5 replies to this topic

[Chinaconqueror]

What was invented during Han dynasty? Were there any achievements in science during Han dynasty? Who were the famous scientist of that time?

[General_Zhaoyun]

I'll narrate abit about the scientists and their invention of Han dyansty:

Owing to the needs of production, effects of development of production and accoumulation of constant researches, the Han Dynasty's scientific technology showed distinct improvements, and Zhang Heng (张衡), Cai Lun (蔡伦) and other successful scientists emerged.


Zhang Heng

Zhang Heng (AD 78- 139 ), a native of Henan Province, was an outstanding scientist of the Eastern Han Dynasty and a world-famous ancient astronomer.

Zhang was born into a rich, scholarly family in the year AD 78. His grandfather had been the "Taishou 太守" (governor) of Shu Prefecture. Zhang had talents at a young age. He travelled to Luoyang, the capital, where he attended the Imperial college. A diligent student, he had a profound knowledge of "5 classics" and "6 Art."

No only was he highly learned, he also had a noble moral character. He was not satisfied with the extravagance of officiadom, having refused several times recommendations and appointments to official positions from the local government and ministers of the imperial court. He even purposely wrote "Erjingfu 二京赋" (poems) to satirise them.

At the age of 34, Zhang was appointed as a "langzhong 郎中" by Emperor Han Andi, who appreciated his talents. He was promoted to the post of "Taishiling 太史令" 3 years later.

The main duty of the Taishiling was , for the Imperial Court, to observe and record various kinds of heavenly bodies and to fix auspicious dates for offering sacrifices to gods, ancestors, and for holding wedding ceremonies and funeral. He would also decide on the abstention of these services. This creates a favourable condition fo r Zhang to pursue research on astronomy and calendar.

In AD 121, he was transferred to the post of "Simaling司马令", who duty was to recruit talents for official positions. Emperor An died 5 years later. He was succeeded by Emperor Han Shundi, who reinstated Zhang to the former post of "Taishiling". At this time, Zhang was 49 years old. Outsiders sympathised with him for retaining the same post after undergoing several changes.

To this end, Zhang wrote "Yingjian 应间" as the answer. In it, he states that a gentlemen did not worry about his disrespectful official position and low renumeration; he only worried about low moral and shallow knowledge. This amply reflected hi noble ideal and sentiment.

As the astronomical observatory in the south of Luoyang was under the charge of a "taishiling", Zhang often carried out research on astronomical phenomenon there. The observatory was measuring 11.7 m from north to south and 8.5m from east to west, its top (which was oval) was the place where observation of celestial phenomina was carried out.

Ancient China had 3 explanations for the structure of the celestial body-
"xuanye 宣夜", "gaitian 盖天" and "huntian 浑天". The "Xuanye Theory" was lost in the eastern Han dynasty. The "Gaitian Theory", however maintainted that the sky was round and the earth was square, which was different from the actual situation of the astronomical phenomena.

Inheriting the results of his predecessors' research and based on his own actual observation, Zhang Heng developed the "Huntian Theory". He was of the opinion that the celestial body was similar to a hen's egg: the sky was vast and the earth was small and looked like an egg-yolk. The sky wrapping up the earth was akin ot an egg shell wrapping up an egg-yolk". Althought there were still unscientific ingredients in the "Huntian Theory", it was one step ahead of the "Gaitian Theory".

Based on the knowledge of the celestial body, Zhang made a 'huntian" instrument (浑天仪), which was a hollow copper ball that could be turned. 28 constellations were carved on it. Several circles, representing the equator, the ecliptic, the meridian, the horizon, etc, were fitted on theb all.

Zhang even made use of the dripping water from a pot to turn the "huntian" instrument. Its speed was the same as that of the rotation of the earth. When the instrument was turned, the astronomical phenomena would appear in proper order, generally corresponding to the changes of the sun, the moon and the stars. Thus, people could see the movements of the celestial bodies from the instrument inside any premises.

"Lingxian 灵宪", an astronomical work compiled by Zhang, presented many new ideas about the astronomical phenomena; it contained China's earliest scientific explanation of solar eclipse and lunar eclipse. It als contained "lingxian" pictures marking the positions of the celestial bodies.

