Fog, rising high above the ground, consists of particles of water and forms clouds. Larger and heavier clouds are called clouds. Some clouds are simple - they do not cause lightning and thunder. Others are called thunderstorms, since it is they who create a thunderstorm, form lightning and thunder. Thunderclouds differ from simple rain clouds in that they are charged with electricity: some are positive, others are negative.

How are thunderclouds formed?

Everyone knows how strong the wind is during a thunderstorm. But even stronger air whirlwinds are formed higher above the ground, where forests and mountains do not interfere with the movement of air. This wind is the main source of positive and negative electricity in the clouds. To understand this, consider how electricity is distributed in each water drop. Such a drop is shown enlarged in Fig. 8. In the center of it is positive electricity, and negative electricity equal to it is located on the surface of the drop. Falling raindrops are picked up by the wind and enter the air currents. The wind hitting the drop with force breaks it into pieces. In this case, the detached outer particles of the drop turn out to be charged with negative electricity. The remaining larger and heavier part of the drop is charged with positive electricity. That part of the cloud, in which heavy particles of drops accumulate, is charged with positive electricity.

Rice. 8. This is how electricity is distributed in a raindrop. Positive electricity inside the drop is represented by a single (large) "+" sign.

The stronger the wind, the sooner the cloud is charged with electricity. The wind expends a certain amount of work, which goes into separating the positive and negative electricity.

Rain falling from a cloud carries some of the cloud's electricity to the ground, and thus an electrical attraction is created between the cloud and the earth.

On fig. 9 shows the distribution of electricity in the cloud and on the surface of the earth. If the cloud is charged with negative electricity, then, trying to be attracted to it, the positive electricity of the earth will be distributed on the surface of all elevated objects that conduct electric current. The higher the object standing on the ground, the smaller the distance between its top and the bottom of the cloud, and the smaller the layer of air remaining here, separating opposite electricity. Obviously, in such places lightning is easier to break through to the ground. We will talk about this in more detail later.

Rice. 9. Distribution of electricity in a thundercloud and ground objects.

2. What causes lightning?

Approaching close to a tall tree or house, a thundercloud charged with electricity acts on it in exactly the same way as in the last experiment we have considered, a charged rod acted on an electroscope. On the top of a tree or on the roof of a house, an electricity of a different kind is obtained through influence than that carried by a cloud. So, for example, in Fig. 9 a cloud charged with negative electricity attracts positive electricity to the roof, and the negative electricity of the house goes into the ground.

Both electricity - in the cloud and in the roof of the house - tend to be attracted to each other. If there is a lot of electricity in the cloud, then a lot of electricity is generated on the house through the influence. Just as rising water can erode a dam and rush in a stormy stream, flooding a valley in its unrestrained movement, so electricity, increasingly accumulating in a cloud, can eventually break through the layer of air separating it from the surface of the earth and rush down towards the earth, towards the opposite electricity. There will be a strong discharge - an electric spark will slip between the cloud and the house.

This is the lightning that struck the house.

Lightning discharges can occur not only between a cloud and the earth, but also between two clouds charged with electricity of various kinds.

3. How does lightning develop?

Most often, lightning that strikes the ground comes from clouds charged with negative electricity. Lightning striking from such a cloud develops like this.

First, electrons begin to flow from the cloud towards the ground in a small amount, in a narrow channel, forming something similar to a stream in the air. On fig. 10 shows this beginning of lightning formation. In that part of the cloud where the formation of the channel begins, electrons have accumulated, which have a high speed of movement, due to which, colliding with air atoms, they break them into nuclei and electrons. The electrons released at the same time also rush towards the earth and, again colliding with air atoms, split them. It is like snow falling in the mountains, when at first a small lump, rolling down, is overgrown with snowflakes sticking to it, and, accelerating its run, turns into a formidable avalanche. And here the electron avalanche captures more and more volumes of air, splitting its atoms into pieces. At the same time, the air warms up, and as the temperature rises, its conductivity increases; it changes from an insulator to a conductor. Through the resulting conductive air channel, more and more electricity begins to flow from the cloud. Electricity is approaching the earth at a tremendous speed, reaching 100 kilometers per second. For comparison, we recall that the speed of a projectile from modern guns does not exceed two kilometers per second.

Rice. 10. The formation of lightning begins in the cloud.

