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Jing Fang
Jing Fang (, 78–37 BC), born Li Fang (), courtesy name Junming (), was born in present-day 東郡頓丘 ( Puyang, Henan) during the Han Dynasty (202 BC – 220 AD). He was a Chinese music theorist, mathematician and astrologer. Although better known for his work in musical measurements, he also accurately described the basic mechanics of lunar and solar eclipses. Yijing The historian Ban Gu (32–92 AD) wrote that Jing Fang was an expert at making predictions from the hexagrams of the ancient ''Yijing''. A book on Yijing divination attributed to him describes the najia method of hexagram interpretation, which correlates their separate lines with elements of the Chinese calendar. Music theory According to the 3rd-century historian Sima Biao, Jing Fang received an appointment as an official in the Music Bureau under Emperor Yuan of Han (r. 48–33 BC).McClain and Ming, 208. Jing Fang was the first to notice how closely a succession of 53 just fifths approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courtesy Name
A courtesy name (), also known as a style name, is a name bestowed upon one at adulthood in addition to one's given name. This practice is a tradition in the East Asian cultural sphere, including China, Japan, Korea, and Vietnam.Ulrich TheobaldNames of Persons and Titles of Rulers/ref> A courtesy name is not to be confused with an art name, another frequently mentioned term for an alternative name in East Asia, which is closer to the concept of a pen name or a pseudonym. Usage A courtesy name is a name traditionally given to Chinese men at the age of 20 ''sui'', marking their coming of age. It was sometimes given to women, usually upon marriage. The practice is no longer common in modern Chinese society. According to the ''Book of Rites'', after a man reached adulthood, it was disrespectful for others of the same generation to address him by his given name. Thus, the given name was reserved for oneself and one's elders, whereas the courtesy name would be used by adults of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emperor Yuan Of Han
Emperor Yuan of Han (Liu Shi 劉奭; 75 BC – 8 July 33 BC) was an emperor of the Chinese Han dynasty. He reigned from 48 BC to 33 BC. Emperor Yuan promoted Confucianism as the official creed of the Chinese government. He appointed Confucius adherents to important government posts. However, at the same time that he was solidifying Confucianism's position as the official ideology, the empire's condition slowly deteriorated due to his indecisiveness, his inability to stop factional infighting between officials in his administration, and the trust he held in certain corrupt officials. Family background When Emperor Yuan was born as Liu Shi in 75 BC, his parents Liu Bingyi and Xu Pingjun were commoners without titles. Bingyi was the great-grandson of Emperor Wu, and his grandfather Liu Ju was Emperor Wu's crown prince, until he was forced by Emperor Wu's paranoia into a failed rebellion in 91 BC while Bingyi was still just an infant. The aftermath of the failed rebellion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The ''law of reflection'' says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of Very high frequency, VHF and higher frequencies is important for radio transmission and for radar. Even hard X-rays and gamma rays can be reflected at shallow angles with special "grazing" mirrors. Reflection of light Reflection of light is either ''Specular reflection, specular'' (mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
53 Equal Temperament
In music, 53 equal temperament, called 53 TET, 53 EDO, or 53 ET, is the tempered scale derived by dividing the octave into 53 equal steps (equal frequency ratios). Each step represents a frequency ratio of 2, or 22.6415 cents (), an interval sometimes called the Holdrian comma. 53-TET is a tuning of equal temperament in which the tempered perfect fifth is 701.89 cents wide, as shown in Figure 1. The 53-TET tuning equates to the unison, or ''tempers out'', the intervals , known as the schisma, and , known as the kleisma. These are both 5 limit intervals, involving only the primes 2, 3 and 5 in their factorization, and the fact that 53 ET tempers out both characterizes it completely as a 5 limit temperament: it is the only regular temperament tempering out both of these intervals, or commas, a fact which seems to have first been recognized by Japanese music theorist Shohé Tanaka. Because it tempers these out, 53-TET can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholas Mercator
