The world around us is amazing. Bogged down in the routine of daily life, we seldom notice it. However, do not know how to form dew, frost, rain and snow, just a shame, because the answer to this question even schoolchildren know.
As dew is formed from the point of view of physics?
The formation of droplets of water in the morning on the grass and plants has long troubled scientists. This issue is Aristotle. However, scientists ' ideas about this natural phenomenon until the XVIII century was erroneous. Considering the forming dew, frost, rain and snow, the researchers believed that this occurs about the same. However, modern science tells us that it is not so. In order to understand how dew is formed, one must first know something about air. And that is an important detail consists in the fact that it contains some moisture. And in the warm air its more than a cold. So in the summer we can see on the leaves of the plants and the grass the dew. The air in contact with a cold surface that leads to condensation of a percentage of the contained moisture. Moreover, the surface temperature must be below a certain value. It is called the "dew point". It depends on the pressure and some other parameters.
Dew or not?
At home you can spend, for example, such an experience. You need to pour water in a glass or metal container. Then need to add ice. However, dew is not formed immediately, but only when the vessel has cooled to a certain temperature. Similarly, in nature. Moist air touches a cold surface, which leads to the formation of drops of dew. The land and trails cool down significantly less than plants, so they can't find her. But not everything we see in the morning on the leaves and the grass is dew. The bulk of the moisture secreted by plants. This process begins a day in order to protect plants from the hot sun. In some regions of the Earth, the dew falls so much that it is used for watering animals.
This is another form of precipitation. To the question about how frost forms, physics provides the following answer: in the process of desublimation gaseous substance (in this case water vapor) goes into the solid state. As we have said, the air initially present moisture. The trees were covered with frost due to the fact that when the thaw comes its evaporation, and then, when the temperature drops, everything freezes. The most suitable place for the formation of beautiful patterns is a rough surface with low conductivity of heat, such as a wooden bench or an open ground. Frost usually appears at night, when there is a light breeze. It helps to ensure that moisture during evaporation in contact with different surfaces. Too much windy weather, on the contrary, prevents the appearance of needles of frost.
How is the snow from a physics standpoint?
Without this atmospheric sludge it is hard to imagine winter in the middle latitudes. Telling how to form dew, frost, rain and snow, you need to understand that the latter represents the ice crystals. They are the result of freezing of water vapor. The cloud contains drops of water. When at low temperatures they freeze, then formed small ice crystals. During the fall they are under the influence of wind "glued" to each other. This explains the beautiful shape of snowflakes. Each of them always has six rays. The angles between them can be 60 degrees or 120 degrees. Such accuracy is connected with the peculiarities of the structure of the water molecule. Two identical snowflakes do not exist. The crunch we hear under your feet, walking through snow-covered trails, is due to the fracture of crystals, which consist of cereals that atmospheric sludge.
What is the color of the snow?
Children love to ask questions about the world. Over time, people cease to wonder at everything around. However, answering the question “how to form dew, frost, rain and snow”, it is impossible not to wonder why the latter seems to us to be just white, because the water is transparent. And here comes physics. We are surrounded by electromagnetic radiation, most of the waves which are inaccessible to the naked human eye. Sun rays contain the visible spectrum, there are seven basic colors: violet, blue, cyan, green, yellow, orange and red. If you merge them together, you get. white. If the object absorbs the light waves, then we see it black. If he reflects them completely, transparent. For example, this is with ice or water. Orange is orange because it absorbs all colors except this one. The snow reflects the entire visible spectrum. So it seems to us white, like the sunlight. Water and ice have a smoother structure, thus appear to be transparent. Considering how snow forms, from the point of view of physics, we can understand that in its structure it consists of many crystals of water, each of which reflects light at different angles.
Why does it rain?
To explain this atmospheric phenomenon from the point of view of physics quite easily. The process is similar to the formation of snow, with the only difference that the rain is at a higher temperature. Water vapor evaporates and is carried to the clouds. At altitude the temperature is much lower. Therefore, the vapor turns into ice crystals. Then falls under the force of gravity. During the flight, the crystals fall under the influence of warm air and thawed. When they reach the earth's surface, they already represent a drop of water. They are called rain. Under the influence of wind flows, clouds can be transported over considerable distances. Sometimes they overcome thousands of kilometers. If the clouds collide with each other, they are combined. When their weight becomes too high, it begins to rain. It is interesting that the drops are identical in form. They differ only in size. There are drops that reach even six millimeters in diameter. Upon impact with the ground, they crash, creating many smaller ones. Most rain can be observed in regions with a hot tropical climate.
There are several options condensation. For example, it may appear exclusively in the morning or only in the winter time. It is separately necessary to consider the situation when water collects on the windowsill. Or sweating a window in one room, while others do not. Condensation is identical in nature to the process of the formation of dew, which we discussed in the beginning of the article.