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Liu An

Liu An is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Liu An rather than just read about it. In short: Liú Ān (Chinese: 劉安, c. 179–122 BC) was a Chinese monarch, philosopher and cartographer. A Han dynasty prince ruling the Huainan Kingdom, Liu An advised his nephew, Emperor Wu of Han (武帝).

Key takeaways

  • Liu An belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Liu An to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Liu An from memory before moving on to harder problems.

Reference excerpt

Liú Ān (Chinese: 劉安, c. 179–122 BC) was a Chinese monarch, philosopher and cartographer. A Han dynasty prince ruling the Huainan Kingdom, Liu An advised his nephew, Emperor Wu of Han (武帝). He is best known for editing the (139 BC) Huainanzi compendium of Daoist, Confucianist, and Legalist teachings and is credited for inventing tofu. Early texts represent Liu An in three ways: the "author-editor of a respected philosophical symposium", the "bumbling rebel who took his life to avoid arrest", and the successful Daoist adept who transformed into a xian and "rose into the air to escape prosecution for trumped-up charges of treason and flew to eternal life."

Life Liu An was the grandson of Liu Bang, the founding emperor of the Han dynasty. After his father died, he became the Prince of Huainan, the lands south of the Huai River, at the age of 16. Liu An had two sons. The younger was Liu Qian (刘迁), who was born by his princess consort and thus became heir to Huainan, while the elder, Liu Buhai (刘不害), was born to a concubine. Liu An favoured Liu Qian over Liu Buhai and never viewed the latter as his son. Liu Qian never regarded Liu Buhai as his elder brother. According to Tui'en Ling (推恩令, Order to Expand Favours), Liu Buhai could become a marquess if Liu An carved a part of Huainan for him as his fief, but Liu An never did. Liu Jian (刘建), son of Liu Buhai, having realized that both he and his father had little chance to be a marquess, became so resentful that he accused Liu An and Liu Qian of a coup attempt. Finally, in a fate similar to his father, Liu An committed suicide in 122 BC after his plot was revealed.

Literature Noted for his literary ability, Liu An was reputed to be able to compose an elaborate work of prose between waking and finishing breakfast. In addition to composing literary pieces himself, Liu An also frequently invited other scholars as guests to his estate. Eight of these scholars in particular became known as the Eight Immortals of Huainan (淮南八仙).

Huainanzi Together with the Eight Immortals of Huainan and/or other members of his literary circle, Liu An published a treatise in 139 BC. known as the Huainanzi, translated as "Book of the Master of Huainan", or the "Huainan Philosophers". This book is considered one of the cornerstones of Taoist philosophy, along with the works of Laozi and Zhuangzi. Along with the earlier ShuJing (Classic of History) of the 5th century BC (Warring States era), this book provided further concrete information on geography, including descriptions of the topography of China. His book was also concerned with mathematics and music, making use of the "Pythagorean comma" and listing the first known Chinese 12 tone musical tuning.

Chu ci One of the two major ancient Chinese poetry collections was the Chu ci, also known as The Songs of the South or The Songs of Chu (the other being the Shijing). The seminal poem of the collection is the "Li Sao", generally agreed to be by Qu Yuan. Liu An wrote an introduction to the "Li Sao" as well as the first known commentary. There is also reasonable evidence that Liu An was the first editor and anthologist of the original Chu ci collection. The poem Zhao yin shi (Summons for a Recluse) is attributed to Liu An. Also, "Yuan You" ("Far-off Journey") shows many similarities to the work of the literary circle around Liu An.

Legend of inventing soy milk According to the legend, Liu An developed soy milk for his old, ill mother. She wanted to taste soybeans but couldn't chew, so Liu An ground the soybeans into milk, apparently upon her suggestion. No contemporaneous sources supports the legend. In the Ming dynasty reference work Bencao Gangmu, author Li Shizhen describes the development of bean curd (tofu) but does not mention a particular inventor. The attribution of the invention of tofu to Liu An was also made by another Ming dynasty writer, Li Yi (李翊). During the Song dynasty in the 10th century, Zhu Xi had already written of the method of Huainan in "Song of Bean Curd" ("豆腐詩"). It is also mentioned in a book that called bean curd "Lai Ki" in the Han dynasty, and the word appeared in an early Song dynasty writing. Other Chinese sources discredit the Liu An invention theory, however, and state that Liu An lived with a lot of vegetarian monks and the method was taught by them. The Chinese Daoists that he recruited used "alchemical" methods to make both soy milk and bean curd, perhaps as a medicine for eternal life. As a powerful noble, Liu An could order the (relative) mass-production of such items and spread them around, thus making him famous for soy milk and bean curd. Still, many place Liu An as the inventor of both bean curd and soy milk. A different tradition could be found in 《金華地方風俗志》 and 《中國風俗故事集》, which mention that soy milk and bean curd were made before the Han dynasty. These traditions date soy milk to the warring states period by the Yan general Yue Yi, These two books are rather recent and the quote in it was only a legend told to bean curd makers orally, without written record.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Liu An

Start with the simplest possible case. Write down what Liu An claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Liu An before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Liu An ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Liu An

In research
Liu An appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Liu An in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Liu An is common in secondary-school and first-year university syllabi. It links to neighbouring topics 122 BC deaths, 170s BC births, 2nd-century BC Chinese philosophers, so understanding it makes those chapters shorter.
In everyday life
Look for Liu An outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Liu An in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Liu An means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Liu An out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Liu An in simple terms?

Liú Ān (Chinese: 劉安, c. 179–122 BC) was a Chinese monarch, philosopher and cartographer. A Han dynasty prince ruling the Huainan Kingdom, Liu An advised his nephew, Emperor Wu of Han (武帝).

Why does Liu An matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Liu An?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Liu An.

Tags

  • 122 BC deaths
  • 170s BC births
  • 2nd-century BC Chinese philosophers
  • 2nd-century BC geographers
  • Ancient geographers
  • Chinese cartographers
  • Han dynasty imperial princes
  • Han dynasty philosophers
  • Patrons of literature
  • Tofu

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