People have always considered lightning a weapon of the gods. Among the ancient Greeks, Zeus the Thunderer ruled over lightning, and among the Hindus, the king of heaven, Indra. The ancient Vikings, who had eaten up fly agarics, clearly distinguished Thor's lightning fist in the sky. The broad-minded Slavs generally armed everyone with electricity - from the pagan god Perun to the Christian prophet Ilya. References to the exceptional power of the thunder weapon can be found in every religion.
In Indian mythology, Indra struck the giant serpent Vritra, forged by underground blacksmiths with lightning-vajra, entangling the earth's waters. The device of any good weapon is usually kept in deep secrecy - lightning is no exception. Although people have learned at the very least to protect themselves from lightning (at the cost of the lives of several lightning rod testers), we are still unable to reproduce this seemingly simple electrical phenomenon. The gods guard their secrets jealously. Modern developers of lightning weapons can only wonder how technically backward ancient India was able to establish the industrial production of vajras.
Three faces of lightning
Before trying to figure out whether it is possible in real life to repeat the military experience of the Indian gods, we briefly summarize the little that is known to mankind about lightning. In nature, there are three types of giant electrical discharges, which are accompanied by flashes in the atmosphere and thunder. Most often we see linear lightning, a little less often its subspecies - flat lightning, which does not strike the ground, but runs along the surface of thunderclouds. Sometimes you can observe a clear lightning, which is a chain of brightly glowing points. And it is quite rare to find an infamous ball lightning. Only linear lightning is relatively well studied. Almost nothing is known about the other two. Under laboratory conditions, it was possible to obtain only similarities of lightning - corona and glow discharges. The only thing they have in common with real lightning isthat they also consist of plasma.
As Franklin and Lomonosov established back in the 18th century, linear lightning is a long spark. The exact mechanism of its occurrence is unknown. One of the lightning theories says that before a thunderstorm begins, local areas of the earth are charged positively, and the lower edges of the clouds are charged negatively. This is because the water droplets that saturate the pre-thunderstorm air, under the influence of the Earth's electric field, acquire a negative charge. Since our planet in general also has a negative charge, under the action of its field, negatively charged droplets move up to the clouds, and positive droplets down to the earth, where they accumulate, creating charged regions.
According to another theory, atmospheric charges are separated during the water cycle in nature. Positively and negatively charged free ions "adhere" to aerosol particles of vapors, which are always abundant in the atmosphere due to natural radiation and cosmic rays. On charged aerosol particles, as they rise upward in ascending air currents, water droplets grow. Water condensation around negatively charged particles is tens of thousands of times faster, so the droplets are heavier and fly slower. As a result of this process, the lower parts of the clouds are charged negatively, and the upper parts are positively charged. In this case, the lower part of the cloud "directs" a positive charge to the area of the earth located under it.
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There are other theories of the occurrence of pre-storm conditions. Whatever the reality, the main thing is that as a result, from the earth's surface and the cloud, something like the monstrous size of a capacitor is obtained, between the plates of which a discharge is about to slip through. But even air saturated with water vapor is a dielectric, that is, it conducts electricity weakly. Plasma channels play the role of giant wires connecting the clouds with the earth's surface. At some point, almost invisible, weakly luminous clusters of ionized particles - the leaders - begin to move from the clouds towards the earth at a speed of several hundred kilometers per second. Leaders' paths tend to be zigzagged. Each leader on its way ionizes air molecules, creating a channel of plasma with increased conductivity. Near the surface, more and more conducting branches - streamers - rush in different directions from the leader. As soon as the leader reaches the ground, a brightly glowing reverse (aka main) discharge runs through the channel he has laid.
The speed of the main discharge is one hundred times higher than that of the leader. Accordingly, the flash lasts for a split second. We manage to notice the lightning because the discharges are repeated several times. Due to the time intervals between them, it seems to the observer that the lightning is flickering. The diameter of the leader can reach several meters, but the thickness of the discharge does not exceed several centimeters. The above diagram of linear lightning explains a lot, but not everything. If lightning is a discharge, then why does it occur at very low (on a planetary scale) electric field strengths? Or, for example, why are lightning strikes 100 km long or more, but never shorter than hundreds of meters?
The behavior of clear lightning is even more mysterious. These lightning bolts look like ordinary ones, only for some reason they split into separate luminous segments, separated by dark constrictions. It is very similar to bright beads stretched across the sky. Who and what "squeezes" the lightning is unknown. On this score, many theories have been created, but none of them allowed to obtain in laboratory conditions anything even remotely similar to clear lightning. And finally, the queen of the ball is the ominous fireball. The behavior of ball lightning, according to a number of scientists, sometimes generally lies "beyond the laws of science." Ball lightning was successfully classified, dividing, as living things, into classes, families, species and subspecies, but they could not understand their inner nature.
It is known that most often they originate when ordinary lightning strikes. But sometimes they arise spontaneously. The diameter of an average lightning bolt ranges from 10 to 30 cm. They glow like 100-watt bulbs. Based on the level of glow and size, scientists made assumptions about the mass of ball lightning (6-7 g), their energy (10,000 J, which roughly corresponds to the energy consumption of 10 household electric ovens) and temperature (300-4500C).
Alas, these assessments also do not bring us closer to unraveling the secrets of ball lightning, nicknamed killer lightning for their tendency to "attack" people. The few survivors of the fireball encounter say that they did not feel the outgoing heat at close range. What then theoretical 4000C, one asks, can we talk about? And sometimes it happened that after the explosion of tiny lightning, 5-6 cm in diameter, destruction remained, which happens when energy is released over a million joules. The manner of movement of ball lightning arouses keen curiosity. Usually their speed is several centimeters per second - they just float in air currents. But sometimes, for no reason at all, with complete calm, they suddenly jump off the spot like crazy and "rush" in one direction or another. Most often - to people or animals.
Lightning weapon
Although we do not understand lightning, it can be argued that if we can accurately recreate the conditions for their appearance, they can be obtained artificially. Perhaps, man-made lightning can even be used (after all, in order to control a complex mechanism, it is not at all necessary to thoroughly understand its structure). We returned to the question posed at the beginning of the article. How to create a weapon of the gods? In other words, what did Indra need to fry the Vritra? To begin with, let's say that Indra was using a regular line lightning. Judging by the description, the effect of using the vajra most closely resembled her blow. Consequently, the Indian god had to stock up on a powerful store of electrostatic charge.
The electric field between Indra and the cunning serpent was supposed to be about a billion volts. The capacity of such an indro-vritra capacitor will be equal to about one thousandth of the capacity of the earth, and the energy will go off scale for a hundred billion volts. The current that flowed between Indra and the serpent was tens of millions of amperes. This is enough to melt an aircraft carrier. But Vritra had to be grounded more reliably. With this (we must pay tribute to the Hindus) Indra did not miss. Ancient frescoes depict him soaring high in the clouds, while Vritra, on the contrary, lies on damp ground. Finally, the god had to create a plasma channel between his electricity storage and Vritra, inventing a replacement for the leader. The flame of a gas burner several kilometers long would be suitable here (as manyas it was before the opponent of Indra) or a powerful laser beam. You can get by with simpler means - for example, a giant parabolic dish. If you make its diameter a little more than a kilometer, you can start up a powerful sunbeam, which ionizes the air. It is, in principle, possible to make all this. But how much will it cost? We have to admit that the ancients were right: lightning is the weapon of the gods.
Yuri Granovsky