In ancient times, fishtail copper tiles were used to prevent lightning, and today there are "lightning-absorbing artifacts": Why is China's lightning protection technology leading the world?

“The storm is coming” and “the dark clouds are pressing down on the city, and the city is about to be destroyed”. When thunderstorm clouds come, they are often accompanied by lightning and thunder, which is chilling. China's exploration of lightning protection started two centuries earlier than the West, and now it leads the world in lightning protection technology with innovative materials technology. Who charges the clouds? From ancient times to the present, how have we avoided danger? Let's explore the evolution of lightning protection devices with Ke Xiaoer!

The principle of lightning formation

The reason why clouds are charged is that water droplets and ice crystals collide and rub in the air flow, generating positive and negative charges, which are then distributed under the action of air flow and gravity to form charge areas of different polarities. When these charges gather to a certain level, they will pass through the air and produce discharge, thus causing lightning.

We have been taught since childhood not to hide under trees on rainy days, otherwise we may be struck by lightning. This is because the branches and leaves on the top of the big trees are pointed and thin, which easily attract lightning. When lightning, which is high voltage electricity, propagates underground using trees as conductors, it will damage nearby objects.

Ancient people's wisdom on lightning avoidance

According to the Tang Dynasty book Zhiguzi, when the Bailiang Palace was hit by lightning during the Han Dynasty, a wizard placed a fishtail-shaped copper tile on the roof to prevent the fire caused by lightning. The fishtail dragon head-shaped tile decoration on the roof can actually avoid lightning, which is the prototype of the modern lightning rod.

In 1688, French traveler Cabriolet de Magalhães marveled in his book "What's New in China" that the dragon head decoration on the roof of Chinese buildings contains a secret: the dragon's mouth spits out a tortuous metal tongue, which stretches towards the sky, and the root of the tongue is connected to a thin iron wire that goes straight into the ground.

According to this record, once lightning strikes a house, the current will first contact the metal tongue and then be led into the ground along the wire, thus preventing lightning from destroying the building. This shows that my country's use of metal needles to attract lightning was at least two centuries earlier than Franklin's lightning experiment.

The truth about lightning rods

Lightning rods use the principle of tip discharge. In thunderstorms, the charge in the clouds gathers on the lightning rod because the tip of the lightning rod attracts more charge. Once the charge in the cloud reaches a critical point, the air is broken down, forming a conductive channel. So to be precise, the lightning rod is not avoiding lightning, but "attracting lightning". Through the down conductor and grounding device, the lightning current is introduced into the ground, thereby protecting the building. Today, lightning rods are more accurately called "lightning rods."

Opening the era of intelligent lightning protection

In January 2024, a breakthrough experiment attracted attention. In a laboratory, a voltage of tens of thousands of volts was instantly generated. Normally, such a high-voltage short-circuit discharge would produce huge sparks and explosions, but when the electrodes at both ends touched, only a slight sound was heard, accompanied by a tiny spark, and the simulated lightning energy instantly disappeared.

This is the result of using the "new phase change material lightning energy absorber" developed by Zhejiang University Wenzhou Research Institute.

The lightning protection principle of phase change materials is based on a physical phenomenon called "dielectric polarization effect". When this material is subjected to the high-voltage impact of lightning, it will undergo a phase change, converting the high-frequency energy of lightning into shock waves. In this process, electrical energy is converted into mechanical energy and released safely, thus achieving a good lightning protection effect.

Since this lightning protection product was put into operation in Tianhuangping Pumped Storage Power Station in Anji, Zhejiang Province, the effect has been very significant. The equipment protected by it has never been damaged by lightning again. The success of this new technology has absorbed the energy of dozens of lightning strikes, and the lightning protection effect is very significant.

From the ancient fishtail copper tiles to the modern lightning rods, and then to today's intelligent lightning protection systems, the development of lightning rods has witnessed the evolution from simple ancient devices to modern high technology.

Lightning rods not only protect countless buildings from damage caused by lightning strikes, but also promote the development of electrical and construction technology. Although lightning cannot be avoided, people can use science and technology to effectively protect themselves and their homes. I believe that in the future, my country's scientific research team will continue to work hard to ensure safe production in various industries.

This article is compiled based on the winning works of the first "Shen Kuo Cup" Popular Science Short Video Creation Competition