Since lightning is an electrical discharge through the thickness of an insulator - air, it occurs most often where the layer of air between the cloud and any object on the surface of the earth is smaller. Direct observations show this: lightning tends to strike high bell towers, masts, trees and other tall objects.
However, lightning does not only rush towards tall objects. From two adjacent masts of the same height, one made of wood and the other of metal, and standing not far from one another (Fig. 15), lightning will rush to the metal one. This will happen for two reasons. Firstly, metal conducts electric current much better than wood, even if it is damp. Secondly, the metal mast is well connected to the ground, and electricity from the ground can flow more freely to the mast during the development of the leader.
The latter circumstance is widely used to protect various buildings from lightning strikes. The greater the surface of the mast metal in contact with the ground, the easier it is for electricity to pass from the cloud to the ground. This can be compared to how a stream of liquid pours through a funnel into a bottle. If the hole in the funnel is large enough, the stream will immediately go into the bottle.
If the hole in the funnel is small, then the liquid will begin to overflow the edge of the funnel and spill out onto the floor.
Lightning can also strike a flat surface of the earth, but at the same time it also rushes to where the electrical conductivity of the soil is greater. For example, damp clay or marshy ground is more likely to be struck by lightning than dry sand or rocky, dry soil. For the same reason, lightning strikes the banks of rivers and streams, preferring them to tall but dry trees towering nearby.
This feature of lightning - rushing towards bodies that are well connected to the ground and well conducting - is widely used to implement various protective devices. This will be discussed in last chapter our book.
Since lightning consists of air heated to a very high temperature, its contact with various flammable materials ignites them. The temperature of the discharge channel reaches tens of thousands of degrees; this is many times higher than the temperature of a burning match, the flame of which can ignite paper, straw, wood, kerosene and many other materials. True, each individual flash of lightning lasts, as we have seen, very short time, but even during this time many materials can ignite.
Even an incomplete count shows that in the USSR in 1938 and 1939 there were about 6,000 fires caused by lightning discharges.
The largest number of fires caused by lightning occurs in rural areas. This is understandable, since buildings there often have wooden or thatched roofs, which easily catch fire.
The damage caused by lightning in industry is quite significant. For example, in America, 55% of oil fires over the past 20 years have been caused by lightning. Of the 620 thousand fires that occurred there in 1937, about 20 thousand were caused by lightning.
When lightning strikes thin wires, such as telegraph wires, they heat up and may melt.
Sometimes the wire completely disappears after a lightning discharge passes through it. This means that it evaporated into metallic vapors, in exactly the same way that water evaporates from a pan when boiled, turning into steam.
Falling to the ground, lightning pierces a certain layer of soil and with its heat sinteres or vitrifies the sand, leaving long tubes. Lightning leaves, as it were, receipts on the ground.
If we explain without abstruse physical terms, then lightning always strikes the highest object. Because lightning is an electrical discharge, and it travels along the path of least resistance. That is why he will first hit the tallest tree in the field and the very tall building in the city. For example, lightning strikes the Ostankino TV tower about 50 times a year!
The length of lightning can be up to 20 km, and its diameter can be from 10 to 45 cm. Lightning “lives” tenths of a second, and its average speed- 150 km/s. In this case, the current strength in lightning reaches 200,000 A.
What to do if lightning catches you in an open area
- Do not hide under tall trees, especially single ones. The most dangerous in in this case Deciduous trees such as oak and poplar are considered. But lightning strikes coniferous trees much less often, because they contain essential oils that have electrical resistance (by the way, linden, walnut and beech are also in the safety zone, they also contain oils). In this case, getting into bushes or low thickets is extremely unlikely.
- In open space, it is best to hide in a hole or trench. In this case, do not lie down on the ground under any circumstances: it is better to sit down, bending your head slightly so that it is not higher than surrounding objects. Keep your legs together to reduce the area of possible damage.
- Don't run. Airflow, which you create while running, can attract ball lightning.
- Fold your umbrella and turn off your mobile phone, and also get rid of other metal objects: place them at a safe distance (at least 15 m).
- If there are two or three of you, everyone should find a separate shelter for themselves, since our body is an excellent conductor for discharge.
