Ball lightning - the main mystery of atmospheric electricity

Ball lightning - the main mystery of atmospheric electricity
Ball lightning - the main mystery of atmospheric electricity
Anonim

Ball lightning looks like a luminous sphere that usually occurs during a thunderstorm. Often such an object hangs or moves at a more or less fixed height above the ground. Sometimes ball lightning explodes when it collides with an object or for no apparent reason. It is noteworthy that there is still no generally accepted physical theory in the world explaining the nature of ball lightning.

Electrical phenomena in the Earth's atmosphere, despite centuries of research, remain largely poorly understood. Ball lightning is probably one of the biggest mysteries, starting from the very fact of their existence, says Doctor of Physical and Mathematical Sciences, senior researcher at the Solid State Theory Sector of the Physico-Technical Institute named after V.I. A.F. Ioffe RAS Mikhail L. SHMATOV. In an interview, the scientist spoke about the most interesting issues related to ball lightning.

─ Is it true that until 2012 the scientific community was not firmly convinced that ball lightning really exists, and only after the sensational observation of Chinese scientists who discovered iron, silicon and calcium in such lightning, they started talking about ball lightning as a real object ? Previously, after all, there were even suggestions that ball lightning is a kind of hallucination caused by the influence of magnetic fields from some ordinary lightning?

─ Nothing fundamentally new happened in 2012; Chinese scientists did not present any revolutionary data based on their observations. The question remains: did they observe ball lightning? Most likely (and this is stated in our joint review with Professor Karl Stefan from the University of Texas at San Marcos) [1], Chinese scientists have seen the consequences of an ordinary lightning strike into a power line. It is sometimes believed that they established the presence of iron, calcium and silicon impurities in ball lightning. But, probably, the registration of the spectral lines of these elements is simply the result of the impact of an ordinary lightning discharge on the power line and the ground, possibly some effects related to the fact that this discharge produced a short circuit of the power line. Let me remind you that all this was near the power transmission line, which means that there could be a short to ground, which led to such consequences.

However, in terms of how people perceive ball lightning, the situation is really difficult. Many people are interested in ball lightning, but there are plasma physicists who know nothing about this object. This is the current situation.

If we talk about hallucinations, it is believed that in some cases people may see some kind of glowing spots due to the action of a very bright flash of light from ordinary lightning. There was also work that, perhaps, magnetic fields from ordinary lightning act directly on the brain and give optical illusions of a more complex origin.

There are a large number of luminous long-lived objects that can be mistaken for ball lightning. A wonderful example that has been discussed in the scientific literature: in some cases, even a bird living in a hollow can be mistaken for ball lightning! The bird can be stained with rotting wood, and rotting wood glows under some conditions.

I believe that in the case of the mentioned observation of Chinese scientists, the results of which were published in their article, the situation is about the same: they could see the consequences of a simple lightning strike, and not ball lightning.

Yes, there are still those who still do not know about ball lightning, as well as those who believe that this is an optical illusion, but today it is already known for certain: ball lightning exists. And we know this, in particular, from a number of reports on the destructive effects caused by such lightning.

─ There is still no consensus on what ball lightning consists of. What's your version?

─ You are right, there are only different hypotheses and models. I believe that ball lightning consists of electrons and almost completely ionized ions (in fact, nuclei) of the elements that make up the air, that is, the fundamental presence of silicon and other elements mentioned earlier is not required in it.

My model is based on the assumption that the main part of ball lightning is a nucleus, consisting of almost completely ionized ions and electrons, oscillating (approx., Oscillating) relative to each other. It turns out that electrons oscillate relative to ions. Jonah also moves. The movement of electrons occurs mainly in the radial direction, the situation with ions is more complicated and depends on the specific parameters of the nucleus. The nucleus is a plasma cloud, similar to plasma clouds that arise in some experiments on laser thermonuclear fusion and in nuclear explosions in the atmosphere (although there are other reasons for the occurrence of oscillations). Other scientists have also considered models with oscillations, but I am the only one who was able to explain the lifetimes and energetics of ball lightning within the framework of such a model.

Reference. Ionization in this situation is the pulling out of one or more electrons, complete ionization of all, that is, a fully ionized ion of an element is its atomic nucleus.

─ Ball lightning has been known for thousands of years. Why has it still not been possible to unambiguously establish their nature so far?