In hundredths of a second, the electron avalanche reaches the ground. This ends only the first, so to speak, "preparatory" part of the lightning: the lightning has made its way to the ground. The second, main part of the development of lightning is still ahead.

The considered part of the lightning formation is called the leader. This foreign word means "leading" in Russian. The leader paved the way for the second, more powerful part of the lightning; this part is called the main part.

As soon as the channel reaches the ground, electricity begins to flow through it much more violently and quickly. Now there is a connection between the negative electricity accumulated in the channel and the positive electricity that fell into the ground with raindrops and through electrical influence - there is a discharge of electricity between the cloud and the earth. Such a discharge is an electric current of enormous strength - this force is much greater than the current strength in a conventional electrical network. The current flowing in the channel increases very quickly, and when it reaches its maximum strength, it begins to gradually decrease. The lightning channel through which such a strong current flows is very hot and therefore glows brightly. But the current flow time in a lightning discharge is very short. The discharge lasts very small fractions of a second, and therefore the electrical energy that is obtained during the discharge is relatively small.

On fig. 11 shows the gradual progress of the lightning leader towards the ground (the first three figures on the left). The last three figures show separate moments of the formation of the second (main) part of the lightning.

Rice. 11. Gradual development of the lightning leader (first three pictures) and its main part (last three pictures).

A person looking at lightning, of course, will not be able to distinguish its leader from the main part, since they follow each other extremely quickly, along the same path. But with the help of a photographic apparatus, both processes can be clearly seen. The photographic apparatus used in these cases is special. Its main difference from ordinary cameras is that its record is round and rotates during shooting - just like a gramophone record. Therefore, the picture taken by such a device is stretched, “smeared”.

After the connection of two electricity of a different kind, the current breaks. However, lightning usually doesn't end there. Often, along the path laid by the first category, a new leader immediately rushes, and behind him, along the same path, the main part of the category again goes. Thus ends the second category.

Such separate discharges, each consisting of its leader and main part, can form up to 50 pieces. Most often there are 2-3 of them. The appearance of individual discharges makes the lightning intermittent, and often a person looking at the lightning sees it flickering.

This is the reason for the flickering of lightning.

Since lightning consists of several rapidly alternating flashes of light, separate images appear on a rotating photographic plate, located at a certain distance from one another. The distance between images will be greater, the faster the plate rotates.

The time between the formation of individual discharges is very short; it does not exceed hundredths of a second. If the number of discharges is very large, then the duration of lightning can reach a whole second and even several seconds. Lightning is not so “fast” as it was imagined before!

We have considered only one type of lightning, which is the most common. This lightning is called linear lightning because it appears to the naked eye as a line - a narrow, bright band of white, light blue, or hot pink. Linear lightning has a length of hundreds of meters to many kilometers. The lightning path is usually zigzag. Often lightning has many branches. As already mentioned, linear lightning discharges can occur not only between clouds and the ground, but also between clouds.

On fig. 12 shows a linear lightning.

Rice. 12. Linear zipper.

4. What causes thunder?

Linear lightning is usually accompanied by a strong rolling sound called thunder. Thunder occurs for the following reason. We have seen that the current in the lightning channel is formed within a very short period of time. At the same time, the air in the channel heats up very quickly and strongly, and from heating it expands. The expansion is so fast that it resembles an explosion. This explosion gives a shaking of the air, which is accompanied by strong sounds. After the sudden interruption of the current, the temperature in the lightning channel drops rapidly as the heat escapes into the atmosphere. The channel cools rapidly, and the air in it is therefore sharply compressed. This also causes a shaking of the air, which again forms the sound. It is clear that repeated lightning strikes can cause a prolonged roar and noise. In turn, the sound is reflected from the clouds, the earth, houses and other objects and, creating multiple echoes, lengthens the thunder. That's why thunder rolls.

Like any sound, thunder propagates in the air at a relatively low speed - approximately 330 meters per second. This speed is only one and a half times the speed of a modern aircraft. If an observer first sees lightning and only after a while hears thunder, then he can determine the distance that separates him from lightning. Let, for example, 5 seconds elapse between lightning and thunder. Since in every second the sound travels 330 meters, in five seconds the thunder traveled a distance five times greater, namely 1650 meters. This means that the lightning struck less than two kilometers from the observer.

In calm weather, thunder is heard in 70–90 seconds, passing 25–30 kilometers. Thunderstorms that pass at a distance of less than three kilometers from the observer are considered close, and thunderstorms passing at a greater distance are considered distant.