- Do not swim in bodies of water during a thunderstorm. If bad weather takes you by surprise, do not run out of the water or wave your arms. Calmly and slowly exit the pond.
- If you are in the mountains, avoid sharp ledges and elevations.
How to Know When Lightning Is About to Strike
If you are in an open area and suddenly feel that your hair is standing on end, and your skin is slightly tingling, or you feel a vibration coming from objects, this means that it is about to boom.
Such sensations appear 3-4 seconds before a lightning strike. Immediately bend forward, placing your hands on your knees (never on the ground!), Place your heels next to each other so that the shock does not pass through your body.
What to do if you are indoors during a thunderstorm
- Close the vents, windows and doors.
- Unplug electrical appliances.
- Move away from windows and metal objects.
- If you need to make an urgent call, make it immediately after the lightning strike - and quickly.
What happens if lightning strikes a person
When a person is struck by lightning, the discharge causes general disturbances. Burns or wood-like red streaks may form where the lightning entered and exited. If the lesion was weak, tinnitus and general weakness appear.
But with severe damage, a person may faint, his body temperature drops sharply, his heartbeat slows down, and his breathing may stop. But the victim can still be saved in time.
Is it possible to survive being struck by lightning?
Yes. Firstly, despite the high temperature during the discharge, the impact does not last long and does not always even lead to serious burns.
Secondly, the main current often passes along the surface of the body, so in most cases a lightning strike is not fatal. By different estimates death occurs in 5–10% of cases.
The likelihood of survival increases if there is a person nearby who knows how to perform artificial respiration and cardiac massage. Even if the person seems dead, be sure to try to help him. Because there is always a chance of survival!
How to provide first aid if struck by lightning
- The victim must be placed on a hard surface.
- If a person is lucky and just has shock (loss of speech, fainting), try to bring him out of this state. If you happen to have ammonia with you, use it. Call an ambulance.
- If a person is unconscious and not breathing, mouth-to-mouth artificial respiration and chest compressions should be performed as soon as possible.
- Try non-stop resuscitation. You have a maximum of 15 minutes, after which the chances of salvation in case of severe damage are extremely small.
If we explain without abstruse physical terms, then lightning always strikes the highest object. Because lightning is an electrical discharge, and it travels along the path of least resistance. That is why he will first hit the tallest tree in the field and the tallest building in the city. For example, lightning strikes the Ostankino TV tower about 50 times a year!
The length of lightning can be up to 20 km, and its diameter can be from 10 to 45 cm. Lightning “lives” tenths of a second, and its average speed is 150 km/s. In this case, the current strength in lightning reaches 200,000 A.
What to do if lightning catches you in an open area
- Do not hide under tall trees, especially single ones. The most dangerous trees in this case are deciduous trees, such as oak and poplar. But lightning strikes coniferous trees much less often, because they contain essential oils that have electrical resistance (by the way, linden, walnut and beech are also in the safety zone, they also contain oils). In this case, getting into bushes or low thickets is extremely unlikely.
- In open space, it is best to hide in a hole or trench. In this case, do not lie down on the ground under any circumstances: it is better to sit down, bending your head slightly so that it is not higher than surrounding objects. Keep your legs together to reduce the area of possible damage.
- Don't run. The air current you create while running can attract ball lightning.
- Fold your umbrella and turn off your mobile phone, and also get rid of other metal objects: place them at a safe distance (at least 15 m).
- If there are two or three of you, everyone should find a separate shelter for themselves, since our body is an excellent conductor for discharge.
- Do not swim in bodies of water during a thunderstorm. If bad weather takes you by surprise, do not run out of the water or wave your arms. Calmly and slowly exit the pond.
- If you are in the mountains, avoid sharp ledges and elevations.
How to Know When Lightning Is About to Strike
If you are in an open area and suddenly feel that your hair is standing on end, and your skin is slightly tingling, or you feel a vibration coming from objects, this means that it is about to boom.
Such sensations appear 3-4 seconds before a lightning strike. Immediately bend forward, placing your hands on your knees (never on the ground!), Place your heels next to each other so that the shock does not pass through your body.
What to do if you are indoors during a thunderstorm
- Close the vents, windows and doors.
- Unplug electrical appliances.
