The article tells about why icicles appear, how to make them yourself and what is their danger in a large city.
On our planet there are manyclimatic zones. There are both hot regions, and those where there is never a summer, and human life is almost impossible. In some places, rains are almost always raining, and in others they are very rare, and it is difficult for residents to imagine frequent thunderstorms and even more so in the water of its non-viable condition - snow and hail.
But all the cold areas and places where in winterperiods, the temperature falls below zero, makes one more familiar to us phenomenon. These are icicles. So why do I have icicles? First you need to understand what cold and ice are.
According to the generally accepted terminology, cooling -this phenomenon, which arises from the lowering of the temperature or the removal of heat from the object in one way or another. For most living forms, low temperatures are fatal, as well as high temperatures. And, incidentally, the absolute cold is designated as -273.15 degrees Celsius. Under such conditions, water not only freezes, but metals become brittle, like glass, and also the movement of elementary particles in matter practically stops.
When the temperature falls below zero degreesCelsius water turns into ice. This is a solid state of matter, which is usually characterized by a liquid form. But if there is no rain in the winter, and all the liquid freezes, why do icicles appear on the eaves of houses? The thing is that in winter, the temperature can vary in fairly wide ranges, and precipitations will begin to melt, and then the frosts come again that will stop. That is why the water, which was snow, starts to drain from the roofs of houses, and as the temperature decreases, it gradually freezes, because of which the drops, slipping on the bases of icicles, do not reach the ground in full, leaving some of the liquid in the form of ice.
But sometimes there is no plus temperature in winter, and ice can still be observed. Why do icicles appear in this case?
In this case, the heating of houses comes into effect. According to statistics in winter, most homes lose up to 30% of heat through the roof, and the snow, albeit slowly, but still melts. This is especially evident in private homes.
These ice formations are quitegreat danger. Especially in cities where there are many high-rise buildings. And all because to get to their cornices is very problematic, and icicles sometimes grow to huge proportions. As a result, a fall can kill an occasional passerby. And, frankly speaking, getting a little piece of ice on the head, fallen from the 15th floor, is a pleasure to itself.
Therefore, every winter, utilities spend a lot of effort to knock down icicles.
There are several ways. The first, the most "natural". On a frosty day you need to patience and a bottle of water. Then find on the street an object from which the liquid would merge slowly and evenly, and ideally - by drop. This process is not fast, but with the advent of the first naled the business will go more fun.
The second way to make it possible at any timeof the year. You just need to prepare the appropriate form, fill it with water and place it in the freezer of the refrigerator. But here the main thing to remember is that the liquid freezes greatly expands and can destroy the material of the mold, so that the glass is not suitable for it.
Well, the third is to get a bar of dry ice andcut a narrow long cone in the form of an icicle from it. True, it will not be an icicle in the usual sense, since dry ice consists of frozen carbon dioxide, which does not melt, but evaporates. Also from it you can get cold "burns" of the skin.
Now we know how the icicles appear, and also learned how to make them.
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