How thunderstorms and lightning for children are formed. Why does the thunder come from? How storm clouds form

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 generated within a very short period of time. At the same time, the air in the channel heats up very quickly and strongly, and it expands from heating. The expansion is so fast that it looks like an explosion. This explosion produces a concussion of the air, which is accompanied by strong sounds. After a sudden cessation of the current, the temperature in the lightning channel quickly drops, as the heat escapes into the atmosphere. The channel quickly cools and the air in it is therefore sharply compressed. It also causes the air to shake, which again produces sound. It is understood that repeated lightning strikes can cause continuous rumble and noise. In turn, sound is reflected from clouds, earth, houses and other objects and, creating multiple echoes, lengthens the thunder. Therefore, there are thunderclaps.

Like any sound, thunder travels through the air at a relatively low speed - about 330 meters per second. This speed is only one and a half times the speed of a modern aircraft. If the observer first sees lightning and only after a while hears thunder, then he can determine the distance that separates him from the lightning. Let, for example, 5 seconds pass between lightning and thunder. Since for every second the sound runs 330 meters, then in five seconds the thunder covered a distance five times greater, namely 1650 meters. This means that 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 from the observer at a distance of less than three kilometers are considered close, and thunderstorms passing at a greater distance are considered distant.

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

Sometimes lightning discharges are observed, which are fireballs. How ball lightning is formed has not yet been studied, but the available observations of 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 Gray, the sky suddenly lit up with a wide red lightning, and with a terrible crash a ball of fire fell from the sky, apparently , at 30-40 centimeters. Scattering sparks, he hit the end of the ridge of the roof, knocked 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 to the roof of the entrance, punched a hole in it, fell into the street and, rolling along it for a certain distance, gradually disappeared. Fire balloon

It didn’t do anything and didn’t harm anyone, despite the fact that there were many people on the street ”.

In fig. 13 shows a ball lightning captured by a photographic apparatus, and Fig. 14 shows a painting by an artist who painted a ball of lightning that fell into the courtyard.

Most often, ball lightning is in the shape of a watermelon or pear. It lasts for a relatively long time - from a small fraction of Fig. 13. Ball lightning. seconds to several minutes.

The most common duration for ball lightning is 3 to 5 seconds. Ball lightning most often appears at the end of a thunderstorm in the form of red glowing balls with a diameter of 10 to 20 centimeters. In more rare cases, it also has large times - 22

Measures. For example, lightning with a diameter of about 10 meters was photographed.

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

Ball lightning can fade quietly, but it can emit a faint crackle or even deafening

Explosion. As it disappears, it often leaves a pungent-smelling haze. Near the ground or in closed rooms, 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 closed rooms, into which they penetrate through open windows or doors, and sometimes even through small cracks. The pipes are a good way for them; therefore, fireballs often emerge from ovens in kitchens. Having circled around the room, ball lightning leaves the room, leaving often along the very path along which it entered.

Sometimes lightning rises and falls two or three times at distances from several centimeters to several

Kikh meters. Simultaneously with these ups and downs, the fireball sometimes moves in a horizontal direction, and then it seems that the ball lightning is making jumps.

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

There is no complete scientific explanation for ball lightning yet. Scientists have stubbornly studied ball lightning, but so far all its various manifestations have not been explained. There is still a lot of scientific work to be done in this area. Of course, there is nothing mysterious, "supernatural" in ball lightning. This is an electrical discharge, the origin of which is the same. as with 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,

Thunderstorms are quite frequent during the warm season - impressive natural phenomena, nevertheless, causing not only curiosity, but also fear. During a thunderstorm, electrical discharges arise between the clouds and the Earth, which are clearly visible and audible: lightning is observed in the form of branching luminous lines piercing the sky, and a little later we hear a rolling sound of thunder. At the same time, as a rule, heavy rain is observed, accompanied by squall wind and hail. Thunderstorms are one of the most dangerous atmospheric phenomena: only floods are associated with more deaths than thunderstorms. Interest in the study of natural electricity originated in ancient times. The first to investigate the electrical nature of lightning was Benjamin Franklin, an American politician, but at the same time a scientist and inventor. It was he who, back in 1752, proposed the first design of a lightning rod. Let's try to figure out what danger a thunderstorm carries, and what you need to know and do to protect yourself.

