A child who counts stars
At night, the stars in the sky shine like pearls. A child is sitting in the yard, leaning against his grandmother, looking up and counting the stars in the night sky. One, two, until hundreds.
Grandma smiled and said, "Silly boy, count the stars again. So many stars are blinking and blurred by your eyes. Can you count it clearly? "
The child said, "Grandma, I can count clearly." The stars are moving, not moving. You see, this star and that star are always so far away. "
Grandpa came over and said, "Son, you look very carefully. Stars in the sky are moving, but the distance between them is constant. Our ancestors divided them into several groups and gave them back.
They have names. Grandpa paused, pointed to the northern sky and said, "Look, those seven stars are connected together like spoons. They are called the Big Dipper." A bright star facing the spoon mouth is Polaris. The Big Dipper always goes around the North Star. "
Is it true what Grandpa said? The child didn't sleep well all night and got up several times to look at the stars. He can see clearly that the Big Dipper slowly turns around the North Star.
The child who counts stars is called Zhang Heng, a native of the Eastern Han Dynasty. When he grew up, he studied astronomy hard and became a famous astronomer.
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Zhang Heng (78 ~ 139), a famous scientist and writer in the Eastern Han Dynasty. His birthplace is now Shiqiao, Nanyang County, Henan Province. His grandfather Zhang Kan was a satrap and an upright official. His father died young, and Zhang Heng's family was poor. Rolling has been diligent and studious since childhood, and has long been famous in the village.
According to historical records, when he was 10 years old, he was already "proficient in the Five Classics and Six Arts" and could read from memory. He has a wide range of interests, often dabbles in natural science books, and writes well.
One day, Zhang Heng read four poems from a collection of poems, describing the changes of the Big Dipper in the evening of each season: "bucket handle refers to the east, and the world is spring; Guide to barrel handle, it's summer in the world; Bucket handle refers to the west, and the world is autumn; Bucket handle refers to the north, and it is winter in the world. " He thinks it's interesting. The stars twinkle in the sky, some like dustpans, some like buckets, some like dogs, and some like bears. What are their operating rules? This is simply wonderful. So Zhang Heng drew a sky map according to the content of the poem and referring to other books. Every night, as long as there are no clouds, he silently observes the night sky in front of the star map. How many mysteries are there in the vast starry sky? He observes, records and thinks. His mind is full of all kinds of questions and colorful fantasies. Later, he finally confirmed that the descriptions in those four poems were not accurate enough. In fact, the barrel handle refers to the northeast in early spring and the southeast in late spring.
The observation of the sun, moon and stars in his youth inspired Zhang Heng's determination to explore astronomical mysteries. Later, he served as the central government official in charge of astronomy twice, and made brilliant achievements in this respect. According to Ci Hai, he correctly explained for the first time that the eclipse was caused by the shadow of the moon entering the earth. 2500 stars visible in the Central Plains were observed and recorded, and the first relatively complete star map in China was drawn. He created the first seismograph in the world; Created a guide car, an automatic drum car and a wooden bird that can fly for miles.
Zhang Heng, who is eager for knowledge, always feels that he lacks knowledge. /kloc-when he was less than 0/7 years old, he left his parents and went to visit his teachers in other places to study alone. In the ancient capital Chang 'an, he visited the local places of interest and investigated the surrounding mountains, rivers, products and the world. At that time, he made many learned friends in Luoyang and Kyoto. One of them is Cui Yuan, who is proficient in astronomy, mathematics and calendar, and is also a famous calligrapher. Zhang Heng visited him for advice. It is precisely because of his open-minded and studious spirit that he has benefited a lot in all aspects. In addition to his outstanding achievements in astronomy, he also attracted worldwide attention in the study of seismology. His seismograph for waiting for the wind came out 1700 years earlier than similar instruments in Europe. He was also one of the six great painters in the Eastern Han Dynasty, and his "Fu to the Second Capital" and "Deliberating the Expo in Ten Years" were talked about by people.
In the north of Nanyang County, there is a Zhang Heng's Tomb Heping reading desk. There is an inscription by Guo Moruo on the tombstone: "Such an all-round developed figure is also rare in the history of the world".
Zhang Heng: Ping Zi, surnamed Nanyang. Grandfather comparable, the word Jun you, less governance "Liang Qiu Yi", Guangwu people, for the prefect of Shu County, worship riding a captain, and later worship Yuyang prefect.