5. Ball lightning

In addition to linear, there are, though much less often, lightning of other types. Of these, we will consider one, the most interesting - ball lightning.

Sometimes there are lightning discharges, which are fireballs. How ball lightning is formed has not yet been studied, but the available observations on this interesting type of lightning discharge allow us to draw some conclusions. Here is one of the most interesting descriptions of ball lightning.

Here is what the famous French scientist Flammarion reports:

“On June 7, 1886, at half past seven in the evening, during a thunderstorm that broke out over the French city of Grey, the sky suddenly lit up with a wide red lightning, and with a terrible crackling, a fireball fell from the sky, apparently 30–40 centimeters across. Scattering sparks, he hit the end of the ridge of the roof, beat off a piece more than half a meter long from its main beam, split it into small pieces, covered the attic with debris and brought down the plaster from the ceiling of the upper floor. Then this ball jumped onto the roof of the entrance, punched a hole in it, fell into the street and, having rolled along it for some distance, gradually disappeared. The ball did not cause a fire and did not hurt anyone, despite the fact that there were a lot of people on the street.

On fig. 13 shows ball lightning captured by a photographic camera, and in fig. 14 shows a picture of an artist who painted ball lightning that fell into the courtyard.

Rice. 13. Ball lightning.

Rice. 14. Ball lightning. (From the artist's painting.)

Most often, ball lightning has the shape of a watermelon or pear. It lasts relatively long - from a small fraction of a second to several minutes. The most common duration of ball lightning is from 3 to 5 seconds. Ball lightning most often appears at the end of a thunderstorm in the form of red luminous balls with a diameter of 10 to 20 centimeters. In more rare cases, it is also large. For example, lightning was photographed with a diameter of about 10 meters.

The ball can sometimes be dazzling white and have a very sharp outline. Typically, ball lightning makes a whistling, buzzing, or hissing sound.

Ball lightning can disappear silently, but it can make a faint crackle or even a deafening explosion. Disappearing, it often leaves a sharp-smelling haze. Near the ground or in enclosed spaces, ball lightning moves at the speed of a running person - approximately two meters per second. It can remain at rest for some time, and such a "settled" ball hisses and throws out sparks until it disappears. Sometimes it seems that ball lightning is driven by the wind, but usually its movement does not depend on the wind.

Ball lightning is attracted to enclosed spaces, which they enter through open windows or doors, and sometimes even through small gaps. The trumpets are a good way for them; therefore fireballs often come from stoves in kitchens. Having circled around the room, ball lightning leaves the room, leaving often along the same path that it entered.

Sometimes lightning rises and falls two or three times at distances from a few centimeters to several meters. Simultaneously with these ascents and descents, the fireball sometimes moves in a horizontal direction, and then it seems that the ball lightning makes jumps.

Often, ball lightning "settles" on the conductors, preferring the highest points, or roll along the conductors, for example, along drainpipes. Moving through the bodies of people, sometimes under clothes, fireballs cause severe burns and even death. There are many descriptions of cases of fatal injury to people and animals by ball lightning. Ball lightning can cause very severe damage to buildings.

There is no complete scientific explanation of ball lightning yet. Scientists have stubbornly studied ball lightning, but so far it has not been possible to explain all its various manifestations. There is still a lot of scientific work to be done in this area. Of course, there is nothing mysterious, "supernatural" in ball lightning either. This is an electrical discharge, the origin of which is the same as that of linear lightning. Undoubtedly, in the near future, scientists will be able to explain all the details of ball lightning as well as they were able to explain all the details of linear lightning.

As a rule, it is observed after lightning. Such phenomena caused a terrible feeling of fear in our ancestors, they considered them a manifestation of the wrath of the gods. During the time 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 person, a personal holiday was dedicated. Perun's Day was celebrated on July 21st. God was revered as giving life-giving rain for nature. On this day, the ancestors praised him, then consecrated their weapons, made a sacrifice, performed a ceremony of commemoration of the soldiers who fell in battles. The day ended with a hearty meal and games.

These times have sunk into oblivion, but the thunder and lightning remained. Let's take a look at specialized reference books or natural history textbooks. There we can read what thunder is - it is the sound of oscillating air around lightning, which 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 travel at a speed of about 300,000 km/s, while sound waves travel much more slowly, about 335 m/s. But not always thunder and lightning are united during a thunderstorm. It happens that a lightning flash has occurred, but no sounds are heard. This can happen if the storm is quite far away. It happens that thunder rumbles, but lightning is not visible - it will be difficult to see it on a clear day and when it forms inside a cloud.

