List of Chinese discoveries

Aside from many original inventions, the Chinese were also early original pioneers in the discovery of natural phenomena which can be found in the human body, the environment of the world, and the immediate solar system. The list below contains discoveries which found their origins in China.

Discoveries

* Circadian rhythm, recognition of: The "Huangdi Neijing", compiled by the 2nd century BC during the Han Dynasty (202 BC – 220 AD), noted the symptoms, behavior, and reactions of people with different diseases (i.e. of the liver, heart, spleen, lung, or kidneys) during different times of a 24-hour day.Temple (1986), 125.] The idea of any organism following a daily circadian rhythm was not accepted in mainstream modern medical science even up until the 1960s, yet it is now well established that patients with Parkinson's disease lose much of their debilitating symptoms between 9 pm and midnight, while paroxysms of patients with asthma usually occur at night when secretion of hormones from the cortexes of the adrenal glands falls to a minimum.Temple (1986), 124–125.] Although the ancient Chinese explained symptoms of diseased patients that followed the pattern of their circadian rhythms in terms of superstitious numerology and cyclic lore, they still documented such cases and expounded on them long before anyone else.Temple (1986), 126.] Chinese works on acupuncture also dealt with circadian rhythm, including the "Noon and Midnight Manual" and the "Mnemonic Rhyme to Aid in the Selection of Acu-points According to the Diurnal Cycle, the Day of the Month and the Season of the Year" (compiled from circa 419 to circa 930 AD).

* Climate change, concept of: In his "Dream Pool Essays" of 1088, Shen Kuo (1031–1095) wrote about a landslide (near modern Yan'an) where petrified bamboos were discovered in a preserved state underground, in the dry northern climate zone of Shanbei, Shaanxi; Shen reasoned that since bamboo was known only to grow in damp and humid conditions, the climate of this northern region must have been different in the very distant past, postulating that climate change occurred over time. [Chan, Clancey, Loy (2002), 15.] [Needham (1986), Volume 3, 614.] It should be noted that Shen also advocated a hypothesis in line with geomorphology after he observed a strata of marine fossils running in a horizontal span across a cliff of the Taihang Mountains, leading him to believe that it was once the location of an ancient shoreline that had shifted hundreds of km (mi) east over time (due to deposition of silt and other factors). [Sivin (1995), III, 23.] [Needham (1986), Volume 3, 603–604, 618.]

* First law of motion, partial description: The Mohist philosophical canon of the "Mojing", compiled by the followers of Mozi (c. 470 – c. 390 BC), provides the earliest known attempt to describe inertia: "The cessation of motion is due to the opposing force...If there is no opposing force...the motion will never stop. This is as true as that an ox is not a horse."Temple (1986), 161.] However, like many of the Hundred Schools of Thought during the Warring States Period (403–221 BC), the doctrine of the Mohist sect had little impact on the course of later Chinese thought, while this passage and others from the "Mojing" were only given serious attention by modern scholarship after the work of Joseph Needham in 1962.

* Geobotanical prospecting: Geobotanical prospecting can be defined as the connection made between the types of vegetation that grow in certain areas and the minerals that can be found underground in those same areas; this observation was first made in China.Temple (1986), 159.] It is now established in modern geobotany that only certain plants can grow in soils which are rich in certain types of minerals, such as "Viola calaminaria" and "Thlaspi" which grow in soils rich in zinc. The Zhou Dynasty (c. 1050–256 BC) Chinese "Classic of Mountains and Rivers", compiled from the 6th to 2nd centuries BC, states that a certain "huitang" plant only grows near ore deposits of gold. As seen in the 5th century BC text "Tribute of Yu", geobotanical prospecting in ancient China was mainly concerned with describing the nature of soil in different regions for agricultural purposes. The "Book of Master Wen", compiled by 380 AD and containing material from as far back as the 3rd century BC, states that the branches of trees tend to droop in soils where an abundance of jade is to be found.Temple (1986), 160.] In about 290 AD, Zhang Hua (232–300) wrote that hematite was found in abundance in any soil where smartweed grew. In the "Illustrated Mirror of the Earth", written in the early 6th century AD, there is a description of a plant with an elegant yellow stalk which was found to grow above copper, and another description of a plant with green leaves and a red stalk where lead is often found below. In his "Miscellaneous Morsels from Youyang", the Tang Dynasty (618–907) author Duan Chengshi (d. 863) noted that silver could often be found in the soil where ciboule onion grew, gold where a certain kind of shallot grew, and copper where ginger grew. Su Song (1020–1101) of the Song Dynasty (960–1279) described how "Portulaca oleracea" could yield mercury if pounded, dried, and allowed to decay. The "Precious Secrets of the Realm of the King of Xin", written in 1421 during the Ming Dynasty (1368–1644), described how mineral trace elements were observed and could be extracted from certain plants, such as copper from "Oxalis corniculata", gold from rape turnip, silver from weeping willows, and lead and tin from mugwort, chestnut, barley, and wheat. Geobotanical prospecting was unknown in the rest of the world until about 1600 when Sir Thomas Challoner and his first cousin Thomas Challoner discovered alum mines on the former's property of Belman Bank, Guisborough, Yorkshire, England. Both Challoner relatives realized here (and later in Italy) that leaves of oak trees were a much darker, richer green and their branches stronger and more spread out where the alum was to be found.

