Rough automatic draft, low quality: expect mistakes and awkward wording. It will be replaced by a better translation. Original →
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FLIGHT OF FIRE ARROWS
Among the explored and unexplored, the nature of lightning has a special place. Each of us has seen it many times, but do we know what it is? How it works, what kind of destruction it produces, and what in general it produces in the atmosphere during a thunderstorm — these questions are the subject of a small but very fascinating book by Basil Schonland, “The Flight of Lightning” *).
The author talks about the cult of thunder and lightning that existed among all ancient peoples, about how people gradually came to understand the nature of lightning and began to writhe in fear of this formidable phenomenon. The book tells in detail about the invention of the lightning rod and the significance of this invention: after all, lightning strikes often led to tragic consequences. B. Schonland says, for example, that a lightning strike in the church of Saint-Nazare in Northern Italy in 1769, in the cellars of which large reserves of gunpowder were stored, caused an explosion that destroyed a sixth of the city.
Lightning was considered a manifestation of sideways anger, a formidable punishment for earthly sins. The reader learned from the book that the houses of the Romans, destroyed by lightning, were not allowed to be restored under any circumstances. But this was the case in ancient and middle ages. In the 18th century, people already knew relatively much about the nature of electricity. Let us recall that the first experiments with electricity — electrification of electricity — were carried out by William Gilbe back in 1600. And the invention of the lightning rod by B. Frankin dates back to the middle of the 18th century. In many European countries at that time there already existed academies of sciences. Nevertheless, lightning rods won their right to exist for a long time. If in America they spread quite quickly, then in Europe the debate continued for a long time: does a lightning rod eliminate danger or, on the contrary, does it increase the likelihood of being struck by a discharge? The question of whether the lightning rod should end with a blunt or sharp end was especially aroused. Let us also recall an interesting and probably well-known fact to the reader that B. Frankin made his first experiments with lightning rods using a kite to which an iron tip was attached. B. Frankin also carried out many other studies on electricity, some of which you also learned from B. Schonland’s book.
The author devotes a lot of space to modern ideas about intracloud discharges and types of lightning. You learned that the length of the visible part of linear lightning (the so-called discharge between the cloud and the ground) outside the cloud sometimes reaches several kilometers. The full length of lightning is even greater, since, on the one hand, the discharge moves in a zigzag manner, and on the other hand, quite a large part of it is “hidden” inside the cloud itself. If we also take into account the figures of 25,000° (this can be the temperature in the lightning channel), 10,000 amperes (at the peak of lightning) and 100 million volts (the minimum discharge voltage), then you can imagine what a formidable phenomenon this is.
Here are a few more interesting ones:
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numbers taken from the book “The Flight of Lightning.” The average number of thunderstorms on the globe is 16,000,000. Every day, about 100 lightning flashes on the ground.
An electric discharge moves in the air at a speed of 100 to 100 thousand kilometers per second. Studying the dynamics of such a process is a complex task. You can read about how it was solved and how the development of lightning was recorded on the pages of the book.
One of the most interesting questions of atmospheric electricity is the question of the distribution of charges on clouds. It turns out that in most cases the lower part of the clouds is negatively charged. B. Schonland describes in detail how the electric field changes during the development of lightning, how charges are restored from the cloud to the ground. There are pages in the book (unfortunately, there are very few of them) devoted to the most challenging and still most understood phenomenon - ball lightning.
The reader learned about different types of discharge in air, how gas initiation and electrification of clouds occur, and the role that water drops and ice crystals play in these processes. The final pages of the book are devoted to various phenomena that accompany thunderstorms. The author talks in detail about “atmospheric” (radio waves emitted during thunderstorms), explains why the charge on the surface of the earth remains constant.
The book is written in good language. A large number of seriously meaningful physical facts and, what is also important, a lot of useful historical information are concentrated in a small volume. The presentation is fully accessible to schoolchildren. It’s just a pity that the book was published as a bit of a bummer.
Yu. M. Brook