Zhang created the seismograph (地动仪) in AD 132. Made of copper, it had an 8-chi circumference and was shaped like a wine vat. There was a pillar in the center, which joined the machines in 8 directions. On the side of the instrument were 8 dragons with copper balls in their mouths. On the table (on which the instrument was placed) were 8 toads with their mouths opening upwards. The dragon in the earthquake are would spit out a copper ball which could drop into the toad's mouth. (Note that 1 'chi' is 1/3 m)

One day, the dragon facing west opened its mouth suddenly, dropping a copper ball into the toad's mouth. As there was no earthquake in luoyang at that time, people grew suspicious of the seismograph. A few days later, however, someone from Longxi came with the report that an earthquake did erupt in that area several days ago. This convinced all the people of the reliability of the instrument. Zhang's seismograph came into existence over 1700 years before Europe's earliest one.

Zhang was squeezed out by eunuchs later on. He left Luoyang and became Prime Minister of Hejian. King Liu Kai (刘开) of Hejian was lordly, luxury-loving and domineering and harmed the common folk. After assuming office, Zhang strengthened the law and punished the principal culprit, improving the situation gradually.

The 61- year old zhang tendered his resignation 3 years later, but the imperial court transferred him to the capital where he was given the post fo "Shangshu 尚书". Before long, he died of illness in Luoyang.

Zhang's character and his huge scientific contributions won people's praise for a long period of time. After the founding of New China, his tomb and the "pavillion" where he studied in his younger days were rebuilt in memory of this great scientist. These were situated in his home village - Shiqiao town, Nanyang, Henan province.

Edited by General_Zhaoyun, 22 August 2004 - 03:43 AM.

[General_Zhaoyun]

Cailun and Paper-making Technology

Cai Lun 蔡伦 (? - 121 AD), a navative of Hunan province, came from a peasant family. Towards the end of Emperor Han Mingdi's reign (approximately AD75 or slightly earlier), he became eunuch in the palace. He was promoted to the post of "Zhongchangshi 中常侍" during Emperor Han Hedi's time. In this capacity, he took charge of incidental matters in the palace and took part in the planning of confidential important matters.

Emperor He and Empress Dowager Deng grealy appreciated Cai's talents and accorded him the additiona post of "Shangfangling 尚方令", whose duty was to take charge of the manufacture of knives, swords and utensils. Cai was a competent official. All the objects he made were of top-grade quality and became the model for manufacturing in future.

In AD 114, to reward Cai for the contribution he made during his long service in the palace, the Empress Dowager conferred the title of Duke of Longting (龙亭侯) on him, enabling him to collect taxes from 300 households yearly.

Cai had an innovative spirit. During his appointment as "Shangfangling", he felt it was clumsy and inconvenietn to write on bamboo and wooden slips. Sometimes, memorials to the Emperor were so heavy that they had to be carried by two men into the palace.

At that time, there was a kind of fine silk that could be used for writing, but it was too expensive and could not be popularly used though it was light and handy.

In 1986, remnants of paper on which maps were drawn were unearthed from the graves of the Warring States period, Qin and Han in Gansu province. These were the earliest paper objects known today. This proves that paper could be used for wriitng had been invented in the Western Han dynasty in China.

Taking his predecessors' experiences as a foundation, Cai carried out experiments repeatedly and finally succeeded in creating a kind of new fibre plant paper by using bark, flax, rags, torn fishing-nets, etc as materials.

In 105 AD, the inventor presented the newly-made paper to Emperor Han Hedi, who heapred praises on him. THe paper had a tough texture, making it suitable for writing . It was also easy to make. The materials for making it were cheap. As soon as the paper was available to the public, it was welcomed at once. People called it "Duke Cai" paper (蔡侯纸).

Thenceforth, paper gradually took the place of bamboo and wooden slips, becoming the main thing for writing. It was convenient for people to write, to carry it along and to bind it into books. It had an inestimable effect on the preservation, spread and exchange of ancient culture.

Paper-making technique was spreaded to korea, Japan, Arabia and other countries in the 7th and 8th centuries. It was spreaded to Europe through Arabia, making an enormous contribution towards the development of civilization in the world.

Paper-making workers in China and Japan honoured Cai as the founder of hte paper industry. THe later generations built a temple and made a statue in Laiyang, Hunan (Cai's native place), in memory of him. An ancestry temple was also built in his graveyard in Yang County, Shaanxi Province.

[General_Zhaoyun]

Zhang Zhongjing and Medicine

The medical achievements since the Spring/Autumn period and Warring states period had been developed to a fairly high level in the Qin and Han dynasties. Many medical specialists and medical treatises had emerged. Zhang Zhongjing
(张仲景), a native of Henan province, was a famous medical specialists of the latter eastern Han dynasty.

Since young, Zhang liked to study, especially medical science. To study medicine, he took Zhang Boxu (张伯祖), a well-knowned physician from the same prefecture, as his teacher.