* Leprosy, first description of its symptoms: The "Feng zhen shi" 封診式 ("Models for sealing and investigating"), written between 266 and 246 BC in the State of Qin during the Warring States Period (403–221 BC), is the earliest known text which describes the symptoms of leprosy, termed under the generic word "li" 癘 (for skin disorders).McLeod & Yates (1981), 152–153 & footnote 147.] This text mentioned the destruction of the nasal septum in those suffering from leprosy (an observation that would not be made outside of China until the writings of Avicenna in the 11th century), and according to Katrina McLeod and Robin Yates it also stated lepers suffered from "swelling of the eyebrows, loss of hair, absorption of nasal cartilage, affliction of knees and elbows, difficult and hoarse respiration, as well as anaesthesia." Leprosy was not described in the West until the writings of the Roman authors Aulus Cornelius Celsus (25 BC – 37 AD) and Pliny the Elder (23–79 AD).

*Negative numbers: The abstract concept was recognised as early as 100 BC–50 BC. A Han Dynasty (202 BC – 220 AD) Chinese work, "Nine Chapters on the Mathematical Art" ("Jiu-zhang Suanshu"), edited later by Liu Hui in 263, used red counting rods to denote positive coefficients and black rods for negative. [Temple (1986), 141.] The Chinese were also able to solve simultaneous equations involving negative numbers (this system is the exact opposite of contemporary printing of positive and negative numbers in the fields of banking, accounting, and commerce, wherein red numbers denote negative values and black numbers signify positive values).

* Snowflake, observation of its hexagonal structure: In his "Moral Discourses Illustrating the Han Text of the Book of Songs" of 135 BC, the Han Dynasty (202 BC– 220 AD) author Han Ying wrote: "Flowers of plants and trees are generally five-pointed, but those of snow, which are called "ying", are always six pointed."Temple (1986), 162.] This was the first explicit reference in world history to the hexagonal structure of snowflakes. From then on, Chinese writers throughout the centuries mentioned the hexagonal structure of snowflakes, including the crown prince and poet Xiao Tong (501–531) and the Neo-Confucian philosopher Zhu Xi (1130–1200). In contrast to Western ideas of snowflakes, Olaus Magnus (1490–1557) wrote in his "A Description of the Northern Peoples" in 1555 that snowflakes could take on many shapes, including crescents, arrows, nails, bells, and even the shape of the human hand. It was not until 1591 that Thomas Hariot (1560–1621) recognized the snowflake's hexagonal structure, but he did not publish his jotted private notes on the subject. Finally, the astronomer Johannes Kepler (1571–1630) wrote the first known European publication on the subject in 1611, the fifteen-page "A New Year's Gift, or On the Six-Cornered Snowflake".

* Solar wind, observation of via comet tails: In the "Book of Jin" compiled during the Tang Dynasty (618–907), a passage written in 635 AD states: "In general, when a comet appears in the morning, its tail points towards the west, and when it appears in the evening, its tail points towards the east. This is a constant rule. If the comet is north or south of the Sun, its tail always points following the same direction as the light radiating from the Sun."Temple (1986), 34.] In other words, as Robert Temple states, "the Chinese observations of comet tails had been refined enough to establish the principle that comet tails always point away from the sun." Furthermore, the text reveals that astronomers by at least the Tang Dynasty understood that, like the Moon, the light shining from a comet was merely reflected sunlight; from the writings of Jing Fang (78–37 BC), Wang Chong (27–100), Zhang Heng (78–139), and others it is apparent that the Chinese already by the Han Dynasty (202 BC – 220 AD) understood that the Moon was illuminated solely by the Sun's rays of light. [Needham (1986), Volume 3, 227 & 411–414.] Although the Chinese explained this constant rule about comets in terms of supernatural "qi", it is now understood in modern astronomy as the concept of 'solar wind', where the powerful force of radiation from the Sun causes comets to turn away from it.