If you want to know how far away a thunderstorm is, it's easy to do so. All you have to do is calculate how many seconds pass between the flash of electrical discharge and the sound of thunder, divide by three, and you will know how many kilometers away from you there is a thunderstorm. If you make several such calculations, then you can find out whether the cloud is approaching or moving away from you. In the case when thunder is not heard, it can be argued that the storm front is more than twenty kilometers away from you.

To understand how lightning is formed, you should remember the school curriculum - the section on electricity. It is known that all objects are charged either positively or negatively. During a thunderstorm, droplets in a cloud condense and pick up positively charged particles. The cloud becomes negatively charged relative to the Earth. In the case when the charge in the rain cloud is too large, a lightning discharge occurs. You can observe the same phenomenon when similar occurs between the clouds.

Now let's figure out what is thunder? During an electric discharge, the air expands very quickly, then contracts, while the air flows rapidly. When there is contact between them, a sound of thunder is heard. The volume of these peals can reach 120 decibels.

After reading this article, you will find out for yourself and be able to explain to little whys what thunder and lightning are, how they are formed and why there is a roar.

Just recently, a clear, clear sky was covered with clouds. The first drops of rain fell. And soon the elements demonstrated their strength to the earth. Thunder and lightning pierced the stormy sky. Where do such phenomena come from? Mankind has seen in them a manifestation of divine power for many centuries. Today we know about the occurrence of such phenomena.

Origin of thunderclouds

Clouds appear in the sky from condensation rising high above the ground and hover in the sky. Clouds are heavier and larger. They bring with them all the "special effects" inherent in bad weather.

Thunderclouds differ from ordinary ones in the presence of a charge of electricity. Moreover, there are clouds with a positive charge, and there are with a negative one.

To understand where thunder and lightning come from, one should rise higher above the earth. In the sky, where there are no obstacles for free flight, the winds blow stronger than on the ground. It is they who provoke the charge in the clouds.

The origin of thunder and lightning can be explained by just one drop of water. It has a positive charge of electricity in the center and a negative charge on the outside. The wind breaks it apart. One of them remains with a negative charge and has less weight. Heavier positively charged drops form the same clouds.

Rain and electricity

Before thunder and lightning appear in a stormy sky, the wind separates the clouds into positively and negatively charged ones. Rain falling on the ground carries some of this electricity with it. An attraction is formed between the cloud and the surface of the earth.

The negative charge of the cloud will attract the positive on the ground. This attraction will be located evenly on all surfaces that are on a hill and conduct current.

And now the rain creates all the conditions for the appearance of thunder and lightning. The higher the object is to the cloud, the easier it is for lightning to break through to it.

Origin of lightning

The weather has prepared all the conditions that will help to appear all its effects. She created the clouds from which thunder and lightning come.

The roof, charged with negative electricity, attracts the positive charge of the most exalted object to itself. Its negative electricity will go into the ground.

Both of these opposites tend to be attracted to each other. The more electricity in the cloud, the more it is in the most sublime object.

Accumulating in a cloud, electricity can break through the layer of air between it and the object, and sparkling lightning will appear, thunder will rumble.

How lightning develops

When a thunderstorm rages, lightning, thunder accompany it incessantly. Most often, the spark comes from a negatively charged cloud. It develops gradually.

First, a small stream of electrons flows from the cloud through a channel directed to the ground. In this place, the clouds accumulate electrons moving at high speed. Due to this, the electrons collide with air atoms and break them. Separate nuclei are obtained, as well as electrons. The latter also rush to the ground. While they are moving along the channel, all the primary and secondary electrons again split the air atoms that stand in their way into nuclei and electrons.

The whole process is like an avalanche. He is moving upwards. The air warms up, its conductivity increases.

More and more electricity from the cloud flows to the ground at a speed of 100 km / s. At this moment, lightning breaks a channel to the ground. On this road, laid by the leader, electricity begins to flow even faster. There is a discharge that has tremendous power. Reaching its peak, the discharge decreases. A channel heated by such a powerful current glows. And you can see lightning in the sky. Such a discharge does not last long.

The first discharge is often followed by a second one along the laid channel.

