colors. Visible light from the Sun or any other light source consists of many wavelengths. Our eyes perceive different wavelengths as different colors.

Different objects have different colors because the individual particles (molecules and atoms) that make up the object have different vibrational frequencies.

When light interacts with an object, the wavelengths that the object reflects or absorbs determine what color our eyes perceive. When an object reflects all wavelengths of light from the Sun that are in the visible spectrum, the object appears white.

When we see a fire truck, it is red because the paint on it reflects certain wavelengths in the red region of the visible spectrum and absorbs other wavelengths.

If we look at the water, it is transparent. This means that wavelengths of light pass through it rather than being reflected back into your eyes.

If you look at an individual snowflake, it is also almost transparent. But when we see snow, that is, a large concentration of snowflakes, then all the light is reflected and does not pass through them. And we see snow in white.

The key factor here is the way light interacts with the mass of complex snowflakes and air that make up the snow. Snowflakes have complex and varied shapes. When light hits a snowflake (ice crystal), it meets a bend and hits another ice crystal, then another, and so on. The process continues until the light reflects off the snow rather than passing straight through it to the ground.

If there is dirt in the snow, then some of the waves will be absorbed, and we will see this dirt. But if the snow is fresh, then most of the light waves will eventually be reflected and we will see snow-white snow.

You may have noticed that sometimes snow can also have a bluish or blue tint. Snow is white when light is reflected only a small number of times by ice crystals without penetrating very deeply into the snow. If we look at a small pile of snow, it will appear white because almost all visible light is reflected.

The situation is different for light that is not reflected, but penetrates into the snow. When this light penetrates the snow, the ice crystals scatter a large amount of light. The deeper the light penetrates, the more scattering occurs.

We see light from the upper layers (up to about 1 cm), while in the lower layers the light is scattered and absorbed. For light that penetrates deeper, the longer wavelengths that exist at the red end of the light spectrum are absorbed, leaving shorter wavelengths on the blue end of the spectrum that are reflected back for us to see.

It can be said that blue light travels most easily through ice. It is important to understand here that spectral selection is associated with absorption, and not with reflection, as is sometimes thought.

In this case, we can talk about snow as a filter that allows or does not allow different colors to pass through. If we have a centimeter layer of snow, then all the light passes through it. If it is a meter or more, then only blue light will pass through it (scatter into it). An analogy can be made with a cup of coffee. When we first pour it, it is light; the more of it, the darker it becomes.

Snow makes winter white, it seems to hide the darkness and dirt of autumn, which is why it brings so much joy. Children especially love him. For them, snow is one of the main winter fun. Children make forts and snowmen out of it, ski and sled on it, or simply wallow in it for hours without any apparent purpose. It’s no wonder that there comes a time when kids begin to ask their parents why the snow is white.

The nature of light and its role

To answer this question comprehensively and clearly, adults must have some knowledge about light, color perception and snow. But we need to start with visible light. Everything around is permeated with electromagnetic waves, but people are able to see only a tiny fraction of them. The visible part of the spectrum consists of waves with a length from 550 to 630 nanometers.

Anything outside this narrow spectrum remains invisible to the human eye. True, waves can be felt by other senses, for example, ultraviolet radiation cannot be seen, but it warms the skin and can even burn it if you stay on a sunny beach for a long time.

Vision is a priceless gift of nature, thanks to which people have the opportunity to create a stable picture of existence and understand the world. However, without light, human vision becomes a useless tool. This is easy to show your child by going into a room where there are no windows, for example, a bathroom. While the light is on, objects around are visible, their colors are distinguishable. But as soon as the light goes out, the room plunges into impenetrable darkness, all things and colors cease to exist for vision until they are illuminated again by the sun, a living fire or an electric light bulb.

Natural phenomena arouse great interest among children. All mothers are faced with simple questions from little whys: “Why is the snow white and the ice transparent?” Logically, snow is a lot of compressed snowflakes consisting of water. Water itself is transparent, which means snow should be invisible. But everything looks different. When you pronounce the word snow, the concept of snow-white immediately pops up. Let's consider from the point of view of physics why snow is white.

Physical mystery

A snowflake consists of microscopic water crystals. Does it really just seem to us that the snowdrift is white? After all, the rainbow is also multi-colored, and this is just an optical illusion. Snow appears snow-white to us when the sun's rays fall on it. Depending on the brightness of the light wave, the color of the snow can be:

• Blue;
• Gray;
• Blue;
• Pink.

For example, when it is cloudy outside, the snow appears gray or blue, and at sunset it appears pink.

It is true that snow is white precisely because of the properties of water. transparent - white snow. A snowdrift is made up of billions of snowflakes, each of which is a crystalline compound of water. The main physical property of water is its ability to absorb red and infrared spectral rays. When the rays pass through the crystals, the light from the sun does not transmit the warm colors of the spectrum, but allows the cool colors to pass through. This is why the color of snow turns from blue to gray.

If the loss of spectral colors does not occur, then the color of the snow appears white.

What about ice?

Ice is also water, only in a different state of aggregation. Then it is transparent and not white? Ice is a crystalline compound. The crystal is always transparent and it doesn’t matter whether it is ice or crystalline salt. An ice block is also a kind of crystal, only large in size. Let's conduct a microscopic examination of the ice.

A snowflake under a microscope is transparent in the light. This is due to the purity and absence of impurities and air bubbles. Letting the sun's rays through, the ice, like a snowflake, will also be transparent.

But a snowdrift is a lot of crystalline snowflakes that reflect the sun's rays. If the surface of the snowflakes were perfectly smooth, then the snow would be transparent. But since the snowflakes fall randomly into the snowdrift, the light is refracted at different angles. This is what gives the snowdrift its white color. No wonder they say that snow seems to be blindingly white. The reflection of sunlight makes us squint against the bright white snow.

If you compare a huge ice floe and a snowdrift, then the rays pass through the ice unhindered, and they are refracted from the snow. If you crush a block of ice, it will turn white, since the water crystals will not be compressed into one whole.

The rays will be refracted and reflected. This is precisely what explains the physical phenomenon, snow is white and ice is transparent. By the way, there are known cases of colored precipitation. Due to chemical impurities, the snow takes on a shade that is unfamiliar to our eyes.