After his death, his wife was poor. Father is always unknown. China's famous astronomer and writer. Invented the world's first earthquake testing instrument-seismograph. Zhang Heng wrote:
And a generalist. He combined his scientific research, mechanical instrument manufacturing, political career and making friends all his life, and also wrote many words, some of which are still in the world.
More than 20 articles, including articles, inscriptions, letters patent, hymns, books, books and other forms; Among astronomical monographs, there are Lingxian, Illustrated Notes on Armies and Notes on Turning Water Leakage into Armies.
, "Xuantu" and the lost Lun Heng.
Foreword:
"Before Tai Su, you were quiet and quiet, lonely and silent, and you couldn't like it. There is only deficiency in syncope, and there is no deficiency outside syncope. If it is, it is permanent. Think about it.
I, Gai, am the root of Tao. Doggett was made, but he was made out of nothing. Tai Su began to sprout, but it is not a good sign. It's the same color as gas, and chaos is not divided. Therefore, "morality"
As the saying goes:' Natural selection, since heaven gave the talent, let it be employed!'. Its gas-solid can not be obtained, and its extended solid can not be obtained. If so, it will be permanent.
. Beggars' Sect is Tao's work. The trunk of pottery is not only cultivated, but also mature. So the vitality is judged, the rigidity and softness are separated, and the turbid qi is ectopic and natural.
The ground is set inside. Celestial bodies are in the sun, so they move in circles; The earth is in the shade, so it is flat and quiet. Take action as action, combination as static, depression as essence and education as time.
Class, Si is Taiyuan, and Gai is the reality of Tao. "
-Zhang Heng's Ling County
Zhang Heng's Road to Success:
The Eastern Han Dynasty was a big country in the world at that time, and it was in a leading position in politics, economy and culture. The economy and culture are developed, prosperous and stable
The peaceful political situation provided a good social environment for Zhang Heng to study.
When he was a teenager, Zhang Heng was talented, modest and studious, good at thinking, thirsty for knowledge and full of enthusiasm for learning. exist
When I was a teenager, I was familiar with classic works such as The Book of Songs, The Book of Changes, Li Ji and Spring and Autumn Annals. At that time, only
Only by reading these classics can you become an official. However, Zhang Heng is open-minded and not bound by traditional ideas. He is not interested in being an official. On the contrary, he is right.
Literature likes it very much, especially the works of Sima Xiangru, Yang Xiong and other writers, which can not only be deeply understood.
And can recite. These works strongly shocked Zhang Heng's young mind, and he hoped that he would become their literature in the future.
Go home. At the same time, he is not satisfied with the life of "behind closed doors, studying sage books". He is eager to travel abroad, contact with reality and enrich himself.
Live to broaden your horizons and seek more knowledge. In 94 AD, 19-year-old Zhang Heng said goodbye to his relatives with the wish of traveling far away.
He left Nanyang, a beautiful hometown where he was born and raised, and embarked on a journey of visiting famous rivers, teachers and friends. Zhang Heng wandered between Weihe River and Weihe River.
In the region, I visited the magnanimous and rich Weihe Plain, watched the majestic and verdant Mount Zhongnan and the steep Huashan Mountain, and visited the people and asked about things.
Production, looking for historical sites, the magnificent capital buildings and street layout of the Western Han Dynasty were carefully investigated. Through this tour, he not only deepened his understanding of his predecessors.
The experience of literary works and the accumulation of a large number of literary materials laid a solid foundation for him to write the famous Xijing Fu later.
Zhang Heng is diligent and studious, with excellent moral character and outstanding talent, and has been inspected by Nanyang County Chief for many times. However, in his view, a gentleman does not worry about himself.
I don't respect my official position, but I'm afraid my moral character is not noble; I'm not ashamed of my salary, but I don't know much.
Bo is a disgrace. Therefore, his study is not limited to the Five Classics, but also includes astronomy, geography, meteorology and literature. As Cui Yuan commented on him.
: "I don't know what it is, it's a pity, but it's very gratifying to hear a kind word." This is Zhang Heng, a studious, unconventional and ambitious person.
Ambition, an aspiring young man whose responsibility is to contribute to society.
After five or six years of hard study and life in Luoyang, Zhang Heng's academic and literary creation level has gradually improved and become a veritable master.
A real young scholar. He has written many works such as Ding Qing Fu, Numerous Fu and Seven Debates, and began to conceive the creation of Erjing Fu.
. However, due to his poor family, he could not study in the capital for a long time, so he had to return to Nanyang as the main book at the invitation of Bao De Guan.