How does thunder appear

Thunder, lightning, rain are inseparable during a thunderstorm.

Thunder occurs for the following reason. The current in the lightning channel is formed very quickly. The air is very hot during this. This is why it expands.

It happens so fast that it looks like an explosion. Such a push shakes the air violently. These vibrations lead to the appearance of a loud sound. That's where lightning and thunder come from.

As soon as the electricity from the cloud reaches the ground and disappears from the channel, it cools very quickly. The compression of air also results in thunder.

The more lightning passed through the channel (there can be up to 50 of them), the longer the air shaking. This sound is reflected from objects and clouds, and an echo occurs.

Why is there an interval between lightning and thunder

In a thunderstorm, lightning is followed by thunder. Its delay from lightning is due to the different speeds of their movement. Sound moves at a relatively low speed (330 m/s). This is only 1.5 times faster than the movement of a modern Boeing. The speed of light is much greater than the speed of sound.

Thanks to this interval, it is possible to determine how far the sparkling lightning and thunder are from the observer.

For example, if 5 seconds elapsed between lightning and thunder, this means that the sound traveled 330 m 5 times. By multiplying, it is easy to calculate that the lightning from the observer was at a distance of 1650 m. If a thunderstorm passes closer than 3 km from a person, it is considered close. If the distance is in accordance with the appearance of lightning and thunder further, then the thunderstorm is distant.

Lightning in numbers

Thunder and lightning have been modified by scientists, and the results of their research are presented to the public.

It was found that the potential difference preceding lightning reaches billions of volts. The current strength at the same time at the moment of discharge reaches 100 thousand A.

The temperature in the channel heats up to 30 thousand degrees and exceeds the temperature on the surface of the Sun. Lightning travels from the clouds to the ground at a speed of 1000 km/s (0.002 s).

The internal channel through which the current flows does not exceed 1 cm, although the visible one reaches 1 m.

Around 1800 thunderstorms occur continuously in the world. The probability of being killed by lightning is 1:2000000 (same as dying from falling out of bed). The chance of seeing ball lightning is 1 in 10,000.

Ball lightning

On the way to studying where thunder and lightning come from in nature, ball lightning is the most mysterious phenomenon. These round fiery discharges have not yet been fully explored.

Most often, the shape of such lightning resembles a pear or watermelon. It lasts up to several minutes. Appears at the end of a thunderstorm in the form of red clots from 10 to 20 cm in diameter. The largest ball lightning ever photographed was about 10m in diameter. It makes a buzzing, hissing sound.

It can disappear quietly or with a slight crackle, leaving a smell of burning and smoke.

The movement of lightning does not depend on the wind. They are drawn into enclosed spaces through windows, doors, and even cracks. If they come into contact with a person, they leave severe burns and can be fatal.

Until now, the causes of the appearance of ball lightning were unknown. However, this is not evidence of its mystical origin. In this area, research is underway that can explain the essence of such a phenomenon.

Having become acquainted with such phenomena as thunder and lightning, one can understand the mechanism of their occurrence. This is a consistent and rather complex physical and chemical process. It is one of the most interesting phenomena of nature, which is found everywhere and therefore affects almost every person on the planet. Scientists have solved the mysteries of almost all types of lightning and even measured them. Ball lightning today is the only undisclosed secret of nature in the field of the formation of such natural phenomena.

16.05.2017 18:00 3519

Where do thunder and lightning come from?

Everyone knows what a thunderstorm is - it is the flashing of lightning and the roar of thunder. Many people (especially children) are even very afraid of her. But where do thunder and lightning come from? And in general, what kind of phenomenon is this?

A thunderstorm is indeed a rather unpleasant and even eerie natural phenomenon, when gloomy, heavy clouds cover the sun, lightning flashes, thunder rumbles, and rain pours from the sky ...

And the sound that arises in this case is nothing more than a wave caused by strong vibrations in the air. In most cases, the volume increases towards the end of the roll. This is due to the reflection of sound from the clouds. This is what thunder is.

Lightning is a very powerful electrical discharge of energy. It occurs as a result of strong electrification of clouds or the earth's surface. Electric discharges occur either in the clouds themselves, or between two neighboring clouds, or between a cloud or the ground.

The process of occurrence of lightning is divided into the first strike and all subsequent after it. The reason is that the very first lightning strike creates a path for an electrical discharge. A negative electrical discharge accumulates in the lower part of the cloud.

