Incredibly useful and informative article about the lightning serve as an excellent (text) supplement this film.
What is lightning, where he directs his rank and how to behave during a thunderstorm. I'm sure it's necessary for you to know!
Lightning — it's a spark of electrostatic charge cumulus clouds, accompanied by a blinding flash and a sharp sound (thunder).
Danger. Lightning discharge is characterized by high currents, and its temperature reaches 000 degrees to 300. The tree is split by a lightning strike, and even catch fire. The splitting of the tree is due to an internal explosion due to flash the internal moisture of wood.
A direct lightning strike to a person usually fatal. Every year the world of lightning killed about 3,000 people.
Precautionary measures before the storm
To reduce the risk of lightning damage economic facilities and buildings arranged in the form of lightning grounded metal masts and stretched high above the buildings of the object leads.
Before the trip to confirm the nature of the weather forecast. If a storm is predicted, then transfer the trip the next day. If you have noticed the storm front, then first determine the approximate distance as the delay time of the first peal of thunder, the first flash of lightning, and the vote is approaching or removed front.
Since the speed of light is huge (300,000 km / s), then we see a flash of lightning instantly. Hence the delay sound will be determined by the distance and the speed of sound (about 340 m / s). We need the time in seconds from the flash of lightning before the first peal multiply by 340 — and get the distance in meters to the storm front.
Example: if the flash to the thunder was 5 s, the distance to the storm front is 340 m / s 5c x = 1700 meters. If over time the delay sound rises, the storm front is removed, and if the delay sound is reduced, and the thunder rumbling and no longer resembles a dry crackling, the approaching storm front. What is a rolling thunder on flat terrain — the further away a thunderstorm.
What to do during a storm
Lightning is dangerous when followed by a flash of thunder follows immediately, and almost no thunder peals. In this case, care should be taken precautions.
If you're in the countryside: Close the windows, doors, chimneys and vents. Do not melt the oven as high-temperature gases from the chimney, have a low resistance. Do not talk on the phone: zipper sometimes gets in the wire strung between the posts.
During lightning strikes do not come close to the electrical wiring, lightning rod, drains from the roof, antenna, do not stand next to a window, if possible turn off the TV, radio and other electrical appliances.
If you're in the woods, then take cover on low-growing area of the forest. Do not cover near tall trees, especially pines, oaks and poplars.
Do not stay in the pond or on the shore. Step away from the shore, walk down the lofty place in the lowlands.
In the wilderness, the field or in the absence of shelter (buildings) do not lie down on the ground, putting the electric current all his body, and squat in a hollow, ravine or other natural depression legs wrapped around his hands.
If you caught the storm front while exercising, stop them. Metal objects (motorcycle, bicycle, ice pick, etc.) Put aside, withdraw from them at 20-30 m
If the storm has found you in the car, do not leave it, thus close the window and lower the antenna of the radio. If the car is dry, it will be able to withstand lightning strikes, protecting you.
We strongly recommend to turn off all cell phones and radios.
Where and why lightning strikes?
© 2008. Julia Kaftanov. From myself clarify more. When moving storm front from the friction of the air between the ground and the clouds formed a huge potential difference. The phenomenon is somewhat similar to a huge natural capacitor to store energy.
So weather-sensitive people can become ill before the storm, even if it was there, in the thin electrical appliances may experience electrical interference and the radio signal can not pass through the storm front.
A discharge of static electricity usually takes the path of least electrical resistance — at an ionized channel paved by "running the leader" (as the wire). Since the difference between the highest object of similar, and cumulus clouds distance less means less and electrical resistance. Consequently, the lightning strike, especially, the object (poles, trees, etc.).
Most of the lightning and electrical discharge occurs between thunderclouds and lightning inside the cloud — about 80%. But the power of electric discharges between the earth and clouds incomparably more, since much higher potential difference "between heaven and earth."
After accumulating a critical static charge from a storm cloud drains a small charge (micro-fireball) — the so-called "running leader" and moves to the ground at a speed of about 20 m / s. Along the way he forms an ionized channel can be split and share — then lightning branches.
Once it reaches the ground or high object which is a static electricity charge, with land in a storm cloud on the laid ionized channel is instant multiple electrical discharge. We see it as a single very bright "whole" lightning, but in the distance we hear the thunder because lightning Instant consecutive one channel is made from 10-15 to 80 and even 100 in extremely rare cases. Can you count the number of thunder at 2 km distance from lightning.
