Now we will talk about what is thunder. This natural phenomenon is usually observed after lightning. Such phenomena caused a terrible sense of fear among our ancestors, they considered them a manifestation of the wrath of the gods. In the days of the ancient Slavs paganism was widespread. They worshiped various gods, including Perun - the god of thunder, lightning and thunder. He was the main in the ancient Slavic pantheon. And, like any great deity, a personal holiday was dedicated to Perun . Perun Day was celebrated on July 21. God was revered as giving life-giving rain for nature. On this day, the ancestors praised him, after they consecrated their weapons, made a sacrifice, performed a ceremony of commemoration of the soldiers who fell in battle. The end of the day was a hearty meal and fun.
These times have sunk into oblivion, but thunder and lightning remained. Let's look in specialized reference books or textbooks of natural history. There we can read what thunder is - the sound of vibrating air around a lightning that quickly heats up and expands. Probably, you have repeatedly paid attention to the fact that sometimes we first see an electric discharge, and only then we hear a roar. This happens because light waves propagate at a speed of about 300,000 km / s, and sound waves are much slower, about 335 m / s. But not always thunder and lightning are united during a thunderstorm. It happens that a flash of lightning occurred, but no sounds are heard. This can be if the thunderstorm is quite far. It happens that thunder booms, but lightning is not visible - it will be difficult to see it on a clear day and when it forms inside the clouds.
If you want to know how far the thunderstorm is, doing this will not be difficult. You just need to calculate how many seconds will elapse between the flash of an electric discharge and the sound of thunder, divided by three, and you will know how many kilometers there is a thunderstorm. If you make several such calculations, then you can find out if a cloud is approaching or moving away from you. In the case when the thunder is not heard, it can be argued that the thunderstorm front is more than twenty kilometers from you.
To understand how lightning is formed, you should recall the school curriculum - a section on electricity. It is known that all objects are charged either positively or negatively. During a thunderstorm, droplets in the cloud, condensing, take away positively charged particles. A cloud becomes negatively charged relative to the Earth. In the case when the charge in the cloud of rain is too large, a lightning discharge occurs. You can observe the same phenomenon when similar occurs between clouds.
Now let's see what is thunder? During an electric discharge, the air expands very quickly, then contracts, and the air flows rapidly. When contact occurs between them, the sound of thunder is heard. The volume of these peals can reach 120 decibels.
After reading this article, you yourself have learned and will be able to explain to little why-you-what thunder, lightning, how they are formed and why the rumble is heard.