How to avoid lightning correctly?

Where is it easy to be struck by lightning? How to prevent lightning? Can you make a phone call when it is thundering? Can you avoid lightning by holding a lightning rod?

…

There have been many thunderstorms recently, so Toutiao specially consulted experts to tell you about the knowledge about lightning.

1. 69% of minefields are outdoors

Here is some data on the "minefield": According to statistics from the Chinese Academy of Meteorological Sciences, the highest proportion of lightning strikes are in farmland (32%), followed by buildings (rural houses, shacks, pavilions, 23%), open areas (13%), followed by water areas (riverside, beach) and under trees. Well, most of them are outdoors.

When it thunders, don't run here, it's very dangerous!

Moreover, lightning likes to take shortcuts, and tall people who stand out from the crowd are more likely to be struck by lightning. So when there is thunder, you should try to lower your height, such as squatting with your legs together (to prevent step voltage), especially in open areas or on top of mountains.

2The probability of being struck by lightning is actually not that high

According to relevant statistics, about 4,000 people are struck by lightning every year worldwide. Based on the world's total population of 7.594 billion, the average probability of each person being struck by lightning is about one in 1.9 million.

Last year, a Wisconsin landmark, the world's largest hanging American flag, was torn in half during a thunderstorm.

However, this is only the global average probability. The probability of being struck by lightning varies greatly in different regions. According to the US Federal Emergency Management Agency, the average probability of an American being struck by lightning is 1 in 600,000. According to data from China's meteorological department, there were 19,982 lightning disasters in the country in 2010. On average, the probability of a Chinese being struck by lightning is about 1 in 1.8 million.

However, the damage caused by lightning is still very large↓

3. The lightning rod is actually a lightning rod. The lightning rod is actually a lightning rod, which is composed of a lightning receptor, a down conductor and a grounding body. Because it is higher than the building, lightning usually hits the lightning rod first, and then is conducted into the earth by the down conductor and the conductor equipped with a grounding device.

When lightning rods first appeared, people thought they could protect houses from lightning strikes, so they were called lightning rods. However, in the National Standard of the People's Republic of China GB50057-2010 "Design Code for Lightning Protection of Buildings", this name has been abandoned and replaced by "lightning rods".

4The first generation of lightning rods was actually made in China

As you may know, American Franklin used a kite to attract lightning and invented the lightning rod. In fact, the prototype of the lightning rod originated in China.

According to the Tang Dynasty book Zhiguzi, during the Han Dynasty, the Bailiang Palace was hit by a fire, and a wizard suggested that a fishtail-shaped copper tile be placed on the roof to prevent the fire caused by lightning. The fishtail-shaped tile actually doubles as a lightning rod and can be considered the prototype of the modern lightning rod.

In order to prevent buildings from being struck by lightning, the ancients would apply a layer of metal film on the tip of the top of the building, and then use conductive materials to connect it to the underground tower core column. The end of the column was connected to the stored metal, perfectly achieving the effect of a lightning rod.

5. Lightning power is at the level of a nuclear power plant

How powerful is lightning?

The discharge process of lightning generally lasts 50 to 100 microseconds.

The voltage of lightning is very high, about 100 million to 1 billion volts.

The average current of lightning is 30,000 amperes, and the maximum current can reach 300,000 amperes.

When the electric charges are neutralized, a large amount of light and heat is released, instantly heating the surrounding air to 30,000 degrees Celsius, which is five times the temperature of the sun's surface.

A moderate thunderstorm can generate up to 10,000 kilowatts of power, equivalent to the output of a small nuclear power plant.

6 Can I use my cell phone during thunderstorm?

In 2013, Dr. Shi Weidong from the High Voltage Research Institute of China Electric Power Research Institute conducted an experiment on CCTV's "Is It Real?" program to simulate lightning discharges. Three puppets were holding a mobile phone, wearing sunglasses, and holding an umbrella. The discharges occurred 20 times, hitting the ground 11 times, the puppet holding the umbrella 8 times, and the puppet holding the mobile phone once. This shows that using a mobile phone will not attract lightning (in fact, the probability of attracting lightning is higher when using a landline).

Experts from the Institute of Lightning Protection Research Association of the Chinese Meteorological Society believe that being struck by lightning is mainly related to whether the person is in a commanding position. Carrying metal objects will increase the probability of being struck.

For example, the following ones - never show off your wealth!

7 Is it more likely to be struck by lightning near power transmission lines?

People who live near high-voltage power lines have a concern: Will the power lines attract lightning strikes? In fact, there are strict lightning protection requirements when designing and building power lines and substations. Lightning conductors are installed above the entire power line, and lightning rods are installed around the substation. This can not only protect power equipment, but also nearby houses.

The two thin wires at the top of the picture above are lightning arresters. In addition, the State Grid also has other lightning arresters: real-time assessment and early warning of lightning strike risks in the power grid↓

The power grid lightning strike path monitoring system captures the occurrence and development path of power grid lightning damage in real time, and accurately captures the time, location and form of lightning strikes.

8 Lightning can also enter the house. There are usually three main ways for lightning to enter the house: power lines, signal lines (such as communication lines, TV antennas, computer network cables) and backlash caused by lightning striking the earth.

Television cables carry lightning into homes.

Therefore, lightning rods can only solve the lightning protection problem of the building itself, but cannot protect various electrical appliances connected to the power supply inside the building, especially televisions, telephones, computers, etc. with signal receiving functions from lightning strikes. Therefore, on rainy days, all kinds of household appliances should be turned off and unplugged as much as possible to prevent lightning from invading from the power line, causing fire or electric shock casualties.

ps: The so-called "lazy man's artifact" lightning protection socket is just a surge protector, and its protection ability against high-intensity lightning strikes is limited.

9 Is it safe to drive during thunderstorm?

A Russian driver survived being struck by lightning twice while driving.

If you are driving when thunder strikes, just park your car in a safe place on the roadside, away from trees, billboards, etc., turn off the engine and sound system, and close all doors and windows to make the vehicle a completely enclosed space. Do not touch the window handles, gear lever, steering wheel, etc., put your hands on your thighs, and wait for the thunderstorm to end.

Because the car shell is made of metal, it is very close to a Faraday cage. Even if the vehicle is unfortunately struck by lightning, the electromagnetic environment inside the car is basically unaffected, and the people inside the car can stay inside safely. However! Lightning protection for cars, airplanes, etc. outdoors is not absolutely safe, so try not to go out on thunderstorms.

10 How to lose weight like lightning? Let's see what kind of lightning it is

Finally, let's talk about lightning, a good friend of thunder and lightning. Generally, the lightning we see is linear lightning and sheet lightning. According to lightning lava, the width of ordinary linear lightning is like this↓

He still looks pretty thin. Have you seen Liu Cixin's "Ball Lightning"? That's another kind of lightning, with a diameter of several meters to tens of meters, and looks like this↓

So, when you make up your mind to become as thin as lightning, be sure to pray that it is not ball lightning.

These knowledge points,

Do you remember?