─ I believe that one of the main problems is the lack of sufficiently large-scale and well-funded research in this area.

Important research on ball lightning was carried out in the United States in the 1960s. The result is Stanley Singer's excellent book The Nature of Ball Lightning. These works were carried out during the Vietnam War, and the maximum task was to "to scare the hell out of the Viet Cong" learned after Singer's death. But now no one faces such tasks, and therefore the interest in ball lightning is moderate. In addition, the great complexity and lack of obvious applied value frightens off many.

However, I think that the study of ball lightning is of great political importance for plasma physics, because at present there is a problem of energy production, and one of the promising solutions, as you know, is controlled thermonuclear fusion.

The position of many researchers in the field of controlled thermonuclear fusion is as follows: if enough money is allocated, then humanity will receive this source of energy, because plasma physics is well understood. But one may ask: why do you even think that you understand plasma physics? Well, we solved one problem, the second is good. But there is such a natural phenomenon as ball lightning. It has been known for thousands of years, is associated with plasma, but has not yet been fully explained. And while we have not explained ball lightning, one can hardly say that plasma physics is well understood.

─ Plasma, as far as I know, is considered the least studied state of matter …

─ Difficult question. I believe that a number of aspects in this area have been studied very well. If the physics of plasma had not been well studied, there would have been no hydrogen bombs, in particular. They did not spare anything. And here they are and, in general, they provide peaceful coexistence on the planet.

─ Is it possible to create ball lightning in the laboratory?

─ I would say that there is no direct answer to this question.And it would be more correct to talk about the creation of ball lightning not so much in the laboratory as at the test site. Why? It is known that ball lightning is a manifestation of thunderstorm activity in the atmosphere, and, generally speaking, in a thundercloud, in some cases, there are gigantic potentials. The potential difference between different points of the cloud or between some point in the cloud and the ground can be hundreds of millions of volts. Under certain conditions, we can even go into the range of several hundred million volts, and perhaps even up to several billion. Therefore, it is better to carry out work in polygon conditions.

There are many attempts to recreate ball lightning in the laboratory. So far, this has not yielded any convincing results. And whether it is possible in principle or not, I cannot say. Within my model, it is better to work on the landfill. Similar experiments were carried out in the United States at least twice ─ with an attempt to use lightning, initiated by rockets pulling a wire behind them. But, as you know, launching a rocket is a serious thing. These experiments took place at special training grounds, in particular, at the base of the National Guard. This kind of research is a very expensive and dangerous undertaking, because a missile can also shoot down an aircraft in case of an unsuccessful launch, and, in any case, if safety precautions are not followed, you can get hit by an initiated lightning.

Missile-free experiments using conventional lightning are also quite possible. There are many reports on the conditions for observing ball lightning. For example, you can reproduce this setting and wait for a normal lightning strike. It is easy to recreate the atmosphere of the appearance of ball lightning, but now I will not dwell on how exactly this can be done. High cost and safety concerns are also important for non-rocket experiments.

- Our compatriot, Nobel laureate Pyotr Kapitsa dealt with ball lightning issues. He wrote that ball lightning, due to its rarity, hardly lends itself to systematic study. What do you think about this?

- And here it is generally not clear how rare this phenomenon is. It is believed that for a person living in the middle zone of the former USSR, the probability of meeting ball lightning in a lifetime is about 5%. That's not a lot. But in the United States in 1963, an interesting poll was conducted: NASA employees were asked how often they saw ball lightning and how often they saw a close strike of ordinary lightning. The number of both turned out to be comparable, which means that it is very difficult to talk seriously about the probability of the generation of ball lightning during an ordinary discharge. The fact is that ball lightning has a short detection range. Moreover, during a thunderstorm, as a rule, all prudent people, if possible, sit indoors. At the same time, simple lightning is visible at great distances, as it is large and bright, and the sound from it is strong. It is quite possible that the frequency of generation of ball lightning by natural discharges is comparable to the frequency of ordinary lightning. We may simply not see ball lightning.

Regarding the fact that ball lightning is observed, regardless of the reasons, is rare, I do not consider this a significant obstacle to research, because a huge amount of observational data has been accumulated and published. At the same time, it is certainly impossible to trust all messages.

