What did a solar-powered “lighter” look like 2,800 years ago?

In the cold winter, it would be such a happy thing if we could light a fire, gather around it to keep warm and share happiness.

Fire is extremely important to human beings. So how did the ancients make fire? -- Drilling wood to make fire, striking stones to make fire! These methods are time-consuming and laborious. Are there any better ways to make fire?

In fact, as early as the Western Zhou Dynasty, our ancestors had already used a portable "lighter". Different from today's lighters, it does not require flint, but only sunlight. Its name is "Yangsui".

In ancient times, people called tools for making fire "flint". Depending on the material, there are wooden flints and metal flints. Wooden flints make fire from wood, while metal flints make fire from the sun, which is what we call "yang flints".

Shen Kuo, a scientist in the Song Dynasty, recorded in his book Mengxi Bitan: "The surface of the sun-flint is concave. The light from the sunlight is all directed inward, one or two inches away from the mirror, and gathered into a point as big as a hemp bean. When it touches something, it will catch fire." This means that when using a sun-flint, you must choose a place with plenty of sunlight, use the reflection and refraction principles of the concave mirror, aim the sun-flint at the sun, adjust the angle, place the flammable material at the reflective focus of the concave surface, so that the sunlight is focused on one point, and after a few seconds or dozens of seconds, the flammable material will be ignited.

The Guo State Museum in Sanmenxia City, Henan Province, houses 30,000 cultural relics unearthed from the Guo State cemetery. Along with these cultural relics, there is also a bronze yangsui dating back 2,800 years.

It has a diameter of 7.5 cm, a silver-white concave mirror on the front, a nose-shaped button on the back, and two colorful tigers, a double-headed dragon and a bird of prey cast beside the button. Overall, its unique shape similar to a teacup lid also makes it more convenient to get fire from the sun.

Making fire more convenient is also inseparable from the complex production process of bronze sun-flint. In order to effectively reflect sunlight, high-quality bronze materials need to be selected, and after multiple grinding and polishing, the surface can be as smooth as a mirror.

The Zhou Li Kaogong Ji also has a precise record of the material formula for making Yang Sui: "There are six kinds of gold, half of which is gold and half is tin, which is called the proportion of Jian Sui." "Gold" refers to pure copper, and "tin" refers to lead-tin alloy, that is, the ratio of copper to tin in making Yang Sui is 2 to 1. The information contained in these cultural relics not only reflects the experience, thinking and wisdom of the makers, but also reflects the profound scientific understanding level of ancient China.

As more advanced fire-making tools became popular, Yangsui gradually withdrew from people's daily lives. However, we can still see the fire-making artifact "Yangsui" at the torch-collecting ceremonies of important sporting events such as the Olympic Games and the Asian Games...

From the process of drilling wood to make fire in primitive society, to the use of fire-making tools in the Bronze Age, to the use of flints in the Iron Age, to the use of lamps in the Ming and Qing Dynasties, to the invention of matches in modern society, the history of human fire-making is also the history of human social civilization development as we gradually move towards scientific progress. Every change and leap in human fire-making has become a milestone in social development.

This is the origin of one of China’s oldest civilizations.