When I opened the door, I was startled by the metal handle flashlight......Take off your sweater at night, sparks all the way ...... with lightning
Even a cat crackles with sound effects......
It's the season when the old friend of static electricity comes to visit, and when it comes to static electricity, we generally think of two things first - one is friction electricity, and the other is that static electricity is really annoying. However, static electricity is not only a kind of friction electricity, and static electricity in some occasions, the harm can be far more annoying, but if properly used, static electricity can serve human beings, so let's talk about it in detail. Triboelectric is not simple
Gallery Copyright**, the use of which may cause copyright disputes in life, the most common static electricity isTriboelectric activation, and it is also the one that usually tortures everyone the most. From the crackle of a handshake to the rumble of lightning, it's all to its credit. Historically, this is alsoOne of the first electrical phenomena to be noticed and recorded by humans: in Greek, electron) is synonymous with amber, which is prone to electricity and dust, and was recorded by the ancient Greek philosopher Thales in the 6th century BC. Although triboelectric induction has long been a household name, scientists have not yet fully understood the ...... of this phenomenonBecause its performance is quite erratic, and its causes are complex and varied. For example, when we go to school, we get the general impression that whoever is more able to grab electrons is negatively charged. If you only consider the materials, it is said that there will be an ultimate boss who will come out on top in the game of electronic grabbing. But in reality, for some materials, the triboelectric competition is not a strong take-all game. It's more like playing rock-paper-scissors: silk loses to paper, paper loses to cotton, cotton loses to glass, glass loses to zinc, and zinc loses to silk at the beginning!It can be seen that the nature of the material is not necessarily the only factor, after research, it is currently recognized that some of the influencing factors are:The properties of the material itself, the surface structure and direction, the local roughness, the strength of friction, the ambient humidity, etc. Static electricity doesn't just come out
Friction can generate static electricity, but it is not only friction that can generate static electricity. Another type of static electricity is piezoelectricity, represented by quartz and tourmaline (also known as tourmaline). What is the principle of piezoelectricity?To use an inaccurate analogy, just like a bus, when there are not many passengers, there are people standing in either direction, and as the bus becomes more and more crowded, everyone will involuntarily expel one direction. From one side, it's all faces, and the other side is all backsThis phenomenon is called polarization and causes a positive charge at one end of the piezoelectric material and a negative charge at the other. Because heat also stresses the crystal lattice, some piezoelectric materials also have a pyroelectric effect. There is also a type of static electricity that is more likely to occur in space. When the high-energy ultraviolet and X-rays in sunlight hit an object, they drive electrons out and leave a positive charge in their original location. Like on the surface of the Moon,The dry, finely fragmented lunar soil particles, because they all carry a positive charge, repel each other, rise from the ground, and levitate several meters high, forming a layer of lunar dust "atmosphere" (not gas)., and once the moon dust encounters foreign objects, it is easy to adsorb. Readers who have removed the styrofoam packaging must have a deep understanding. The electrostatic suspended lunar dust interfered greatly with the lunar exploration equipment, and our first Yutu had a power problem just over a month ago (the second day on the moon), which was probably caused by the failure caused by the moon dust entering the interior. The same principle is true for the dust raised by the Apollo rover, not the effect of a terrestrial studio. 
The Jade Rabbit lunar rover is from WikipediaHow harmful is static electricity?