Because of his leisure time at work, he was able to concentrate on literary creation. With his love for his hometown, he also created a rich * * *
Du Nan Fu praised my hometown for its magnificent mountains and rivers, fertile land and rich products. In addition, he also wrote the masterpiece Erjing Fu.
Namely: Xijing Fu, Tokyo Fu, and many poems, poems, essays and books.
From 108 to11year, Zhang Heng lived in his hometown and devoted himself to studying. After unremitting efforts, I am studying.
I learned something by asking a lot of questions. During this period, Zhang Heng began to read Yang Xiong's Xuan Jing intensively. Ty Xuan Jing is a research book.
The philosophical works of Zhou phenomenon also talk about astronomical calendar and other issues. In particular, "Huntian Theory" is particularly attractive to Zhang Heng. But because it's written better than
Simplicity makes Zhang Heng feel dissatisfied, and he is going to do further research on this basis. In the process of studying Xuan Jing.
During middle school, Zhang Heng made great efforts, made detailed research and analysis while intensive reading, and once wrote notes and drew Xuan Jing.
I read The Mystery Map. Notes on Taixuan Jing and Taixuan Tu are Zhang Heng's experiences in reading Taixuan Jing. In these two books, reflect
This paper introduces some philosophical thoughts of Zhang Heng. Unfortunately, these two books have not been handed down. Through the study of Taixuan Jing, Zhang Heng also came into contact with a lot.
The legacy of materialism and atheism in China's ancient history. Xuan Jing's materialistic factors inspired Zhang Heng's pursuit of nature.
A thirst for truth. After reading Taixuan Jing intensively, Zhang Heng gradually turned from literary creation to philosophical research, especially for the greatest in the universe.
The laws of natural phenomena, such as astronomy, calendar, mathematics and other scientific theories began to learn. And make scientific instruments to realize astronomical phenomena.
Careful observation and long-term measurement.
While studying Xuan Jing, Zhang Heng also became interested in Mo Jing. Mo Jing is a disciple of Mozi and his later studies.
A book summarizing the development of Mozi's thought. It recorded and summarized a lot of knowledge about handicrafts in the Spring and Autumn Period and the Warring States Period, and put forward the ancient
Many concepts and viewpoints in physics and mathematics. This book not only covers a wide range of social sciences such as epistemology, logic and economics.
Capacity also includes natural science knowledge such as time, space, material structure, mechanics, optics and geometry, some of which are asked.
The topic is well elaborated and thoroughly reasoned, which has very important scientific value and is a rare work in classical philosophy and natural science.
Treasure. However, Mohist thought has been neglected for a long time, and Mohist scientific achievements have been ignored. Zhang Heng can break through the shackles of Confucianism,
Committed to the study of Mohism, which required extraordinary courage at that time.
Zhang Heng reads ancient books and is good at taking the essence, so as to forge ahead in scientific research and find another way. This is our ancestor.
The greatest and most glorious tradition in the history of China's science is worth learning by future generations.
Zhang Heng thought:
(A) celestial evolution thought:
How everything in the world originated and developed is the core of cosmology. "In the history of human understanding, from
Since then, there have been two views on the law of the development of the universe, one is metaphysical and the other is dialectical, which have formed mutual opposition.
Two world views. " (Selected Works of Mao Zedong * * *, Volume I, On Contradiction) The materialistic and dialectical view of the universe is positive to the law of the development of the universe.
It is true and scientific, and the idealistic metaphysical world outlook is a distorted and inverted reflection of the law of the development of the universe.
Zhang Heng's Original Picture and Lingxian are two important works that reflect his philosophical world outlook. In these two books, Zhang Heng
Inherited the materialism tradition from the Spring and Autumn Period and the Warring States Period to the Han Dynasty, and put forward philosophical thoughts such as "Tai Zhi", "Tai", "Tai Su" and "Yuan Qi".
Category to discuss the origin of the universe. He said: "Yuan, intangible and the like, the root of nature, built in the beginning, is one of them." so-called
"The root of nature" refers to the root of everything in the world. Here, Zhang Heng clearly points out that the earliest origin of everything in the world is neither what.
The will of gods and gods is not an absolute theory, but an "invisible" and "yuan", that is, the beginning.
In Zhang Heng's view, the generation of heaven and earth can be divided into three stages. The first stage is called "I", which is a geometric space that has existed for a long time.
. "There is only emptiness in fainting, nothing outside fainting", and the whole space is silent, without any substance. However, there is everything in the universe.