- Move away from windows and metal objects.
- If you need to make an urgent call, make it immediately after the lightning strike - and quickly.
What happens if lightning strikes a person
When a person is struck by lightning, the discharge causes general disturbances. Burns or wood-like red streaks may form where the lightning entered and exited. If the lesion was weak, tinnitus and general weakness appear.
But with severe damage, a person may faint, his body temperature drops sharply, his heartbeat slows down, and his breathing may stop. But the victim can still be saved in time.
Is it possible to survive being struck by lightning?
Yes. Firstly, despite the high temperature during the discharge, the impact does not last long and does not always even lead to serious burns.
Secondly, the main current often passes along the surface of the body, so in most cases a lightning strike is not fatal. According to various estimates, death occurs in 5–10% of cases.
The likelihood of survival increases if there is a person nearby who knows how to perform artificial respiration and cardiac massage. Even if the person seems dead, be sure to try to help him. Because there is always a chance of survival!
How to provide first aid if struck by lightning
- The victim must be placed on a hard surface.
- If a person is lucky and just has shock (loss of speech, fainting), try to bring him out of this state. If you happen to have ammonia with you, use it. Call an ambulance.
- If a person is unconscious and not breathing, mouth-to-mouth artificial respiration and chest compressions should be performed as soon as possible.
- Try non-stop resuscitation. You have a maximum of 15 minutes, after which the chances of salvation in case of severe damage are extremely small.
There is a common stereotype that lightning strikes from top to bottom. This is far from true, because in addition to ground-based lightning, there are also intra-cloud lightning and even lightning that exists only in the ionosphere.
Lightning is a huge electrical discharge, the current in which can reach hundreds of thousands of amperes, and the voltage can reach hundreds of millions of watts. The length of some lightning in the atmosphere can reach tens of kilometers.
The nature of lightning
For the first time physical nature lightning was described by the American scientist Benjamin Franklin. In the early 1750s, he conducted an experiment to study atmospheric electricity. Franklin waited for the stormy weather to set in and launched a kite into the sky. The snake was struck by lightning, and Benjamin came to the conclusion about the electrical nature of lightning. The scientist was lucky - at about the same time, the Russian researcher G. Richman, who also studied atmospheric electricity, died from a lightning strike in the apparatus he designed.
The processes of lightning formation in thunderclouds have been most fully studied. If lightning passes through the cloud itself, it is called intracloud. And if it hits the ground, it is called ground.
Ground lightning
The process of ground lightning formation includes several stages. First, the electric field in the atmosphere reaches its critical values, ionization occurs and finally a spark discharge is formed, which strikes from the thundercloud into the ground.
Strictly speaking, lightning strikes only partially from top to bottom. First, an initial discharge rushes from the cloud towards the ground. The closer he gets to earth's surface, the more the electric field intensity increases. Because of this, a response charge is ejected from the surface of the Earth towards the approaching lightning. After this, the main lightning discharge is emitted through the ionized channel connecting heaven and earth. He really hits from top to bottom.
Intracloud lightning
Intracloud lightning is usually much larger than ground lightning. Their length can be up to 150 km. The closer the area is to the equator, the more often intracloud lightning occurs in it. While in northern latitudes the ratio of intra-cloud and ground-based lightning is approximately the same, in the equatorial zone intra-cloud lightning accounts for approximately 90% of all lightning discharges.
Sprites, elves and jets
In addition to the usual thunderstorm lightning, there are such little-studied phenomena as elves, jets and sprites. Sprites are similarities to lightning that appear at altitudes of up to 130 km. Jets form in the lower layers of the ionosphere and appear as blue discharges. Elven discharges also have a cone shape and can reach a diameter of several hundred kilometers. Usually elves appear at an altitude of about 100 km.
This was 20 years ago. We were then vacationing in a village in Mordovia. In those parts. and in the Penza region, too, in the summer there were often strong thunderstorms. The discharges were very strong, each thunderstorm brought some losses. Usually in terms of equipment (TVs and refrigerators instantly burned out, power lines were cut), but often people also suffered. Who stood under the tree, to whom ball lightning came through the house open window flew into the air, and someone stepped on a broken electrical wire in the rain.
