Summer is coming, and lightning will once again showcase its power on the weather stage. When encountering lightning outdoors, * hide in a closed car. So, the question is: why can cars be lightning protected, and is it really an ideal place to avoid lightning strikes?
Is the car intact after being struck by lightning?
Many people may have seen a real-life video of a car speeding on a highway during a thunderstorm, suddenly hit by a lightning bolt falling from the sky. Even more surprisingly, the car that was struck by lightning was still able to continue driving safely. If you search online again, you will find that there is more than one similar video. It can be seen that cars are not afraid of lightning strikes, which is not an accidental event.
Regarding this issue, the car show "TopGear" once conducted an experiment on lightning strikes on cars: the host sat inside a Volkswagen Golf car and used a high-voltage discharge device to electrocute the car with 600000 volts of high voltage, simulating whether the car would cause harm to the driver and passengers when struck by lightning. Experiments have shown that after receiving a high-voltage electric shock, only the indicator lights on the dashboard of the vehicle were affected, all other instruments were normal, and the vehicle body was not damaged. The host sitting in the car was also unharmed. From the experiment in TopGear, it can be seen that cars are indeed "not afraid" of lightning strikes, and passengers inside the car will not be harmed.
Why is that? Experts point out that this is related to the Faraday cage effect.
Faraday cage: the "golden shield" for lightning protection?
Cars are not afraid of lightning strikes because of the existence of Faraday cages. So, what is Faraday cages?
The Faraday cage is a cage made of metal or a good conductor, invented by the founder of electromagnetism and British physicist Michael Faraday, and named after him. It is mainly used to demonstrate the principles of equipotential, electrostatic shielding, and high-voltage live working. In 1836, Faraday discovered that excess charge on a charged conductor only exists on its surface and does not affect any objects enclosed within it. To prove this fact, he built a room with a metal foil shell and used high voltage electricity from an electrostatic generator to shock the shell of the room. The voltage tester shows that there is no excess charge in the room. The metal shell of the room provides a "protective" effect on its interior, preventing it from being affected by external electric field changes. This is the Faraday cage effect. Using this principle, the high-voltage live operator's * is made of metal wire. When it comes into contact with the high-voltage line, an equipotential is formed, which prevents current from passing through the operator's body and provides good protection.
Speaking of which, it is not difficult to understand why cars are not afraid of lightning strikes. The car shell is made of metal, which is very close to the conditions of a Faraday cage. With this' iron cloth shirt ', even if the driver is unfortunately struck by lightning during thunderstorms, the electromagnetic environment inside the car is basically not affected due to the Faraday cage effect, and people inside the car can safely stay inside. At the same time, lightning current will use rainwater to reach the position of the axle through the surface of the vehicle, and quickly transmit the current to the ground through wet tires. So, the interior of the car is an ideal lightning protection location outdoors.
Faraday cages have also been well applied in aircraft lightning protection and building lightning protection. According to statistics, almost every normally operating aircraft is struck by lightning once a year, but most of them do not result in catastrophic consequences. This is mainly due to the fact that the current commercial aircraft shells are made of metal materials, which have good shielding effects against lightning strikes, and the personnel and equipment inside the aircraft are relatively safe. High rise buildings are easily struck by lightning, and cage type lightning protection nets made using the principle of Faraday cages can effectively reduce the harm caused by lightning strikes to human health. For example, in the sports stadium "Bird's Nest", the steel components in the main steel structure and the steel bars in the reinforced concrete are effectively connected by welding, so that the "Bird's Nest" itself forms a huge lightning protection net. The steel structure of the "Bird's Nest" becomes a huge lightning receiving device, which can quickly guide lightning into the ground, thus ensuring the safety of the audience in the stadium.
However, it should be noted that outdoor lightning protection for cars, airplanes, etc. is not safe. When a car is struck by lightning, the instantaneous high voltage may also damage the electronic components inside the car, causing the electrical equipment inside the car to malfunction, and in severe cases, a fire may occur. In addition, the metal parts of the vehicle roof and wheels may also leave ba marks after being struck by lightning.
How to drive safely in thunderstorm weather?
From the previous introduction, we know that even if the body of a car can form a Faraday cage, which is a "golden shield", we cannot drive recklessly during thunderstorms. The following points still need to be noted.
When encountering lightning and thunder during driving, please park the car in a safe place on the roadside, stay away from trees, billboards, etc., turn off the engine, audio system, radio, etc., and close all windows to create a closed space for the vehicle. Do not touch the car window handles, gear shift lever, steering wheel, etc. Place your hands on your thighs and wait for lightning weather to move away.
If the car is struck by lightning while driving, do not rashly get off the car to check its condition, because at this time, the outside of the car is much more dangerous than the inside. Instead, you should follow the method introduced above and wait until the thunderstorm * has passed before getting off the car.
One thing to say later is that if you listen to the weather forecast in advance and know that thunderstorms will occur, try to drive less or not at all. Wait until the weather is good before going out. This is the only way to avoid lightning strikes and ensure safety and reliability.