The law of change and development. With this foundation, we can create something from scratch. First of all, there are different kinds of material vitality, mutual
Mixed up, kept running, disorderly. This is the second stage, called "Pang Hong". After a long time, this group of Yuan
Air and polluted air gradually separate, the sky forms outside, and the earth settles inside. The harmony between heaven and earth gives birth to all things. This stage is called
"Tai Yuan". As a result, all kinds of celestial bodies were formed in the sky, and everything was produced on the ground. Zhang Heng believes that everything in the world is inseparable from the original chaos.
Develop from the vitality of. The primordial qi is material, including yin and yang with different qualities, and natural phenomena are also different and interact with each other.
Ring, reflecting the different material properties of yin and yang and their interaction. This is a primitive materialism of the origin of the universe and everything.
Generation theory.
The story of astronomer Zhang Heng.
Zhang Heng is from Nanyang. He left his hometown at the age of seventeen and went to Chang 'an and Luoyang successively, studying hard in imperial academy. At that time, Luoyang and Chang 'an were both very prosperous cities, and the princes and nobles in the city lived a luxurious life. Zhang Heng doesn't like these. He wrote two literary works, Xijing Fu and Tokyo Fu (Xijing is Chang 'an and Tokyo is Luoyang), satirizing this phenomenon. It is said that in order to write these two works, he spent ten years studying the spirit of learning after careful consideration and repeated revisions, which shows that he is very serious.
But Zhang Heng's major is not literature, and he is particularly interested in mathematics and astronomical research. When the court heard that Zhang Heng was a learned man, it called him to be an official in Beijing. First as a doctor in the palace, then as an official, he was put in charge of observing astronomy. This job coincides with his interest in research.
After his observation and research, he came to the conclusion that the earth is round and the moon reflects the light of the sun. He also thinks that the sky is like an eggshell, wrapped outside the ground; The ground is like egg yolk, in the middle of the sky. Although this theory is not completely accurate, it was impossible to express this scientific opinion more than 800 years ago without being praised by later astronomers.
Not only that, Zhang Heng also made an instrument for measuring astronomy with copper, called "Hunyi". It is engraved with astronomical phenomena such as the sun, moon and stars. He tried to use water power to turn the instrument. It is said that the stars can be seen clearly on the armillary sphere.
During that period, earthquakes often occurred. Sometimes once a year, sometimes twice a year. A big earthquake happened, which affected dozens of counties. Walls and houses collapsed, killing and injuring many people and animals.
At that time, the feudal emperors and ordinary people regarded the earthquake as an ominous sign, and some even took the opportunity to publicize superstition and deceive the people.
However, Zhang Heng does not believe in God or evil spirits. After careful investigation and experiments on the recorded earthquake phenomena, he invented an instrument for predicting earthquakes, called "seismograph".
The seismograph is made of bronze, a bit like a jar. There are eight dragons carved around, and the bibcock extends in eight directions. Every dragon has a small copper ball in its mouth: under the tap, a bronze toad crouches, aiming at the dragon's mouth and opening it. When there is an earthquake in any direction, the dragon mouth in that direction will automatically open and spit out copper balls. The copper ball fell into toad's mouth and made a loud noise, giving people an earthquake warning.
One day in February of AD 138, Zhang Heng's seismograph suddenly opened its mouth to the west and spit out a copper ball. According to Zhang Heng's design, this is to report the earthquake in the west.
However, there was no sign of an earthquake in Luoyang that day, and there was no news of an earthquake nearby. Therefore, people have been talking about Zhang Heng's seismograph as a lie, and some even say that he intends to spread rumors.
A few days later, someone rode a fast horse and reported to the court that there was a big earthquake in Jincheng and Longxi, more than 1000 miles away from Luoyang, and even the mountains collapsed. Everyone is convinced.
"3" The Story of Zhang Heng
Zhang Heng's story:
Rolling loves to think since he was a child, and he always wants to get to the bottom of everything around him. One summer night, Zhang Heng, grandpa and grandma were enjoying the cool in the yard. He sat on the bamboo bed, upturned his head, looked blankly at the sky, raised his fingers from time to time and counted the stars carefully.
