Religion and thought
After the Han fell in 220 there was war for a long time. People looked for comfort and answers in ideas.
- Buddhism came from India along the Silk Road. It teaches kindness, calm and freedom from suffering. Monks such as Faxian, Xuanzang and Yijing travelled to India and brought books home; the books were translated into Chinese. Rulers and families built temples, pagodas and cave shrines.
- Daoism says: live with nature and keep balance. Daoist thinkers talked about a simple life. Daoist alchemists mixed minerals to look for a medicine for long life.
- Confucianism teaches duty to family, teachers and ruler. From the Sui time an exam (keju) chose officials, and in the Tang it grew bigger. So learning the Confucian books could give a person a job.
Most people did not choose only one. A family might follow Confucian duty, visit a Buddhist temple and enjoy a Daoist garden.
Literature and art
The Tang is called the golden age of Chinese poetry. About 48,000 poems from this time are still kept.
- Poetry: Li Bai wrote free, joyful poems about the moon, mountains and wine. Du Fu wrote about hunger, war and ordinary people, so he is called the poet-historian. Wang Wei and Bai Juyi wrote simple, beautiful verse. Earlier, Tao Yuanming wrote about quiet farm life.
- Calligraphy: writing with a brush is an art. Wang Xizhi (about 350) is the most famous master. In the Tang, Yan Zhenqing wrote bold, strong letters.
- Painting: Gu Kaizhi (about 400) painted people and feelings on silk. Wu Daozi painted giant temple walls. Hills-and-water landscapes became a favourite.
- Cave and temple art: huge Buddha statues at Yungang and Longmen, and thousands of wall paintings at Dunhuang. The Sui built the great Zhaozhou stone bridge (about 605) that still stands.
Science
Scientists, doctors and farmers made big steps in this age.
- Mathematics: Zu Chongzhi (about 480) found pi between 3.1415926 and 3.1415927. He did it by using polygons with more and more sides inside a circle, as in the 3D scene.
- Farming: Jia Sixie wrote a big book about crops and soil (about 544).
- Medicine: Sun Simiao (Tang) wrote huge books on medicines and taught kindness to every patient.
- Astronomy: the monk Yi Xing measured shadows at many places and made a new calendar (about 725).
- Printing: text was cut on wooden blocks, inked and pressed on paper. The Diamond Sutra (868) is the oldest dated printed book we have.
- Gunpowder: in the late Tang, alchemists mixed saltpetre, sulphur and charcoal and found it by accident.
Try it: be Zu Chongzhi
1. In the 3D, move the Sides slider from 6 to 96 and read the pi value.
2. Before you slide, guess: will 24 sides be above or below 3.14? Check.
3. At home: tie a string round a bangle, then measure across it. Divide the string length by the width. You should get a number near 3.14.
Key formulas and definitions
- Key terms: Buddhism = kindness, calm, comes from India
- Daoism = live with nature; Confucianism = duty and learning
- Keju = exam to choose officials (Sui, Tang)
- Tang poets: Li Bai (free), Du Fu (people and war)
- Pi = circle length / width; Zu Chongzhi: 3.1415926 to 3.1415927
- Diamond Sutra, 868 = oldest dated printed book
Worked examples
1. Put these in order on the time line: Xuanzang goes to India, Diamond Sutra is printed, Sui joins China, Zu Chongzhi finds pi.
Step 1: find each year. Zu Chongzhi about 480, Sui joins China 581, Xuanzang 629, Diamond Sutra 868. Step 2: sort from small to big. Answer: Zu Chongzhi, Sui, Xuanzang, Diamond Sutra.
2. Why did learning Confucian books help a young man in the Tang?
Step 1: the Sui and Tang rulers chose officials by an exam. Step 2: the exam asked about the Confucian books. Step 3: so a man who learned them well could pass and get a government post, whatever his family.
3. A polygon with 6 sides gives pi about 3.0. A polygon with 12 sides gives 12 x sin(15 degrees) = 3.106. Which is closer to the real pi and why?
Step 1: real pi is 3.14159. Step 2: 3.106 is only 0.035 away; 3.0 is 0.14 away. Step 3: with more sides the polygon hugs the circle better. So 12 sides is closer. Zu Chongzhi kept adding sides.
Common mistakes
- Thinking Buddhism started in China. It came from India, and Chinese monks travelled there to bring books.
- Mixing the poets: Li Bai is the free, joyful poet; Du Fu writes about ordinary people and war.
- Saying the printing press with moving letters was used in the Tang. Tang printing used one carved wooden block per page.
- Thinking one person had to follow only one idea. Many families mixed Confucian, Daoist and Buddhist ways.