Noticing that Zhongjing took learning seriously and studies assidiously, Dr. Zhang passed on all his medical knowledge and skills to him. This laid a good foundation for the young man's research in future.

Later, Zhang Zhongjing was elected as "xiaolian 孝廉", and took up the post of "Taishou 太守" (governor) of Changsha for a time. But he did not seek fame and wealth and could not bear the sight of officials intriguing against each other, so he resigned and concentrated solely in medical research.

A tangled warfare erupted among warlords and diseases were prevalent after the suppression of the Yellow Turban's uprising. There were originally over 200 people in Zhang's caln. Two-thirds of them died of illness. Seven-tenths of the death were caused by "Cold and Fever" (generally refers to cholera, dysentry, flu and other diseases). This triggered his strong determination to conquer these ailments.

He gathered prescriptions from all sources, painstakingly carried out research and ceaselessly accumulated clinical experiences. Based on this, Zhang compiled an unprecendented famous medical work titled 'On Cold and Fever and Related Diseases" (伤寒杂病论).

Consisting of 16 volumets, this book contained a detailed exposition of pathology, diagnoses, treatments and medication of "Cold and Fever", laying the foundation for Chinese therapeutics on these diseases. Later generations systematised it into two books titled "On Febrile Diseases" (伤寒论) and "Jinkui Yaolue" (金匮要略).

Not only was the physician proficient in treatment, he also attached importance to prevention. To reduce sickness, he presented this health-care method: Restrict food and drinks; lead a regular life; and have appropriate hours of work and rest.

Later generations physicians attached great importance to Zhang's medical achievements. Hua Tuo (华佗), who emerged slightly later than him, and
Sun Simiao (孙思邈), a celebrated material medica specialist of the Tang dynasty, held him in great esteem. Common folk's physicians mostly preserved his prescriptions to be used as an important reference for treatment.

Zhang passed away around AD 219 at the age of 70. His medical contribution earned him the good repuation as a "Medical Saint".

Besides Zhang Zhongjing, the Tang Dynasty's superb skill for the prevention of decomposition of corpses was worth mentioning. The male and female corpses unearthed in a Han grave at Pheonix Mountain in Hubei and Han Grave No.1 in Changsa, Hunan, belonged to the Western Han dynasty and were well-preserved.

After a medical examination, it was discovered that the connective tissues beneath the skin of the corpse still had elasticity and the color of the arteries was similar to that of a fresh cropses.

Physical exercise therapy had been further developed. Acupunctual therapy- China's original creation -had also been tremendously developed. "Mingtang Canon of Yellow Emperor (黄帝明堂经), a systematic treatise on acupuncture, had emerged. Gold and silver needles used in acupuncture therapy had been preserved till now.

Knowledge of material medica was richer than before. "Chinese Herbal Medicine" (神农本草经), compiled in the early Eastern Han dynasty, is China's extant earliest material medicaa treatise, whihc recorded over 300 kinds of medicine, including ginseng, "huanglian", licorice roots, angelica and others commonly used today.

[General_Zhaoyun]

Mechanical Manufacture

Distance-recording "Drum" carriages, driven by gear, were created in the Western Han Dynasty. When the carriage covered a certain distance, the wooden figure in it would automatically beat the drum to announce the mileage.

"Compass" carriages were also created by using the composition of mechanical transmission. No matter how the carriage moved, the finger of the wooden figure in it would always point to a fixed direction. It was one of the earliest cybernetics machines in the wolrd.

Mechnical bows unearthed in Mancheng, Hebei, were fitted with a gadget with graduation for aiming . The principle of this gadget was similar to that of a telescopic sight on a modern day gun. It could enhance the accuracy of shooting.

Ding Huan (丁缓), an artisan of the western han era, manufactured a kind of incense burner, which was fitted with a few rings looped together. No matter how the rings were burnt, balance could invariably be maintained within. Its principle resembled the universal trestle in modern gyroscope, and was over 1500 years earlier than similar assumptions put forward by Europe.

[General_Zhaoyun]

Mathematic Achievements

"Zhoubi Mathematics 周髀算经" (in a book form) was written in the western han dynasty. It was China's extant and earliest work on astronomy and mathematics. It summarised the mathematical knowledge used in ancient astronomy in China including the use of the Pythagorean theorem of right-angled triangles.

"Nine Chapter Arithmetic 九章算术" was a mathematic treatise compiled in the eastern Han era. Its content included 246 problem sums and their solutions, involving arithmetic, elementary algebra, elementary geometry and so on. It laid the foundation of the development of China's ancient mathematics.