At the same time, about one and a half thousand thunderstorms act on the Earth, the average intensity of discharges is estimated at 100 lightning per second, or over 8 million per day. Thunderstorms are distributed unevenly over the planet's surface. Thunderstorms are observed over an ocean about ten times less than over continents. In the tropical and equatorial zones (from 30 ° north latitude to 30 ° south latitude), about 78% of all lightning discharges are concentrated. The maximum thunderstorm activity occurs in Central Africa. In the polar regions of the Arctic and Antarctic and over the poles, thunderstorms practically never happen. The intensity of thunderstorms follows the sun: the maximum thunderstorms occur in the summer (at mid-latitudes) and in the afternoon. The minimum of registered thunderstorms falls on the time before sunrise. The geographical features of the area also affect thunderstorms: strong thunderstorm centers are located in the mountainous regions of the Himalayas and the Cordilleras.

During a thunderstorm, a huge voltage arises between the clouds and the Earth, reaching a value of 1,000,000,000 V. At this voltage, the air is ionized, turning into plasma, and a gigantic electric discharge with a current strength of up to 300,000 A. The plasma temperature in lightning exceeds 10,000 ° C. Lightning is manifested by a bright flash of light and a shock wave of sound, which is later heard as thunder. Lightning is also dangerous because it can strike completely unexpectedly, and its path can be unpredictable. However, the distance to the thunderstorm front and the speed of its approaching or receding can be easily determined using a stopwatch. To do this, it is necessary to detect the time between the flash of lightning and the clap of thunder. The speed of sound in the air is about 340 m / s, so if you heard thunder 10 seconds after the flash of light, then about 3.4 km before the thunderstorm front. By measuring in this way the time between a flash of light and thunder, as well as the time between different lightning strikes, it is possible to determine not only the distance to them, but also the speed of approach or removal of the thunderstorm front:

where is the speed of sound, is the time between the flash of light and the thunder of the first lightning, is the time between the flash of light and the thunder of the second lightning, is the time between the lightning. If the speed value turns out to be positive, then the thunderstorm front is approaching, and if it is negative, it moves away. It should be borne in mind that the direction of the wind does not always coincide with the direction of the thunderstorm.

If, nevertheless, you are caught in a thunderstorm, then you should follow a number of simple rules to protect yourself:

Firstly, during a thunderstorm, it is advisable to avoid open areas. Lightning is more likely to strike the highest point; a lonely person in the field is that very point. If for some reason you are left alone in the field with a thunderstorm, hide in any possible depression: a groove, hollow or the lowest place of the field, squat down and bend your head. It should be remembered that sandy and stony soils have lower electrical conductivity, which means they are safer than clay soils. Do not hide under freestanding trees, as they are primarily susceptible to lightning strikes. And if you are in the forest, it is best to hide under low-growing trees with a dense crown.

Secondly, during thunderstorms, avoid water, as natural water is a good conductor. A lightning strike spreads around the reservoir in a radius of about 100 meters. Often it hits the banks. Therefore, during a thunderstorm, it is necessary to move away from the coast, while you cannot swim and fish. In addition, it is advisable to get rid of metal objects during a thunderstorm. Watches, chains, and even an umbrella open over your head are potential targets for a strike. There are cases of lightning striking a bunch of keys in a pocket.

Thirdly, if a thunderstorm caught you in the car, it protects you from lightning well enough, since even with a lightning strike, the discharge goes along the metal surface. Therefore, close the windows, turn off the radio and GPS navigator. Do not touch any metal parts of the vehicle. It is very dangerous to talk on a mobile phone during a thunderstorm. It is best to turn it off during a thunderstorm. There were cases when an incoming call caused a lightning strike. A bicycle and a motorcycle, unlike a car, will not save you from a thunderstorm. It is necessary to dismount, lay the vehicle on the ground and move about 30 m away from it.

There are different types of lightning in nature: linear (ground, intra-cloud, lightning in the upper atmosphere) and ball lightning - glowing formations floating in the air, a unique rare natural phenomenon. If the nature of linear lightning is clear and its behavior is more predictable, then the nature of ball lightning still holds many secrets. Despite the fact that the probability of a person being struck by ball lightning is small, nevertheless, it poses a serious danger, since there are no reliable methods and rules for protecting against it.