It was incredible story a guy who was 16 years old and died when he accidentally stepped on a bare wire in the dark. The fact is that a thunderstorm hit the pole and it fell, pulling the wires with it. A man passing by wanted to pull the guy out, but it was raining, everything around was wet. The man tried to throw away the wire with a wet branch, but also received a shock, although not as strong. He brought the dead man in his arms home to his mother. The shock of the situation was that the previous, older brother died at the same age and just as absurdly - the guys were playing with a homemade crossbow in the forest, he stood by a pine tree and was shot in the head.
My grandmother was terribly afraid of thunderstorms. She closed all the doors and windows, went to the farthest room, sat on the bed and read prayers non-stop. Why the village did not have a lightning rod system - I don’t know. They were most afraid of ball lightning, since they appeared and behaved unpredictably.
We were visiting then. During the day a terrible storm broke out. Lightning strikes were heard more and more often, a thunderstorm raged right above us. At that moment the phone rang. I don’t know why I decided to pick up the phone, because I was visiting. But I was the closest to the phone. The moment I picked up the phone, lightning struck this very house. The sister saw a bright wave running through the wires to the telephone. She didn't have time to scream. I was stunned and my hand went numb for a few seconds. I guess I was lucky. Just a concussion and a slight concussion. I don’t know why we weren’t told in detail anywhere about behavior during a thunderstorm. That you can’t talk on the phone, you can’t ride a bike, you can’t hide under a tree, you can’t swim in a thunderstorm...
I recently found a very useful article on a hunters’ website about behavior during a thunderstorm - http://www.nexplorer.ru/news__11294.htm. This is very important! Believe me, all these tips are hard-won. They appeared because someone got hurt or died. I have seen signs in the mountains (for example, in Crimea) that a group of people were killed by lightning. These people died so that we could learn from their mistakes. Please read these rules carefully. You can save someone's life.
What to do during a thunderstorm to avoid being struck by lightning.
Thunderstorms in summer are a common and dangerous phenomenon. You need to know how to protect yourself during a thunderstorm, what to do to avoid being struck by lightning, how to escape from ball lightning, where lightning strikes... Remember two basic rules of behavior during a thunderstorm: avoid open areas and avoid water.
How to behave during a thunderstorm.
When powerful cumulonimbus and tower-shaped clouds form at any point on the horizon of a thunderstorm front, you should carefully monitor the development of cloudiness. It must be remembered that the wind does not give a correct idea of the direction of movement of a thunderstorm. Thunderstorms often go against the wind!
The distance to an approaching thunderstorm can be determined by counting the seconds separating the flash of lightning and the sound of the first clap of thunder:
A second pause means that a thunderstorm is at a distance of 300-400 m,
- three second - 1 km,
- four-second - 1.3 km, etc.
A thunderstorm is one of the most dangerous natural phenomena for humans. An instant lightning strike can cause paralysis, deep loss of consciousness, respiratory and cardiac arrest. When struck by lightning, specific burns remain on the victim’s body in the form of reddish stripes and burns with blisters. To avoid being struck by lightning, you need to know and follow some rules of conduct during a thunderstorm.
What is lightning?
Lightning is an electrical discharge high voltage, enormous power current, high power and very high temperature, occurring in nature. Electrical discharges occurring between cumulus clouds or between a cloud and the ground, are accompanied by thunder, heavy rain, often hail and heavy winds. There are many types of lightning. IN middle lane the most common are linear and ball lightning. They differ in appearance, but equally dangerous to humans.
What to do during a thunderstorm.
Summer thunderstorms are a common occurrence, but not everyone knows how to protect themselves during a thunderstorm or what to do to avoid being struck by lightning.
Employees of the Russian Ministry of Emergency Situations in the Moscow region give a number of simple tips What to do during a thunderstorm:
First, during a thunderstorm you should avoid open areas. Lightning, as you know, strikes the highest point; a lonely person in a field is that very point. If for some reason you are left alone in a field with a thunderstorm, hide in any possible depression: a ditch, hollow or the lowest place in the field, squat down and bend your head, rescuers advise.
Secondly, during a thunderstorm, avoid water, as it is an excellent conductor of current. A lightning strike spreads around a body of water within a radius of 100 meters. It often hits the banks. Therefore, during a thunderstorm, it is necessary to move away from the shore; you cannot swim or fish.
