We often talk on our site about weather, hurricanes, thunderstorms, and other weather events that may be interesting from a scientific point of view and can harm a person’s economic activity or his life and health. Very often, such phenomena contribute to the appearance of lightning in the atmosphere. This is also a very interesting and incompletely studied phenomenon that arises from the appearance of charged particles in the air. In fact, this is somewhat reminiscent of the static discharge from a woolen sweater, but only the scales are larger. Nevertheless, during the formation of lightning there should be many factors that we will talk about today. Moreover, we have already talked about interesting facts related to this phenomenon. Now we need to understand the nature of the appearance of the “arrows of Zeus”.
What is lightning?
According to science, we can say that lightning is a spark discharge that occurs in the atmosphere. Among the main manifestations can be called a bright flash of light and a loud sound, which is usually called thunder. In addition to the Earth, lightning can be found on other planets, for example, Venus, Jupiter, Saturn, Uranus and others, where there is some kind of gas environment.
A huge amount of energy is released during a lightning strike. As a result, its temperature is several times higher than the surface temperature of the Sun. The current in the lightning discharge on Earth reaches 500 amperes, and the voltage reaches several million volts.
Just because of the large amount of energy, lightning rarely lasts longer than a fraction of a second. As a rule, the value reaches a quarter of a second (0.25), but there are exceptions. So, the longest lightning is fixed at almost eight seconds (7.74).
Definition of lightning according to Ozhegov’s dictionary:
LIGHTNING, and, g. 1. Instant spark discharge in the air of accumulated atmospheric electricity. It is linear, zigzag, spherical and dry.
Now we will not dwell on the definition of lightning as a mark for urgent news or a print publication, although the essence is clear, and it is precisely because of the transience or, if you want, lightning speed of the event that they are called.
What are lightning bolts?
Before telling in detail about the types of lightning, it must be said what they generally are. Four main types were given a couple of lines above, namely: linear, zigzag, ball and dry.
Linear lightning is a short sharp discharge that flashes instantly, illuminates the sky and disappears. Sometimes even the lightning itself is not visible, since it passes very quickly and often even does not hit the ground, but between the clouds.
It is customary to call zigzag a little longer lightning bolts, which have a curved path and give at least a few fractions of a second to examine themselves. Sometimes you can even notice a slight ripple of light in them.
Ball lightning is an extremely rare occurrence. If we meet ordinary lightning several times a year, and residents of some regions – several times a week, then the chance to see ball lightning does not exceed one in ten thousand. That is why the phenomenon is considered very mystical, and if you saw it, you are very lucky. You have to run for a lottery ticket.
With a dry lightning, everything is simple. This is usually called lightning, which occurs without rain. Not the most common occurrence, but occasionally happens anyway. And certainly more often than ball.
How does a lightning strike happen?
We have already decided that lightning is a powerful electric discharge that occurs when the charge accumulates inside the clouds and the appearance of a large difference in the electric potentials of objects. As a result, lightning can occur between neighboring clouds, between a cloud and the earth, and even inside one cloud, which also happens very often. In any case, the cloud must be electrified. But how is it electrified?
This process is familiar to us since childhood. It is enough to recall how a comb, balloon or many other things are electrified during friction. A similar process occurs in the clouds at high altitude and on a significantly large scale.
The fact is that the clouds are a huge water ball, albeit not quite spherical in shape. Its height can reach several kilometers, but in a different state of aggregation there is water in it at all heights. Up to three or four thousand meters, this is a drop, and above it is ice crystals.
These crystals have different sizes and are constantly mixed. Smaller ones fly up due to ascending air currents from warm earth. Rising, they constantly encounter larger crystals. As a result, the entire cloud begins to become electrified like objects in the examples above. The positively charged particles are on top, and the negatively charged ones are on the bottom.
When the potential difference is very high, a discharge occurs. If there are not enough conditions for the formation of a discharge inside the cloud, then the discharge occurs to the ground. At the same time, it is accompanied by a bright flash with the release of heat. Due to the release of a huge amount of energy, the air around the lightning instantly heats up to several tens of thousands of degrees and expands explosively in a small volume. This blast wave is called thunder, diverging up to a distance of 20 km from the lightning itself.
At the same time, lightnings consist of several discharges that go continuously one after another, but each one lasts thousandths and millionths of a second.
Why does lightning have this form?
We know that lightning strives to strike an object at the shortest distance. But why is she so curved? This is by no means the shortest distance at which it would be straight, like a geometric ray.