The behavior of ball lightning is unpredictable. She can appear unexpectedly anywhere, including in enclosed spaces. Cases of the appearance of ball lightning from a telephone receiver, electric shaver, switch, socket, loudspeaker have been noted. Quite often, it enters buildings through pipes, open windows and doors. There are cases when ball lightning penetrated into the room through narrow slots and even a keyhole. The sizes of ball lightning can be different: from several centimeters to several meters. In most cases, ball lightning easily hovers or rolls above the ground, sometimes bouncing, but it can also hover above the ground. According to eyewitnesses, ball lightning reacts to wind, draft, ascending and descending air currents. But this is not always the case: there are cases when ball lightning did not react in any way to air currents.

Ball lightning can suddenly appear and just as suddenly disappear without harming a person or premises. For example, it can fly through the window and fly out of the room through an open door or chimney, flying past you. In this case, you should be aware that any contact with a person leads to severe injuries, burns, and in most cases to death. Therefore, if you see ball lightning, it is safest to move away from it as far as possible.

In addition, ball lightning often explodes. The resulting air shockwave can injure a person or cause damage. For example, there are cases of lightning explosions in stoves, chimneys, which led to serious destruction. The temperature inside ball lightning reaches 5000 ° C, so it can cause a fire. The statistics on the behavior of ball lightning indicate that in 80% of cases the explosions were not dangerous, but serious consequences still occurred in 10% of the explosions.

According to the proposed method, we propose that you calculate the distance to the lightning discharge and its speed if the first thunder was heard 20 seconds after observing the first lightning, and the second one 15 seconds after observing the second lightning. The time between lightning is 1 minute.

Ancient people did not always consider thunder and lightning, as well as the accompanying thunderclap, as a manifestation of the anger of the gods. For example, for the Greeks, thunder and lightning were symbols of supreme power, while the Etruscans considered them to be omens: if a flash of lightning was seen from the east, it meant that everything would be fine, and if it sparkled in the west or northwest, vice versa.

The idea of \u200b\u200bthe Etruscans was adopted by the Romans, who were convinced that a lightning strike from the right side was sufficient reason to postpone all plans for a day. The Japanese had an interesting interpretation of heavenly sparks. Two vajras (lightning bolts) were considered symbols of Aizen-meo, the god of compassion: one spark was on the deity's head, the other he held in his hands, suppressing with it all the negative desires of humanity.

Lightning is a huge electrical discharge, which is always accompanied by a flash and thunderous rumblings (a shining discharge channel, reminiscent of a tree, is clearly visible in the atmosphere). In this case, a flash of lightning is almost never one, it is usually followed by two, three, often reaching several tens of sparks.

These discharges are almost always formed in cumulonimbus clouds, sometimes in large stratus clouds: the upper boundary often reaches seven kilometers above the planet's surface, while the lower part can almost touch the ground, staying no higher than five hundred meters. Lightning can form both in one cloud and between nearby electrified clouds, as well as between a cloud and the ground.

A thundercloud consists of a large amount of steam, condensed in the form of ice floes (at an altitude exceeding three kilometers, these are almost always ice crystals, since the temperature indicators here do not rise above zero). Before the cloud becomes a thundercloud, ice crystals begin to actively move inside it, while streams of warm air ascending from the heated surface help them to move.

The air masses carry away smaller pieces of ice with them, which, while moving, constantly bump into larger crystals. As a result, smaller crystals are positively charged, while larger crystals are negatively charged.

After small ice crystals collect at the top and large ones at the bottom, the top of the cloud is positively charged, the bottom negative. Thus, the strength of the electric field in the cloud reaches extremely high levels: a million volts per meter.

When these oppositely charged regions collide with each other, at the places of contact, ions and electrons form a channel through which all charged elements rush down and an electric discharge is formed - lightning. At this time, such a powerful energy is released that its power would be quite enough to power a 100 W light bulb for 90 days.

The channel heats up to almost 30 thousand degrees Celsius, which is five times the temperature of the Sun, forming a bright light (the flash usually lasts only three quarters of a second). After the formation of the channel, the thundercloud begins to discharge: the first discharge is followed by two, three, four or more sparks.

A lightning strike resembles an explosion and causes the formation of a shock wave, extremely dangerous for any living creature that finds itself near the channel. A shock wave of the strongest electrical discharge a few meters away from itself is quite capable of breaking trees, injuring or concussion, even without a direct electric shock:

• At a distance of up to 0.5 m to the channel, lightning can destroy weak structures and injure a person;
• At a distance of up to 5 meters, buildings remain intact, but can knock out windows and stun a person;
• At large distances, the shock wave does not bear negative consequences and turns into a sound wave known as thunderclaps.