* Spontaneous combustion, recognition of: In his "Record of Strange Things" written sometime before 290 AD, the Jin Dynasty official and poet Zhang Hua (232–300) wrote the earliest known account acknowledging spontaneous combustion: "If ten thousand piculs of oil are accumulated in store, the oil will ignite itself spontaneously. The calamitous fire which occurred in the arsenal of the time of the Emperor Wu [of the Jin Dynasty] in the Taishi reign-period [265–74 AD] was caused by the stored oil."Temple (1986), 166–167.] There were other mentionings of spontaneous combustion in early Chinese literary works, while more often than not fires were blamed on arsonists.Temple (1986), 167.] The 13th-century work "Parallel Cases Solved by Eminent Judges" recounts an event in 1050 where imperial guards were charged in a court of law with the crime of allowing a fire to spread in the palace at Kaifeng; their sentence was commuted from the death penalty to a light punishment when artisans confessed that the chemical-enhanced (perhaps quicklime) oily curtains they made had the propensity to catch fire spontaneously when left out in the open, a statement which convinced Emperor Renzong (r. 1022–1063) since a random fire had recently started in oiled garments of Emperor Zhenzong's (r. 997–1022) mausoluem. The author of "Parallel Cases Solved by Eminent Judges" noted that Zhang Hua had once believed oil stored in an arsenal spontaneously combusted, yet he concludes that what happened in that ancient arsenal was most likely the result of oiled garments, not just oil by itself. The first acknowledgement of spontaneous combustion anywhere else in the world was made by J. P. F. Duhamel in a French scientific paper published in 1757, in which he described oiled canvas sails catching fire after being left out in the summer sun for only a few hours.

* Sunspots, recognition of as solar phenomena: The astronomer Gan De (fl. 4th century BC) from the State of Qi during the Warring States Period (403–221 BC) was the first known writer to attribute sunspots as characteristics of the sun and true solar phenomena.Temple (1986), 29.] The next known recording of a sunspot in China was in 165 BC, yet the first precisely dated sunspot observed from China occurred on May 10, 28 BC, during the Han Dynasty (202 BC – 220 AD). From 28 BC to 1368 AD, a total of 112 other instances of sunspots were recorded by the Chinese.Temple (1986), 30.] In the West, from the time of Aristotle (384–322 BC) of ancient Greece to the time of Galileo Galilei (1564–1642), it was commonly believed that the heavens were perfect, including the sun. After the first written observation in the West of sunpots by Einhard (d. 840) in his "Life of Charlemagne" in 807 AD, the sun's periodic blemishes were explained by Western thinkers as being small invisible satellites or transits of Mercury and Venus; it was only in the 17th century that these beliefs were overturned.Temple (1986), 29–30.]

* True north, concept of: The Song Dynasty (960–1279) official Shen Kuo (1031–1095), alongside his colleague Wei Pu, improved the orifice width of the sighting tube to make nightly accurate records of the paths of the moon, stars, and planets in the night sky, for a continuum of five years. [Sivin (1995), III, 17–18.] By doing so, Shen fixed the outdated position of the pole star, which had shifted over the centuries since the time Zu Geng (fl. 5th century) had plotted it; this was due to the precession of the earth's rotational axis.Sivin (1995), III, 22.] Needham (1986), Volume 3, 278.] When making the first known experiments with a magnetic compass, Shen Kuo wrote that the needle always pointed slightly east rather than due south, an angle he measured which is now known as magnetic declination, and wrote that the compass needle in fact pointed towards the magnetic north pole instead of true north (indicated by the current pole star); this was a critical step in the history of accurate navigation with a compass.Sivin (1995), III, 21–22.] [Elisseeff (2000), 296.] [Hsu (1988), 102.]

ee also

*Chinese exploration
*List of Chinese inventions
*Science and technology in China

Notes

References

*Chan, Alan Kam-leung and Gregory K. Clancey, Hui-Chieh Loy (2002). "Historical Perspectives on East Asian Science, Technology and Medicine". Singapore: Singapore University Press. ISBN 9971692597
*Elisseeff, Vadime. (2000). "The Silk Roads: Highways of Culture and Commerce". New York: Berghahn Books. ISBN 1-57181-222-9.
*Hsu, Mei-ling. "Chinese Marine Cartography: Sea Charts of Pre-Modern China," in "Imago Mundi", Volume 40 (1988): 96–112.
*McLeod, Katrina C. D. and Robin D. S. Yates. "Forms of Ch'in Law: An Annotated Translation of The Feng-chen shih," "Harvard Journal of Asiatic Studies", Vol. 41, No. 1 (Jun., 1981): 111-163.
*Needham, Joseph. (1986). "Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth". Taipei: Caves Books, Ltd.
*Sivin, Nathan (1995). "Science in Ancient China: Researches and Reflections". Brookfield, Vermont: VARIORUM, Ashgate Publishing.
*Temple, Robert. (1986). "The Genius of China: 3,000 Years of Science, Discovery, and Invention". With a forward by Joseph Needham. New York: Simon and Schuster, Inc. ISBN 0671620282.