The earth's surface has a positive charge. Therefore, electrons (negatively charged particles, one of the basic units of matter) located in the cloud are attracted to the ground like a magnet and rush down.

As soon as the first electrons reach the earth's surface, a channel (a kind of passage) free for the passage of electrical discharges is created, along which the remaining electrons rush down.

The electrons near the ground are the first to leave the channel. Others are rushing to take their place. As a result, a condition is created under which the entire negative discharge of energy comes out of the cloud, creating a powerful flow of electricity directed to the ground.

It is at this moment that a flash of lightning occurs, which is accompanied by peals of thunder.

Electrified clouds create lightning. But not every cloud contains enough power to break through the atmospheric layer. For manifestation of force, elements certain circumstances are necessary.

Air masses are in constant motion. Warm air goes up, and cold air goes down. When particles move, they are electrified, that is, they are saturated with electricity.

Different parts of the cloud accumulate an unequal amount of energy. When it becomes too much, there is a flash, which is accompanied by thunder. This is the storm

What are lightning bolts? Someone might think that lightning is all the same, they say a thunderstorm is a thunderstorm. However, there are several types of lightning that are very different from each other.

Line lightning is the most common variety. It looks like an upside down overgrown tree. Several thinner and shorter "processes" depart from the main canal (trunk).

The length of such lightning can reach up to 20 kilometers, and the current strength is 20,000 amperes. Its speed is 150 kilometers per second. The temperature of the plasma filling the lightning channel reaches 10,000 degrees.

intracloud lightning- the emergence of this type is accompanied by a change in electric and magnetic fields, and the emission of radio waves. Such lightning is most likely to be found closer to the equator. It is extremely rare in temperate climates.

If there is lightning in the cloud, then a foreign object that violates the integrity of the shell, for example, an electrified aircraft, can also force it to get out. Its length can vary from 1 to 150 kilometers.

ground lightning- This is the longest type of lightning, so the consequences of it can be devastating.

Since there are obstacles in its path, in order to get around them, lightning is forced to change its direction. Therefore, it reaches the ground in the form of a small staircase. Its speed is approximately 50 thousand kilometers per second.

After the lightning passes its way, it finishes its movement for several tens of microseconds, while its light weakens. Then the next stage begins: the repetition of the path traveled.

The most recent discharge surpasses all previous ones in brightness, and the current in it can reach hundreds of thousands of amperes. The temperature inside the lightning fluctuates around 25,000 degrees.

lightning sprite. This variety was discovered by scientists relatively recently - in 1989. This lightning is very rare and was discovered quite by accident. Moreover, it lasts only some tenths of the 1st second.

Sprite differs from other electrical discharges in the height at which it appears - about 50-130 kilometers, while other species do not overcome the 15-kilometer barrier. In addition, the lightning sprite has a huge diameter, which can reach 100 km.

Such lightning looks like a vertical column of light and flashes not one by one, but in groups. Its color can be different, and depends on the composition of the air: closer to the ground, where there is more oxygen, it is green, yellow or white. And under the influence of nitrogen, at an altitude of more than 70 km, it acquires a bright red hue.

pearl lightning. This lightning, like the previous one, is a rare natural phenomenon. Most often, it appears after the linear one and completely repeats its trajectory. It represents balls located at a distance from each other and resembling beads.

Ball lightning. This is a special variety. A natural phenomenon where lightning takes the form of a ball that shines and floats across the sky. In this case, the trajectory of its flight becomes unpredictable, which makes it even more dangerous for humans.

In most cases, ball lightning occurs in combination with other types. However, there are cases when it appeared even in sunny weather. The size of the ball can be from ten to twenty centimeters.

Its color is blue, or orange or white. And the temperature is so high that if the ball suddenly bursts, the liquid surrounding it evaporates, and metal or glass objects melt.

A ball of such lightning can exist for quite a long time. When moving, it can suddenly change its direction, hang in the air for a few seconds, deviate sharply to one side. She appears in one instance, but always unexpectedly. The ball may descend from the clouds, or suddenly appear in the air from behind a pole or tree.

And if ordinary lightning can only strike something - a house, a tree, etc., then ball lightning can penetrate into a closed space (for example, a room) through an outlet, or turned on household appliances - a TV, etc.

What lightning is considered the most dangerous?