Rolling thunder

A few seconds after the lightning strike was recorded, due to a sharp increase in pressure along the channel, the atmosphere heats up to 30 thousand degrees Celsius. As a result of this, explosive vibrations of the air occur and thunder occurs. Thunder and lightning are closely interconnected with each other: the length of the discharge is often about eight kilometers, so the sound from its different parts reaches at different times, forming thunderous rumblings.

Interestingly, by measuring the time that elapsed between thunder and lightning, you can find out how far the epicenter of the thunderstorm is from the observer.

To do this, you need to multiply the time between lightning and thunder by the speed of sound, which is from 300 to 360 m / s (for example, if the time interval is two seconds, the epicenter of the thunderstorm is a little more than 600 meters from the observer, and if three - at a distance kilometers). This will help determine if a thunderstorm is receding or approaching.

Amazing fireball

One of the least studied, and therefore the most mysterious natural phenomena, is ball lightning - a luminous plasma ball moving through the air. It is mysterious because the principle of the formation of ball lightning is still unknown: despite the fact that there are a large number of hypotheses explaining the reasons for the appearance of this amazing natural phenomenon, there were objections to each of them. Scientists have not been able to experimentally achieve the formation of ball lightning.

Ball-shaped lightning can exist for a long time and move along an unpredictable trajectory. For example, it is quite capable of hovering in the air for several seconds, and then darting to the side.

Unlike a simple discharge, a plasma ball is always one: until two or more fire lightnings were simultaneously recorded. Ball lightning sizes vary from 10 to 20 cm. Ball lightning is characterized by white, orange or blue tones, although other colors are often found, up to black.

Scientists have not yet determined the temperature indicators of ball lightning: despite the fact that according to their calculations, it should fluctuate from one hundred to a thousand degrees Celsius, people who were near this phenomenon did not feel the heat emanating from ball lightning.

The main difficulty in studying this phenomenon is that scientists rarely manage to record its appearance, and eyewitness testimonies often cast doubt on the fact that the phenomenon they observed was really ball lightning. First of all, the testimony differs as to the conditions in which she appeared: mainly she was seen during a thunderstorm.

There are also indications that ball lightning can appear on a fine day: descend from clouds, appear in the air, or appear from behind some object (tree or post).

Another characteristic feature of ball lightning is its penetration into closed rooms, it was even noticed in the cockpits (a fireball can penetrate through windows, go down through ventilation ducts and even fly out of sockets or TVs). Also, situations were repeatedly documented when the plasma ball was fixed in one place and constantly appeared there.

Often, the appearance of ball lightning does not cause trouble (it quietly moves in air currents and after some time flies away or disappears). But, sad consequences were also noticed when it exploded, instantly evaporating the liquid located nearby, melting glass and metal.

Possible dangers

Since the appearance of ball lightning is always unexpected, having seen this unique phenomenon near you, the main thing is not to panic, not to move abruptly and not to run anywhere: fire lightning is very susceptible to air vibrations. It is necessary to quietly leave the trajectory of the ball and try to stay as far from it as possible. If a person is in the room, you need to slowly walk to the window opening and open the window: there are many stories when a dangerous ball left the apartment.

Nothing can be thrown into the plasma ball: it is quite capable of exploding, and this is fraught not only with burns or loss of consciousness, but cardiac arrest. If it happened that the electric ball caught a person, you need to transfer him to a ventilated room, wrap him up warmer, do heart massage, artificial respiration and immediately call a doctor.

What to do in a thunderstorm

When a thunderstorm begins and you see the approach of lightning, you need to find shelter and hide from the weather: a lightning strike is often fatal, and if people do survive, they often remain disabled.

If there are no buildings nearby, and a person is in the field at this time, he should take into account that it is better to hide from a thunderstorm in a cave. But it is advisable to avoid tall trees: lightning usually marks the largest plant, and if the trees are of the same height, it hits the one that conducts electricity better.

To protect a detached structure or structure from lightning, a high mast is usually installed near them, at the top of which a pointed metal rod is fixed, securely connected to a thick wire, at the other end there is a metal object buried deep in the ground. The scheme of work is simple: the rod from a thundercloud is always charged with a charge opposite to the cloud, which, flowing down the wire under the ground, neutralizes the charge of the cloud. This device is called a lightning rod and is installed on all buildings in cities and other human settlements.

Lightning is a powerful electrical discharge. It occurs when clouds or earth are strongly electrified. Therefore, lightning strikes can occur either inside a cloud, or between adjacent electrified clouds, or between an electrified cloud and the ground. A lightning strike is preceded by an electrical potential difference between adjacent clouds or between a cloud and the ground.