Most static electricity is harmful and annoying. Although the causes of static electricity are varied, the main theme is the word "quiet". If an electric charge is generated but does not flow, it can accumulate and become a disaster. In the northern winter, the house is heated and the environment is dry, and if you don't use a humidifier (even if you use it, it may be a drop in the bucket), the static electricity when walking around or changing clothes is difficult to channel, and it accumulates on the surface of the body, waiting for an opportunity to vent. Like the little sparks that usually make our fingers tingle, the voltage can reach tens of thousands of volts. This number sounds terrifying, and the physical formula behind it goes like this:Amount of charge = capacitance voltageIt can be seen that the capacitance and voltage are inversely proportional, the smaller one is, the larger the other. When we shake hands, there is a tiny capacitance between our hands, so with just a small charge, a high voltage can be created to break through the air, creating that little arc that makes us tremble. But don't be afraidIt's the current, not the voltage, that really killsThe amount of charge of living static electricity is very small, so the current is also very weak, and it will not be fatal or disabled. But everyone bewareIf this small arc that can penetrate the air is put in a dangerous situation, it can cause a catastrophe。For example, if the tank truck is not fully loaded, the oil sloshing in the tank may cause friction and electricity**. In the early days, the rear of the tanker truck was equipped with an iron chain hanging to the ground, which was to send static electricity to the earth in time. Now the anti-static measures are more and more reliable: the iron chain is replaced with conductive rubber to ensure that the earth is held at all times, and it will not be intermittent or sparked. The tire material is also made of conductive rubber. A grease baffle is placed in the oil tank to reduce the impact and bump of the oil. At gas stations, there will be many measures to prevent static electricity from loading and unloading oil products to refueling car owners, such as discharging first and then refueling. There are also flour mills and other industries with serious dust, in addition to open flames, static electricity is also strictly guarded, becauseStatic electricity can cause dreaded dust** and can also affect the normal production of flour. And friends who like to install their own computers are even more deeply aware that touching the computer motherboard or memory chip with bare hands may "turn bricks". The reason for this is the same formula above, the high voltage generated by static electricity breaks down the chip. Therefore, the electronic equipment sent by the manufacturer is usually wrapped in a bag that can slow down or guide away static electricity. When we disassemble and assemble these devices, we also have to touch the wall first, or hold the metal shell of the large machine with the other hand. Masters who are specialized in circuit maintenance always have a piece of grounded conductive rubber on their desks, and they also wear conductive "handcuffs" on their wrists. 
Anti-static packaging outside electronic equipment The author actually took a picture in the upstream of electronic equipment production-In the semiconductor industry, static electricity is the enemy。In the factory, ultra-clean clothing is not only worn to cover the whole body to prevent dander from falling off, but also to weave conductive filaments into the clothes, and the soles of shoes are mixed with carbonaceous conductive rubber. Even if you walk in the "gray zone" on the periphery of the workshop, wear anti-static slippers. The author has worn this kind of slippers for a few years, the soft and hard are suitable, durable and wear-resistant, it is said that a set at home can be happily petted by the cat. But!Wearing these slippers will greatly increase the risk of electric shock!(Leave the reader to ponder: Why?)Let's weigh it up and put up with the crackling. Frequent flyers may have noticedThere are many small spiky spines on the wings. They are not communication antennas, nor can they boost power, but are used to release static electricity, and the daimyo electrostatic brush。The high-speed friction between the airplane and the air inevitably generates static electricity, but there is no way to use mopping equipment like a fuel tanker, so these small spikes are installed using the principle that static electricity is released into the air at a sharp shape. The largest electrostatic discharge phenomenon that can be experienced in daily life should be lightning, but this topic is too big to talk about. Make good use of static electricity
While most static electricity is harmful, it can create value if it is induced to act according to our will. Probably the most successful use case for static electricity is photocopiers. It first fills the semiconductor with static electricity, and then irradiates the place where there should be a word with light, turning the semiconductor here into a conductor, eliminating the static electricity here, leaving the unirradiated electrostatic area to adsorb the toner. By introducing and confined a large amount of electric charge to the location we designed, and creating a strong electric field, we can accelerate charged particles, study fundamental physics and many related disciplines. Compared with cyclotrons, this electrostatic accelerator has a low cost and a small footprint, and is widely used in the world. 
Electrostatic Accelerator from Wikipedia allows the static electricity generated by the piezoelectric effect to flow and can be used to make quartz resonators. This is the core component of quartz watches, which have brought great convenience to people's lives (although with the popularity of mobile phones, watches seem to be just clothing). In the spraying industry, the principle of homogeneous repulsion of electrostatic electricity can be used to evenly disperse the droplets. And when they are close to the spraying target, they can be adsorbed by induction electrostatics. This scene is actually very familiar, basically the principle of the moon dust destroying the lunar rover, but when used in the right place, it is another effect. Therefore, it seems to be an unbreakable truth that a lot of understanding can turn enemies into friends!Planning and production
This article is a work of popular science China-Star Project.
Produced by the Department of Science Popularization of the China Association for Science and Technology.
Producer: China Science and Technology Press***, Beijing Zhongke Galaxy Culture Media***
Author丨Qu Jiong, popular science author.
Review丨Liu Qian, researcher of Beijing Planetarium.
Curated |Ding Kun.
Editor丨Ding Kun.