The number of people who find themselves at a short distance from an ordinary lightning strike is comparable to the number of people who have ever watched ball lightning. By the way, pilots saw quite a lot of fireballs. This question was very carefully studied by I.M. Imyanitov is an outstanding researcher of atmospheric electricity. He came to the conclusion that ball lightning occurs in the clouds a hundred times more often than at low altitudes.

─ By the way, at what height is ball lightning usually observed?

─ Ball lightning has one very interesting property ─ that it very often hangs or moves at a fixed height, for example, in the area of ​​one meter or one and a half meters above the ground. And this is actually a very non-trivial fact, because it is obviously affected by both the force of gravity and the Archimedean force. It turns out that ball lightning is pretty light. And, it would seem, if ball lightning is heavier than air, then it should fall, and if it is lighter than air, it should take off. But ball lightning, at least in some cases, has an electrical charge that affects its movement. But this is a separate and very complex issue, so we will not go into details now. In general, ball lightning was observed directly on the ground or on the floor of the premises, and at the mentioned height of a meter and a half, and at an altitude of several kilometers.

─ How long does ball lightning live?

─ The lifetime of ball lightning is one of the best recorded parameters. The lower limit is a few seconds. Apparently, the regional features of ball lightning are important, since the results of works written in different countries give slightly different boundaries for the lifetime. It is safe to say that ball lightning can definitely live for a few seconds. But with the upper limit, the question is very difficult. There are, for example, published data on the observation of M.T. Dmitriev [3]. He saw the fireball for about a minute and a half. Probably, we can say that at low altitudes ball lightning can live for at least three minutes. The literature also mentions reports that ball lightning lived up to 15 minutes. But I know of only one or two messages of this kind.

In addition, there is a very insidious effect, outwardly similar to ball lightning, ─ the lights of St. Elmo on a flying electric field concentrator. If we have a strong enough field, and the fields under the thunderclouds (and in them) can be of the order of a kilovolt per centimeter, and there is some object or objects, for example, a swarm of beetles, then a glow may appear on these beetles or other objects. Scientists have specially studied this question. It was found that it is very difficult to distinguish ball lightning from the lights of St. Elmo from a long distance, even if the concentrator of the electric field does not fly.

─ Have you yourself ever observed ball lightning?

─ No.

─ Would you like to?

─ Not really. The fact is that within the framework of my model, if you are completely unlucky, you can get severe radiation damage, including lethal, from a distance, in unique cases, of tens of meters. Ball lightning is very dangerous for humans.

A very interesting story, which looks semi-fantastic, but is well documented and described in the Journal of Technical Physics in 1981 [5], took place in Khabarovsk, where ball lightning melted 440 kilograms of soil. It looks like a terrible fairy tale, but very serious studies of this soil were carried out at the Institute of Nuclear Physics of Moscow State University and other scientific organizations. In particular, from attempts to reproduce a slag of approximately the same composition, it became clear that the melting was caused either by radio waves or by hard radiation, that is, gamma radiation, and what exactly ─ there is no final conclusion.

Ball lightning is also dangerous for technology, in particular, due to its ability to influence the operation of electrical circuits. Both old literature and relatively modern stories describe when ball lightning turned on electric lamps. In principle, it can knock out electronics [6], but for a modern aircraft, for example, knocking out electronics is a very bad event. There are reports that the pilots of military aircraft even had to eject because of the damage to the aircraft by ball lightning [7], but what were the specific mechanisms of damage, I do not know.

─ Ball lightning is always associated with ordinary lightning, or can it occur independently of it?

─ In some cases, the birth of ball lightning can be associated with a specific ordinary lightning, but there are also known cases when ordinary lightning did not precede the birth of ball lightning. There are reports of the observation of ball lightning in clear weather.

- Your works are also devoted to the radiation hazard of ball lightning. How real is this threat?

- I am interested in the radiation hazard of ball lightning and atmospheric electricity in general. In the past and the year before last, I published two articles [8, 9], where, within the framework of my ball lightning model, I explained some parameters of gamma radiation fluxes recorded in one case in Japan [10], and in the other in Armenia [11].

Since about 1980, the fact of the generation of X-ray and gamma radiation in thunderclouds has been clearly established. There are both short, sufficiently powerful pulses, and long streams of gamma radiation lasting, for example, seconds or minutes, as well as events that can be interpreted as the generation of a large number of pulses. The question of what is the nature of long-term impulses is open.