Zhang Heng said to Grandpa, "I counted for a long time and saw some stars moving. What was originally in the east of the sky has gone to the west. Some stars appeared and some disappeared. Aren't they running? "
Grandpa said, "The stars will move. If you want to know the stars, you must look at the Big Dipper first. Look at the bright seven stars over there, gathered together like spoons, it's easy to find ... "
"oh! I found it! " Xiao Zhangheng asked excitedly, "So, how does it move?" Grandpa thought for a moment and said, "At about midnight, it moved to the top. At dawn, Beidou turned over and hung upside down in the sky ... "
That night, Zhang Heng couldn't sleep and got up several times to watch the Big Dipper. He was very happy when he saw the spoon-shaped Big Dipper upside down! I thought: Why does the Big Dipper turn like this? What is the reason? At dawn, he hurried to ask grandpa, who couldn't explain it clearly. So, with this question, he went to read astronomical literature.
Later, when Zhang Heng grew up, the emperor learned that he was outstanding in literary talent, so he called Zhang Heng to Luoyang, the capital, as an imperial adviser, mainly in charge of astronomical calendars. In order to explore the mysteries of nature, young Zhang Heng often studies alone in his study and often stands on the observatory to observe the sun, moon and stars.
He founded the theory of "Huntian" and made the Huntian instrument according to this theory. This big copper ball is mounted on an inclined shaft, and it rotates by water power. Its rotation speed is exactly the same as that of the earth. On this artificial celestial body, you can see the stars in space accurately.
(3) Extended reading of Zhang Heng's story: Like his grandfather, Zhang Heng studied hard since childhood and made a fuss when he was a teenager. /kloc-left home to study abroad after 0/6. He first went to Sanfu (now Xi City, Shaanxi Province), an academic and cultural center at that time.
The magnificent mountains and rivers in this area and the magnificent ruins of the ancient capital of Qin and Han dynasties provided him with rich literary creation materials. Later, he went to Luoyang, the capital of the Eastern Han Dynasty. There, he went to imperial academy, the highest institution of learning at that time, met Cui Yuan, a famous scholar later, and became close friends with him.
Rolling has a wide range of interests. He taught himself the Five Classics, which has infiltrated the Six Arts. He also likes to study arithmetic, astronomy, geography and mechanical manufacturing. However, in his youth, most of his interests were still poetry, words and prose. Although he is above others, he is not proud. Usually calm and indifferent, do not like to associate with laity.
The story of Zhang Heng inventing the seismograph.
In A.D. 132 (the first year of Yangjia), Zhang Heng invented the earliest seismograph in Taishiling, called Hou Feng Seismograph. According to "Zhang Hengchuan in the Later Han Dynasty", the seismograph is made of pure copper, with a round diameter of eight feet, and the convex top cover is shaped like a wine bottle, decorated with the image of tortoise, bird and beast in seal script. There is a big column in the middle, running along the eighth route, and the engine is safely turned off.
It has eight directions, and there is a dragon in each direction. There is a copper bead in the dragon's mouth, and there is a toad under each dragon. If there is an earthquake on both sides, the copper beads in the longkou in that direction will fall into the toad's mouth, so that the direction of the earthquake can be measured. After testing, it conforms to the established system, if God helps. No one has ever recorded it since it was recorded in a book.
On one occasion, when Yi Long had the opportunity, the ground did not move, and Luoyang scholars blamed it for its distrust. A few days later, the messenger came. Sure enough, there was an earthquake in Longxi, and everyone was shocked. Since then, the court has asked historians to record the location of the earthquake.
There are two popular versions about the structure of the seismograph: Wang Zhenduo model, that is, the "single column" is a cylinder similar to an inverted wine bottle, and the mechanism for controlling the longkou is around the "single column". This model has been basically rejected. The other model was put forward by Feng Rui of Seismological Bureau, that is, the "single column" is a pendulum (see the Book of the Later Han Dynasty), and there is a small ball under the pendulum, which is located at the intersection of the "m"-shaped slideways (that is, the "Guan" mentioned in the Book of the Later Han Dynasty). During the earthquake, the "single column" moved the ball, and the ball hit the mechanism of controlling the longkou.
In addition, Feng Rui's model also changed the toad from facing the bottle to facing the bottle and acting as the foot of the musical instrument. The model is simulated and tested, and the results are consistent with the historical records.
Earthquakes are frequent in the world, but it is after19th century that earthquakes can really be observed with foreign instruments. Hou Feng seismograph is the ancestor of seismographs in the world. Although its function is still limited to measuring the approximate location of the epicenter, it has surpassed the development of world science and technology for about 1800 years.