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

What causes cloud electrification? After all, they do not rub against each other, as is the case with the formation of an electrostatic charge on the hair and on the comb.

A thundercloud is a huge amount of steam, part of which is condensed in the form of tiny droplets or pieces of ice. The top of a thundercloud can be at an altitude of 6-7 km, and the bottom hangs above the ground at an altitude of 0.5-1 km. Above 3-4 km, the clouds consist of pieces of ice of different sizes, since the temperature there is always below zero. These pieces of ice are in constant motion caused by the 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 pieces of ice, 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 - positively. Over time, positively charged small pieces of ice appear in the upper part of the cloud, and negatively charged large ones - at the bottom. In other words, the top of the thundercloud is positively charged and the bottom negative.

The electric field of the cloud has a tremendous 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 luminous plasma channel through which the rest of the charged particles rush behind them. This is how a lightning discharge 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 discharging through these channels, and we see external manifestations of these atmospheric phenomena in the form of lightning.

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

We ourselves can simulate lightning, albeit miniature. The experiment should be performed in a dark room, otherwise nothing will be seen. We need two oblong balloons. We inflate them and tie them up. Then, making sure that they do not touch, at the same time rub them with a woolen cloth. The air filling 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 in a thunderstorm.

Everyone who saw the lightning noticed that it was not a brightly glowing straight line, but a broken line. Therefore, the process of forming a conductive channel for a lightning discharge is called a "step leader". Each of these "steps" is a place where 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 air is the dielectric, and clouds and earth are the plates. The capacity of such a capacitor is small - about 0.15 μF, 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 a millionth of a second.

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

There are several types of lightning in shape and direction of discharge. Discharges can occur:

• between a thundercloud and the ground,
• between two clouds,
• inside the cloud,
• leave the cloud in the clear sky.

A thunderstorm is an atmospheric phenomenon, albeit not so rare as, for example, the northern lights or the lights of St. Elmo, but from this it is no less bright and impressive with its indomitable strength and primordial power. It is not for nothing that all romantic poets and prose writers love to describe it in their works, and professional revolutionaries see a thunderstorm as a symbol of popular unrest and serious social upheaval. From a scientific point of view, a thunderstorm is a torrential rain, accompanied by a squalling increase in wind, lightning and peals of thunder. But, if with a downpour and wind, you probably already understand everything, then it is worth telling a little more about the rest of the components of a thunderstorm.

What is thunder and lightning

Lightning is a powerful electrical discharge in the atmosphere that can occur between individual cumulus clouds, and between rain clouds and the ground. Lightning is a kind of giant electric arc, the average length of which is 2.5 - 3 kilometers. The incredible power of lightning is evidenced by the fact that the current in the discharge reaches tens of thousands of amperes, and the voltage reaches several million volts. Considering that such a fantastic power is released within a few milliseconds, a lightning strike can be called a kind of electrical explosion of incredible power. It is clear that such a detonation inevitably causes the appearance of a shock wave, which then degenerates into a sound wave, and decays as it propagates in the air. Thus, it becomes obvious what thunder is.

Thunder is sound vibrations that occur in the atmosphere under the influence of a shock wave caused by a powerful electrical discharge. Taking into account the fact that the air in the lightning channel instantly heats up to a temperature of about 20 thousand degrees, which exceeds the temperature of the Sun's surface, such a discharge is inevitably accompanied by a deafening roar, like any other very powerful explosion. But lightning lasts less than a second, and we hear thunder in long rolls. Why does this happen, why does the thunder rumble? Scientists studying atmospheric phenomena also have an answer to this question.

Why do we hear thunder rolls

Thunderclaps occur in the atmosphere due to the fact that lightning, as we have already said, has a very long length and therefore the sound from its various sections does not reach our ear at the same time, although we see the light flash itself entirely at one moment. In addition, the reflection of sound waves from clouds and the surface of the earth, as well as their refraction and scattering, contributes to the occurrence of thunderclaps.