The fact is that when a discharge is formed, the electrons accelerate to near-light speeds, but they periodically encounter obstacles in the form of air molecules. At each such “meeting” they change the direction of their movement and we get a stepwise structure of lightning, which we are used to, and which is schematically drawn as the logo of Opel cars.
Can a person create lightning?
Yes, a person can create lightning. Each child can put a little experience at home by rubbing two balls and then bringing them closer. If you do this in the dark, you can see a small discharge and a crack or click. This is lightning and thunder in miniature.
Such zippers can be encountered by wearing a wool sweater, combing your hair, and in many other situations. Even a lighter with a button creates a lightning bolt that ignites the gas. Similar equipment is installed in gas stoves and auto-ignited.
But a person can create more serious lightning. I’m not even talking about open-air laboratories that form a discharge for its study, although it can also be very strong in this way. I mean the lightning that appears in a nuclear explosion.
The fact is that during the course of a nuclear explosion reaction, gamma radiation produces an electromagnetic pulse with a voltage level of 100-1000 kV / m. This not only destroys the unprotected electromagnetic lines of bunkers, mines and other objects, but also leads to the formation of lightning. True, this lightning strikes the sky, that is, in the opposite direction, if I may say so. A discharge appears before the arrival of the fire hemisphere and very quickly disappears. This happens from about 0.015 to 0.5 seconds of the process of the reaction of a nuclear explosion.
Where do lightning come from before an earthquake?
There are lightnings that manifest themselves during earthquakes. Until the end, their nature is still unknown, but they also arise due to the accumulation of charge. Only in this case is this due to the friction of the rock layers with each other.
Initially, scientists did not take seriously the stories that earthquakes were accompanied by lightning, but the recent appearance of cameras made them think about it. As a result, they began to set up experiments and came to the conclusion about the friction of the rock layers.
Much more famous are lightning during volcanic eruptions, which are also called “dirty lightning.” They also arise as a result of friction between particles flying out of the vent.
The formation of lightning accompanies other phenomena, for example, dust storms, tornadoes and some others, leading to the same accumulation of charge.
What is ball lightning, and how does it appear?
In addition to ordinary lightnings, with which it is becoming less or less clear, although some questions remain, there are ball lightnings that have not been thoroughly studied at all and no one can explain where they come from, why and where they disappear.
Initially, ball lightning is a luminous ball (sometimes the shape may vary slightly), which is estimated to have a temperature of 500-1000 degrees Celsius, can move in space, pass through glass and explode a few minutes after it appears. So far nothing is known.
The first mention of them dates back to BC. True, then it was very allegorical and included talking about fire birds and the like. Now it is very similar to the description of ball lightning, but one cannot speak with confidence about this.
Until recently, many scientists generally did not believe in the existence of such a phenomenon, and eyewitnesses considered statements to be a result of damage to the retina after being struck by ordinary lightning. Moreover, everyone was talking about a different form. Now they began to believe in it and started research, but there is still little information.
Someone considers them to be clots of gas, someone special particles with a huge amount of energy, and someone even speaks of higher forces.
However, this does not negate the fact that ball lightning can damage objects that they come into contact with. For example, to melt glass and metal, set fire to a tree and boil water. There are even stories about how they closed high-voltage transmission lines, creating an arc.
There are several hypotheses of this phenomenon, each of which has not yet been confirmed, but not refuted either.
One of them says that ball lightning is a specific interaction of nitrogen with oxygen, as a result of which energy is generated for its existence. According to another hypothesis, the phenomenon is a spherical vortex of dust particles with active gases. They became so because of the received electric discharge. As a result, ball lightning is a bit of a battery. This hypothesis explains the specific odor and a loop glow next to ball lightning.
There is a hypothesis that disputes both previous ones, telling us that the existence of ball lightning is impossible without feeding it with energy from the outside. But such a hypothesis is collapsed by the lack of evidence for the existence of the waves necessary for feeding the length.
All this once again proves that ball lightning must be feared, since there is not even a clear description of how to act when it appears. The most important recommendation is to immediately leave the zone of its operation, but without unnecessary haste, so as not to disturb the movement of air and not to carry it along with you.
What do we know about lightning?
We know a lot about ordinary lightning, although not all. There is almost nothing about ball ones, but given the frequency of their appearance, we can assume that this is not so scary, although work in this direction should and should be continued research.
Lightning has become an integral companion of our lives. They manifest themselves in many areas and force themselves to respect because of the destructive power hidden in them.
Nevertheless, there are quite effective means of dealing with them. It is only necessary to comply with elementary safety rules (do not stand in a thunderstorm near trees, do not fly kites, and indeed it is better not to leave the house) and put lightning rods on the house. In this case, everything will be much simpler and safer.