"Running a leader" — an ionized charge of electricity flowing from a storm cloud. In the photo at the top of the page is clearly visible as a storm front trickles down "fleeing leaders", leaving a slabosvetyaschiysya branching channel. And it is very well seen a bright powerful channel "from the ground to the sky" with the flash on the cloud, for which there is a direct lightning strike. All such active channels at the entrance to the storm cloud very clearly highlighted, and itself out "running leader" of the cloud — not yet.
In the fourth left zipper is very clear that the powerful beats along the discharge channel of the ground and has not yet reached a fork. And the far right at the top of a "weak" category — a movement "running leader" of the cloud. On the far left end of the third left fork of lightning even seen a very bright "moving leader" in the form of a point a small bowl.
Those who believe that a bolt of lightning hit the ground from a cloud, and widely disseminate these false information on the Internet, we strongly advise you to read the big physics — in the XX century with the advent of photography in the active life of our lightning phenomenon has been very well documented.
I can only assume the nature of ball lightning: a mysterious fireball can be a very big "running leader" who is able to see with the naked human eye (and not just to fix a special photo), followed by a fully ionized channel is closed, and therefore became a full-fledged lightning impossible.
If "moving leader" was "feeble" and collapsed before it is fully formed ionized channel, lightning occurs. Most of the outputs of the "running of leaders" does not end with lightning. "Running leader", which forms a usual lightning "between heaven and earth", lives about 50-80 seconds, as it needs time to reach the surface.
"Running a leader", immediately followed by an electrical discharge and lightning on special photographs resembles a small bright spark and is a bunch of ionized gas (low-temperature plasma clot). It is by photographing lightning and what happens immediately before the discharge, in the XX century, the discovery was made, correctly describing the phenomenon of lightning.
If the "running leader" was very large in size, it begins to meet more substantial resistance to the environment, its velocity slows dramatically, ionized channel behind it has time to fully or partially close. So full of lightning discharge does not occur, and we can observe the phenomenon of ball lightning (eg on the tornado and the tornado as in the photo). In an effort to take the least amount of a substance in the plasma state adopts a spherical shape (the area of the outer surface of the ball is minimal among other bodies at a fixed volume).
In fact, there is a three-phase states, which describe the different behavior of the mathematical model of "running-leader" — the formation of a "moving leader," which is not over by any discharge (over 99%), "running leader" who was "lucky" and who managed to form a fully ionized channel , the movement of which ended with lightning (less than 1%), and "overgrown", followed by partly or fully ionized channel is closed, and he formed the naked eye fireball (extremely rare).
If we consider the phenomenon of lightning in terms of fashion today, catastrophe theory, it is the lightning bolt must be considered as a phase change of the system of 'natural capacitors. " Only lightning and "running leader" who was "lucky" to cause an abrupt change in the state of electrical potential storm clouds and the earth's surface and thus can be considered as a "catastrophe." The moment of the beginning of an abrupt change of state of the system is the moment of reaching the "running leader" of the other clouds, or the surface of the earth (as well as wood, lightning, etc.).
The moment of abrupt changes in the state of the system (ie lightning) can be described by a set of delta functions approximated by the number of instant electric discharges, the argument is the time.
Or "sterile", "running leader," which is not ended by lightning, much more "overgrown", a fireball from the point of view of the modern theory of accidents do not cause abrupt changes in the state of 'natural capacitors "- storm clouds and the ground. That is why the fireball can not be regarded as a phenomenon that causes an abrupt change of the system as a whole, because it does not entail a full lightning formed from the entire length of the ionized channel.
In extreme cases, ball lightning, getting outside energy supply (eg, by a powerful tornado rotation, as in the photo), entails the local electric micro-level in their localized area. These micro-lightning and electrical discharges take place between localized in a neighborhood of ionized channels. If the energy supply of ball lightning from the outside and there is no link to the source is completely lost, the fireball does not generate a local electric discharges at all.
But anyway, at the time of its existence (since inception until the destruction of) the behavior of ball lightning is caused solely by local changes of the system and does not affect its global status and behavior, as opposed to the usual lightning.