How did the ancients understand the earth light and aurora thousands of years ago?

Earth light and aurora are both electrical phenomena in the atmosphere, and there are abundant records in this respect in ancient China.

I. Records of Ground Light in Ancient China Before the earthquake, there was a kind of light similar to lightning on the ground, which was called earthquake electro-light, or ground light for short. The reason is not clear. Generally speaking, before and after a strong earthquake, the electric field intensity of the source and its nearby rocks often increases, and so does the electric field intensity of the atmosphere. At the same time, seismic activity makes a lot of underground gas enter the atmosphere along the cracks. When the crust rises, these gases are ionized by the electric field of the crust and enter the atmosphere, further enhancing the electric field of the atmosphere. When the atmospheric electric field is strong enough, it can make the air discharge and emit light, which is terrestrial light.

In ancient China, the records of terrestrial light were more common in local chronicles, such as:

Chengdu Record: February 4, 1993, before the Chengdu earthquake. Is there a fire underground? .

Records of Wanli:1the night of May 26th, 509. Wuchang Prefecture saw blue light flashing like electricity for six or seven times, and weak sound like thunder beating drums, causing an earthquake. .

Zheng De's Record: A.D. 15 13 12.30 Jun County, Sichuan Province? A fireboat saw the sky, which sounded like thunder, and the next day it became an earthquake? .

"Jiangling County Records" records: Late at night on August 5, A.D. 163 1, before the Jiangling earthquake in Hubei? The sky suddenly turned red? .

Yuanjiang County Records: 1637 Before the April 8 earthquake in Yuanjiang, Hunan Province, There was light that day, and the earthquake shook for a moment? .

According to Yingshang County Records, on August 24th, A.D. 1652, when Yingshang, Anhui Province was hit by an earthquake, the city was red? .

"Shuyang County Records" records: In the autumn of A.D. 1846, before the earthquake in Liyang, Jiangsu, there was a red light from north to south? .

In all these words? Firelight? 、? Electric fire? 、? Red light? 、? Red light? 、? Biguang? And so on are nouns used by the ancients to describe terrestrial light. These records are accurate and vivid, and they are extremely precious materials in the history of science. Their significance lies in that the ground light can reflect the activity of rock strata, which is closely related to earthquakes, especially helpful to the prediction of impending earthquakes.

For example, on May 29 1976, there was a strong light in Longling and Luxi areas of Yunnan Province, and local people issued earthquake warnings accordingly, which evacuated the masses and avoided heavy casualties.

Second, the ancient people's understanding and recording of the aurora is a beautiful natural phenomenon, giving people a fascinating feeling. Named after the fact that it usually appears in the polar regions, there are northern lights and southern lights. Our country is located in the northern hemisphere, so we can only see the Northern Lights. Generally speaking, there are more opportunities to see aurora in high latitudes, and occasionally in middle and low latitudes, but the brightness is much weaker.

On a clear night, the northernmost part of our country sometimes sees an arc or ribbon light in the sky, just like snakes and dragons swimming and dancing; Sometimes you will see a cloud-like light block or screen, which seems to be a rosy cloud reflecting the sky. Fireworks are flying and bizarre.

How is this magnificent aurora formed? This question has been raised for a long time. Qu Yuan, a Warring States poet, asked in Tian Wen: If it is not a good day, what will Candle dragon do? ? That is to say, since the sky above the north cannot be illuminated by sunlight, where does the energy of atmospheric luminous phenomena such as Candle dragon (the ancient name of aurora) come from?

It is generally believed that the aurora is caused by the influence of the earth's magnetic field on countless charged particles emitted by the sun, and their moving directions have changed. They descend to the upper layer near the north and south poles along the earth's magnetic field line and drill into the atmosphere at high speed. These charged particles collide with molecules and atoms in the atmosphere, causing the atmosphere to ionize and emit light. This is Aurora. All kinds of atoms emit different colors of light, so the aurora presents colorful colors; Generally yellow-green, but there are also white, red, blue, gray-purple, or both.

Aurora has been recorded for a long time in ancient China. Thousands of years ago, it appeared in the legendary era of the Yellow Emperor. Big lightning around the big dipper pivot? . This may be the earliest aurora record in China.

Hanshu contains the earliest and most accurate aurora records in the world:

? Filial piety was established in September of the first year. Wenchang produced a meteor, white, candlelight, four feet long and big, shaking like a snake. There are hectares, which can be five or six feet long. It surrounds a big place and twists and turns, running through the west of Zigong, between the northwest and the sea. After coming out, it looked like a ring. The North disagreed and stayed for a while. ?

The meaning of this passage is: in September of the first year of the establishment of filial piety, Wu Zixu was equivalent to 65438+1October 27 in 32 BC; ? Meteor? Is the aurora; ? Wenchang? It is Wenchang constellation, which refers to the position where the aurora appears; ? White, light and candles? Is the color and brightness of the record; ? Can it be four feet long and a big circumference? And then what? Can it be five or six articles long, around the house? It describes the size range of the aurora. The article also describes the change of aurora: moving like a snake? , refers to the state in which the aurora begins to swing; ? What's the matter? (? Hey? Pass? Qu? ), indicating that it was more curved later. Through the purple palace west, between the northwest and the sea? In other words, the aurora runs through the west of the purple crown constellation until the northwest of Beidou, and the purple (due north) sea (north 30? Between the west). ? The back is like a ring, and the north is not harmonious? In other words, the aurora finally bends into a ring, leaving only a gap in the north. ? Stay for a while? It means that the aurora stays for about a quarter of an hour (equivalent to 14 minutes now).

There are only more than 70 words on it, describing the time, place, color, brightness, motion state, range, size, orientation and residence time of the aurora. Such an incisive and complete record fully meets the requirements of the modern world for the Aurora Observatory. No wonder Japanese scientists and historians praised it greatly: we can't help but marvel at the accuracy of the description of human natural science in the Han Dynasty in the first century BC. ?

Ancient records about aurora in China are very rich, most of which are relatively clear. At that time, there was no name for aurora, but it was named according to the shape, size, movement, change and color of various aurora phenomena.

This classification nomenclature was first seen in historical records? Official books. It can be seen that this classification nomenclature has existed at least in the sixth century BC. Nine years of Qing Shunzhi (1652), My Humble Opinion by Ding Huang 16? Fragrant? Some of them have sketches of the aurora, some are well drawn, almost identical to modern aurora photography, but some are far-fetched.

Aurora is an important topic in the study of the relationship between the sun and the earth, which is closely related to astrophysics and geophysics. Especially in ancient times, there were neither precise astronomical instruments for observing solar activities nor instruments for recording geomagnetic and ionospheric disturbances, so the historical materials of aurora recorded in ancient times can be said to be priceless.

It can help people understand the changing laws of solar activity, geomagnetism and ionosphere in the past, and also explore the changing process of ancient magnetic pole position.

Of course, the electrical knowledge listed above is sporadic and fragmentary, and most of them are records or descriptions of some electrical phenomena. Nevertheless, this knowledge is still a part of the history of electricity development. Electricity, like all disciplines, cannot be born suddenly. It must follow the process of dialectical development and go through various stages from simple to complex and from low to high. It is impossible to produce modern electricity under the historical conditions of ancient China, but it is still a brilliant contribution that slave society and feudal society may make, and its value and significance cannot be underestimated.