Lightning is one of those natural phenomena that have long inspired fear in the human race. The greatest minds, such as Aristotle or Lucretius, sought to understand its essence. They believed that it was a ball consisting of fire and clouds squeezed in water vapor, and, increasing in size, it breaks through them and quickly falls to the ground with a spark.
The concept of lightning and its origin
Most often, lightning is formed in thunderclouds, which are quite large in size. The upper part can be located at an altitude of 7 kilometers, and the lower - only 500 meters above the ground. Given the atmospheric temperature, we can conclude that at the level of 3-4 km, the water freezes and turns into ice floes, which, colliding with each other, are electrified. Those that have the largest size receive a negative charge, and the smallest - positive. Based on their weight, they are evenly distributed in the cloud in layers. Approaching each other, they form a plasma channel, from which an electric spark, called lightning, is obtained. She got her broken shape due to the fact that on the way to the ground various air particles are often found that form obstacles. And to get around them, you have to change the trajectory.
Physical description of lightning
A lightning bolt emits from 109 to 1010 joules of energy. Such an enormous amount of electricity is spent to a greater extent on the creation of a light flash and a shock wave, which is also called thunder. But even a small part of lightning is enough to create inconceivable things, for example, its discharge can kill a person or destroy a building. Another interesting fact suggests that this natural phenomenon is capable of melting sand, forming hollow cylinders. This effect is achieved due to the high temperature inside the lightning, it can reach 2000 degrees. The time of impact on the ground is also different, it can not be more than a second. As for power, the pulse amplitude can reach hundreds of kilowatts. Combining all these factors, we get the strongest natural discharge of the current, which brings death to everything that it touches. All existing types of lightning are very dangerous, and meeting with them is extremely undesirable for humans.
Thunder
It is impossible to imagine all types of lightning without a roll of thunder, which does not carry the same danger, but in some cases can lead to a network failure and other technical problems. It arises due to the fact that a warm wave of air, heated by lightning to a temperature hotter than the sun, collides with the cold. The sound resulting from this is nothing but a wave caused by air vibrations. In most cases, the volume increases towards the end of the rumble. This is due to the reflection of sound from the clouds.
What are the lightning
It turns out they are all different.
1. Linear lightning is the most common variety. The electric peal looks like an upside-down, overgrown tree. Several thinner and shorter “processes” depart from the main channel. The length of such a discharge can reach 20 kilometers, and the current strength is 20,000 amperes. The speed is 150 kilometers per second. The temperature of the plasma filling the lightning channel reaches 10,000 degrees.
2. Intra-cloud lightning - the origin of this species is accompanied by a change in electric and magnetic fields, radio waves are also emitted. Such a roll is most likely to be found closer to the equator. In temperate latitudes, it appears extremely rarely. If there is lightning in the cloud, then an extraneous object that violates the integrity of the shell, for example, an electrified plane or a metal cable, can cause it to get out. The length can vary from 1 to 150 kilometers.
3. Ground lightning - this type goes through several stages. On the first of them, impact ionization begins, which is created in the beginning by free electrons, they are always present in air. Under the influence of an electric field, elementary particles acquire high speeds and are sent to the ground, colliding with the molecules that make up the air. Thus, electronic avalanches arise, otherwise called streamers. They are channels that, merging with each other, cause a bright, thermally insulated lightning. She reaches the earth in the form of a small staircase, because there are obstacles in her path, and in order to get around them, she changes direction. The speed is approximately 50,000 kilometers per second.
After the lightning passes its way, it finishes the movement by several tens of microseconds, while the light weakens. After this, the next stage begins: repeating the path traveled. The most recent discharge exceeds all previous ones in brightness, the current strength in it can reach hundreds of thousands of amperes. The temperature inside the channel fluctuates around 25,000 degrees. This type of lightning is the longest, so the consequences can be devastating.
Pearl zippers
Answering the question about what lightning can happen, one should not lose sight of such a rare natural phenomenon. Most often, a discharge passes after a linear one and completely repeats its trajectory. Only now it looks like balls located at a distance from each other and resembling beads made of precious material. Such lightning is accompanied by the loudest and rumbling sounds.
Fireball
A natural phenomenon when lightning takes the form of a ball. In this case, its flight path becomes unpredictable, which makes it even more dangerous for humans. In most cases, such an electric lump occurs in conjunction with other species, but the fact of its appearance even in sunny weather has been recorded.
How is ball lightning formed? This is the question most often asked by people who are faced with this phenomenon. As everyone knows, some things are excellent conductors of electricity, and so it is in them, accumulating its charge, that the ball begins to arise. It can also appear from the main lightning. Eyewitnesses claim that it arises simply from nowhere.
The diameter of the lightning ranges from a few centimeters to a meter. As for color, there are several options: from white and yellow to bright green, it is extremely rare to find a black electric ball. After a rapid descent, it moves horizontally, about a meter from the surface of the earth. Such lightning can suddenly change its trajectory and just as suddenly disappear, releasing enormous energy, due to which melting or even destruction of various objects occurs. She lives from ten seconds to several hours.
Sprite zipper
More recently, in 1989, scientists discovered another type of lightning, which was called a sprite . The discovery happened by accident, because the phenomenon is extremely rare and lasts only tenths of a second. From other electric discharges they are distinguished by the height at which they appear - approximately 50-130 kilometers, while other subspecies do not overcome the 15-kilometer boundary. Also, sprite zipper has a huge diameter, which reaches 100 km. They look like vertical pillars of light and flash in groups. Their color varies depending on the composition of the air: closer to the ground, where there is more oxygen, they are green, yellow or white, but under the influence of nitrogen, at an altitude of more than 70 km, they acquire a bright red hue.
Thunderstorm Behavior
All types of lightning carry an extraordinary danger to human health and even human life. To avoid electric shock, the following rules should be followed in an open area:
- In this situation, the highest objects fall into the risk group, so you should avoid open areas. To become lower, it is best to sit down and put your head and chest on your knees, in case of defeat this pose will protect all vital organs. In no case should you lie flat so as not to increase the area of a possible hit.
- Also, do not hide under tall trees and lampposts. Unprotected structures or metal objects (for example, a picnic canopy) will also be an undesirable shelter.
- During a thunderstorm, you need to immediately get out of the water, because it is a good conductor. Once in it, a lightning bolt can easily spread to a person.
- In no case should you use a mobile phone.
- For first aid to the victim, it is best to perform cardiopulmonary resuscitation and immediately call the rescue service.
House Rules
Indoors, there is also a danger of defeat.
- If there is a thunderstorm on the street, the first thing to do is close all the windows and doors.
- It is necessary to disconnect all electrical appliances.
- Do not get close to wired phones and other cables, they are excellent conductors of electricity. Metal pipes have the same effect, so do not be near plumbing.
- Knowing how ball lightning is formed and how unpredictable its trajectory is, if it does get into the room, you must immediately leave it and close all windows and doors. If these actions are impossible, it is better to stand still.
Nature is still beyond human control and carries many dangers. All types of lightning are, in essence, the most powerful electric discharges, which are several times higher in power than all current sources artificially created by man.