Thunder is the sound of lightning striking the air. When the first bolt of lightning strikes the ground, it carries an electrical charge. A spark charge bursts out of the ground towards her. When they are connected to the cloud, a current begins to rise, gaining strength up to 20,000 amperes. And the temperature of the channel through which the current is directed can become higher than 250,000 C. From such a high temperature, air molecules scatter, and it itself expands at a supersonic speed and forms shock waves. The deafening rumble generated by such waves is called thunderohm. Due to the fact that the speed of light significantly exceeds the speed of sound, lightning is visible immediately, and thunder heard much later. thunderbut occur due to the fact that the sound comes from different parts of the lightning, which has a significant length. In addition, the discharge itself does not occur in an instant, but lasts a certain time. The sound generated by this can be reflected by an echo from the surrounding objects: mountains, buildings and clouds. Therefore, people hear not one sound, but several echoes catching up with each other, thunderbone of which can exceed 100 decibels. To roughly calculate at what distance the lightning struck, you need to note the number of seconds that elapsed between the flash and the impact thunderand. And then divide the resulting figure by three. Comparing such calculations, one can also conclude whether a thunderstorm is approaching or, conversely, receding. Usually, thundernew rumbles can be heard at a distance of 15 to 20 kilometers from a lightning flash.

No matter how much science explains the essence of atmospheric electricity, people all the same shudder at lightning strikes and involuntarily shrink in anticipation of a thunderclap. Obviously, the memory of distant ancestors, who tried to find at least some protection from heavenly fire, speaks in most people.

Of course, there is nothing supernatural in atmospheric electricity, but this lightning and the thunderclaps that follow them do not look less impressive and menacing. So what exactly is lightning?

As you know from the school physics course, all objects have a very definite electric charge. The collision of charged particles with each other leads to the creation of large areas of positive and negative charges. When such regions are close enough to each other, a breakdown occurs and charged particles rush into the created channel. People perceive this breakdown as a lightning discharge.

If it is more or less clear with lightning, why is it followed by a terrifying roar, reminiscent of an artillery cannonade? After all, the same physics convinces people that the electric current cannot be seen, heard or otherwise detected, with the exception of special devices.

As it turns out, the whole point is in the air, or rather, in its properties. The fact is that, being, in fact, an insulator, at the moment of breakdown it heats up to a temperature of about 30,000 ° C. Moreover, the rate of heating and, accordingly, the expansion of the air environment expands explosively, which leads to the appearance of a shock wave, which the human ear perceives as a roar or thunder.

Therefore, lightning and thunder are inseparable because thunder is the result of lightning. Conversations that there is supposedly lightning without thunder and vice versa are groundless.

On the other hand, there are many unexplained things associated with lightning and its manifestations. Such types of lightning as linear, cord, cord, and ribbon are quite well-known and relatively well studied. In turn, they are single and branched. The most mysterious and so far unexplored lightning is ball lightning. The greatest number of oddities and mysteries, both documented and unproven, are associated with it.

It has been repeatedly noted by many eyewitnesses that lightning flickers. The fact is that lightning consists of many successive discharges lasting only a few tens of millionths of a second. This creates the flickering effect.

Lightning discharges are like between separate thunderclouds, between a cloud and the ground, and sometimes the discharge, for unclear reasons, goes vertically into the sky.

As for lightning coming from clouds into the ground, two types of them are known, positive and negative. Moreover, according to scientists, it is the positive discharges as more powerful that lead to fires.

Of course, everyone knows such an atmospheric phenomenon as a thunderstorm. Every day on Earth there are at least one and a half thousand thunderstorms. Most of them are observed over the continents, over the oceans there are much less. The maximum thunderstorm activity can be observed over the territory of Central Africa. Over the Arctic and Antarctic, this phenomenon is practically absent.

Thunderstorm is one of the most dangerous natural phenomena. Few people know, but the number of deaths that occurred during a thunderstorm can only be compared with floods. Inside a thundercloud or between the earth's surface and cumulus clouds, electrical discharges occur - lightning, which are accompanied by peals of thunder. Why does thunder rumble during a thunderstorm? Many are interested in this question, but before answering it, it is necessary to understand what a thunderstorm and lightning are. What is their nature, from what do they arise?

Storm

The thunderstorm is "triggered" by the energy generated by air convection. Warmer air rises upward, if the moisture reserve in the upper layers is sufficient, the prerequisites for the formation of a thunderstorm arise. In the upper layers of the atmosphere, there is a difference in electrical charges between pieces of ice due to their rapid movement. High humidity, ice floes and warm air rising from the ground contribute to the emergence of thunderclouds. Thunderstorms give rise to such a terrible phenomenon as tornadoes, which so often occur over the American continent. Tornadoes form under storm clouds.

