Li Chunfeng was a Chinese mathematician,
astronomerAn astronomer is a scientist who studies celestial bodies such as planets, stars, and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
, and
historianAn historian is an individual who studies and writes about history, and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all events in time...
who was born in today's
Baoji, ShaanxiBaoji is a prefecture-level city in Shaanxi province, China.-Geography:It has a population of 3,670,000 according to the 2001 Chinese census, making it the 25th largest city in China, and a surface area of 18172 km². The city itself has a population of approximately 800,000. Surrounded on three...
during the
SuiThe Sui Dynasty followed by the Tang Dynasty and preceded by the Southern and Northern Dynasties in China. It ended nearly four centuries of division between rival regimes....
and
TangThe Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...
dynasties. He was first appointed to the Imperial Astronomy Bureau to help institute a calendar reform. He eventually ascended to deputy of the Imperial Astronomy Bureau and designed the Linde calendar. His father was an educated state official and also a Taoist. Li died in
Chang'anChang'an is an ancient capital of more than ten dynasties in Chinese history. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" ; yet after its fall in the year 23 AD, the old name was restored...
in 670.
The Sui Dynasty was integral for uniting China, so it was a good time for learning.
Li Chunfeng was a Chinese mathematician,
astronomerAn astronomer is a scientist who studies celestial bodies such as planets, stars, and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
, and
historianAn historian is an individual who studies and writes about history, and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all events in time...
who was born in today's
Baoji, ShaanxiBaoji is a prefecture-level city in Shaanxi province, China.-Geography:It has a population of 3,670,000 according to the 2001 Chinese census, making it the 25th largest city in China, and a surface area of 18172 km². The city itself has a population of approximately 800,000. Surrounded on three...
during the
SuiThe Sui Dynasty followed by the Tang Dynasty and preceded by the Southern and Northern Dynasties in China. It ended nearly four centuries of division between rival regimes....
and
TangThe Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...
dynasties. He was first appointed to the Imperial Astronomy Bureau to help institute a calendar reform. He eventually ascended to deputy of the Imperial Astronomy Bureau and designed the Linde calendar. His father was an educated state official and also a Taoist. Li died in
Chang'anChang'an is an ancient capital of more than ten dynasties in Chinese history. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" ; yet after its fall in the year 23 AD, the old name was restored...
in 670.
Background and career
The Sui Dynasty was integral for uniting China, so it was a good time for learning. But when Li was sixteen the Sui fell, and the Tang rose. Nevertheless, the Tang did not harm the conditions for education. Indeed, it rather strengthened it. The Imperial Academy's math teaching was formalized. He was appointed as an advanced court astronomer and historian, once he had been appointed into the Imperial Astronomy Bureau in 627. Once several years had passed, he then was promoted to deputy of the Imperial Astronomy Bureau in 627.
Finally, he became deputy in 648. He was given these titles because the
Chinese calendarThe Chinese calendar is lunisolar, incorporating elements of a lunar calendar with those of a solar calendar. It is not exclusive to China, but followed by many other Asian cultures. It is often referred to as the Chinese calendar because it was first perfected by the Chinese around 500 BCE...
of the era, despite that it had only been used for several years, was already having accuracy problems in predicting eclipses. In fact, Li was appointed partially because of his critique of the Wuyin calendar. Wang Xiaotong had been chosen to study the problem earlier. This was a very important job because of the Chinese belief in the
Mandate of HeavenThe Mandate of Heaven is a traditional Chinese philosophical concept. Tian would bless the authority of a just ruler, but would be displeased with a despotic ruler and would withdraw its mandate...
. So if one altered the calendar, that person would have some control over the connection between the heavens and the emperor.
Astronomy and calendar
In 665, Li introduced a reform
calendarA calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...
. It was called the Linde calendar. It improved the prediction of planets' positions and included an “intercalary month.” That is similar to the idea of a leap day. It would catch up a lunar year to a solar year because twelve lunar months are 1.3906 days short of one solar year. It was added every three years. The Linde calendar is the most prominent accomplishment of Li.
Li wrote a document complaining about the use of outdated equipment in the Imperial Astronomy Bureau, so he was commanded to construct a new armillary sphere. He completed it in 633. His construction had an additional third ring as opposed to the more common design of only two rings.
Mathematics
Li added corrections to certain mathematical works. Examples of this are in
Nine Chapters on the Mathematical Art by
Liu HuiLiu Hui was a Chinese mathematician who lived in the Wei Kingdom. In 263 he edited and published a book with solutions to mathematical problems presented in the famous Chinese book of mathematics known as The Nine Chapters on the Mathematical Art.He was a descendant of Marquis of Zixiang of Han...
. He demonstrated that the least common multiple of the numbers two, three, four, five, six, seven, eight, nine, ten, eleven, and twelve was 27720, the answer was flawed in the original text. Yet another instance of this was in Zu Geng's work about the area of a
sphereA sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
. Li gave 22/7 (3.1428571428571428571428571428571) instead of three as a better approximation of what we know now as
piPi or π is a mathematical constant whose value is the ratio of any circle's circumference to its diameter in Euclidean space; this is the same value as the ratio of a circle's area to the square of its radius. The symbol π was first proposed by the Welsh mathematician William Jones in 1706...
. He began each annotation with the words “Your servant, Chunfeng, and his collaborators comment respectfully on…” Li did write some mathematical works of his own, little is known about them. They are usually dismissed as unimportant in comparison to his other accomplishments. With Liang Shu and Wang Zhenru, he wrote
Shibu Suanjing (十部算经) in 656. These were ten mathematical manuals submitted to the emperor.
Literary works
Li contributed to the
Book of SuiThe Book of Sui was the official history of the Chinese dynasty Sui Dynasty, and it ranks among the official Twenty-Four Histories of imperial China. It was compiled by a team of historians led by the Tang Dynasty official Wei Zheng and was completed in 636.-External links:* of the Book of Sui,...
and
Book of JinThe Book of Jin is one of the official Chinese historical works. It covers the history of Jin Dynasty from 265 to 420, which written by a number of officials commissioned by the court of Tang Dynasty, with the lead editor being the Prime Minister Fang Xuanling, drawing mostly from the official...
, which cover the history of the Sui and Jin dynasties. He wrote about the discoveries in
astrologyAstrology is a group of systems, traditions, and beliefs which hold that the relative positions of celestial bodies and related details can provide information about personality, human affairs, and other terrestrial matters. A practitioner of astrology is called an astrologer...
,
metrologyMetrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement.-Introduction:...
, and
musicMusic is an art form whose medium is sound. Common elements of music are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...
. These are the
official historiesThe Twenty-Four Histories is a collection of Chinese historical books covering a period of protohistory and history from 3000 BC to the Ming Dynasty in the 17th century. The whole set contains 3213 volumes and about 40 million words...
of the periods. The book
Massage-Chart Prophecies is generally credited to Li. The book is a collaboration of attempts to predict the future using numerology. Therefore, Li is often thought of as being a prophet. The book gets it title from a poem near the end, discussing how much time it would take to tell the story of thousands of years, it would be better to take a break and enjoy a massage. Li wrote a book discussing the importance of astrology in Chinese culture called
Yisizhan in 645. This is around when he would have been working on the Linde calendar. Yet another of is works is
Commentary on and Introduction to the Gold Lock and the Flowing Pearls. In this book he describes Taoist customs that was probably part of influence from his father.
External links