The thunderstorm is understood as set of several natural phenomena: thunder, lightning, strong wind, quite often rain. These phenomena are preceded by formation of storm clouds. A thunderstorm - the phenomenon, very curious in terms of physics.
Lightning
Rain clouds which are loaded electrically are called storm. In the center of a rain drop a charge positive, on a surface – negative. The falling drops get to strong air flows and scatter on a part, at these parts a negative charge. The largest and heavy part has positive. These large drops accumulate in one of parts of a cloud, giving also to it the positive charge. Small drops are carried away on the earth.
Between the earth and a cloud there is an attraction. The more electricity collects in a cloud, rather it will break through an air layer to the Earth's surface. Then between a cloud and a surface there will be a strong category – a lightning. Such categories can happen also between two opposite loaded clouds. Shortly before formation of a lightning from a cloud electrons begin to flow, air heats up that improves its conductivity. Electricity on the educated channel moves with a speed up to 100 kilometers per second down.
Negative electricity from this channel connects to positive the Earth's surface. The luminescence of a lightning occurs because the channel of the movement of electricity is strongly warmed. The category of a fraction of a second lasts. Often on the way of the first category goes following at once therefore the lightning seems the person as the uneven line zigzag. A linear lightning – the most widespread type of a lightning. There can be a so-called fireball having rounded shape less often. It can last up to several minutes, but is more often – up to 5 seconds. Most often it appears already at the end of a thunderstorm in a look is dazzling a bright sphere, makes the whistling or hissing sound. At disappearance, cotton can be distributed, often there is a haze with a pungent smell. The fireball is attracted to buildings where gets through windows and chimneys. It leaves usually on the same way, as came.
Thunder
The lightning usually is followed by a loud sound which is called a thunder. It arises because air in the channel extends from rapid heating. Expansion on a sound is similar to explosion. Explosion rends the air with a characteristic sound. On the termination of current of electricity the channel also quickly cools down and air sharply compresses that again causes concussion of air and a loud sound. Categories go one by one therefore the roar turns out intensive and long. Reflection of a sound from surrounding objects and the cloud creates an echo that does a sound rolling. Acoustic speed is not so big as the speed of current of electric discharge. Therefore at first the person sees a lightning, and after – hears a thunder.