(4) Extended reading of Zhang Heng's story:
In terms of scientific inventions, Zhang Heng has made great contributions to China and the world culture. China's armillary sphere developed rapidly from the middle of BC 1 century. Geng Shouchang of the Western Han Dynasty invented the earliest armillary sphere. Around the year 125, Zhang Heng made a complete armillary sphere on the basis of Geng Shouchang, Fu 'an and Jia Kui, plus the horizon ring and meridian ring.
Joseph Needham gave a high evaluation: "Zhang Heng is the pioneer of demonstrating the armillary sphere (a model with a ground in the middle), and at the same time he successfully used hydraulic power to run rings (including observation) on the armillary sphere. He combined demonstration and observation to some extent. Since then, the methods of making and using these two sabers have not changed much after hundreds of years "; "As far as we know, the earliest information about the faint Yi is Zhang Heng (about AD 125)."
He also succeeded in creating the world's earliest armillary sphere (also known as elephant) that rotates by water. According to the Records of Song Shu Tian Wen Zhi, there were still armymen in the Eastern Jin Dynasty. In A.D. 132, Zhang Heng made a seismograph to measure earthquakes, which was very scientific and accurate. In history, it is said that "the test is based on things, and the agreement is like a god." In addition, Zhang Heng also made three-wheeled self-rotating vehicles, guided vehicles and self-flying wood carvings.
The story of Zhang Heng inventing the seismograph.
Zhang Hengguan heaven and earth.
Zhang Heng was an outstanding scientist in the Eastern Han Dynasty. He loves to think since he was a child, and he always wants to get to the bottom of everything around him.
One summer night, Zhang Heng, grandpa and grandma were enjoying the cool in the yard. He sat on the bamboo bed, upturned his head, looked blankly at the sky, raised his fingers from time to time and counted the stars carefully.
Zhang Heng said to grandpa, "I counted for a long time and saw some stars moving. What was in the sky has gone to the west. Some stars appeared and some disappeared. Aren't they running? "
Grandpa said, "The stars will move. If you want to know the stars, you must look at the Big Dipper first. Look at the seven bright stars over there. Together, it's like an iron for ironing clothes. It is easy to find ... "
"oh! I found it! " Xiao Zhangheng was very excited and asked, "So, how does it move?"
Grandpa thought for a moment and said, "About midnight, it moved to the horizon. At dawn, Beidou turned over and hung upside down in the sky ... "
That night, Zhang Heng couldn't sleep and got up many times to see Beidou. In the dead of night, he saw the bright big dipper hanging upside down. How happy he feels! He thought: Why does this Beidou turn like this? What is the reason? At dawn, he hurried to ask grandpa, who couldn't explain it clearly. So, with this question, he went to read astronomical literature.
Later, when Zhang Heng grew up, the emperor learned that he was outstanding in literary talent, so he called Zhang Heng to Luoyang, the capital, as an imperial adviser, mainly in charge of astronomical calendars.
In order to explore the mysteries of nature, young Zhang Heng often studies alone in his study and often stands on the observatory to observe the sun, moon and stars. He thought, if we can make an instrument that can observe the sky from above and the earth from below, and predict what will happen in nature, it will be of great help to people to prevent disasters and expose those absurd superstitious stories!
Therefore, Zhang Heng analyzed and studied the observation data from books, and began the trial production of the instrument of "observing the sky and the earth". He first wrote a book about his research called Lingxian. In this book, he tells people that the sky is spherical, like an egg, the sky is like an eggshell, wrapped outside the ground, and the ground is like an egg yolk. This is the so-called "Huntian Theory".
Then according to this theory, Zhang Heng began to design and manufacture instruments. I don't know how many stormy mornings and sleepless nights passed, when the armillary sphere, one of the most advanced astronomical instruments in the world, was born. This big copper ball is very similar to today's globe. It is mounted on an inclined shaft. Through hydraulic rotation, its rotation speed is exactly the same as that of the earth. On this artificial celestial body, you can see the stars in space accurately. Zhang Heng said: "There are 2,500 visible stars in the sky, but we often only see 120."
Later, after studying hard, Zhang Heng invented and created the world's first instrument that can predict earthquakes-the seismograph. This seismograph is also made of steel, shaped like a wine jar, surrounded by eight dragons, and each longkou contains a small copper ball. As long as the copper ball in the dragon's mouth spits out, it means that there is an earthquake in that direction. The test was very effective, and there was no failure.
Zhang Heng's creation and invention in science is great because he loved science since childhood, studied diligently, observed experiments persistently, and was able to combine book knowledge with practical experience and obtain it through his own hard research and creation.