It is very dangerous to talk on the phone during a thunderstorm. mobile phone. It is best to turn off your cell phones during a thunderstorm. There have been cases when an incoming call was caused by lightning.
During a thunderstorm, it is advisable to get rid of metal objects. Watches, chains, and even an umbrella open above your head are potential targets for a strike. There are known cases of lightning striking a bunch of keys in a pocket.
To avoid being struck by lightning if you are in the forest.
Lightning in a forest almost never strikes the ground, with the exception of clearings, because trees are natural lightning rods, and the probability of lightning hitting a particular tree is directly proportional to its height. Therefore, stay away from tall trees. The smartest option is to sit between low-growing trees with dense crowns. At the same time, determine the approximate height of the trees you have chosen and try to be located from them at a distance not exceeding this height. Let’s say that the height of the trees is approximately 4-5 meters; accordingly, you need to place them between them so that each tree is at least 4-5 meters away. This is called the "cone of protection". It is better to sit in the so-called “fetal position” - the back is bent, the head is lowered on the legs and forearms bent at the knees, the feet are joined together.
1. That lightning most often strikes oaks, poplars, and elms.
2. Less often, lightning strikes spruce and pine.
3. Very rarely does lightning strike birches and maples.
During a thunderstorm in the forest you cannot: choose shelter under tall trees or near trees previously struck by a thunderstorm, split (the abundance of trees struck by lightning indicates that the soil in this area has high electrical conductivity, and a lightning strike in this area of the terrain is very likely), you cannot put up tents in the open, sit near burning fire (smoke is a good conductor of electricity).
To avoid being struck by lightning if you are in a field.
At the first signs of an approaching thunderstorm, you must: move as quickly as possible towards the nearest reliable shelter (forest, village), moving away from isolated trees or groves at the same time. If a free-standing tree is located on your way to the village, you should not go there. Priority task is removal from possible discharge zones. You need to move away at least 150-200 m. With the onset of a thunderstorm, if you still haven’t reached the shelter: you need to sit down as low as possible, and when the thunderstorm comes very close, lie down on the ground. And lie quietly, humbly, motionless. It should be remembered that sandy and rocky soils are safer than clay soils. And don’t rush to move when the thunderstorm starts to go away - wait 20-30 minutes after the last lightning strikes.
During a thunderstorm, you must not: move, especially walk straight; hiding in haystacks, under lonely trees or islands of trees, especially touching them with your hands and other parts of the body. Human psychology is such that in the big and powerful he tends to see protection. During a thunderstorm, the opposite law works: the smaller you are, the greater your chances of not getting discharged. Therefore, we avoid the trees.
To avoid being struck by lightning if you are near a body of water.
If a thunderstorm approaches, immediately leave the pond and go as far as possible from coastline. When a thunderstorm approaches, a person on a boat must immediately moor to the shore. If this is not possible, drain the boat, change into dry clothes, if available, raise the protective awning, put a life jacket, boots, equipment, etc. under you. electrically insulating items, cover with polyethylene so that rainwater flows overboard, not into the watercraft, but the polyethylene should not come into contact with water!
During a thunderstorm, you must not: climb into the water, hide in floodplain bushes and under trees.
To avoid being struck by lightning if you are in the mountains.
In mountainous areas, when a thunderstorm approaches, you should try to descend from high places - ridges, hills, passes, peaks, etc. It is dangerous to be near watercourses (cracks, gutters, etc.), since during a thunderstorm even small cracks filled with water become a conductor for the flow of electricity. It is best to stop near a high vertical plumb line (“finger”). In this case, the height of the plumb line must be at least 5-6 times greater than the height of the person; accordingly, the safety zone will be equal to the height of the plumb line measured in the horizontal plane. However, you cannot get closer than 2 m to the wall. You can hide in natural niches-caves in the slope, but also no closer than 2 m from the wall. Collect metal objects - climbing pitons, ice axes, saucepans - in a backpack and lower them on a rope 20-30 m down the slope.
During a thunderstorm in the mountains you cannot: lean or touch rocks, steep walls when moving or resting, or hide under rocky overhangs.