There are reports of observation of not only single ball lightning, but also entire groups of ball lightning [4]. In Armenia, at the Aragats station, among other things, the observation of visible light that comes from the clouds is carried out. In 2019, an article by A. Chilingaryan [11] with colleagues was published on how they saw gamma radiation and a group of luminous spots. They offered some explanation for where the light spots came from, about 10 pieces. I admit that they could see a group of ball lightning [9].

─ Can even groups of ball lightning exist?

─ Yes. Such events are rare, but they do happen. There are documented stories of pilots who, in emergency situations, such as an emergency landing at an airfield through a thunderstorm, saw dozens of fireballs in the clouds [4]. I repeat that the probability of encountering ball lightning in a cloud is about a hundred times greater than at our usual heights, that is, at ground level and a few meters above it [2].

In general, the radiation hazard of ball lightning was first seriously discussed in 1962. Earlier, in 1886, Scientific American (now a magazine, and the old issues look like a newspaper) had a unique publication that described the story of how a family in Venezuela observed a bright light in their home and at the same time felt a specific smell (ball lightning reports sometimes mention a smell like burning black powder or sulfur). People began to pray, they thought that the end of the world had come (a completely natural assumption for the 19th century and for a religious family), but this activity was interrupted by vomiting. In the future, people developed blisters on the skin, which became ulcers, and hair began to fall out. What, if not radiation, does it look like? Moreover, this fact can hardly be considered falsification, because it was described both before the discovery of natural radioactivity, and before the creation of X-ray sources, and even more so before the creation of powerful sources of ionizing radiation. 90 years later, Eugene Garfield interpreted this incident as a possible radiation injury from fireball.

Rosalyn Krysik observed another interesting effect: a ball of lightning flew up to the glass door, and the glass glowed. It was not a reflection because the lightning was bluish in color and the glow was yellow. Subsequently, Karl Stefan and his colleagues conducted a series of experiments, and it turned out that a similar effect can be caused by the action of ultraviolet or harder radiation [1].

─ Can ordinary lightning also pose a radiation hazard?

─ Yes. It has been established that a certain amount of ordinary lightning (how much is unknown, approximately from 0.01% to 1%) generates streams of hard radiation. Oddly enough, these streams are clearly visible from satellites, because radiation interacts with air - it is simply absorbed and scattered, scattering leads to a decrease in the photon energy.The intensity decreases with increasing distance and in a situation where there is practically no absorption and scattering, simply due to the fact that the same number of quanta falls on a larger area. But a more significant effect is observed in a fairly dense atmosphere - this is the scattering and absorption of gamma and X-ray radiation by air. Therefore, it turns out that if the thunderstorm is at an altitude of several kilometers and, especially, higher, then it is easier to see the hard radiation from the satellite than from the ground.

─ Mikhail Leonidovich, tell us in the end, how can you protect yourself when you encounter ball lightning? What can and cannot be done?

─ The same safety rules apply here as when encountering ordinary lightning. For example, many people know that you cannot stand under trees during a thunderstorm ─ a lightning strike into a tree can lead to a discharge from its trunk into a person standing next to it. The situation with ball lightning is contradictory. There are different recommendations, but I consider one of them dangerous. The general recommendation regarding ball lightning looks as if, in terms of danger, ball lightning is a big angry dog: you do not need to tease it, but you need to retreat slowly, and slowly ─ a fundamental thing. Why slow? In principle, this is the correct advice, because a sudden movement can create a slight vacuum, which will bring the ball lightning closer to a person. But sometimes there are recommendations not to move at all! This is a strange advice, given that there are a number of reports about the radiation hazard of ball lightning, and corresponding to a severe injury, up to vomiting during observation, and these are very large doses of radiation, this is a risk of death.

Summing up, I want to say that ball lightning has its own specific difficulties. On the one hand, we do not know how rare or often ball lightning occurs ─ this is due to the small detection radius, ball lightning is really rarely observed. But, on the other hand, it has been known for thousands of years, and the last hundred years of data on ball lightning has become more and more, there are many very interesting publications, in particular, about the danger of ball lightning. One of the best books published so far is a work by Walter Brand entitled "Fireball" in German, 1923. It is quoted to this day. Recently, this book in a slightly enlarged version was published in English, and in our library I read its translation into Russian. I highly recommend this work to anyone interested in such natural phenomena as ball lightning.

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