Usually, the first thunder and lightning strike is followed by the second. This is due to the fact that the electrons in the first flash create an opportunity for the second passage of electrons. Therefore, subsequent flashes occur one after another, almost without time intervals, hitting the same place.

Lightning emerging from a cloud with its electric discharge can cause serious harm to a person and even kill. And even if her blow does not hit a person directly, but has to be nearby, the health consequences can be very bad.

To protect yourself, you must follow some rules:

So during a thunderstorm, in no case should you swim in the river or the sea! You must always be on dry land. In this case, it is necessary to be as close to the surface of the earth as possible. That is, you do not need to climb a tree and even more stand under it, especially if it is alone in the middle of an open place.

Also, do not use any mobile devices (phones, tablets, etc.) because they can attract lightning.

Lightning is a powerful electrical discharge. It occurs when there is a strong electrification of the clouds or the earth. Therefore, lightning discharges can occur either within a cloud, or between neighboring electrified clouds, or between an electrified cloud and the ground. A lightning discharge is preceded by the occurrence of a difference in electrical potentials between neighboring clouds or between a cloud and the ground.

Electrization, that is, the formation of attractive forces of an electrical nature, is well known to everyone from everyday experience.

If you comb clean dry hair with a plastic comb, they begin to be attracted to it, or even sparkle. After that, the comb can attract other small objects, such as small pieces of paper. This phenomenon is called electrification by friction.

What causes clouds to become electrified? After all, they do not rub against each other, as happens when an electrostatic charge forms on the hair and on the comb.

A thundercloud is a huge amount of steam, some of which is condensed in the form of tiny droplets or ice floes. The top of a thundercloud can be at a height of 6-7 km, and the bottom hangs above the ground at a height of 0.5-1 km. Above 3-4 km, the clouds consist of ice floes of different sizes, since the temperature there is always below zero. These ice floes are in constant motion, caused by ascending currents of warm air from the heated surface of the earth. Small pieces of ice are easier than large ones to be carried away by ascending air currents. Therefore, "nimble" small ice floes, moving to the upper part of the cloud, all the time collide with large ones. Each such collision leads to electrification. In this case, large pieces of ice are charged negatively, and small pieces are positively charged. Over time, positively charged small pieces of ice are at the top of the cloud, and negatively charged large ones at the bottom. In other words, the top of a thundercloud is positively charged, while the bottom is negatively charged.

The electric field of the cloud has a huge intensity - about a million V/m. When large oppositely charged regions come close enough to each other, some electrons and ions, running between them, create a glowing plasma channel through which the rest of the charged particles rush after them. This is how lightning occurs.

During this discharge, huge energy is released - up to a billion J. The temperature of the channel reaches 10,000 K, which gives rise to the bright light that we observe during a lightning discharge. Clouds are constantly discharged through these channels, and we see the external manifestations of these atmospheric phenomena in the form of lightning.

The incandescent medium expands explosively and causes a shock wave, perceived as thunder.

We ourselves can simulate lightning, albeit a miniature one. The experiment should be carried out in a dark room, otherwise nothing will be visible. We need two oblong balloons. Let's inflate them and tie them up. Then, making sure that they do not touch, simultaneously rub them with a woolen cloth. The air that fills them is electrified. If the balls are brought together, leaving a minimum gap between them, then sparks will begin to jump from one to the other through a thin layer of air, creating light flashes. At the same time, we will hear a faint crackle - a miniature copy of thunder during a thunderstorm.

Everyone who has seen lightning has noticed that it is not a brightly glowing straight line, but a broken line. Therefore, the process of formation of a conductive channel for a lightning discharge is called its "step leader". Each of these "steps" is the place where the electrons accelerated to near-light speeds stopped due to collisions with air molecules and changed the direction of movement.

Thus, lightning is a breakdown of a capacitor, in which the dielectric is air, and the plates are clouds and earth. The capacitance of such a capacitor is small - about 0.15 microfarads, but the energy reserve is huge, since the voltage reaches a billion volts.

One lightning usually consists of several discharges, each of which lasts only a few tens of millionths of a second.

Lightning most often occurs in cumulonimbus clouds. Lightning also occurs during volcanic eruptions, tornadoes, and dust storms.

There are several types of lightning according to the shape and direction of the discharge. Discharges can occur:

• between the storm cloud and the earth,
• between two clouds
• inside the cloud
• move out of the clouds into the clear sky.