Lightning

An interesting fact - lightning occurs not only on Earth. Astronomers have recorded lightning on Jupiter, Saturn, Venus and Uranus. The strength of the current in a lightning discharge ranges from 10 thousand to 100 thousand amperes, and the voltage can reach 50 million volts! Lightning reaches gigantic sizes - up to 20 kilometers. The temperature inside a lightning bolt can be five times the temperature on the surface of the sun.

The appearance of lightning in a thunderstorm is facilitated by the electrification of clouds. This is due to the fact that the thundercloud is very large. If the top of such a cloud is at a height of seven kilometers, then its lower edge can hang above the ground at a height of half a kilometer. At an altitude of 3-4 kilometers, water freezes and turns into small pieces of ice, which are in constant motion from the rising warm air currents rising from the ground.

Colliding with each other, the ice floes are electrified. Smaller ones are charged "positively", and larger ones - "negatively". Due to the difference in weight, small pieces of ice are at the top of the thundercloud, and large pieces are at the bottom. It turns out that the top of the cloud is positively charged, and the bottom is negative.

Approaching each other, differently charged regions create a plasma channel through which other charged particles rush. This is the lightning that we see. Since any current flows along the path of least resistance, lightning looks like a zigzag.

Thunder

In ancient times, people were equally afraid of thunder and lightning. It is not for nothing that many peoples called the Supreme God the Thunderer. Any lightning strike is accompanied by thunder. In fact, thunder is air vibrations. Flying lightning creates strong pressure in front of itself, this comes from strong heating. Then the air is compressed again. The sound wave is repeatedly reflected from the clouds, and at this moment there is a thunderclap.

By the way, by the time interval between a flash of lightning and thunder, you can determine the approximate distance to a thunderstorm. The speed of sound depends on the density of the air, you can take its approximate value equal to 300 meters per second. Having done simple calculations, anyone will receive an approximate distance to the raging elements. If the distance to the thunderstorm is very large (at least 20 kilometers), then the sounds of thunder will not reach a person's ears.

During a thunderstorm, you must not hide under trees standing alone. The chances are very high that lightning will strike the tree. Better to wait out the thunderstorm indoors with closed windows. If this is not possible, then a thicket of the forest is suitable for shelter.

Thunderstorms are frightening. No matter where we are. At home or outdoors. It's scary anyway. Dazzling glare, rolling rumble frightens. Sounds seem to catch up with each other, now approaching, then moving away. In ancient times, people considered the heavenly rumble to be the wrath of the gods. And lightning - a punishing sword. But we understand that there is a more earthly explanation for these phenomena. Why does the thunder rumble? Why is he inseparable from lightning? Why does it rain during a thunderstorm?

How do thunderclouds form?

There is water in the outside air. In the form of steam. Under the influence of high air temperature, warm steam rises from the water surface of the earth. Warm air drives it from below.

Temperatures are lower in the upper atmosphere. The higher the water vapor rises, the colder it gets around it. Accordingly, it cools down.

The atmosphere contains more than just gases and water. Dust is also present. The cooled steam condenses around its smallest particles. Small water droplets and ice floes turn into clouds. They are different. In the form of feathers or huge piles, white stripes on a heavenly slope, or torn rags.

Thunderclouds are formed by the collision of air masses. Then many, many water crystals are collected in the upper part. It turns out a kind of white dense shroud. It illuminates the entire cloud with cold, which takes on a rich shade of lead. That is why we call such clouds "lead", "heavy".

Spawn of Thunder and Lightning

Thunderclouds give birth to bliskavits. And lightning, in turn, is a heavenly rumble. How does this happen? Why does the thunder rumble?

1. Droplets and ice floes in the upper part of a thundercloud interact with air molecules and are charged with electricity. When they get heavy, they fall down. So the bottom of the cloud is charged negatively.

2. At the same time, a positive charge accumulates at the top of the cloud. And plus and minus attract.

3. Under the influence of positive and negative attraction, tension arises. Given the size of the cloud (up to ten kilometers wide), this voltage reaches hundreds of millions of volts. This is how lightning is born.

4. A spark emerging from a cloud follows to the ground. Its temperature is enormous - over twenty degrees. As a result of the rapid movement of the fiery arrow, great pressure is created in the atmosphere. And immediately behind it, the air is sharply compressed, returning to its original state. An explosive sound is produced. This is how thunder is born.

FAQ:

Why do we first see lightning and then hear the sound of thunder?

Because the speed of light is hundreds of millions of times the speed of sound.

Why do we hear thunder rolls?