Nicholas (Nikolaus) Mercator (c. 1620, Holstein – 1687, Versailles), also known by his German name Kauffmann, was a 17th-century mathematician. He was born in Eutin, Schleswig-Holstein, Germany and educated at Rostock and Leyden after which he lived from 1642 to 1648 in the Netherlands. He lectured at the University of Copenhagen during 1648–1654 and lived in Paris from 1655 to 1657. He was mathematics tutor to Joscelyne Percy, son of the 10th Earl of Northumberland, at Petworth, Sussex (1657). He taught mathematics in London (1658–1682). On 3 May 1661 he observed a transit of Mercury with Christiaan Huygens and Thomas Streete from Long Acre, London. On 14 November 1666 he was elected a Fellow of the Royal Society. He designed a marine chronometer for Charles II. In 1682 Jean Colbert invited Mercator to assist in the design and construction of the fountains at the Palace of Versailles, so he relocated there, but a falling out with Colbert followed. Mathematically, he is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cent (music)
The cent is a logarithmic unit of measure used for musical intervals. Twelve-tone equal temperament divides the octave into 12 semitones of 100 cents each. Typically, cents are used to express small intervals, or to compare the sizes of comparable intervals in different tuning systems, and in fact the interval of one cent is too small to be perceived between successive notes. Cents, as described by Alexander John Ellis, follow a tradition of measuring intervals by logarithms that began with Juan Caramuel y Lobkowitz in the 17th century. Ellis chose to base his measures on the hundredth part of a semitone, , at Robert Holford Macdowell Bosanquet's suggestion. He made extensive measurements of musical instruments from around the world, using cents extensively to report and compare the scales employed, and further described and employed the system in his 1875 edition of Hermann von Helmholtz's ''On the Sensations of Tone''. It has become the standard method of representing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Fourth
A fourth is a musical interval encompassing four staff positions in the music notation of Western culture, and a perfect fourth () is the fourth spanning five semitones (half steps, or half tones). For example, the ascending interval from C to the next F is a perfect fourth, because the note F is the fifth semitone above C, and there are four staff positions between C and F. Diminished and augmented fourths span the same number of staff positions, but consist of a different number of semitones (four and six, respectively). The perfect fourth may be derived from the harmonic series as the interval between the third and fourth harmonics. The term ''perfect'' identifies this interval as belonging to the group of perfect intervals, so called because they are neither major nor minor. A perfect fourth in just intonation corresponds to a pitch ratio of 4:3, or about 498 cents (), while in equal temperament a perfect fourth is equal to five semitones, or 500 cents (see additive s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huainan
Huainan () is a prefecture-level city with 3,033,528 inhabitants as of the 2020 census in north-central Anhui province, China. It is named for the Han-era Principality of Huainan. It borders the provincial capital of Hefei to the south, Lu'an to the southwest, Fuyang to the west, Bozhou to the northwest, Bengbu to the northeast and Chuzhou to the east. Huainan is one of the core cities of Hefei Metropolitan Circle and is known for its coal industry and thermal power plants. Its built-up area made of 4 urban districts (all but Panji not yet conurbated) and Fengtai County largely being urbanized, was home to 1,868,944 inhabitants as of 2020. Its city flower is the Chinese rose (''Rosa chinensis'') and its city tree is the Old-World Plane Tree (''Platanus orientalis''). It is also considered to be the hometown and birthplace of tofu. Administration The prefecture-level city of Huainan administers seven county-level divisions, including five districts and two counties. *Tianjia'a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liu An
Liú Ān (, c. 179–122 BC) was a Han dynasty Chinese prince, ruling the Huainan Kingdom, and an advisor to 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 He 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 bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huainanzi
The ''Huainanzi'' is an ancient Chinese text that consists of a collection of essays that resulted from a series of scholarly debates held at the court of Liu An, Prince of Huainan, sometime before 139. The ''Huainanzi'' blends Daoist, Confucianist, and Legalist concepts, including theories such as yin and yang and Wu Xing theories. The ''Huainanzi''s essays are all connected to one primary goal: attempting to define the necessary conditions for perfect socio-political order. It concludes that perfect societal order derives mainly from a perfect ruler, and the essays are compiled in such a way as to serve as a handbook for an enlightened sovereign and his court. The book Scholars are reasonably certain regarding the date of composition for the ''Huainanzi''. Both the ''Book of Han'' and ''Records of the Grand Historian'' record that when Liu An paid a state visit to his nephew the Emperor Wu of Han in 139 BC, he presented a copy of his "recently completed" book in twenty-on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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