To avoid being struck by lightning if you are in a car.
The machine protects the people inside quite well, since even when struck by lightning, the discharge occurs on the surface of the metal. Therefore, if a thunderstorm finds you in your car, close the windows, turn off the radio, cell phone and GPS navigator. Do not touch door handles or other metal parts.
To avoid being struck by lightning if you are on a motorcycle.
A bicycle and a motorcycle, unlike a car, will not save you from a thunderstorm. It is necessary to dismount, lay down the vehicle and move to a distance of approximately 30 m from it.
If you are in a country house or garden during a thunderstorm, you should:
Close doors and windows and eliminate drafts.
- Do not light the stove, close the chimney, since the smoke coming out of the chimney has high electrical conductivity and can attract an electric discharge.
- Turn off the TV, radio, electrical appliances, disconnect the antenna.
- Turn off communication devices: laptop, mobile phone.
- You should not be near a window or in the attic, or near massive metal objects.
If there is a thunderstorm outside:
Do not be in open areas, near metal structures or power lines.
- Do not touch anything wet, iron or electrical.
- Remove all metal jewelry (chains, rings, earrings) and put it in a leather or plastic bag.
- Do not open your umbrella over yourself.
- Under no circumstances should you seek shelter under large trees.
- It is not advisable to be near the fire.
- Do not go near wire fences.
- Do not go out to remove clothes drying on the lines, as they also conduct electricity.
- Do not ride a bicycle or motorcycle.
- Do not swim, move away from the pond.
- It is very dangerous to talk on a mobile phone during a thunderstorm; it must be turned off.
- A thunderstorm usually hits the highest point on its path. Lonely man in a field - this is the one high point. It’s even worse to be on a lonely hill in a thunderstorm! If for some reason you are left alone in a field with a thunderstorm, hide in any possible depression: a ditch, hollow or the lowest place in the field, squat down and bend your head. Lying on wet ground during a thunderstorm is not recommended.
- Never try to hide under a lonely tree.
- During a thunderstorm, do not swim, fish, or stay near bodies of water.
How to escape from ball lightning.
If you are at home or in any room during a thunderstorm, you should not be near batteries, windows, electrical appliances, antennas, wires and metal objects. Close windows, doors, chimneys and vents to avoid drafts that attract ball lightning.
Ball lightning looks like a freely floating horizontally or chaotically glowing ball with a diameter of several centimeters to several meters. Ball lightning can exist from a few seconds to three tens of seconds. It has great destructive power, causing fires, severe burns and sometimes death of humans or animals. It appears unpredictably and also disappears unexpectedly. Penetrates even into a closed room through a switch, socket, pipe, or keyhole.
Remember, if you witness a phenomenon such as ball lightning, try not to move or run away from it. Lightning is attracted to moving, tall, metal and wet objects. If ball lightning flies into the room, you need to slowly, holding your breath, leave the room. If this is not possible, you need to stand without moving. After 10-100 seconds, she will go around you and disappear. Ball lightning can appear without causing harm to a person or premises, but it can explode, and the resulting air wave can injure a person. Ball lightning has a temperature of about 5000° C and can cause a fire.
Help for a lightning strike victim.
To provide first aid to a person struck by lightning, he should be immediately moved to a safe place. Touching the victim is not dangerous; no charge remains in his body. Even if it seems that the defeat is fatal, it may actually not be so.
If a lightning victim is unconscious, place him on his back and turn his head to the side to prevent his tongue from sticking into his airway. It is necessary, without stopping for a minute, to perform artificial respiration and cardiac massage until medical help arrives.
If these actions helped and the person shows signs of life, before the doctors arrive, give the victim 2-3 tablets of analgin, and place a wet, cold cloth folded in several layers on the head. If there are burns, they must be poured with plenty of water, the burned clothing should be removed, and then the affected area should be covered with a clean dressing. When transporting an injured person to the nearest medical institution, he must be placed on a stretcher and his well-being must be constantly monitored.
For relatively mild lightning injuries, give the victim any painkiller (analgin, tempalgin, etc.) and a sedative (valerian tincture, Corvalol, etc.)
Andrey Shalygin PhD, DBA, Editor-in-Chief National Explorer