Because the waves of sound meet various obstacles (clouds, earth) on their way and are reflected from them. This happens many times. Hence the rolling thunderous sounds.

Sometimes we see bliskavitsa, but we do not hear the rumbles. Why?

The thunderstorm is too far from us, more than twenty kilometers.

What is thunder? Thunder is the sound that accompanies a lightning strike during a thunderstorm. Sounds simple enough, but why does lightning sound like this? Any sound consists of vibrations that create sound waves in the air. Lightning is a huge discharge of electricity that shoots through the air, causing vibrations. Many have wondered more than once about where lightning and thunder come from and why thunder precedes lightning. There are quite explainable reasons for this phenomenon.

How does the thunder rumble?

Electricity passes through the air and vibrates the air particles. Lightning is accompanied by incredibly high temperatures, so the air around it is also very hot. Hot air expands, increasing the strength and amount of vibration. What is thunder? These are the sound vibrations arising from lightning strikes.

Why does the thunder not thunder at the same time as the lightning?

We see lightning before we hear thunder, because light travels faster than sound. There is an old myth that by counting the seconds between a flash of lightning and thunder, you can know the distance to the place where the storm is raging. However, from a mathematical point of view, this assumption has no scientific basis, since the speed of sound is approximately 330 meters per second.

Thus, for the thunder to travel one kilometer, it will take 3 seconds. Therefore, it would be more correct to count the number of seconds between the flash of lightning and the noise of thunder, and then divide this number by five, this will be the distance to the thunderstorm.

This mysterious phenomenon is lightning

The heat from the lightning electricity increases the ambient temperature to 27,000 ° C. Since lightning travels with incredible speed, the heated air simply does not have time to expand. The heated air is compressed, and its atmospheric pressure increases several times and becomes 10 to 100 times more than normal. Compressed air is forced outward from the lightning channel, forming a shockwave of compressed particles in each direction. Like an explosion, rapidly propagating waves of compressed air create a loud, booming burst of noise.

Based on the fact that electricity follows the shortest path, the prevailing number of lightning strikes is close to vertical. However, lightning can also branch out, as a result of which the sound color of the thunder rumble changes. Shock waves from different lightning forks bounce off each other, and low-hanging clouds and nearby hills help create a continuous grumbling of thunder. Why does the thunder rumble? Thunder is caused by the rapid expansion of air surrounding the path of lightning.

What causes lightning?

Lightning is an electric current. Inside a thundercloud high in the sky, numerous small pieces of ice (frozen raindrops) collide with each other as they move through the air. All these collisions create an electrical charge. After a while, the whole cloud is filled with electric charges. Positive charges, protons, form at the top of the cloud, while negative charges, electrons, form at the bottom of the cloud. And as you know, opposites attract. The main electrical charge is concentrated around anything that sticks out above the surface. It can be mountains, people, or lonely trees. The charge goes up from these points and eventually combines with the charge coming down from the clouds.

What is causing the thunder?

What is thunder? This is the sound caused by lightning, which is essentially a stream of electrons flowing between or within a cloud, or between a cloud and the ground. The air around these streams is heated to the point that it becomes three times hotter than the surface of the Sun. Simply put, lightning is a bright flash of electricity.

Such a stunning and at the same time frightening sight of thunder and lightning is a combination of dynamic vibrations of air molecules and their violation by means of electrical forces. This magnificent show once again reminds everyone of the powerful force of nature. If there was a rumble of thunder, lightning will soon flash, it is better not to be outside at this time.

Thunder: fun facts

• You can judge how close the lightning is by counting the seconds between the flash and the thunderclap. There are about 300 meters per second.
• During a large thunderstorm, it is common to see lightning and hear thunder, and thunder during snowfall is very rare.
• Lightning is not always accompanied by thunder. In April 1885, five lightning strikes struck the Washington Monument during a thunderstorm, and no one heard the thunder.

Watch out for lightning!

Lightning is a rather dangerous natural phenomenon, and it is better to stay away from it. If you are indoors during a thunderstorm, avoid water. It is an excellent conductor of electricity, so you shouldn't shower, wash your hands, dishes, or do laundry. Avoid using a telephone as lightning can strike outside telephone lines. Do not turn on electrical equipment, computers and appliances during a storm. Knowing what thunder and lightning are, it is important to behave correctly if suddenly a thunderstorm caught you by surprise. It is worth staying away from windows and doors. If someone is struck by lightning, you need to call for help and call an ambulance.